Discovering sauergut, the great secret of German lagers, brewing a Helles

We have made it a habit in recent years to brew at least one lager beer a year. Every good homebrewer will know the difficulty of brewing a good lager at home and doing this is a very nice challenge for us, which also allows us to continue learning. Obviously, within lagers there are a multitude of styles, each with its own characteristics and peculiarities. For 2021 we decided to try it with a Munich Helles, a style that we love to drink. As I always do, I started a research work on the style to try to end up with the best possible result. And it was during this process, while looking for information about yeast strains suitable for this style, where almost by chance I discovered in a forum the word sauergut, totally unknown to me until that moment. I tried to look for more information about this term and the truth is that it is not abundant. Possibly this is due to the fact that most of the brewing literature and the more general sources of information that we usually handle come from the Anglo-Saxon culture, mainly from the USA, and in many cases these sources have been dragging myths, incomplete or outright false information about some styles. Of course there is information in German about sauergut, but my limited knowledge of the language prevents me from finding it useful. The fact is that little by little I got more information on the subject of what seems to be the best kept secret of German lagers.

Starter of the German lager X strain

And what on earth is sauergut, you may be wondering. Here I will try to explain it in a nutshell and give you a couple of facts so that you can see that it is something that is really established in the production of the acclaimed German lagers, especially in the Bavarian region. It all comes from the well-known German purity law, the Reinheitsgebot. According to this law, it is not permitted to acidify either the mash or the boil by adding lactic acid or any other chemical compound. For beers brewed under this law, there are two alternatives to reduce the pH of the mash and/or boil. The first is the use of acid malt (sauermalz in German), which many of you will know and possibly have used in your brewing. The second is to use an acid wort or sauergut. Although the original reason for using sauergut may have been to adhere to the aforementioned law, there are several studies that seem to demonstrate the benefits of its use over the addition of lactic acid. Among other things, sauergut allows almost twice as much zinc to be extracted from the malt in the mash, this element being an important nutrient for the yeast, as well as helping with the beer’s body and foam. In addition, many products of the metabolism of Lactobacillus (the main character in the production of sauergut) act as antioxidants in the beer. Aside from these less tangible benefits, sauergut is supposed to have a contribution to the final taste of the beer, giving a light yogurt-like, somewhat acidic touch that would be the particular hallmark of Helles and other Bavarian lagers. I discovered most of this information in a document on the German Brewing website entitled “On Brewing Bavarian Helles – Adapting to Inert Brewing”. That document is a guide to brewing the perfect Helles with a lot of steps to follow, some more complicated than others. I will comment later on which ones we followed since it was, among others, one of our reference sources for brewing.

As I was curious, I decided to look around to see if, indeed, the use of sauergut was something widespread at the level of professional breweries (especially in Bavaria) and not just something elevated to the altars by a handful of homebrewers. I first came across this brewery machinery page where you can see a reactor for sauergut brewing and maintenance. From what I have been able to read afterwards it also seems to be common in many German breweries, especially in the south. Later on, I received an email informing me that Doug Piper (I highly recommend his youtube channel, where he usually invites experts to talk about many topics and brewing styles) was going to talk in one of his videos about lager brewing, being one of his guests Tobias Zollo, brewmaster of Weihenstephan. I took the opportunity to ask about sauergut and Tobias himself confirmed that the use of sauergut is something common in the production of lagers (in the link you can listen to the complete answer). Curiosities of life, as I write this, I just received an email about an entry in Brulosophy where an exbeermiment is made with sauergut. Who would have thought it when a year ago I had not even heard of this word.

Calculations for the yeast starter

Making a small parenthesis on the subject of sauergut, let’s go with the rest of the ingredients we used. First we selected the yeast. After reading several opinions I came to the conclusion that there were several reliable alternatives that were not superior to each other. Among the handful of yeasts that were recommended as good choices for the style, I opted for German Lager X. This strain is from White Labs’ The Vault collection and is identified by the code WLP835. Strains from this collection are only available for short periods of time and when I saw it available it seemed like a good candidate for our Helles, as the White Labs website describes it as a strain that produces a malty, creamy profile with low sulfur and ester production. It is also taken for granted that this strain originates from the Andechs monastery in Bavaria (White Labs states that it is the strain from a “famous Bavarian monastery”).

For both the grain and the hops it was simpler, as this is not a style that allows too many frills with these ingredients and it is better to play it safe. In the case of the malt I decided on a Pilsner base plus a not too high percentage of Vienna Barke malt and a small touch of Carahell, all of them from Weyermann. As for the hops, as it could not be otherwise, Germanic hops to choose from those we had in stock. Halletauer Mittelfrueh for bitterness and Tettnager for aroma (the latter, although of German origin, grown near us in Olite by Queen Country).

The information, both for the part of the ingredients and the process, including of course the sauergut issue, I gathered from different sources. Mainly from the German Brewing page, as well as from their forum. I also found good notes on another blog, The Quest For Edelstoff, even if they were posts from a few years ago. In the end, all these sites in one way or another had for the most part a couple of original sources, the books by Kunze (Technology Brewing and Malting) and Narziss (Abriss der Bierbrauerei), two real bibles of beer in general, and German beer in particular.

One more note before describing the recipe and the brewing process we follow. The article I mentioned at the beginning of this post is a very complete guide that some of you may remember, as it was quite fashionable in homebrewing circles a few years ago. In it the authors, always based on contrasted information, offer a method for homebrewing with the minimum introduction of oxygen throughout the process. Some of you may remember it by the terms LODO brewing or Low-ox brewing. Among many other things, it is a method in which antioxidants (sodium metabisulfite, ascorbic acid,…) are used from the mash and great emphasis is placed on having closed circuits to avoid exposure to oxygen as much as possible. It is not easy to carry out at home, because it requires a series of adaptations of the equipment. Because of this, it was not our intention to follow this method to the letter, even though its authors claim that any deviation from it can spoil the spectacular final result. Even so, and anyway, we decided to apply several of the steps described in this method. Mostly because we brew beer because we find it fun and because, well, I don’t think everything is black and white, and we had probably never put so much care into brewing a lager (or rather any other beer), so the result could be better or worse, but not bad. You can read the whole article if you are curious and want to go further, because the level of detail is very high and all the whys and wherefores are very well explained.

Sauergut, ready to be used

HELLES WITH SAUERGUT

MALTS/MALTS
3.00 Kg (6.61 lbs) (83.3%) Pilsner malt (Weyermann) (3.3 EBC)
0.50 Kg (1.10 lbs) (13.9%) Vienna Barke malt (Weyermann) (7.0 EBC)
0.10 Kg (0.22 lbs) (2.8%) of CaraHell malt (Weyermann) (25.6 EBC)
HOPS
30.00 g (1.06 oz) Hallertauer Mittelfrueh (3.00% AA) pellets (first wort hopping, boiled 60 minutes, 12.0 IBUs)
10.00 g (0.35 oz) Queen Country (Olite) Tettnager (6.13% AA) in pellets (boiled 15 minutes, 6.3 IBUs)
YEAST
White Labs German Lager X (WLP835).  Two-step starter, 1.5 liters each step, to obtain 21.2 million cells per mL of wort when inoculated (1.86 million cells x mL wort x degree plate).
THEORETICAL NUMERICAL DATA
Volume: 16.00 L      OG: 1.046     DF: 1.007      %Alc: 5.1%      IBUs: 18.4     Color: 7.5 EBC     BU/GU: 0.401              Efficiency: 65%
WATER PROFILE
The water was taken the day before so that the chlorine could evaporate. On brewday we boiled it to eliminate as much oxygen as possible and added salts (and phosphoric acid) and sodium metabisulfite (600 mg) as an antioxidant. The mineral profile, without taking into account the contribution of sodium metabisulfite, was as follows:
Ca: 68 ppm; Mg: 3 ppm; Na: 7 ppm; SO4: 40 ppm; Cl: 45 ppm HCO3: 1 ppm.
MASH
Hochkurz mash: 62ºC (143.6ºF) 30 minutes, 72ºC (161.6ºF) 30 minutes and 76ºC (168.8ºF) 10 minutes. In the first minutes we added 225 mL of sauergut with the intention of lowering the pH of the mash 0.1, until a theoretical pH of 5.4.
BOILING
60 minutes. 5 minutes before finishing the boil we added 400 mL of sauergut with the intention of lowering the pH of the boil 0.4, up to a theoretical 5.0.
FERMENTATION
In FastFerment placed inside the Ferminator. We inoculated the yeast at 7ºC (44.6ºF) and raised to 9ºC (48.2ºF) for 24 hours. We left it at 9ºC (48.2ºF) for 15 days, after which we lowered the temperature by 1ºC per day until reaching 5ºC (41ºF). At this temperature of 5ºC (41ºF) we left it for 15 more days. After this time, we lowered the fermenter to our basement and left it for another 3 weeks at 14ºC-15ºC (57.2ºF-59ºF) before bottling. We bottled 9 liters (2.38 gallons) of the Helles in a small corny, force carbonating with CO2. The rest, about 5 liters (1.32 gallons), we bottled to obtain about 2.5 volumes of CO2 carbonation.

As I am sure you would  have noticed, among the highlights of the process, and I will explain the reasons below, are the high inoculation rate, the use of sodium metabisulfite as an antioxidant, the addition of sauergut in the mashing and boiling, and the mashing and fermentation temperatures. The inoculation rate is much higher than we are used to seeing in most places. Normally for lager beers it is normal to read that an optimal inoculation rate is 1.5 million cells x mL wort x ºPlato. This would give for our recipe about 17.2 million cells per mL of wort. However, to perform the cold fermentation that we were going to follow (more or less approximately), to ensure a healthy fermentation it is necessary to raise this amount considerably more. It is recommended between 20-30 million cells per mL of wort and we went up to 21.2 million cells per mL of wort (or 1.85 million cells x mL of wort x ºPlato). For the starter calculation we used Yeast calculator. According to this calculator we had to make two steps of 1.5 L each, with magnetic stirring, to reach the target number of cells. This was considering of course the date of manufacture of our German Lager X vial of yeast. This high number of yeast cells is ideal for the fermentation that we were going to follow, where it is inoculated at around 6ºC (we did it at 7ºC) and it is raised afterwards to 8ºC-9ºC. At this temperature most of the fermentation takes place and then it is gradually lowered to 3ºC-5ºC (we did it at 5ºC).

In the case of mashing we used the process followed in the production of many German beers, called Hochkurz, which is a mixture of the words Hoch (high) and kurz (short). This is because it starts at a higher temperature than usual (between 62ºC-65ºC) and because the duration of the mash is shorter than other types of mashing in which there are more steps. We started at 62ºC, maintaining 30 minutes. In this step the activity of beta-amylase is favored. We then moved to 72ºC for another 30 minutes, favoring alpha-amylase activity, and finished with 10 minutes at 76ºC to inactivate the enzymes. In theory, this type of maceration favors a more complete conversion of sugars than a maceration with a single infusion temperature.

