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)


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)
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)
Belle Saison  (Lallemand)  (One dry sachet, previously rehydrated)
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%
Ca: 178 ppm; Mg: 3 ppm; Na: 7 ppm; SO4: 347 ppm; Cl: 13 ppm; HCO3: 120 ppm
63.5ºC (146.3ºF) for 60 minutes
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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Discovering non-Saccharomyces yeasts

Last April, the annual Spanish Homebrewers Association (ACCE) Congress should have been held in Valladolid, but due to the COVID-19 pandemic, the event had to be postponed. In that Congress, one of the seminars, the one I was most looking forward to, was going to be about using non-Saccharomyces yeasts for brewing. Finally, the ACCE organization, with support from Associació El Tirador, decided to give it a different approach, in my opinion much more interesting. What was going to be a seminar has been transformed in an experiment in which several ACCE members are going to be able to participate. Fortunately, we were chosen among the several homebrewers who wanted to take part in the experiment, so we would be able to tell you about how all of this turns out.

The seminar that was going to be imparted in the Congress, finally was transformed in an online event for ACCE members. Later, it was also uploaded to youtube so everybody who is interested can watch it (in Spanish). The seminar, very informative, was imparted by Enric Pardo, whose nick in the ACCE forum is Cannavarra. Joan Montasell, technical sales manager of Lallemand, helped him also with some more information. By the way, this activity is going to be sponsored by Lallemand, which will supply the different strains of yeasts, and by Agronet Brewing, which will supply hops for the experiment.

In the seminar, which you can see (in Spanish) in above video, they described several yeast species, most of them already in use in oenology and that, due to their characteristics, could be interesting candidates to try in brewing. The following list gather all the different species that were subject of the seminar: Candberlindnera (sp. subsufficients and fabianii), Debarandomandces (sp. hansenii, nepalensis and vanriji), Hanseniaspora (sp. valbandensis, uvarum and vineae), Lachancea (sp. thermotolerans), Meschnikowia (sp. pulcherrima), Pichia (sp. apotheca and kluandveri), Schizosaccharomandces (sp. japonicus and pombe), Torulaspora (sp. delbrueckii), Wickerhamomandces (sp. anomalus) and Zandgossacharomandces (sp. bailii). As you can see, a whole world to discover.

Metschnikowia pulcherrima

From all of these yeasts, considering the knowledge about them, their potential and availability, two of them were selected for the experiment, Metschnikowia pulcherrima and Torulaspora delbrueckii. To see what those two species can contribute to beer, an experiment was designed in which several ACCE members will brew a standard recipe, with the same ingredients and parameters of process. The differences will be in the way these yeast are pitched.

Recipe will be a simple smash (single malt, single hop) beer, with 100% pale malt and mosaic hops. Hops will be boiled to give approximately 30 IBUs and will also be used for a  dry-hop (10 g/L) four days after pitching, looking for some biotransformation by the yeasts. The mash will be a simple infusion at 65ºC (149ºF), adjusting mash pH. Before, chloride and sulfate will also be adjusted in the water profile. Fermentation will take place, preferably, at 18ºC (64.4ºF). A series of parameters will be measured through all the process to get the most possible information. There will also be a thread in the ACCE forum to follow the experiment and, if the Congress can be finally held, we will take bottles of the different beers to Valladolid to compare them.

Torulaspora delbrueckii

There will be 9 groups of about 8 brewers, with each group pitching yeasts in a different way. There will be a control group whose members will only pitch Saccharomyces cerevisiae yeast (Nottingham Ale). The rest of the groups will pitch as follows:

Group 1. Pitch of 100% Torulaspora delbrueckii.

Group 2. Copitch of Saccharomyces cerevisiae (Nottingham ale) and Torulaspora delbrueckii in a 1:1 ratio (0.5 g/L of each strain)

Group 3. Copitch of Torulaspora delbrueckii and Saccharomyces cerevisiae (Nottingham ale) in a 1:10 ratio (0.05 g/L of T. delbrueckii and 0.5 g/L of Nottingham ale).

Group 4. Sequential pitch of Torulaspora delbrueckii followed 24 hours later by Saccharomyces cerevisiae (Nottingham ale) (0.5 g/L of each strain)

Group 5. Pitch of 100% Metschnikowia pulcherrima.

