Brewday 17/11/17 Kolsch

Impromptu Brewday

Due to a work cancellation I found I had the opportunity (and more importantly, the ingredients) to brew some beer. I had plenty of German malts so I decided to make another Kolsch.

Recipe BIAB:

• Mash water vol 28lt
• 3kg Pilsner Malt
• 1kg Vienna Malt
• 250g Wheat Malt
• 150g Carapils Malt
• 25g Perle 4.4% (60 min)
• 25g Perle 4.4% (15 min)
• 5g Irish moss (15 min)
• 1 pk Safale K97 German Ale Yeast
• Mash for 90 mins at 68ºC
• Boil for 1 hour
• 21.5lt into the fermenter

Results:

After recent poor efficiency scores I did a bit of research to see how I could improve things. One suggestion I came across was to mill the grains much finer than normal but since I buy all my grain pre-crushed that wasn't an option. Another common idea was mashing with a smaller quantity of water and then sparging. There are various options; cold water sparge, warm water sparge, dunk sparging, trickle sparging, all of which seem to have worked for other homebrewers. However the most straightforward suggestion was simply to extend the mash time to 90 minutes, which I did and it worked! I got a higher OG than anticipated due to the higher efficiency score, I was only expecting 1.045 at 70% efficiency.

Efficiency 75%
OG 1.048

FG 1.011
IBU 23

ABV 4.82% (expected)

So it's now fermenting away, I'll leave it for about 10 days before bottling. 

Update 28/11/2017

The K97 yeast has an ideal fermentation range of 15-20ºC, I pitched at 18ºC which was as low as I could reasonably get with my immersion chiller and 12ºC ambient water temperature. After 24 hours I noticed the temperature of the fermenter had risen to 20ºC, meaning I needed to chill it somehow. Short of emptying the fridge which wouldn't have been too popular I had to resort to a  more basic method. By wrapping the fermenter in a wet towel and standing it in a pan of cold water the temperature came down to 18ºC within 24 hours and stayed at 17ºC for the duration of the fermentation period. Luckily for me my fermenting buckets fit neatly inside my pan.

Hi-tech cooling system

Update 31/01/2018

After several weeks conditioning in a temperature controlled area (under the stairs - temperature 10-12ºC in January) I tried this beer and have to say am well pleased with the result. It's crisp and clean but with that distinctive Kolsch-y flavour. I think the attention I paid to temperature for fermentation and conditioning has paid off.

Unfiltered and unfined!