In the case of the water treatment, in addition to adding the salts and a little phosphoric acid (sorry, Reinheitsgebot) to seek a pH around 5.5 in the mash (before adding the sauergut), we also added 600 mg of sodium metabisulfite. This amount was following the German Brewing people’s recommended dosage of about 25-30 mg/L (in the case of no sparging) of sodium metabisulfite to act as an antioxidant. This slightly increases the sodium in the water, but only a few ppm which will not affect the taste.

Ferminator display during fermentation

Back to sauergut. There are different ways to prepare it (and keep it), but in our case it was going to be for a single use. The first thing to have ready is wort as sterile as possible. In our case, we used about 2 liters of spare wort form the one that we preprared for our test with the wild yeasts that we collected from fruits a couple of years ago. This wort, in anticipation of making this sauergut, we had prepared it with a recipe very similar to that of this Helles, as well as following the same type of mash (Hochkurz). The microorganism involved in the preparation of the sauergut is Lactobacillus amylolyticus. This type of Lactobacillus is naturally present in malt and malt is what we use for the preparation, although pure cultures of Lactobacillus can be used to inoculate the sauergut wort (L. Delbrueckii, L. Amylovorus, L. Acidophilus, etc). All of them must be homofermentative, that is to say, they must produce lactic acid as the main fermentation product. We boiled the 2 liters of leftover wort and transferred them to a pair of sanitized glass jars. One was left with 750 mL and the other with about 500 mL. We cooled the wort until it reached about 48ºC, at which point we added 15 g of uncrushed Weyermann Pilsner malt to the jar with the 750 mL of wort and 10 g of the same malt to the jar with the 500 mL, following the recommendation to add 20 g of malt per liter of wort in the above-mentioned article. We left the jars closed to avoid exposure to oxygen in a water bath maintaining the temperature at 48ºC (with a sous vide cooking apparatus that recirculates and maintains the water temperature), the ideal temperature for the fermentation of this type of Lactobacillus (and also a temperature too high for the growth of pathogenic bacteria). Although it is advisable to lower the pH to 4.5 before adding the malt, to avoid pathogen growth (with acid malt or sauergut brewed earlier to be purists), we did not do it this time. Theoretically, after 24-36 hours an acidity of 0.8% is reached and although this acidity then continues to increase, the speed of this acidification decreases very significantly, so this period is enough. We had it fermenting for 48 hours, after which we put it in the refrigerator until the day of brewing the Helles. I cautiously took a small sample from both jars and in the larger one the pH was at 3.58, while in the smaller one it had dropped to 3.48. Of course, I also tasted it and the flavor was very pleasant. Slightly acidic, but also with an important touch of raw cereal. For lack of a better description, I would say it was like a malt yogurt.

There are several strategies for using saugergut. Ours was to lower the pH of the mash to 5.4 with sauergut (from a theoretical value of 5.5) and to lower the pH of the boil, at the end of the boil, to 5.0, also with sauergut. Taking this 0.8% acidity as a theoretical value, 60 mL of sauergut would be needed for each kg of malt in the recipe to lower the mash pH by 0.1. In the case of boiling, this amount would be half, 30 mL per kg of malt in the recipe. In our case, after applying these calculations roughly, we added 225 mL at the beginning of the mash and 400 mL at 5 minutes to the end of the boil. A pH of 5.4 in the mash is a balanced value that favors both alpha- and beta-amylase and in theory can result in a fuller-bodied beer. This same value during boiling favors optimal formation of the hot break, and DMS evaporation is greater than at lower pHs. Finally, lowering the pH to 5.0 with sauergut at the end of the boil facilitates the formation of cold break.

Helles before packaging

On brewing day the process was as described in the recipe, with no major incidents to report. We started with the dechlorinated water after collecting it the night before, boiling it for a few minutes and adding calcium chloride and calcium sulfate, as well as a few mL of phosphoric acid to adjust the pH, and sodium metabisulfite as an antioxidant. Once the grain was added, taking care not to oxygenate too much, we did not stir as much as other times to avoid the introduction of oxygen into the mash. Once settled we added the 225 mL of sauergut to, in theory, lower the pH by 0.1. After finishing the Hochkurz mash described above we removed the grain and began heating the wort to boil. In a sample from the end of the mash the pH was at 5.48, somewhat higher than expected, although we had not measured the pH before adding the sauergut either. Before the boiling started we added 30 g of Hallertauer Mittelfrueh as first wort hopping, and then kept it for the whole boiling. With 15 minutes to go, we addded 10 g of Tettnager and with 5 minutes to go, we added another 400 mL of sauergut to leave the pH at 5.0, at least in theory. This value, in addition to favoring cold break, also seems to help beer stability, as Weihenstephan’s brewmaster commented in response to my question about the use of sauergut. After measuring a sample, our end-of-boil pH was 5.20, also somewhat higher than expected. It is possible that maybe our sauergut did not have enough acidity or another factor affected these values, but we were not far off either.

The biggest problem during the brewing process was when it came to cooling the wort. It is supposed to be cooled as soon as possible to about 5ºC-6ºC, but with the inmersion chiller and an ice bath we could not go below 16ºC. Not being ideal, I decided not to inoculate the yeast and put the fermenter in the Ferminator set at 5ºC, leaving it there overnight. The initial density was 1.047, practically the theoretical value (1.046). Early the next day the wort was already at 7ºC, so we inoculated the starter, removing as much wort as possible from the starter. At the end of that day we raised the temperature of the Ferminator to 8ºC, leaving it that way all day. On the second day we raised it one more degree, to 9ºC. At thius point there was already a significant krausen (we took a little look by opening the lid of the fermenter and it seems that the high inoculation rate worked well). We kept it at 9ºC for 15 more days, 17 from the brewing day. The density at this point was 1.009 (versus a theoretical DF of 1.007). From there, we lowered the temperature 1ºC per day until we reached 5ºC, leaving it at that temperature for 15 days. Here I decided to take the beer out of the Ferminator and leave it in the cellar for another 3 weeks at a temperature of about 14ºC-15ºC. Almost two months after brew day we bottled 9 liters in a small 9.5 liter corny keg and the rest, about 5 liters, we bottled with sugar for carbonation around 2.5 volumes of CO2. The final density was 1.008, for 5.1% alcohol. The smell was very interesting and the taste was very good, quite clean and with a good malt presence. In a future post we will tell you how it turned out and if we noticed the addition of sauergut. Be that as it may, with this brew I can say that I have learned more than with any other, and for that alone it was worth it.

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Sour ale fermented with Kveik and Lactobacillus and with lots and lots of fruit

In recent years it is difficult to walk into a pub or a brewery and not see boards filled with a majority of NEIPAs or similar hoppy beers that are almost all over the place. There is usually only a minimal spot left for two other types of beers. Imperial Stouts above 10% ABV and sour ales, the latter often with added fruit. All this despite the fact that some of us would like to see a little more variety and to be able to have a beer from one of the many styles that are brewed all over the world from time to time. That is why we are so grateful when we go to a place where we can choose and enjoy a Helles, a Saison or a Brown Ale, for example. However, and although it may seem otherwise after this vindictive introduction, this entry is going to be about one of these trendy styles, specifically sour beers with fruit. Of these three types of beers, probably the one that possibly generates the most disagreements among purists. It is even the case that, not without some reason, some even deny their definition as beers. For my part, I have never been too intransigent in terms of styles and I prefer that everyone brews what their knowledge and creativity suggest to them. And although I admit that I am almost always more inclined towards the more classic styles, every now and then it is fun to drink (and brew) some of these beers.

Kveik Midtbust, from Stordal, Norway

Of course, since we were going to brew a sour ale with fruit, we wanted to do something as interesting as possible. Nowadays it is a rare if a brewery does not have one or more of these types of beers, with any fruit or vegetable you can imagine. However, most of them are made with the kettle sour method and often lack complexity. Not that we have anything against this method, in fact our first sour beer was brewed this way. In the post about brewing a gose with apricots you can read what kettle sour is all about if you are not familiar with it. This time we wanted something with a bit more character and for that, as has been the case in the past, we looked to a brewery whose beers we had enjoyed in recent times. This time it was Vault City Brewing, a relatively new brewery from the UK that has quickly made a name for itself by brewing exclusively sour ales with huge amounts of fruit. If you have tried any of their beers, I am sure you know what I am talking about. Also, fortunately, on their website they have a blog where they share a lot of things about their day to day life, including very interesting information for the homebrewer. Specifically, they have two entries in which they discover part of their “secrets”. In one of them they talk about the mixed culture they use to ferment their base beer, a golden sour to which they then add fruit and/or hops. They do not go into detail, but they mention that it is a mixture of Kveik yeast and several strains of Lactobacillus. They indicate that they ferment at a high temperature, which favors the production of esters by the yeast (as you know, many Kveik yeast strains can ferment at high temperatures without creating off-flavors) and accelerates the activity of the Lactobacillus, which can create a generous amount of lactic acid (and other compounds) in a relatively short time. As for the second entry, they detail the amount of fruit they use in their beers. They say that they normally 300 g of fruit per liter of beer, although they have even gone as far as 999 g/liter!!! in a special edition of their Apritcot Sour, which we were lucky enough to drink and enjoy. A real monster.

One of the two strains of Lactobacillus we were using for this beer

Once we had decided to brew this type of beer, there were still some important questions to be addressed. One of them, the fermentation temperature, was relatively easy to decide. Lactobacillus strains have an ideal fermentation temperature of around 37ºC-38ºC (98.6ºF-100.4ºF), so this would be the temperature at which we would set the fermentation.

Secondly, we had to decide which microbes were going to be part of the process. A few years ago, together with several homebrewers, we got hold of several unpurified Kveik strains that were sent to us from Norway. At the time we propagated them for distribution among us and I still had some varieties that I had not used. One of them was Midtbust, from Stordal, which according to Lars Marius Garshol’s Farmhouse Yeast Registry is composed of 6 different strains of Saccharomyces cerevisiae. Its ideal inoculation temperature is, according to this registry, 33ºC (91.4ºF), but considering that it is not an excessively expressive strain, we decided to go for it. We still had to choose the Lactobacillus strains. Here there was not much to choose from and we decided on a mixture of Lactobacillus plantarum (Lallemand’s Sour Pitch) and Lactobacillus Brevis (WLP672 from White Labs), which was what we had on hand.

Finally, it was down to choosing the fruit. Here we decided that we were going to split the batch in two and use two types of fruit. For one part, we would add apricots, which we had used before in a gose and liked what they added to the beer. And for the other part, a classic in sour beers, a blend of blackberries, raspberries and blueberries.

Apricots for one of the parts of the batch

Once these three issues were addressed, it was time to design the recipe with the rest of the ingredients. For the grist, we opted for almost three-quarters Pilsner malt and a little more than a quarter wheat malt. Vault City labels, in addition to barley malt and wheat malt, also list the use of oats. We assume that both wheat and oats play a role in providing proteins, which primarily influence the mouthfeel, but they possibly play a role in the flavor as well. We, for this time, omitted the oats. As for the hops, since Lactobacillus strains are generally inhibited by hops, we were only going to use a small amount in the boil to get about 5.2 IBUs. We believed that this amount would not affect Lactobacillus brevis (more tolerant to IBUs) and only slightly to Lactobacillus plantarum.

