Fruit Gose – Part 1/2 – Base beer

Time to get back to sour beers. As the result for our first sour beer, a gose with apricots, was more than satisfactory we decided to brew something similar, but more volume this time. As we’ve already told you, we like gose more when it is combined with fruit. Since we were brewing more volume, we would be able to try different fruits with an initial base beer. To not make this entry too long, in this first part we’ll tell you about brewing the base beer, a quite standard gose beer. In the second part we’ll talk you about the fruits we chose and how we added them to the beer.

For this brew we used for the first time an electric kettle we purchased from another fellow brewer from the ACCE (Spanish Howebrewer Association). It is a 40 L Royal Catering with a PID controller and a recirculation system.

Mashing in our new brewing system

To prepare the recipe we decide to go with something very similar to what we did in our first gose beer, changing only the origin of the malts, and adjusting everything for a bigger volume. Everything except a little detail, salt and coriander, whose amount we dind’t modify in the initial writing of the recipe by mistake. We noticed it when we cooled the beer after acidification with Lactobacillus and after pitching yeast. We left coriander as it was, but in the case of salt, we tried to fix it adding the missing amount (6 g, 0.21 oz) directly to the fermenter. Below you can check the recipe and process summary for the base gose beer.

GOSE (BASE BEER)

MALTS/GRAINS
1.80 Kg (3.97 lbs) (57.1%) wheat malt (Weyermann) (3.0 EBC)
1.35 Kg (2.98 lbs) (42.9%) Pilsen malt (Grannaria) (5.0 EBC)
HOPS
8.00 g (0.28 oz) Hallertauer Tradition (6.70% AA) leaf (boil 55 minutes, 8.1 IBUs)
ADJUNCTS
3.00 g (0.11 oz) table salt (sodium chloride) and 3.00 (0.11 oz) g coriander seeds (boil 10 minutes) + 6.00 g (0.21 oz) of table salt (sodium chloride) directly to the fermenter after pitching yeast
BACTERIA / YEAST
Sour Pitch from Lallemand (Lactobacillus Plantarum). 3.3 g (0.12 oz) dispersed in a small volume of wort . Before pitching Lactobacillus the wort was boiled for 10-15 minutes for sterilization, then was cooled to 40ºC (104.0ºF) and preacidified with lactic acid until it reached a pH of approximately 4.5. Fermented for 24 hours at 37,5ºC (99.5ºF) and another 24 hours at 30ºC (86.0ºF). After 48 hours pH was 3.30.
Safale K-97  (1 sachet, previously rehydrated). Fermented after boiling and cooling after Lactobacillus fermentation. Fermentation temperature around 19-20ºC (66-68ºF)
THEORETICAL DATA
Volume: 15.50 L (3.41 gallons)     OG: 1.041     FG: 1.009     ABV: 4.3%     IBUs: 8.1     Color: 6.5 EBC     BU/GU: 0.195     Efficiency: 65.00%
WATER PROFILE
Ca: 111 pm; Mg: 3 ppm; Na: 7 ppm; SO4: 132 ppm; Cl: 140 ppm
MASH
 60 minutes at 66ºC (ºF)
BOIL
55 minutes

Sour pitch and Safale K-97, the fermentation couple for this gose

We started the brew day boiling water to remove chlorine in the morning. In the afternoon, to shoot for a mash pH of about 5.35 (according to Bru’n Water) and to get the water profile shown above, we added 58.8 mL (1.99 oz) of sulfuric acid and 4.7 g (0.17 oz) of calcium chloride to 23.85 L (5.25 gallons) of water. After adding grain when water was at 68.7ºC (20.4ºF), we set the PID controller to 66ºC (150.8ºF) for an hour. All this time we kept the pump recirculating the wort. After this, pre-boil gravity was 1.035 (theoretical value: 1.031). We remove the bag with the grains and we boiled the wort for about 15 minutes to sterilize it before pitching Lactobacillus. It was our first experience with the Sour Pitch from Lallemand and we stuck to the instructions they provided. We cooled the wort with a cooper immersion chiller until it reached 40ºC (104.0ºF) and we preacidified with lactic acid to a pH of about 4.40 to avoid growth of unwanted bugs. We added 3.3 g (0.12 oz) of Sour Pitch (recommend dose is 10 g/100 L, 0.35 oz/22 gallons) for about 16 liters (3.52 gallons) of wort. We added this amount rehydrated in a small volume of the same wort. Then we set the PID controller at 37.5ºC (99.5ºF) for fermentation with Lactobacillus. We kept the spare contents of the sachet closed in the refrigerator for a future brew day.

Coriander seeds and salt

After 24 hours pH has dropped to 3.55. Since the drop in the pH value seemed to go fast, we set the temperature of the PID controller to 30ºC. After 48 hours pH value was 3.30, more or less what we were looking for. To stop acidification and kill Lactobacillus, we boiled for 55 minutes, adding 8 g (0.28 oz) of Hallertauer Tradition at the beginning of the boil, for 8.1 IBUs. Ten minutes before the end of the boil we added freshly crushed coriander seeds and salt (as I mentioned before a lesser amount that it should have been), as well as a small amount of yeast nutrients to help yeast ferment at a not so ideal pH. We cooled the wort until it reached 20ºC (68.0ºF) with an immersion chiller while we rehydrated Safale K-97, responsible for finishing the fermentation job. After cooling, we transferred the wort to a Brew Bucket fermenter and pitched yeast. It was then when I noticed that the amount of coriander seeds and salt added was not what it should have been. I didn’t add more coriander seeds, but I did add another 6 g (0.21 oz) of salt directly to the fermenter. It wasn’t a good day for memory, we also forgot to take a reading of the gravity at this point.

Fruits for our gose base beer

With the fermentation chamber temperature set at 18ºC (64.4ºF), the beer temperature was 19ºC-20ºC (66.2ºF-68.0ºF) during the most active part of the fermentation. After 3-4 days the temperature started to drop and 6 days after pitching yeast we decided it was time to divide the beer in three equal parts to add fruits. We’ll tell you about that in another entry, although as an advance you can see in picture above which the fruits we added this time were.

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1 Response to Fruit Gose – Part 1/2 – Base beer

  1. Pingback: Gose with fruit tasting (1/3) – Gosepi – Gose with pineapple | LOS CHICOS

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