Group 6. Copitch Saccharomyces cerevisiae (Nottingham ale) and Metschnikowia pulcherrima in a 1:1 ratio (0.5 g/L of each strain)

Group 7. Copitch of Metschnikowia pulcherrima and Saccharomyces cerevisiae (Nottingham ale) in a 1:5 ratio (0.1 g/L of M. pulcherrima and 0.5 g/L of Nottingham ale).

Group 8. Sequential pitch of Metschnikowia pulcherrima followed 48 hours later by Saccharomyces cerevisiae (Nottingham ale) (0.5 g/L of each strain)

We have been selected to be part of group 2, so we will copitch Torulaspora delbrueckii and Saccharomyces cerevisiae in a 1:1 ratio. We will receive yeasts and hops in a few days (every participant has to use his/her own malt) and we will start planning our brewday. It goes without saying that I am very excited to be part of this experiment and that I think that it is a great initiative. Let’s hope that we can get some interesting conclusions from the results. We will see in a few weeks.

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Tasting our first try at a milkshake IPA

More than a year ago I published how we brewed our first try at a Milkshake IPA. I still have pending to post the end result of this first try. Maybe it was the fact that the result was far from what we expected, but I kept this entry waiting to be published for a few months. Beers do not always turned out expect, but you can always learn something from it.

First try at a MIlkshake IPA

There were a few things that made this beer not so enjoyable. The main one was a quite perceptible oxidation that showed just a few weeks after bottling. Maybe we were not cautious enough when the beer was exposed to oxygen and you know these mistakes are too obvious in this kind of beer. We will tell you about in future entries but, apart from trying to avoid oxygen exposure in a better way, we have started to use a small amount of ascorbic acid to hop forward beers at bottling with very good results.

APPEARANCE: Althoug at first it had a golden color, soon it acquired an amber-ish and darker tone as time passed, due to the oxidation I have previously commented. Quite hazy, but without the type of haziness we aimed for. White foam of medium persistence.

AROMA: Dominated by citrus and tropical hops, but below what it was supposed to be. There was also a sweet-ish aroma that I couldn’t identify that wasn’t pleasant. Low presence of malt with light hints of cereral.

FLAVOR: It is no easy to describe flavor of this beer. Although the first two weeks, nice tropical and citric flavors were present, soon these flavors faded out, leading to a sweeter and in some way medicinal flavor. It suspect that this medicinal flavor was due to chlorophenols. I don’t know for sure the cause for the sweet flavor. Malt only gave a light touch of cereal. I didn’t find any yeast character either.

MOUTHFEEL: Medium body and carbonation, it wasn’t as creamy as I would had expect according to the ingredients we used. It had also some astringency that didn’t help.

As you can see, it wasn’t our best beer. Looking back (we had brewed a much better second version of this style) I would change a few things. Firstly, I think that the apple puree is not worth the effort. Then, it is mandatory with these styles to avoid as much as possible the oxidation of the beer. We’ve made some improvements to avoid or minimize oxygen exposure and, as I told you before, we are using ascorbic acid at bottling and this definitely retards oxidation. I wasn’t happy either with the cryo hops we used. I don’t know, maybe they were not in a good condition, but I don’t think they impart anything “special”. In addition, they stay in suspension for a long time, leaving particles that in my opinion give some astringency. I guess that keeping the beer cold for some time or even using some kind of clarifying agent would solve this problem, but for now I will stick with normal hop pellets. The chlorophenols detected probably came because there was still some chlorine in the water we used for brewing. Usually we collect water the day after brewday so chlorine evaporate from water overnight but for this beer we forgot to do so. And lastly, I also think that a starter for the yeast (Juice #A38 from Imperial Yeast) would have benefit the fermentation and the final result. I’ve read a lot of positive comments from homebrewers about this strain, but it didn’t work for us this time. So you see, we couldn’t enjoy this beer as we would have liked it, but a least we learned some lessons for the future.

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Belgian Pale Ale, recipe for Match Beer 2020

First weekend of April we were supposed to be celebrating the annual ACCE (Spanish Homebrewers Association) Congress. There, the final phase of Match Beer 2020, the brewing competition between teams of homebrewers organized by ACCE was going to be held. A few months before, as it is usual, the beer styles for this year were announced after those who were members of ACCE voted. They were Berliner Weise (23a), Belgian Pale Ale (24b) and Brett Beer (28a). As always, when I found out where the styles were, the desire to brew them all caught me. However, sometimes life gets in the middle and weeks passed without me being able to brew any of them. One day, my teammates from Legamia started talking about a day to gather our beers and to select the ones that would be send for competition. I only had time to brew one of the styles. After giving it some thought, I finally decide that we were going to brew a Belgian Pale Ale.