As a preliminary work before the brew day, the days before we prepared an apricot puree (2.8 kg of fruit that ended in 2.3 kg of puree) that we kept in the freezer until its use. We also made a starter of both Kveik yeast (we had not touched the tube since 2018 and the starter showed signs of fermenation in half an hour!!!) and Lactobacillus brevis. The latter we made because it was past its expiration date and we read that, in those cases, it was better to make a starter to re-activate and propagate the bacteria. The Kveik Midtbust starter was kept at room temperature, around 20°C (68ºF), while the Lactobacillus brevis starter was ketp at 38°C (100.4ºF), its ideal growth temperature. Fortunately, both showed signs of activity and grew adequately (spectacularly in the case of the Kveik).

Blueberries, raspberries and blackberries, ready to be converted in purée

Before describing the brew day, here you can read the recipe and the main data of the process.

SOUR ALE WITH FRUITS

MALTS/GRAINS
1.70 Kg (3.75 lbs) (73.9%) Pilsner malt (Weyermann) (3.3 EBC)
0.60 Kg (1.32 lbs) (26.1%) wheat malt (Grannaria) (3.9 EBC)
HOPS
10.00 g (0.35 oz) Glacier (3.53% AA) pellets (boil 10 minutes, 5.2 IBUs)
YEAST/BACTERIA
Kveik Midtbust from Stordal (unpurified strains), starter 500 mL.
Lactobacillus plantarum (Sour Pitch de Lallemand) 2 g (0.07 oz) added directly to the wort
Lactobacillus Brevis  (WLP672 de White Labs), starter 200 mL
THEORETICAL NUMERICAL DATA
Volume: 10.00 L (2.64 gallons)     OG: 1.047   FG: 1.007     ABV: 5.3%     IBUs: 5.2     Color: 6.4 EBC     BU/GU: 0.110     Efficiency: 65%
WATER PROFILE
Water was collected the day before brew day to evaporate chlorine and we added salts to et the following mineral profile:
Ca: 128 ppm; Mg: 15 ppm; Na: 7 ppm; SO4: 96 ppm; Cl: 143 ppm HCO3: 1 ppm
MASH
65ºC (149ºF) for one hour
BOIL
45 minutes
FERMENTATION
In an 11 liter PET demijohn. Four days at 37°C (98.6ºF), after which we removed from the ferminator and left at room temperature for a day before dividing the batch and adding the fruit (2.3 kg apricot puree for about 6 liters of beer and a puree composed of 500 g raspberries, 340 g blueberries and 430 g blackberries to about 3 liters of beer. The purees were in the freezer for a few days and were added after thawing and tempering). After adding the fruit, we left the beer with apricots to ferment at 37°C (98.6 F) for 11 days and the beer with berries for 13 days. We finally bottled about 7 liters of the beer with apricots (2 bottles of 75 cL, 5 bottles of 37.5 cL and 10 bottles of 33 cL) with enough sugar for a carbonation of 2.6 volumes of CO2. While of the beer with red fruits we bottled a little less than 3 liters (1 bottle of 75 cL, 3 bottles of 37.5 cL and 5 bottles of 33 cL), with enough sugar to obtain an equal carbonation of 2.6 volumes of CO2.

First time using the Ferminator to control fermentation temperature

On brew day we performed the usual tasks such as milling the grain and adjusting the water (collected the day before to evaporate the chlorine overnight) to the desired mineral profile to obtain an approximate mash pH of 5.38 (according to Bru’n Water spreadsheet). The rest of the process went smoothly, with a one-hour mash at about 65°C (149ºF) and then a 45 minute boil, somewhat shorter than usual, in which we added 10 g of glacier hop pellets in the last 10 minutes to get about 5.2 IBUs. Due to the temperature at which we were going to ferment (37ºC-38ºC), this time the cooling of the wort was much faster as we did not have to lower the temperature so much. The original gravity was 1.047, just the theoretical value. We transferred the wort to an 11-liter PET demijohn and, before adding the yeast and bacteria, we left the demijohn in a new device that we were using for the first time, the Ferminator. It is a fermentation chamber that is assembled and disassembled with expanded polystyrene panels and that cools or heats its interior thanks to Peltier plates. After a couple of uses, fermenting this beer at 37ºC (98.6ºF) and a lager at 6ºC (42.8ºF) we are delighted with the equipment.

After about 12 hours, the airlock was bubbling at a good rate, with the liquid quite cloudy, probably due to the microorganisms in suspension. This turbidity increased with time and on the second day a krausen formed that barely lasted a day. After four full days of fermentation, my idea was to add the fruit on the fifth day, but after removing the demijohn from the Ferminator, I realized I had made a small mistake. I had not thaw the apricot puree and the puree of raspberries, blueberries and blackberries had not been frozen. I solved this by leaving out the apricot puree at room temperature and putting the berries puree in the freezer until the next day. The beer was kept at room temperature during this time.

Transferring wort through filters before bottling

The next day, the first thing I did was to take the berries puree out of the freezer so that it could thaw and reach room temperature as soon as possible before mixing it with the beer in the afternoon. So, with the two purees thawed and more or less at room temperature, I transferred them to a pair of fermenters. The apricot puree to a 10 liter capacity plastic fermenter into which I then poured about 6 liters (1.59 gallons) of beer. The berries puree went to a 5 liter capacity glass demijohn into which I poured about 3 liters (0.79 gallons) of beer. I do not know if you have done the calculations, but if not, I will tell you. For the beer with apricots the amount of fruit was 383 g/L (), while for the beer with red berries the amount of fruit was 423 g/L. In both cases, this is a significant amount of fruit, unimaginable a few years ago and something I would not have thought I would ever use. Even above the Vault City average of 300 g/L, although far from their monstrous record.

Since I had to do all these transfers, I took the opportunity to make a gravity reading. It was at 1.007, just the theoretical final value. Of course, I tasted some of this base beer and, although less acidic than expected, the flavor was very pleasant. It gave me the sensation of having quite a few esters and a touch of lactic acid. I also did a pH measurement and the result corroborated the fact that it was not too acidic on the palate, as it has a pH of 4.16. Here I began to doubt whether it had been a good idea to add hops during the boil, even though it would have been a small amount and to provide only 5.2 IBUs. Due to this low acidity, I decided to put the fermenters back in the Ferminator at 37ºC (98.6ºF) to continue fermenting and see if it would lower the pH and increase the acidity.

Samples of the two beers before bottling. Left, with aprictos. Right, with blueberries, raspberries and blackberries

Finally, to avoid a mess, we bottled each of the beers on two different days. The beer with apricots was bottled 11 days after adding the fruit. Looking almost identical to orange juice, the final density of this beer was 1.008, one point higher than the density of the base beer. I do not know if the fruit added some unfermentable sugar, which is unlikely, or one of the two measurements was incorrect. Anyway, it was not a big deal either. Completely cloudy, it was thus left at 5.1% ABV. What did drop considerably with respect to the last measurement was the pH, which was 3.78, something that was noticeable in both aroma and flavor, both of which were very promising. In order to be able to bottle without clogging everything up, we also debuted a filter (Classic Bouncer) which, in theory, should prevent fruit debris from passing into the bottling vessel. It has several different sizes of mesh size that can be used. At first we tried the smallest (178 µm), but it quickly became clogged and there was no way to get the beer through, so we had to end up with the intermediate mesh size, 304 µm. This filter let pass some of the apricot puree, which was otherwise quite integrated into the liquid, so that is how it stayed.

We bottled the red fruit beer a couple of days later, so it spent 13 days at 37°C (98.6ºF) after adding the fruit. Although the amount of fruit was much higher than in the beer with apricots, in this case the puree remained forming a very compact debris in the middle of the fermenter and this made filtering during racking (this time directly with the 304 µm filter) much easier, leaving the beer quite clear and of a nice burgundy color. The final density in this case was 1.006, for 5.4% ABV. There were also differences in the final pH, as this beer finished with a pH value of 3.65. With a spectacular fruity aroma, in taste it did not give the sensation of being more acidic than the apricot beer, quite the contrary. However, the acidity was very pleasant and smooth. We only had to wait for beer to carbonate to see if this experiment in brewing these two beers was worthwhile or not.

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Brownie with Imperial Stout

Time to go back to cooking recipes for a moment. Previous entries in this category have been based on spent grain from previous brewdays, such as this vegan burger or this walnut biscotti. This time, instead of spent grain, we are going to use beer that we brewed ourselves. Specifically, an Imperial Stout that we named Cricket Balls and that we brewed using the reiterated mashing technique. The idea came after seeing how they cooked this recipe on The Craft Beer Channel (highly recommended if you are not already following it). With its considerable 11.5% ABV, I have shared almost all the bottles of Cricket Balls with friends and familiy. This recipe, apart from being very tasty, was going to allow me to open a bottle, drink a glass of the beer and use the rest for the brownie. There was not much else to think about.

Ingredients for the brownie

This time we followed the recipe from The Craft Beer Channel to the letter, without complications. Here are the ingredients we used.

CHOCOLATE BROWNIE WITH IMPERIAL STOUT

165 mL of an Imperial Stout (in our case our Cricket Balls)
180 g butter
270 g dark chocolate
225 g sugar
110 g flour
40 g cocoa
3 eggs
4 biscoff biscuits
1 dash vanilla extract

Mixing the dough

The process is quite simple to follow and, apparently, the key is to use the ingredients indicated in the correct proportions so that we get a very juicy brownie. First, heat the beer over low heat for about 10 minutes (while you drink the other half of the bottle, for example). After this time, remove from the heat and add the butter and chocolate, stirring until both are melted. In this step I had to heat a little bit more to get all the chocolate to melt well. Once the chocolate and butter are melted and well mixed with the beer, you can optionally add a little vanilla extract. Then add the sugar, cocoa and flour (the last two better sifted), mixing everything well until it is a homogeneous dough. Before adding the eggs, the mixture should be allowed to cool so that they do not cook. After adding the eggs, stir everything again, without overdoing it too much. Just enough to mix everything well, because if you mix it too much, the texture will be cakey and not fudgy. Pour the dough into a 20 x 20 cm mold, spreading it well. The mold should be greased with a little butter so that the brownie does not stick. Break the biscuits into pieces and place them on top.

Brownie, final result

Now the final step. Bake it at about 175ºC for 20 minutes. After that time, the brownie will still be wobbly, so let it rest and cool so it settles and gets some consistency. Once cooled, you can sink your teeth into it.

The result is a brownie with a very fudgy texture, with chocolate as the protagonist. The biscuits give it a very nice crunchy touch. The beer is not too noticeable, but it does add a touch of coffee (in this case our Imperial Stout had a lot of coffee) and toasty flavors. I also think it provides  some bitterness, which I think is fine as it keeps the whole thing from being too sweet.