Grist for the Belgian Pale Ale

To be honest, I did not know anything about the style. And, in fact, I was surprised when I saw that the color of this beer was between cooper and amber. I don’t know why, but I thought they would be golden colored. Anyway, I needed to make some research. After searching for a while I saw that there wasn’t a lot of information about this style. Finally, I discover this article by Gordon Strong on Brew Your Own (only for subscribers), that I thought was the most complete. I must admit that, after reading this article and the BCJP guidelines about the style I was a little bit disappointed since, at first sight, the style seemed a little bit boring. However, I had no other choices if I wanted to participate with my team, so at least I would try to brew it right.

Let’s begin with some history. Belgian Pale Ale was a style created in Belgium in the beginning of twentieth century to compete with the rising acceptance of styles like English Pale Ales and continental lagers in that country. Therefore, the best way to describe them is to say that they are the Belgian version of English Pale Ales. Because of this, restrain is the norm for almost all of their attributes. They are lightly malty, but not too much. Some hints of bread, honey, biscuits or caramel, but always restrained. The yeast can contribute some fruity esters, but only a few or, even none at all, phenols, so characteristic of a lot of Belgian yeast strains. Regarding alcohol, as expected, much less than other Belgian styles, they are about 5% ABV. The color is similar to English Pale Ales, from cooper to amber. The main example today is from De Koninck brewery, in Antwerp.

A Belgian strain from an English yeast lab. It seemed a good choice, although its best before date had passed a few months ago

With all this information it was time to start. First, the selection of the ingredients for the recipe. I got the first problems while selecting malts, because I didn’t have normal Pale malt. I had some English malt (I don’t remember if it was Maris Otter or Golden Promise), but in my mind they didn’t fit here. So I chose to use Pilsner malt as my base malt. I would have to compensate this with the specialty malts. A considerable amount of Munich I malt, plus lower percentages of a couple of caramel malts (Caramunich I and Carabelge) and a touch of aromatic malt to round the grist. I didn’t give too much thought when selecting hops. One variety, Hallertauer Mittlefrueh (from Queen Country in Olite), with three additions for bitterness in different times of the boil. Finally, I had to pick a yeast strain. A tough decision because Belgian strains, for better or for worse, are in general very expressive. And for this style, esters and, above all, phenols should be restrained. I remembered that, a couple of years before I bought some yeast strains from Brewlab with a shared order with other members of ACCE. A Belgian strain was included in that purchase. I wasn’t sure, but I thought that I had bought it because it was a less expressive Belgian strain. To make things more complicated, its best before date had already passed more than a year before. So I had to make a starter a few days before brewday to see if I could make it grow.

Wort for the Belgian Pale Ale

Two weeks before brewday, I started propagating the yeast. After a couple of days, with 50 mL of sterile wort, something started to grow, good news. After a few more steps to increase the cell count, I ended with a liter of wort with enough cell mass to ferment the beer. I kept this starter in the fridge so the yeast would flocculate.


1.75 Kg (3.86 lbs) (58.3%) Pilsner Premium (Weyermann) (2.0 EBC)
0.65 Kg (1.43 lbs) (21.7%) Munich I (Weyermann) (15.0 EBC)
0.25 Kg (0.55 lbs) (8.3%) Carabelge (Weyermann) (35.0 EBC)
0.10 Kg (0.22 lbs) (3.3%) Aromatic malt (150.0 EBC)
10.00 g (0.35 oz) Hallertauer MIttelfruh (Queen Country) (5.30% AA) pellets (boil 60 minutes, 11.1 IBUs)
10.00 g (0.35 oz) Hallertauer MIttelfruh (Queen Country) (5.30% AA) pellets (boil 30 minutes, 9.4 IBUs)
10.00 g (0.35 oz) Hallertauer MIttelfruh (Queen Country) (5.30% AA) pellets (boil 5 minutes, 5.4 IBUs)
Belgian Ale  (Brewlab)  (Starter from a yeast slant)
Volume: 11.50 L (3.0 gallons)    OG: 1.052   FG: 1.009     ABV: 5.6%     IBUs: 25.9     Color: 23.7 EBC     BU/GU: 0.501     Efficiency: 65.00%
Ca: 165 ppm; Mg: 24 ppm; Na: 7 ppm; SO4: 94 ppm; Cl: 236 ppm; HCO3: 120 ppm
66.0ºC (150.8ºF) for 75 minutes
60 minutes

On brewday, since I forgot to collect water the night before to leave it so the chlorine could evaporate, I boiled it for a while and left it to cool until a few hours later when we started brewing. First of all, we added salts to get the water profile shown above. In this case, 6.7 g (0.24 oz) of calcium chloride and 4.0 g (0.14 oz) of magnesium sulphate. In addition to adjust mash pH, we wanted to rise chloride level to boost maltiness.