So, you know. The next time you feel like drinking an Imperial Stout, but a whole bottle seems like too much, if you feel like cooking a bit you can give this delicious brownie a try. And if the beer is homebrewed, all the better.

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Getting back at Weissbiers – Part 1/2 – Classic Weissbier

Since the day I started brewing at home, back in 2011, I have brewed beers with more or less success, but I have almost never had the feeling of having brewed a really bad beer, one of those that goes down the sink. With one exception, a Weissbier I brewed in my early years as a homebrewer, which was one of the most insipid beers I’ve ever brewed. I was left with that little thorn in my side and, a couples of years ago, with a few years and quite a few more batches of experience I decided it was time to settle the score and try again.

Those of you who are readers of the blog already know that when I go to work out a style, especially the first few times, I like to find out as much as possible about it. Later, I review all that information and based on it I make the decisions that I think might be good to get the best possible result. On this occasion, in view of my previous fiasco, I didn’t want to take any chances, so the reading on Weissbier was more thorough than usual. Among the different sources I consulted, the main article I used, for being the most complete, was the one entitled “Brewing Bavarian Weissbier – all you ever wanted to know”, from Brau magazin. As you can see, the title says it all, and it really lives up to it, with very complete and detailed information. Another very complete article, this one in Spanish (among its sources it also draws, of course, from the previous article) is an article on Weizenbier from Cervezomicon. With these two articles, not much more information would be needed to brew a good Weissbier, but as information is never too much, I also consulted a couple of articles from Craft Beer & Brewing, “Traditional Hefeweizen: Worth the Trouble?” by Stan Hieronymus and “Brewer’s Perspectives – Hefeweizen” by Emily Hutto.

Grist for Weissbier

As there is a lot of information available in the articles linked above, here I will only make a small summary of the most practical aspects. Although there are different substyles within the Bavarian wheat beers (hefeweizen, kristallweizen, dunkelweizen, weizenbock,…), on this occasion the idea was to make a classic Hefeweizen or Weissbier, with bottle refermentation. This style is pale in color, with high carbonation and a dry finish, which makes it very refreshing. Like the other substyles within this family, Weissbier is brewed with at least 50% wheat malt and has a relatively low bitterness (between 9 and 15 IBUs is typical). However, the main characteristic of the style and what distinguishes it from other wheat beers is the character provided by the yeast used. Weissbier yeast is POF+ (i.e., it produces phenols) and it is usually the combination of these phenols and esters also produced by the yeast that sets the aroma and flavor. The main compounds are ester isoamyl acetate (banana flavor and aroma) and phenol 4-vinyl guaiacol (clove flavor and aroma). In order to enhance one or the other or to seek a balance, there are several strategies, depending on the objective. Mainly, malt percentages, mash and fermentation temperatures are the knobs that we will be able to turn to reach the profile we are looking for. It is possible to brew a Weissbier with a simple infusion, but to get more control over the production of esters and phenols, a step mash with different temperatures is almost a must. Within this step mash, the issue of decoction (removing a part of the mash, boiling it for a short time and returning it to the main mash to raise the temperature) can enter into this step mash. This decoction can be single, double or triple and adds complexity to the elaboration. Because of this, we opted for a step mash but without decoction.

Munich Classic, from Lallemand, of the few dry yeasts for Weissbier with good reviews

Getting into more detail, let’s get to our recipe. The idea was to look for a balanced profile between banana and clove, so following the guidelines of the Brau magazine article, we decided the ingredients and process based on this objective. At the same time that I explain our decision, I will explain the reasons in case you opt for another profile.
In terms of grist we opted for almost 60% wheat malt and approximately 40% Pilsen malt. The wheat malt was divided into 38% light malt and 22% dark malt. When going up from 50% wheat malt, the 4-vinylguaiacol precursor (ferulic acid) is in lower quantity (barley contains more of this compound), so for strains that produce a lot of this compound, using a higher percentage of wheat malt is an option to consider. If what you want to do is to pull towards clove, you should leave it at 50% wheat malt.
In the case of hops, you do not need to think too much. Aim within the range of 9 to 15 IBUs, in principle all in one addition. If possible, German noble hops are preferred. We opted for Hallertauer Tradition, boiled for 60 minutes to get about 11.7 IBUs.
Yeast is a key aspect and there are several alternatives, both liquid and dry. Here we had to go to a plan B because the initial plan was not possible. Our idea was to brew with White Labs WLP300 (equivalent to WY3068 from Wyeast Yeast), whose origin is the Weihenstephan brewery, and which is one of the most recognized weizen yeasts by home brewers. The thing is, we started a starter of this liquid yeast too late and it was not ready for brew day. Luckily, we had a sachet of Lallemand Munich Classic dry yeast on hand. The origin of this yeast is not well known, but many speculate that it is a dry version of the Weihenstephan strain. Moreover, among the dry yeasts, it is almost the only one that has some recognition among homebrewers for this style. It is even used successfully in several commercial breweries, so it did not seem like a bad alternative.
The mash is another of the keys to brewing a good Weissbier and, as we mentioned before, it is practically essential to make a step mash. In our case we opted for the following regimen: mash in at 40ºC (104ºF), 10 minutes at 45ºC (113ºF), 5 minutes at 55ºC (131ºF), 30 minutes at 63ºC (145.4ºF) and 30 minutes at 72ºC (161.6ºF). The first step at 40ºC (104ºF) is to mix the grains and gradually heat up to 45ºC (113ºF), which is the ideal temperature for the formation of the 4-vinylguaiacol (clove) precursor. Here, if you do not want too much clove character, it is advisable not to exceed 15 minutes. The third step is to heat to 55°C (131ºF) and reach the protein rest, where the larger proteins are broken down to avoid excessive viscosity. Here we only left it for 5 minutes so as not to break too many proteins and damage the foam. Finally, the two typical German steps, the maltose rest and the saccharification rest. In the first of the two, 63°C (145.4ºF) for 30 minutes, conditions are ideal for beta-amylase to produce maltose from malt starches. After those 30 minutes, not all the sugars are converted, so it is moved to 72°C (161.6ºF) for another 30 minutes to bring the mash to ideal conditions for alpha-amylase. This temperature is above the malt starch gelatinization temperature and alpha-amylase completes the conversion of the sugars. This last rest also has another advantage, and that is the formation of glycoproteins that help with the formation of foam and give wheat beers that characteristic mouthfeel.
I have left the water for last. We only add some calcium chloride to try to get closer to the profile that is considered appropriate for the style, which you can see here. According to Bru’n Water the pH would be a little high, about 5.7. However, on this occasion we were not too concerned for several reasons. The first is that this pH, together with the temperature of 45ºC (113ºF), is ideal for the formation of ferulic acid. At this pH, turbidity is also favored, which is not a problem in Weissbier. Finally, the yeasts used for these beers tend to reduce the pH more than usual during fermentation, so it does not matter if the mash pH is a little high.

Enormous krausen during fermentation

Below you have the recipe hand process we followed:

CLASSIC WEISSBIER

MALTS/GRAIN
1.50 Kg (3.31 lbs) (40.5%) Pilsen malt (Grannaria) (5.0 EBC)
1.40 Kg (3.09 lbs) (37.8%) light wheat malt (Grannaria) (3.9 EBC)
0.80 Kg (1.76 lbs) (21.6%) dark wheat malt (Weyermann) (17.0 EBC)
HOPS
12.00 g (0.42 oz) Hallertaur Tradition (6.70% AA) leaf (boil 60 minutes, 11.7 IBUs)
YEAST
Munich Classic (Lallemand-Danstar)  (One sacchet of dry yeast, previously rehydrated)
THEORETICAL NUMERICAL DATA
Volume: 15.50 L (3.96 gallons)     OG: 1.049   FG: 1.010     ABV: 5.2%     IBUs: 11.7     Colour: 11.1 EBC     BU/GU: 0.238
WATER PROFILE
The water was taken the day before to allow the chlorine to evaporate and salts were added to achieve the following mineral profile:
Ca: 129 ppm; Mg: 3 ppm; Na: 7 ppm; SO4: 12 ppm; Cl: 172 ppm HCO3: 120 ppm
MASH
Mash in at 40ºC (104ºF), 10 minutes at 45ºC (113ºF) (ferulic acid rest), 5 minutes at 55ºC (131ºF) (protein rest), 30 minutes at 63ºC (145.4ºF) (maltose rest) and 30 minutes at 72ºC (161.6ºF) (saccharification rest).
BOIL
60 minutes
FERMENTATION
In Brewbucket of 27 liters of capacity. Two days at 18ºC (64.4ºF), after which we took it out of the fridge and let it rise freely to promote the formation of esters. It was like this for four days at about 19ºC-20ºC (66ºF-68ºF). After that time, we left the fermenter for two weeks in a cellar at about 15ºC (59ºF). We bottled about 13 liters (3.43 gallons) (3 bottles of 50 cL and 33 bottles of 33 cL) with sugar for a carbonation of 3.2 volumes of CO2.

Weissbier at bottling

I am not going to detail the whole process in detail so as not to make the entry too long, but I will detail some things about how the process actually went and why we took some decisions. Everything went pretty much as detailed above, except for a few numbers. We finally transferred 14 liters to the fermenter because we left quite a bit of volume behind due to having too much leftover ground malt. The original gravity was a little lower than theoretical, 1.044, finishing after fermentation at 1.009, which gave the beer an ABV of 4.6%.
You may have noticed we used a fermenter with a capacity of almost twice the volume of wort that we put in it. We did this to simulate an open fermentation, which usually takes place in fermenters that are as high as they are deep, as is typical in many breweries that brew this type of beer. This causes the yeast to have less pressure and enhances the production of esters and phenols. This is probably true but difficult to verify at home (well, when tasting the final result you can get an idea), but what was certainly spectacular was the krausen after two days of fermentation at 18ºC (64.4ºF). From the 14 liter mark it had risen to the 20 liters mark, as you can see in picture above. I had never seen one like this.
After those two days at 18ºC (64.4ºF) we left the beer at room temperature, which is also typical, to raise the temperature and further promote those esters and phenols characteristic of Weissbier. After four days where the temperature hovered around 19ºC-20ºC (66ºf-68ºF), we moved the fermenter to the cellar, where the beer reached about 15ºC (59ºF) and was kept for about two weeks until we bottled. In total, about 13 liters (3.43 gallons) divided into 3 bottles of 50 cL and 33 bottles of 33 cL. I will tell you about the result in another post, but I can tell you that the thorn in my side is no longer there.

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Book review – The Homebrewer’s Almanac by Marika Josephson, Aaron Kleidon & Ryan Tockstein

About five years ago, the available supply of books for the homebrewer was not exactly scarce but, with some exceptions, the vast majority were more or less in-depth educational treatises that tried to cover needs from the most basic to more or less intermediate levels. Of course, there was also another series of books with more advanced techniques or processes or about some particular styles. However, all of them followed, shall we say, orthodox techniques based on many years of experience. Because of this, the book about which this review is about, was a bit of a small revolution, for its great originality. Written by the founders of Scratch Brewery in Illionis (one of the nicest I’ve seen, if only in picture), Marika Josephson, Aaron Kleidon and Ryan Tockstein, the book is a sort of seasonal guide describing how to use in brewing a multitude of plants and ingredients that can be foraged.