Krausen one day after pitching yeast

Everything went more or less as expected without any worth mentioning issue. We mashed for 75 minutes with our PID set at 66ºC (150.8ºF) and then we boiled for an hour with three hop additions 60 minutes, 30 minutes and 5 minutes before the end of the boil (this last one to left some hop aroma). After a fast cooling, with the wort at 19ºC (66.2ºF) we transferred it to a PET demijohn and we pitched the yeast starter after decanting first most of the liquid from this starter. Since we didn’t have any information about this strain, we weren’t sure about the attenuation we were going to get from it. We could only wait. Final gravity was 1.047, a little bit less than planned. We were very happy with the color, very similar to some classic examples of the style.

After one day in the fermentation chamber, set at 18ºC (64.4ºF), nothing seemed to happen, so we got a little bit anxious and rise the temperature of the fermentation chamber to 20ºC (68.0ºF). In a few hours the airlock started bubbling and a nice thick light brown krausen formed. This relaxed us a little bit and, with fermentation started, we lower the temperature of the fermentation chamber to 18.5ºC (65.3ºF).

Two days into fermentation

We left it ferment for two weeks and then we measured gravity, 1.008 (82.1% apparent attenuation, not bad). That would give us a 5.1% ABV, perfect for this style. It was going good, but there were still some things to do. We had to try to clarify the beer. For this, we lowered the temperature of the fermentation chamber to 7.5ºC (45.5ºF) for 3-4 days before bottling. On bottling day we only bottled 8 liters to avoid most of the trub. We ended with 24 33 cL bottles with enough sugar to get 2.3 volumes of CO2 in the final beer.

Two months after bottling, the members of our team Legamia gathered to taste the different beers we had brewed and to select which ones we would send to competition. As always, it was a pleasure to meet and taste the beers in a festive and fun mood. And no less important, with comments from other fellow homebrewers which help us to keep on learning and improving. Finally, we were lucky again and, as it happened last year, our beer was selected to represent our team in the Belgian Ale category.

Belgian Pale Ale, final result

This year we were not able to advance to the final round. However, our Belgian Pale Ale scored good ratings, enough to left us satisfied with our first try at this style. The following tasting is not based on my impressions, but on the ones received from homebrewers of other temas who judge the beer. This way is easier for me because I can leave my subjective opinion behind.

APPEARANCE: cooper amber color, with a little haze. White to cream foam with fine bubbles and medium retention.

AROMA: Balance is towards malt with hints of caramel, honey, toasted bread and nuts. Low presence of hops, of herbal type. Some fruity esters like apple and/or pear of low to medium level. Low spicy phenols.

FLAVOR: Balance is again towards malt, with notes of biscuit, toasted bread and caramel in the end. Low to medium floral hop flavor. Medium bitterness finishing with a good balance. Low to medium fruity esters, above all in the aftertaste, and low spicy phenols. Some final astringency.

MOUTHFEEL: Medium body and medium carbonation. No presence of alcohol. Very low creaminess and a little bit of astringency.

All of them seem to agree that it is a very drinkable beer and a good example of the style. The average score was 36 points, which left us proud of our work. I basically agree with all the opinons reflected in the scoresheets. We are very happy with some aspects of the beer (color, balance in aroma and flavor characteristic of the style,..) and of course some things could be better (more foam retention, better clarity, avoid this little astringency,…). For the time we had to brew it, we are quite happy with the result. It is a beer that we wouldn’t probably had brewed because based on the description it seems a little bit boring but me, my brother and my father had drank it with pleasure. A beer easy to drink, well balance and that you can drink anytime. Thanks again to Match Beer we discover a style that was not in our plans but that left us a very good impression. If you haven’t brewed one yet; I recommend you to do it, I think it will surprise you.

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Gose with fruit tasting (3/3) – Gosegra – Gose with pomegranates

To finish our round of tastings of the three goses with fruit we brewed at the same time it’s time to tell about the final result of the ones we added pomegranates, named Gosegra. Before starting, as some of you may recall, we noticed that, before bottling, the final gravity of this beer was 1.016, while the other two, the one with pineapple and the one with blackberries reached a final gravity of 1.008. We were afraid that the beer hadn’t completely attenuated and, when we opened the first bottles, our fears came true. It was impossible to open one bottle without losing at least half of the liquid inside because of the high pressure. We tried to open the caps a little bit to free some CO2 but it wasn’t enough. At least, we didn’t have any bottle bomb. Nevertheless, we were able to drink it, at least some of it. Next time we won’t risk to bottle with such a high final gravity (comparing with the theoretical value, of course).

Gosegra, gose with pomegranate molasses

Regarding appearance, this version with pomegranate molasses is, by far, the haziest of the three. Maybe some of this haziness can be explained with the mix between the liquid and the yeast due to the excess of gas. Apart for this haziness, it is light pink in colour and it has a white foam that disappears quite rapidly.

In the aroma there are, above all things, fruity esters coming very likely from the pomegranates. There is almost no sign of malt and none sign of hops.

Flavourwise, acidity is quite appealing, in part because the pomegranates, after the fermentation of all the sugars, leave a good mix of fruity esters. It seems a little bit more bitter that the other two goses we brewed at the same time. As in aroma, no signs of hops and only a little bit of grains.

It has a medium body and the dryness is much lower than in the other two versions we brewed with pineapple juice and blackberries. Carbonation, as you may expect, was sky high.

In spite of the little disaster that was bottling before fully attenuation, what we were able to drink has left me with the feeling that pomegranates can be very interesting ingredient for future brews, with acid beers like this or other type of non sour dark ales. We will keep you posted when we used them again in new brews. In that case, for security reasons, we will make sure that the attenuation reaches the final point before bottling.

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Book review: Designing Great Beers by Ray Daniels

Designing Great Beers was, if I remenber correctly, the second book about homebrewing that I purchased. Written by Ray Daniels, founder and director of The Cicerone Certification Program, what attracted me from this book was that it was written to help brewing specific beer styles. After gaining some experience in all-grain brewing, I was interested in learning about the different beer styles, the ingredients and processes that were part of them. The description of the book under its title, “The Ultimate Guide to Brewing Classic Beer Styles” fitted perfectly for what I was looking for.

The book is divided in two parts. In the first one, after three shor chapters that don’t contribute too much, there are some chapters about beer basic ingredients: malt, water, hops and yeast. The different types of malts, hops and yeasts are discussed, as well as the parameters and processes in which those ingredients are involved, including a good number of calculations. Although if you don’t have any other sources of information you can find something useful here, these chapters are in general quite simple deep and you can find more in deep (and updated) information from a lot of different sources.

The secon part is the one that it is reall y interesting and it is about brewing “classic” beer styles. Not all the styles are covered, but you can find a good number of them. There are chapters for German Barley Ales (Kölsch and Altbier); Barley Wine; Bitters and Pale Ales (including IPAs); Bock Beer; California Common; Fruit Beer; Mild and Brown Ales; Old Ale; Pilsners and other Pale Lagers; Porter; Scottish and Scotch Ales; Stout; Vienna, Marzen and Oktoberfest and Wheat Beers.

Each chapter is put together in a very organized manner. As a general rule, after a brief introduction, a description of the evolution of the beer style through history is made, since its origins until present day (well, at least until year 2000, when my edition was published). Here, the numbers and ingredients that have defined the style through the years are specified. This part, althouth may not include practical information about brewing the style, would pleased those of you who, like me, have interest in knowing about brewing history. Later, there is a part about brewing the style today. Here, each of the ingredients is treated separately, describing which is suitable for the style (base and special malts, hops, water profile and yeast). In addition, the steps to follow in processes like mashing and fermentation are detailed. Everything is based in contemporary commercial examples as well as in information compiled from recipes that got at least to second round in the American Homebrewers Association competition. Serveral tables and graphics, along a understandable text, help to summarize and see everything easily. Finally, a summary with keys about brewing the style closes each chapter.

It’ s been a long time since I hadn’t have a look at this book, but it is, without a doubt, one of the books I’ve learned more from. As I said before, in the first years of my homebrewing career, I tried to brew different styles to learn about them and this book was a must to plan my recipes and processes. Not only helped me to know about beer styles, it also showed me what the different ingredients could contribute to beer. Maybe this is not a book for experienced homebrewers (unless they don’t control about one of the styles described in the book), but I highly recommend this book to those who are starting to brew. Or even to those who have some experience, but want to learn what defines a style and, while doing that, can learn about different ingredients and processed in brewing.