The book, accompanied by amazing pictures, is divided by seasons, with chapters for each of the ingredients that can be found in each of them. These chapters all follow the same structure, starting first with an introduction. Then, information is provided to forage the different parts of the plant in question and how to use each of them when brewing beer. This is one of the strong points of the book. For each plant, depending on the case, we can have information from the roots to the leaves, through the flowers, fruits and / or even bark. A huge amount of information compiled by the authors based on trial and error. Finally, to close the chapter, there are one or two examples of beer recipes using the ingredients just explained. Harvesting times, types of storage, quantities and how to use them… a veritable encyclopaedia that allows us to immerse ourselves in the most experimental part of brewing.

It is hard to find weaknesses in the book. Perhaps the worst thing, which is not a fault but rather a drawback in certain cases, is that the ingredients that are part of the book are those that grow in the region where the brewery is located and may not always be available in our area. Even so, many of them are widely distributed and surely with the book you have the option to try a multitude of things. We have brewed several recipes inspired by some of the chapters, including this saison with dandelion and honeysuckle, and we are very happy with the results. It is definitely a highly recommended book for the brewer who already masters the most common techniques and wants a little experimentation in their beers.

 

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Brewing Brut IPAs, playing with enzyme amyloglucosidase

Before writing this entry, I have just put the finishing touches for a new recipe of a Brut IPA that we are going to brew soon. This one will the third Brut IPA in our brewing history. To get to this number means that we quite liked the previous ones that we brewed. A bit strange if we consider that it is not a style which is readily available or even appreciated. Moreover, it is not unusual to see this style mocked. However, since I read something about it, I thought it was an interesting concept. It is true that I had not drink a good commercial example of the style yet. And maybe that could be part of the problem, the lack of good commercial Brut IPAs. In our case, we had good results with the first two recipes that we brewed and we like them a lot. But before explaining how we brewed them, let us take some time to review the style with some tips and tricks from some people that know well about it.

Grains for our first Brut IPA

First, a brief description before we explore some tips from the experts. A Brut IPA is not a big mystery. It should be a very dry beer, with a very light pale colour and with lots of hop aroma and flavor, usually on the tropical side. Besides, it should not have any grain character. It does not look too complicated at first glance although, as is almost always the case, problems may arise. So some advice to avoid them is always welcomed. And nothing better that to follow advice from Kim Sturdavant, former brewer of the now defunct Social Kitchen & Brewery, who is considered as the pioneer of the style. In the article from Brew Your Own about Brut IPAs (for subscribers only), Kim gives a number of tips to avoid some problems that could appear brewing this style.

Amyloglucosidase enzyme, ready to be added

Firstly, the ingredients. For Kim, fermentables should come from Pilsner malt and adjuncts like flaked corn and/or flaked rice. None of them will give too much flavour, leaving more than enough space for hops to shine. Hops should have tropical and/or resinous character, at least if we want to stick to the original recipe. Yeast, to avoid interfering with hops, should ferment as clean as possible. Lastly, the star of the show, the one without which it is practically impossible to brew this style, amyloglucosidase enzyme. This enzyme is able to hydrolyse the alpha 1-6 bond found in branched dextrins left over from the action of alpha and beta amylase on amylopectin, the predominate type of starch found in all of the grains used in brewing. It can also break alpha 1-4 bonds from the end of starch chains to yield glucose. And what does this all mean? Well, giving this enzyme time enough, amyloglucosidase is able to provide sugars that yeast can easily ferment, leaving almost no unfermentable sugars. Because of this, Brut IPAs have very low final gravity, even below 1.000, which make them very dry beers (and also with low calories, by the way).

In the article, a couple of tips are mentioned to get a good result in an apparently easy to brew beer. The first one is about the time of addition of the amyloglucosidase. There are two options, add it in the mash o during fermentation. According to Kim, the key is to add the enzyme in the mash. The reason behind this is that doing it this way, the enzyme have enough time to act on complex sugars and then is denaturalized during the boil, so it would not work anymore during fermentation. If the enzyme is added during the fermentation phase, it continues working and it can give some troubles with the production of some undesired compounds like for example diacetyl. To make things worse, if added during fermentation, it can degrade hop flavour and aroma. The other tip is to get a good foam, since foam retention is not especially good in this type of beer. To avoid this, a small amount of dry malt extract can be added in the boil, once the enzyme is denaturalized.

Mini brewbucket, the fermentor for our Brut IPAs

With all this information and a little more that I found online, I designed our first Brut IPA recipe, almost two years ago. The grist was composed of Bohemian Pilsner floor malted malt from Weyermann and wheat flakes in a ratio of 2:1. I opted for the always clean and reliable Safale-US05 for the yeast. As for hops, this time we used Cenntenial in the boil and whirlpool and Azacca and Idaho #7 for dry hop. Following the tip mentioned above, we added a handful of dry malt extract to promote a good foam retention. We also modified the mineral profile of our water following advice from Matt Sager, brewer for Danville Brewing to get a ratio of 1:1 for chloride and sulphate. We mashed at around 63ºC (145.4ºF) to promote fermentability of the wort. We added the enzyme during this step, although due to an mistake in the instructions we used less than the recommended amount. Specifically we added 0.07 mL/L while the recommended amount is 03.-0.8 mL/L. Because of this attenuation was higher than expected, something we corrected with our second recipe. To avoid an extra-long post, I will left details of the recipes and the process for both recipes below.

For our second version, almost a year after the first one, we did not make a lot of changes. One of them was an obvious one, correct the amount of enzyme we added during the mash. We used 0.38 mL/L this time. We also changed the base malt, in this case using floor malted Hanna malt from Crisp instead of Bohemian Pilsner. We used flaked corn in the same proportion. Finally, we used Centennial again in the boil and whirlpool, but we decided to use a single hop variety for dry hop, Medusa. We did it that way because it was the first time for us with this particular hop and we wanted to see which it could add to the beer.

Hop for dry-hopping our first Brut IPA

Next you can find information for both recipes as well as the process we followed. The numerical data are real in this case, not the theoretical ones as it happens in other posts.

BRUT IPA 2019 EDITION

MALTS/GRAINS
2.00 Kg (4.41 lbs) (65.6%) de Bohemian Pilsner – Floor malted (Weyermann) (4.0 EBC)
1.00 Kg (2.20 lbs) (32.8%) flaked corn (2.6 EBC)
0.05 Kg (1.76 oz) (1.6%) light dry malt extract (8.0 EBC) (added at boil)
HOPS
15.00 g (0.53 oz) Centennial (Lupulina) (10.00% AA) pellets (boil 15 minutes, 17.6 IBUs)
85.00 g (3.00 oz) Centennial (Lupulina) (10.00% AA) pellets (whirlpool 15 minutes at 80ºC (176ºF), 22.9 IBUs)
56.00 g (1.98 oz) Azacca (Yakima Valley) (13.80% AA) pellets (dry hop, after 8 days of fermentation, for 6 days)
56.00 g (1.98 oz) Idaho #7 (Yakima Valley) (12.50% AA) pellets (dry hop, after 11 días of fermentación, for 3 days)
YEAST
Safale US-05 (Fermentis)  (One sachet of dry yeast, previously rehydrated)
NUMERICAL DATA
Volume: 11.50 L (3.04 gallons)     OG: 1.051   FG: 1.007     ABV: 5.8%     IBUs: 40.5     Colour: 7.3 EBC     BU/GU: 0.752
WATER PROFILE
Water was collected the day before brewday to allow chlorine to evaporate. We added salts and phosphoric acid to adjust mash pH and get the follwing mineral profile:
Ca: 111 ppm; Mg: 35 ppm; Na: 7 ppm; SO4: 137 ppm; Cl: 140 ppm HCO3: 40 ppm
MASH
60ºC-63ºC (140ºF-145ºF for 75 minutes, with 0.07 mL/L of amyloglucosidase
BOIL
75 minutes (adding yeast nutrients as well as light dry malt extract)
FERMENTATION
In Brewbucket mini for 14 days at 18ºC-20ºC (64.4ºF-68.0ºF). After that time, we trasnferred to a PET demijohn to clear the beer a little bit, 4 days at 12ºC (53.6ºF). We bottled about 10 liters (2.64 gallons)(10 50 cL bottles y 9 33 cL bottles) with priming sugar enough to get a carbonation of 2.4 volumes of CO2.

Medusa, dry-hop hop for our second Brut IPA

BRUT IPA 2020 EDITION

MALTS/GRAIN
2.00 Kg (4.41 lbs) (65.6%) Hanna Floor malted (Crisp) (2.0 EBC)
1,00 Kg (2.20 lbs) (32.8%) flaked corn (2.6 EBC)
0.05 Kg (1.76 oz) (1.6%) light dry malt extract (8.0 EBC) (added at boil)
HOPS
15.00 g (0.53 oz) Centennial (Lupulina) (10.00% AA) pellets (boil 15 minutes, 17.6 IBUs)
85.00 g (3.00 oz) Centennial (Lupulina) (10.00% AA) pellets (whirlpool 15 minutes at 80ºC (176ºF), 22.9 IBUs)
56.00 g (1.98 oz) Medusa (Yakima Valley) (3.00% AA) pellets (dry hop, after 4 days of fermentation, for 11 days)
56.00 g (1.98 oz) Medusa (Yakima Valley) (3.00% AA) pellets (dry hop, after 9 días de fermentation, for 6 days)
YEAST
Safale US-05 (Fermentis)  (One sachet of dry yeast, previously rehydrated)
NUMERICAL DATA
Volume: 11.50 L (3.04 gallons)   OG: 1.049   FG: 1.004     ABV: 5.9%     IBUs: 40.5     Colour: 5.5 EBC     BU/GU: 0.752
WATER PROFILE
Water was collected the day before brewday to allow chlorine to evaporate. We added salts and phosphoric acid to adjust mash pH and get the follwing mineral profile:
Ca: 111 ppm; Mg: 35 ppm; Na: 7 ppm; SO4: 137 ppm; Cl: 140 ppm HCO3: 40 ppm
MASH
62ºC-65ºC (143.6ºF-149.0ºF) for 75 minutes, with 0.38 mL/L of amyloglucosidase
BOIL
75 minutes (adding yeast nutrients as well as light dry malt extract)
FERMENTATION
In Brewbucket mini for 15 days at 18ºC-20ºC (64.4ºF-68.0ºF). After that time, we trasnferred to a PET demijohn to bottle. We bottled about 10 liters (2.64 gallons)(22 33 cL bottles) with priming sugar enough to get a carbonation of 2.3 volumes of CO2.

As you can see, only a few differences between both. Maybe the most important one, apart from the little changes in malts and hops, was the dry hop start and finish time. It was not something we thought about, it just came that way. The correct dosing of the enzyme the second time showed results, with the beer reaching a final gravity of 1.004, versus 1.007 the previous year.

Brut IPA 2020 edition, at bottling

Regarding appearance, both had a light golden colour (a little bit lighter the 2020 edition) and were quite hazy. Picture below does not do much justice to the real colour, being more similar to the one of picture above, right before bottling. Foam was very white in colour and have a medium-high retention, with a thin layer staying until the end. I am happy with this because it seems that the addition of dry malt extract worked and it helped with foam.

Aroma wise, only hops, no trace of malt or yeast aromas. In the case of the first recipe, with Azacca and Idaho #7, the aroma was awesome. A festival of citrics with lemon, orange and grapefruit, along a hint of apricots and pineapple. In this style, where hops are the absolute star of the show, it is important to use fresh hops with good aroma in order to get good results. In our case, hops for dry hopping were from Yakima Valley and it showed. In the second recipe, the aroma was more unidimensional since we used only one variety, but it served us to know well this hop, Medusa, with its lime and lemon notes. I do not want to forget either about the Centennial hops we added at whirlpool and that I am sure provided its part in final aroma and flavour of the beers.

The flavour was also a showcase of hops. Citric notes in both recipes and also stone fruit and tropical fruit notes in the first recipe. Here I think I detected some grain flavour, mainly from corn. Although corn is usually used to lighten the body of beers and minimize malt flavour, I think it gives a nice sweet touch to the beer, at least for my palate. I do not think these beers would have ended like they did substituting corn for rice. Bitterness was medium for both of them.

Lastly, mouthfeel. With medium-high carbonation, both of them seemed to be quite dry (in spite that the first one did not have a very low final gravity). Both of them were light bodied, although with kind of a creaminess that I do not know if it could come from corn.

Brut IPA 2019 edition with Azacca and Idaho #7, final result

And that is all. Very easy to drink because of their dryness and light body, you can drink one after one without getting tired. They were very refreshing and made an ideal summer beer. If we add to that the explosion of aroma and flavour coming from hops, we end with a beer we loved. In fact, sharing the first one with some other fellow homebrewers we had very good opinions about it. Even people who are professional brewers told us that they would ask for this beer in a bar, which made us very glad. In spite of its bad reputation, if you have some really good hops around and you are a little tired of hazy IPAs and NEIPAs, give Brut IPA an opportunity. Who knows, maybe it surprises you as it did with us.

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Capturing wild yeasts, first try

Capturing wild yeast to be able to use them for brewing (also known as bioprospecting) had been a project that I have had in my mind for a few years. I had been reading about it and I knew it was something that demanded patience and that it was not easy, with a high chance of having multiple failures before having a good result. But it was also something that could be fun and, well, I could always try to refresh my memories from microbiology classes back at the University years ago. The thing is that, among the workshops announced for the Spanish Homebrewers Association of 2019 in Bilbao, there was one with the following title: “Hunting wild yeasts”. It was like a signal to start taking this project seriously. The workshop was delivered by Aitor Lekuona, a microbiologist specialized in fermentations and brewing science, with an impeccable presentation that I loved. His advice, along additional information that I gathered from the internet (basically from the essential Milk the Funk wiki) were the pillars in which I based my “hunt”. In addition, I was able to have a chat with Aitor after the workshop and, after telling him about my intentions to capture some wild yeasts for brewing, he offered to help me to solve any doubt I could have. Of course, I did not miss the opportunity and, when I did not know what to do, I contacted him and he kindly advised me. Because of this, first of all I would like to thank him because if it was not for his help, maybe this project would have failed a few months ago.

Fruits selected for this first try at bioprospecting

Almost of the sources agree that spring and summer are the best times of the year to capture wild yeasts. As usual, I postponed everything for a few months until an afternoon in mid-September, when the summer of 2019 was in its last days, I spent some time collecting fruits from which I hoped I could get some interesting microorganisms. The possibilities are endless (fruits, flowers, bark,…) but I decided to pick some apples and some blackberries. In the case of apples, just because I had read that they were a suitable fruit for yeasts and, in the case of blackberries, it was just a matter of availability. For any sample you pick, you have to be careful and try to pick fruits that have not been treated with chemicals as pesticides and the like. In my case, after a walk in the forests around my neighborhood, I collected some samples from red apples that grow wild without any human intervention, a few blackberries and some green apples from trees that grow also without any chemical treatment. I collected all of these samples in 50 mL sterile centrifuge tubes.

Once I collected the fruit samples, to try to grow the yeasts in them, I decided to do it with three different methods: the one described by Aitor Lekuona in the workshop I previously mentioned, one developed by David Thorton from Southyeast Labs and the one proposed in the Sui Generis Brewing blog. Next, I will give a little description for each one of them.

Growth in the three samples following the method described by Aitor Lekuona

In the method described by Aitor Lekuona you start with a wort with an original gravity around 1.020. This wort must be boiled to sanitize it, without adding hops. Once the wort is cooled down, 20-25 mL of it are poured in 50 mL sterile tubes containing the samples. You let it ferment for a minimum of 2-3 weeks, shaking and opening the caps a little bit to let carbon dioxide from fermentation escape. After a few weeks, you can streak agar plates to purify strains.

The method developed by David Thorton starts with a wort of similar original gravity, 1.024, that must be also boiled without hops. In this case, adding yeast nutrients is recommended. 75 mL of this wort are transferred to a 250 mL flask and then the sample is added, in this case the fruit. Then put it on a stirplate, covering the top of the flask with some aluminum foil. Let it ferment for 48 hours. As soon as froth appears, put an airlock on the flask while keeping it in the stirplate. After another 48 hours, decant and discard the liquid and keep the biomass. Add 75 mL of fresh wort, this time of an original gravity between 1.032-1.040 and again with some nutrients, and purge with carbon dioxide. Keep the flask in the stirplate with the airlock until fermentation is finished. Then decant and discard the liquid again and keep the biomass. In the last step, purge again with carbon dioxide and add another 75 mL of wort, this time with an even higher original gravity, 1.083. Do not forget to add some yeast nutrients too. Put the airlock on and keep the flask in a stirplate until the gravity drops around 1.008. Finally, you can purify strains in agar plates if you want. This method is designed to capture mostly Saccharomyces yeasts and lactic acid bacteria.

The third method is the one recommended in the Sui Generis Brewing blog. Start with 250 mL of a wort with an original gravity between 1.045-1.065, hopped to around 10-25 IBUs and with 0.5 mL of phosphoric acid to reduce pH. Boil to sanitize, cool and add about 35 mL of cheap vodka. The low pH should inhibit the growth of pathogenic bacteria, hops should inhibit lactic acid bacteria and alcohol should avoid the growth of a lot of microorganisms that do not tolerate alcohol. Let it ferment with an airlock to avoid mold and acetic acid bacteria.

Flask after the second step of the Thorton’s method

That is enough for theory. In practice, I started with around 250 mL of a wort of 1.024 original gravity from malt extract that I could use for both the Thornton and Lekuona methods. For the Sui Generis Brewing method, I made a wort of 1.050 original gravity, again from malt extract. To this wort, I added 0.5 mL of 10% phosphoric acid. I boiled it for about 10 minutes with some Northern Brewer hops to got about 25 IBUs. Finally, after cooling it down, I added 35 mL of vodka.

I transferred 20-25 mL of the first wort (1.024 O.G. without hops) to each of the three sterile tubes which contained pieces of red apple, 3-4 blackberries and pieces of green apple, respectively. I kept these tubes well closed. In addition, I added 75 mL of the same wort to a 250 mL flask, previously sterilized. I added some red apple pieces to this wort, just because it was the sample of which I have the greater amount (and also because I have a feeling that it could be my best bet). I covered the top of the flask with some aluminum foil and let it ferment. Finally, I transferred the hopped wort with vodka to a previously sterilized 500 mL flask. This flask received also some red apple pieces and then I put an airlock on it. It was time to wait for the magic to happen.

The next day, intrigued by expectation, I went directly to see how everything was. There was no visible activity in both flask. However, in the 50 mL tubes something was fermenting. After shaking them and loosening the caps a little bit, some hiss confirmed that some carbon dioxide had formed.

Two days later, from the 50 mL tubes the carbon dioxide continued to escape every time I loosened the caps. Besides, the three of them had some froth. I considered that they were already “inoculated”, so I removed fruits from them as aseptically as possible, avoiding this way the growth of molds. In the flasks, nothing interesting yet after three days.

Pellicle in the flask of the Sui Generis Brewing method

After a week and a half, in the bottom of the tubes whatever which had grown started to sediment. In that moment I noted what I thought were phenolic aromas in the tubes and, in the case of the tube inoculated with the green apple, some interesting esters too. As for the other two methods (I had put the airlock in the flask of the Thorton method a few days ago) I was supposed to remove the liquid from the flask of the Thorton’s method. Although it was clear that it was some fermentation activity, visually there was very little amount of biomass, so I opted for adding 75 mL of a fresh wort of 1.040 original gravity with some nutrients without removing the liquid. However, I did remove the fruit pieces from the flask when I added this fresh wort. In the flask of the Sui Generis Brewing method, when I was ready to dump it, some signs of activity showed. This activity increased and the next day a fine pellicle with quite big bubbles had formed.

The next days, the amount of biomass in the bottom of the 50 mL tubes was quite big. Or at least that was what I thought. For the Thorton method I had to perform the third step. This time I removed the liquid because after stopping the stirplate, a nice amount of biomass could be seen at the bottom of the flask (see picture above). I purged with carbon dioxide and added 75 mL of fresh wort with an original gravity of 1.083 plus some nutrients. I put the airlock on the flask and kept it on the stirplate. A couple hours later a krausen formed in the surface.

Several weeks passed without me being able to do anything apart from taking a look once in a while. Even though the pellicle that had formed in the flask of the Sui generis brewing blog got me amped, I think I should had tried something with it earlier (inoculate some wort, purify strains in agar plates,…), but I had no time to do it. Furthermore, I was not convinced with the aroma coming out the flask, and the fruit was still in the flask. So I decided to dump it, ending this part of the experiment. However, I think the method is valid and it could give good results and I have no doubts that I will use it again in the future. I still had two parts of this wild yeasts hunt experiment going on.

Everything set to streak agar plates

A couple of months after I collected the fruits I took some time to streak some plates with the samples from the tubes to purify strains. At this point, I asked Aitor Lekuona for advice, since I did not know if I should take the sample for streaking with or without shaking the tubes. He told me that probably the population of yeasts was big enough without shaking, but he recommended me to take two samples of each tube, one without shaking them and one after shaking them and letting them stand for 30 seconds. This way, the variety of microorganisms could be greater. So that is what I did.

I had prepared the agar plates a few days before following the instructions from (again) the Sui Generis Brewing blog (its “Your Home Yeast Lab” section is awesome!!). I had kept them several days in the fridge, where nothing had grown, so maybe I had made them correctly. I streaked two plates for each sample (before and after shaking the tubes) from the three tubes “inoculated” with red apple, blackberries and green apple, respectively. I also streaked two plates for the sample of the Thorton method, again before and after shaking the liquid. I left the plates at room temperature to see the growth.