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Testing reiterated mashing – Cricket Balls (Imperial Stout based on Black & Deep from Drunken Bros)

In spring 2019 Drunken Bros Brewery announced that they were not going to brew Black & Deep, their iconic Imperial Stout brewed through the years before with some minor changes with the help from people outside the brewery through a crowdfunding. In order to not let people down because of this, in a generous act, they made their Black & Deep recipe public. That way, they were encouraging homebrewers to brew it at home.

In Legamia, the regional homebrewers association I am part of, we saw it as an opportunity to organize something around that recipe. It was decided that any of us who wanted to give it a go would brew that beer, according to our own possibilities or ideas, and in a few months we would gather to taste the results. This was something that motivated me, especially for two reasons. In the first place, we had never brewed a beer with such a high ABV. And then, it gave me the opportunity to test a new method, reiterated mashing, which can be used to brew this kind of beers.

Black & Deep recipe, published by Drunken Bros Brewery (click to enlarge)

Since this time we already had the recipe (although as you will see we changed it a little bit), our revision of the style was not as deep as usual and it consisted in reviewing the presentation about Imperial Stout that Mikel Muñoz, one of the brewers from Drunken Bros, offered in the Spanish Homebrewers Association Congress in 2019 in Bilbao. From it we learnt a lot of things. One of the most important ones was the fact that in order to get a high ABV they prefer to do it starting with a higher original gravity and less attenuation from the yeast than starting with a lower original gravity and more attenuation.

Before explaining the process of reiterated mashing, I’m going to describe the approach for our recipe. It was very similar to the original recipe, most of the changes were due to the availability of ingredients. Regarding malt grist, and keeping the percentages as close to the original recipe as possible, we kept Maris Otter, roasted barley, Crystal T50 and Crystal DRC. However, we replaced chocolate malt by Carafa I and dextrin malt by chit malt. Also, since the recipe does not specify the type of oats used, we pick naked malted oats for our version.

For hops, as they are only used for bitterness, we used mostly Saphir and some of Northern Brewer, in both cases to finish some open bags we had. Lastly, we picked Sigmund’s Voss Kveik from The Yeast Bay as the yeast, inspired by the experiences with Kveik yeast in this style that renowned homebrewer David Heath shared in the Spanish Homebrewers Association Congress in 2018 in Cadiz. Kveik yeasts are known to be fast fermenters and they are able to tolerate high ABV. They also perform a quite clean fermentation in restrained temperatures, so this kind of yeast seemed like a good choice for this beer.

Voss Kveik, our chosen yeast for this high ABV beer

Once we set up our recipe, it was time to focus in the process we should follow to get such a high original gravity (remember, 1.119!!). As I’ve already stated before, one of the few options we had to reach those numbers was to test the reiterated mashing method. Basically this method consists in performing a first mash, with more or less half of the grains in the recipe and, once it is finished, remove grains and use the wort from this first mash as the mash liquor for the second mash with the rest of the grains. This way we could get a wort with a high original gravity that, after a longer than usual rolling boil, would concentrate even more. To understand the details behind this method I researched about reiterated mashing online. There is not a ton of information about it and, even though other people wrote about it, it seems that Chris Colby is one of the pioneers of this method, at least in the homebrew scale. His articles about it, in his blog (theory and practice of reiterated mashing) and in Brew Your Own (only for subscribers) helped me a lot to plan our process. Based on the information from those articles, I planned the first mash with half of the total weight of the grains, but only with malt base, Maris Otter in this case. Then, the second mash would be with the other half of the weight of malts, the rest of base malt plus special malts. Also, I calculated a 55% efficiency (10% less of our usual efficiency).

Before describing the details of the recipe and process, there were a couple of things I had also to decide. First, water treatment. I wanted to maintain a chloride to sulphate ratio of 1.5, as described in the original recipe, but I didn’t know when to add the corresponding salts to do that. Drunken Bros people recommend to add them in the boil, but we usually add them to adjust mash pH. And in this case we have two mashes, a total mess. In the end I decided to add them in the first mash to adjust the pH to 5.5 as predicted by Bru’n Water and we would see how we treated the second mash.