Around the same time, thanks to an event organized by our homebrew club, Legamia, I was able to inoculate what had grown inside the flask of the Thorton method, without purifying, since I did not dump the liquid after streaking plates. The event consisted in brewing a batch of wort in a commercial brewery (thanks to Tito Blas brewing for this), with a recipe that the members of the club had designed (75% pale ale malt and 25% wheat malt, 1.050 O.G. and 25 IBUs). Then the wort was divided and each one of the club members would ferment it as they liked. I had 20 liters of wort and I took 5 liters for this experiment. I inoculated these 5 liters of wort with a mini-starter that I made from what had grown in the flask of the Thorton method (the biomass that was left from a starter made with 250 mL of wort with 1.035 original gravity). It took it a few days to start, at least to show some signs of fermentation, but finally a nice white krausen formed. Fermentation seemed to go well and, at bottling, final gravity was 1.005 (5.9% ABV) and pH was 3.8. It did not look bad at all. I tasted it at bottling and it was not bad, some cidery flavor, a little bit tart, but quite pleasant. However, as my homebrew club colleagues could attest, after carbonating it was barely drinkable. A lot of solvent off-flavors, a lot of acetic acid… A complete disaster. I wonder if exposing the beer to oxygen at bottling had something to do with this. Or maybe it was just the evolution of the beer and the microorganisms in it. Anyway, a little failure.

Growth in the agar plates

However, I had still the agar plates, so I could keep on trying. As you can see in above picture, all the plates showed some growth and each of them had some kind of purified strain. In one of them, probably because my technique was not aseptic enough, some mold growth was observed. I kept this plates in the fridge for a few months because I was not able to find some time to play around with them. When finally I found some time, I had some serious doubts that, starting from a single colony, I could get something to grow and obtain something good, but I tried anyway. To do this, I went back to Aitor Lekuona’s presentation. Then I selected which, with the naked eye, I thought were yeast colonies, considering their morphology. Medium size, a more or less rounded shape, white or pinkish color and quite opaque.

Before picking this colonies, I prepared five sterile tubes to which I added about 25 mL of sterile wort with an original gravity of 1.040, prepared from malt extract. I kept these tubes with the wort in a pressure cooker with the cap loose for 15 minutes at maximum pressure. After cooling them down, it was time to go for unique strains. As aseptically as I could, I selected those colonies which I thought seemed the best for my purposes. I inoculate each of the five 50 mL tubes with 25 mL of sterile wort with a different strain. Of these five unique strains, a couple of them came from the sample of green apples (a white one and a pinkish one), one white colony from the sample of blackberries, one pink colony from the sample of red apple and another white colony also from the sample of red apples but with the Thorton method.

Growht in tubes from unique strains

Fortunately, after the first day signs of fermentation were present, with carbon dioxide escaping the tubes when loosening the caps a little bit. This activity increased with time and in the third day I had to be careful when loosening the caps so the liquid and foam would not spill outside the tubes. After five days growing, I decided to go a step further and see the behavior of these strains in a more or less real environment, but on a small scale. My idea was to prepare 1 liter of hopped wort with an original gravity around 1.050 and with 20-25 IBUs and divide it in four equal parts to brew four mini-batches. It was four because I discarded one of the tubes because I found the aroma a little bit off. The four final candidates were the two colonies from the green apples, the colony from the blackberries and the colony from the red apples obtained with the Thorton method.

After inoculating each one of the four 500 mL bottles (previously sanitized) with a different strain, after 9 hours the four airlocks were bubbling. After 18 hours, all of them showed a nice krausen, specially the one of the strain from the red apple obtained with the Thorton method, that reached the neck of the bottle. I forgot to take a picture of that moment, but in picture below you can see the remainders of what was the krausen in each bottle. I left the bottles a few days more at room temperature, around 20ºC (68ºF) to let them ferment completely. In all, 11 days passed, when I took some samples to measure final gravity and pH. And of course, to taste the results of these mini-batches.

Mini-batches of four differnt unique strains

Next, you can see a summary of my notes from this tasting session for the four samples:

SAMPLE A (green apple – white colony)

pH 4.68; DF 1.014; 4.79% ABV / Good aroma, apple-like. It has also some hints of juniper/pine. Nice flavor. Good flocculation.

SAMPLE B (green apple – pinkish colony)

pH 4.79; DF 1.015; 4.63% ABV / Little aroma of any type. It has some herbal notes. Quite clear, good flocculation.

SAMPLE C (blackberries – white colony)

pH 4.73; DF 1.016; 4.46% ABV / Low aroma. Good flocculation, clearer than samples A and B. The flavor is not nice, somewhat strange.

SAMPLE D (red apple – white colony obtained with Thorton’s method)

pH 4.62; DF 1.012; 4.95% ABV / Similar in appearance to the other three samples. More aroma than samples B and C and little less than sample A, but nicer, fruitier. Nice flavor, quite clean.

Once I finished tasting and measuring all of them, I discarded samples B and C (pinkish colony from green apples and white colony from blackberries) for not having pleasant enough organoleptic properties. In addition, these two samples were also the ones with the less attenuation and higher pH values of the four. In fact, pH values seemed to me a little bit high in all cases comparing with usual values for a brewing Saccharomyces strain. Anyway, I kept tubes from samples A and D (white colony from green apples and white colony from red apples) so I could continue to test them. Both of them seemed promising to me, especially the one from red apples. My idea is to brew a small batch, around 3 liters, for each one of them, then pitch a starter, let it ferment, bottle and carbonate, to see if they can offer something that could be interesting for future brews. It would be very exciting to have a nice beer fermented with wild yeast captured by me.

This is all for now in my project of bioprospecting. I hope you find it interesting and, if some of you are doing something similar, please feel free to share your thoughts. I will keep on telling you how this project follows and if these strains are good enough to keep them. It has been a long entry, but I thought that it would be better to put everything in a single post. It has been a lot of months since I started until now and although it takes a lot of work, I must say that I am pretty happy with how everything went so far. It was very entertaining, I learned a lot of new things and, although I had some small disappointments, so far the project outcome is very positive. I thought about doing something similar in 2020 and, in fact, I collected some samples (flowers and cherries this time), but seeing that I had a limited free time I decided to discard these samples and focus in the samples that I have already. I will try to capture some new wild yeast in 2021.

 

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Discovering non-Saccharomyces yeast. Coinoculation with Torulaspora delbrueckii and Saccharomyces cerevisiae

As I recently told you, the ACCE (Spanish Homebrewers Association) organized an interesting experiment with non-Saccharomyces yeasts. In that entry you can read all the details about it, including the different groups in which we were divided. We were in group two, in which we were asked to brew a beer coinoculating in a ratio of 1:1 Torulaspora delbrueckii and Saccharomyces cerevisiae (Nottingham from Lallemand) (0.5 g/L of each one). In this entry you can read how the brewing day was and a first tasting of the beer before we shipped a few bottles to be tasted in five different cities by a panel of experienced homebrewers and judges.

Yeasts and hops for the recipe

The recipe had been previously designed by the organization and it would be the same for all groups, except for yeasts. It was a SMASH (single malt and single hop) with pale ale malt and mosaic hops. In addition, after boiling, we had to add 20 g/L of dextrose. This was to increase the glucose rate in the wort, something that should stimulate the metabolism of both Torulaspora Delbrueckii and Metschnikowia pulcherrima, the other non-Saccharomyces yeast that is part of the experiment. Apart from the ingredients, the process had also a set of parameters that we had to follow in order to avoid differences that were not due to the action of the yeasts. The mash should be a infusion mash at 65ºC (149ºF) for a time enough to complete conversion of sugars, adjusting the pH to a value of 5.3. The wort should be boiled for 30 minutes, adding enough hops to get about 30 IBUs. The pH value after boiling should be around 5.2, with the original gravity about 1.055. The water used for brewing should be free of chlorine and we had some margin in regard of the mineral profile, with the condition of not having more than 100 ppm of chloride and sulfate. With this premises, we had to adjust the brewing process according to our equipment to try to stay as close as possible to the set parameters.

In our case, we decide to brew a 15 L (3.96 gallons) batch. This way, we could follow the process as asked and we could also keep some Torulaspora delbrueckii to play with it in future brews. The most significant thing we did was to modify the water profile to try to adjust to the theoretical mash pH. We added 3.2 g (0.11 oz) of calcium sulfate and 2.8 g (0.10 oz) of calcium chloride, as well as 4.5 mL of phosphoric acid 75%. According to Bru’n Water, with these additions we should get a mash pH about 5.3.

Mashing at 65ºC (149ºF)

Once we started the brewday, we kept the mash temperature at 65ºC (149ºF) with the aid of a PID controller, but mash pH was little bit higher than expected, 5.4. That also caused that the post boil pH was also a little bit off, 5.3. We could have tried to adjust pH, but we thought that that difference was not important considering the risk of lowering the mash pH too much. We boiled for 30 minutes, adding 16 g (0.56 oz) of mosaic hops at the beginning of the boil to get about 30 IBUs and, after flame out, we added 310 g (0.68 lbs) of dextrose. We cooled down the wort to 22ºC-23ºC (71.6ºF-73.4ºF) and, since we could not get it at a lower temperature, we transfer the wort to a Brewbucket fermenter, keeping it in our fermentation chamber at 10ºC (50ºF) to see it we could lower the temperature a little bit more before inoculating yeasts. The original gravity was on point, 1.055. After a couple of hours, the wort was a little bit over 18ºC (64.4ºF), so we pitched both yeasts (Torulaspora delbrueckii and Saccharomyces cerevisiae) with a ratio of 1:1 by weight,   0.5 g/L of each one. Both of them in dry form and without rehydrating. We set our fermentation chamber at 16.5ºC (61.7ºF) to try to keep fermentation temperature around  18ºC (64.4ºF).

Next day, the airlock showed activity indicating that fermentation was active. Temperature had raised to 19.4ºC (66.9ºF), so I set the temperature of the fridge to 15ºC (59ºF) to avoid fermentation temperature from going too high. At the end of that day, it was 18.4ºC (65.1ºF) and the airlock was bubbling intensely. I took the first gravity reading 30 hours after pitching and it showed 1.036. The next five days I took a gravity reading each day, writing down the temperature of the beer as well. The next two gravity readings were 1.014 and 1.005. In the samples for this readings I perceived some esters that I had not noticed in “normal” fermentations with only clean Saccharomyces yeasts and that made me thought that could be due to the activity of Torulaspora delbrueckii. After 78 hours fermentation seemed to be completed, so I added 10 g/L of mosaic hops for dry hopping. The dry hop charge was scheduled on day four looking for some biotransformation, but in our case maybe it was a little bit too late, considering the gravity readings. As for temperature, those days the beer remained all the time between 18ºC-19ºC (64.4ºF-66.2ºF). After another two days taking gravity readings, since it had been stable at 1.005 and it was three days since I had added the dry hop charge, I set the fridge at 5ºC (41ºF), the minimum temperature it can reach.

Final result, first bottle

After 5 days at cold temperature, 10-11 days from brewday, we found some time to bottle. Final gravity was, again, 1.005, with gave us a 6.6% ABV beer. Aroma was great due to mosaic hops. With 10 g/L of hops, the trub formed by hops and the yeast cake was quite big, so we had to be careful to avoid some of this trub entering the bottles. To do so, we only bottled 13.25 L ( gallons), adding enough sugar (dissolved in water, boiled and cooled down) to get 2.1 volumes of CO2 after carbonation. We got 28 33 cL bottles and 7 50 cL bottles. As I explained before, 15 of these bottles will go to 5 tasting panels in different cities to see if it is possible to obtain some conclusions from this experiment.

I had already opened the first bottle after two weeks of carbonation. First impression had been good. It has a nice orange color with a white head of medium retention. It has a notable aroma of tropical fruits and peaches, characteristics that also show in flavor. Medium carbonation and body, bitterness is not too high. It has a dry finish. I think it could be some contribution from non-Saccharomyces yeast, but with this amount of dry hops it is difficult to say what it is, at least without a control beer to compare. Fortunately, in all the tasting panels there will be control beers so we should be able to see if Torulaspora delbrueckii and Metschnikowia pulcherrima can impart interesting things in brewing. We will have the answer in a few weeks.

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Tasting Yellow Galaxy (OP series #2)

After the success with our first Oat Pale Ale, a beer that left us one of the greatest impressions among the ones we have brewed so far, we decide to start a series of beer based in this first recipe. In this second installment of this OP series we brewed Yellow Galaxy, in which we introduced some changes, mainly in regard to hops. This time we chose Galaxy and Amarillo to impart flavor and aroma… and at the same time they gave this beer its name.

Yellow Galaxy, OP series #2

Before describing the results, I would like to comment that, as I told you in the entry about the brewing of this beer, this time we kegged it for an event with some friends and we bottled only a tiny part of the batch, 5 bottles of 33 cL. As a matter of fact, the picture illustrating this entry correspond to one of those bottles, showing some oxidation since it was a few weeks old (by then we had not started to use ascorbic acid at bottling to retard oxidation yet). The kegged beer was far clearer and appealing, both visually and organoleptically.

APPEARANCE: Yellow to orange in color, quite hazy. The beer darkened in the bottles as time passed due to oxidation. White and creamy head with great retention.

AROMA: A lot of hops in the front, with tropical notes and some citric hints. Malt presence is light, with some bready notes. Probably yeast is also contributing something, but it is difficult for me to discern exactly what.

FLAVOR: Tropical fruits, orange and peach are the most prominent characteristics. Here, malt it is more recognizable with notes of cereals and biscuits that go well with the fruity flavors from hops. It was curious to hear some people not used to drink craft beer say that the tasted mango in the beer. Medium bitterness, maybe a little bit bitterer than the first beer of the series. However, a residual sweetness, probably from the malt, balance this bitterness nicely.

MOUTHFEEL: Medium to high body with medium carbonation. Mouthfeel is rather creamy, probably thanks to malted oats. A little astringency prevents this beer from being as good as the first one.

Although it did not reach the level of the first OP, we were happy again with this second beer of this OP series. Probably the texture and smoothness was not so spectacular like in the first recipe. In addition, the pairing of Galaxy and Amarillo, despite not being bad, it did not convince me. The best thing, without a doubt, was the big flavor and aroma that can be packed in a beer with such a low ABV like this. It is time to think for the third installment of this series.

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Double batch of Saison, one with dandelion and the other with Japanese Honeysuckle

Among the books about homebrewing that I’ve collected through the years, one of the most interesting and original that I have is The Homebrewer’s Almanac, written by Marika Josephson, Aaron Kleidon and Ryan Tockstein. They’re the founders of Scratch Brewing, a brewery from Illionis that, besides being located in one of the most beautiful spots I’ve seen for a brewery (at least what I could see from pictures), is known for brewing beers with a lot of different natural ingredients foraged around the brewery. I will write about the book in a future entry, but this time I’m going to focus in a beer (in fact, two versions of the same beer) that we brewed following guidelines from this book. After some time thinking about which of the ingredients described in the book we could use first, we decided to give a try with dandelion and Japanese honeysuckle, due to the availability and the season when we were going to brew.

Dandelion (left) and Japanese honeysuckle (right)

Since these two plants grow in different seasons, dandelion in the first sunny days of spring and Japanese honeysuckle in the first part of summer, we had to plan ahead. So one day in last year mid-March, my brother and I went for a walk in one of the local forests around our neighborhood and picked some dandelion flowers (you can also use other parts of the plant). At home, we only kept the petals from the flowers, 79 g (2.8 oz), which we kept in the freezer until brewday. A few months later, in the first week of August, I picked some Japanese honesuckle flowers to brew the next day. According to the book, both plants can be used at the end of the boil, so we decided to make only one wort that, after one hour boiling, we would separate in two to add to each one of them one of the plants.

Japanese honeysuckle and dandelion, ready to be used

But before we could add them we needed a recipe. In this case, we went for a saison, a style that we thought it could go well with these additions. This time we would ferment with Belle Saison from Lallemand, that it is not considered one of the most characterful saison strains, but it is a very reliable fermenter. In addition, that lack of character from this strain maybe could make the aromas and flavors from the plants more recognizable. As for the grains, I didn’t give it too much thought. Although trying to make sense, I emptied some bags from malts that I’ve used before. Specifically, three base malts (Bohemian Pilsner floor malted from Weyermann, pale ale from Dingemans and Pilsen malt from Grannaria), as well as some wheat flakes and a little amount of biscuit malt. Base malts were 68% of the grist, wheat flakes 23% and biscuit malt 9%. For hops, it was going to be our first time using hops from Queen Country, a hop plantation located in Olite, Navarra. We were going to use the variety Saphir, of German origin. One addition boiled for 60 minutes and another one boiled for 15 minutes, for a total of 31 theoretical IBUs.

Saphir hops from Queen Country, in Olite (Navarra)

SAISON WITH DANDELION/JAPANESE HONEYSUCKLE

MALTS/GRAINS
1.00 Kg (2.20 lbs) (32.3%) Bohemian Pilsner – Floor malted (Weyermann) (4.0 EBC)
0.74 Kg (1.63 lbs) (23.9%) pale ale malt (Dingemans) (9.0 EBC)
0.70 Kg (1.54 lbs) (22.6%) wheat flakes (4.0 EBC)
0.36 Kg (0.79 lbs) (11.6%) Pilsen malt (Grannaria) (5.0 EBC)
0.30 Kg (0.66 lbs) (9.7%) Biscuit malt (50.0 EBC)
HOPS
10.00 g (0.35 oz) Saphir (Queen Country) (4.10% AA) pellets (boil 60 minutes, 8.5 IBUs)
40.00 g (1.41 oz) Saphir (Queen Country) (4.10% AA) pellets (boil 15 minutes, 22.7 IBUs)
YEAST
Belle Saison  (Lallemand)  (One dry sachet, previously rehydrated)
THEORETICAL DATA
Volume: 11.50 L (3.0 gallons)    OG: 1.053   FG: 1.008     ABV: 6.0%     IBUs: 31.3     Color: 14.7 EBC     BU/GU: 0.585     Efficiency: 65.00%
WATER PROFILE
Ca: 178 ppm; Mg: 3 ppm; Na: 7 ppm; SO4: 347 ppm; Cl: 13 ppm; HCO3: 120 ppm
MASH
63.5ºC (146.3ºF) for 60 minutes
BOIL
60 minutes

In addition to the ingredients described above, we also added 11.4 g (0.40 oz) of calcium sulphate to adjust mash pH.

Rehydrating yeast

After collecting enough water the day before to let chlorine evaporate overnight, we performed the mash in our electric kettle controlling mash temperature with a PID controller. Everything went fine, with the temperature stable around 63ºC-64ºC (145.4ºF-147.2ºF). After one hour, we removed the bag with the grains and boiled wort for another hour, adding hops as described above. When the boil was finished, to be able to add dandelion petals and Japanese honeysuckle flowers separately, we took 5 liters of wort to a smaller kettle, leaving the rest in the big kettle. In the small kettle we added 34 g (1.20 oz) of Japanese honeysuckle flowers, while in the big kettle we added 79 g (2.79 oz) of dandelion petals. These amounts were based in the guidelines from The Homebrewer’s Almanac for these plants. After boiling these two parts for 5 minutes more, we left them both undisturbed for 10 minutes once the heat was off. After that we cooled down both worts, one of them with an immersion chiller and the other one in the sink with cold water and ice. Since it was August and it was hot outside, it took us a while to lower the temperature, so once we got both worts at 24ºC-26ºC (75.2ºF-78.8ºF), we transfer them into two separate PET bottles and we put them in our fermentation chamber which was set at 10ºC (50.0ºF) to lower the temperaturea little more while we rehydrated yeast and cleaned everything.

High krausen in both PET bottles

When we finished cleaning, we distributed yeast proportionally to the volumen in each PET bottle and, after some shaking to oxygenate them, we left them in our box room in the basement of the building. There, the temperature would be around 20ºC-22ºC (68.0ºF-71.6ºF) the next days. This time our fermentation chamber was not available so we had no other choice. Original gravity was 1.049, a little bit lower than expected because we obtained more volume than planned.

After 18 hours, there was a nice krausen in both bottles. It was around 20ºC (68.0ºF) in the box room, so the beers could be at 22ºC-24ºC (71.6ºF-75.2ºF), which should be good for this yeast strain. Krausen was present for 2-3 days. We left them some days more and, after 10 days of fermentation, they were both clearer and, hopefully, both had finished fermenting. We put the PET bottles in the fermentation chamber, still set at 10ºC (50.0ºF) to let them clear a little bit more. I also tried to smell the aroma from the bottles and, while I didn’t notice anything special in the one with dandelion, the one with Japanese Honeysuckle had a characteristic strong aroma.

Both beers before bottling. Left, with dandelion. Right, with Japanese honeysuckle

A couple of days later, we gathered again to bottle these two batches. Beersmith had estimated a final gravity of 1.008 but, having fermented with this strain before, it seemed a little bit high. After measuring final gravity, it was indeed lower than that. Final gravity was 1.002, with gave us 6.2% ABV in both beers. We got 3.6 liters (0.76 gallons) of saison with Japanese honeysuckle and 4.8 liters (1.06 gallons) of saison with dandelion. We added sugar (in syrup form, previously boiled and chilled) to get about 2.5 volumes of CO2 of carbonation. We bottled 10 33 cL bottles of saison with Japanese honeysuckle and 14 33 cL bottles of saison with dandelion. At this point, it was clear that Japanese honeysuckle had imparted much more than dandelion to the beer. I’ll tell you about the final result in a future post.

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