Secondly, the addition of coffee. In the original recipe a particular amount is recommended, to be added after performing a cold brew for 72 hours. In our case, I decided to keep the proportional amount of coffee for our recipe, performing a cold brew with 50 g (1.76 oz) of freshly grounded coffee. However, after doing some research and reading this article about coffee addition to beer in Scott Janish’s blog, I keep the cold brew for only 24 hours, since it seems that flavor extraction peaks after 16 hours with this technique. Based on that article too, I added another coffee addition after primary fermentation. Other 30 g (1.06 oz) of coffee added directly to the fermenter, half of them coarsely grounded and the other half as whole beans, looking for flavor (grounded coffee) and aroma (whole beans).

Coffee for cold brew, before grinding

Complete recipe and detailed process are described below:


5.00 Kg (11.02 lbs) (77.3%) Maris Otter (Thomas Fawcett) (5.0 EBC)
0.40 Kg (0.88 lbs) (6.2%) Roasted Barley (1000.0 EBC)
0.35 Kg (0.77 lbs) (5.4%) Carafa I (Weyermann) (900.0 EBC)
0.25 Kg (0.55 lbs) (3.9%) Crystal T50 (Simpsons) (133.0 EBC)
0.20 Kg (0.44 lbs) (3.1%) Chit Malt (Best) (2.5 EBC)
0.15 Kg (0.33 lbs) (2.3%) Naked Malted Oats (Simpsons) (3.0 EBC)
0.12 Kg (0.26 lbs) (1.9%) Crystal DRC (Simpsons) (300.0 EBC)
50.00 g (1.76 oz) Saphir (Queen Country) (4.10% AA) pellets (boil 60 minutes, 34.4 IBUs)
5.00 g (0.18 oz) Northern Brewer (11.20 AA) leaf (boil 60 minutes, 8.5 IBUs)
50 g (1.76 oz) freshly grounded coffee, cold brewed for 24 hours. Liquid from cold brew added 10 minutes before the end of the boil
1 teaspoon of yeast nutrients, boil 15 minutes
30 g (1.06 oz) coffee, 15 g freshly grounded and 15 g whole beans, added to the fermenter 48 hours before bottling
Sigmund’s Voss Kveik (The Yeast Bay)  (Starter from 1 vial)
Volume: 9.00 L (2.38 gallons)    OG: 1.119   FG: 1.046     ABV: 10.0%     IBUs: 42.9     Color: 151.0 EBC     BU/GU: 0.361     Efficiency: 55.00%
Ca: 171 ppm; Mg: 3 ppm; Na: 7 ppm; SO4: 113 ppm; Cl: 172 ppm; HCO3: 120 ppm
Reiterated mashing (two consecutive mashes)
First mash with 3.25 Kg (7.17 lbs) of Maris Otter and the total volume of water for recipe, 21.41 liters (5.66 gallons). Salts added to adjust pH to 5.5. Keep at 69.0ºC (156.2ºF) for 60 minutes
Second mash with the rest of Maris Otter and all the special malts, using as mash liquor the wort obtained from the first mash. Keep at 69.0ºC (156.2ºF) for 70 minutes
90 minutes

Cricket Balls wort before fermenting

As you can see above, due to the huge original gravity, I decided to prepare a starter a few days before brewday. Well, in fact, it was because of that original gravity and because the vial of yeast had passed its date and I didn’t want to take risks. I started three days before brewday. I prepared 600 mL of sterile wort that was transferred to a previously sanitized 2 L flask and then I added the contents of the vial and kept it stirring a couple of days until visible signs of fermentation were observed. After this, I added, in the same flask, 500 mL more of fresh sterile wort and kept it stirring one more day. On brewday, I stopped stirring and left the flask at room temperature so the yeast could flocculate, since in my experience Kveik yeasts (at least the ones I’ve worked with) flocculate in a short time.

The day before brewday, I also grinded the coffee I was going to add at the end of the boil next day (50 g) and put it in a mesh bag. It was coarsely grounded, only to break the beans in a few fragments. I kept the bag with the coffee in a pot with pre-boiled and chilled water (about 500 mL), covered for 24 hours.

Finally, since this time I was not going to have my brother helping me and I wanted to have everything ready, also the day before I prepared all the material needed and crushed the grains. Since I needed to perform two mashes, the brewday was going to be longer than usual. I divided the crushed grains for the first and second mashes this day too.

Cricket Balls, fermenting

When brewday arrived, I was excited to see how this new process was going to work. It was time to start. I added the corresponding salts to the water (3.9 g of calcium sulphate and 5.6 g of calcium chloride) to adjust pH for the first mash and left the chloride to sulphate ratio in 1.52 while water was heating. When water temperature reached 69ºC (156.2ºF) I added the grains for the first mash, 3.25 Kg (7.17 lbs) of Maris Otter, and stirred well to avoid clumps. After a few minutes, and when temperature was stabilized at 69ºC (156.2ºF) I turned on the pump to recirculate wort during this first mash. One hour later, I removed the bag with the grains, trying to get as much liquid from it as I could. To make things easier I put another bag with the rest of the grains for the second mash, keeping the wort from the first mash in the kettle. I stirred thoroughly and heated the mash to achieve the same mash temperature as for the first mash, 69ºC (156.2ºF). I put the lid on the kettle and turned on the pump again so the wort would recirculate. I kept this second mash a little bit longer to help enzymes with conversion. In this second mash, wort became totally black, making the name we have chosen for the beer more than suitable. Also, wort was getting so viscous than sometimes, the pump couldn’t recirculate it and I had to stir well in order for the pump to recirculate wort again. I take a pH reading in this second mash and it had decreased, probably due to the darker malts, to 5.18. Nothing too alarming, but maybe next time it could be a good idea to mix the malts evenly between mashes to avoid these differences in mash pH values. After 70 minutes, I ended the second mash, which had been between 68ºC-72ºC (154.4ºF-161.6ºF) all the time and started heating again to boil as soon as possible, removing the bag with the grains for the second mash.

As in the original recipe, I boiled vigorously for 90 minutes. Half an hour into the boil I added hops to get around 43 IBUs. With 15 minutes left, I added a teaspoon of yeast nutrients and 5 minutes later, I added the liquor from the cold brew to boil for the last 10 minutes. When the boil was finished, it was time to cool the wort with an immersion chiller. It was summer and tap water was not too cool, so when the wort was a little below 30ºC (86.0ºF) I stopped. There were 9.5 liters (2.51 gallons) of wort that were transferred to an 11 liters (3 gallons) PET demijohn, trying to splash as much as I could to oxygenate wort. It was the darkest and more viscous wort I had ever seen. It was time to measure the original gravity and see if my calculations for this reiterated mashing were right or wrong. I couldn’t help to smile proudly when I saw that the hydrometer showed an original gravity of 1.120!!! A point above the theoretical value. I couldn’t be happier. I still had to pitch yeast, but I cleaned everything while the wort cooled a little bit more before doing it. Finally, with the wort at 23ºC (73.4ºF) I pitched the starter, discarding most of the wort from it. This time, fermentation was going to be at room temperature, since Kveik is capable of fermenting at these temperature without off-flavors.

Cricket Balls at bottling

Seven hours after pitching yeast, a good krausen was starting. At the end of the day it was so thick that it reached the neck of the demijohn, with the airlock bubbling like crazy. This first day temperature went from 25ºC (77.0ºF) to 29ºC (84.2ºF). Next day, krausen decreased and temperature went back to 25ºC (77.0ºF). Five days after brewday krausen was gone, but airlock was still bubbling, although slower than the days before. Since I didn’t want to rush things, I forgot about the beer for a few days.

Almost a month after brewday, out of curiosity, I measured gravity. The hydrometer showed 1.038, for an ABV of 11.2%!!! I also took a sample to taste it and the first impression was good. A lot of coffee, alcohol wasn’t overwhelming considering such a high ABV and mouthfeel was great. Things looked good so far. Three weeks later, we proceeded to bottle the beer (this time with the help of my brother again). A couple of days before bottling, I added another 30 g (1.06 oz) directly to the fermenter, inside a mesh bag. Half of the coffee beans were coarsely crushed and the other half remained as whole beans. This dry-beaning was going to impart flavor and aroma for 48 hours.

At bottling time, we followed directions from Drunken Bros and we added sugar to get a low carbonation (about 1.8 volumes of CO2). We bottled almost 8 liters (2.11 gallons), with 20 33 cL bottles and 2 50 cL bottles. Since brewday, 49 days had passed. A lot of time, but it was worth it. Although I am not a big fan of such strong beers and I don’t known when we will brew something similar, the fact that I could test a new method for this type of beers and that everything went quite well made this brew one of the best experiences I’ve had since I started homebrewing. If you haven’t tried reiterated mashing yet, I encourage you to give it a try, I’m sure you will not get disappointed.

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