Saturday, September 05, 2009

Brew day (1 of 2): Gust Front Leipzig-Style Wheat

So, after all of my Gose talk, I finally got off my fanny and put my research into action today. Our Gust Front Leipzig-Style Wheat (technically a Leipziger Gose should be from Leipzig, hence my designation "Leipzig-Style") is actually going to take two different brew days, so this is just recapping the first leg of the journey to Gose.

In preparation for today, I made a 500mL lactobacillus starter on Thursday. I pitched around 115°F and kept it wrapped up to try and keep the temperature somewhat steady. Whenever it dropped to 80°F or so we would immerse it in hot water to raise the temperature back to around 110°F. We probably ended up doing this two or three times a day.

This morning, I brewed up six gallons of a 50% barley-50% wheat wort. I mashed in at 152°F at 9:50am, adding 1/4 tsp. acid blend to the mash. After an hour I decocted one gallon for fifteen minutes, bringing my mash-out temperature to around 164°F. I recirculated for ten minutes and sparged from 11:20 to 12:20, collecting six gallons. I boiled the wort for ten minutes to kill any nasties and chilled to 110°F. My temperature-corrected gravity at that point was 1046 and my pH was 5.5.

At that point I pitched my lacto starter. I took a pH reading and found my starter was down to 3.8, which yielded a noticeably tart taste (along the lines of lemonade) but nothing as extreme as a Berliner Weisse. Initially I was shooting for a pH of around 3.6 because the brewer at Bayerischer Bahnhof said the final acidity of the Gose should be 3.2-3.6. I thought it was odd that another professional German brewer said he shot for a pH of 4.0 before boiling when brewing a Berliner Weisse, which is more sour than a Gose. However, it occurred to me that pH actually drops during fermentation so maybe I should shoot closer to 4.0. Of course, given my inability to keep my temperatures up (right now I literally have my carboy under about four blankets; that's my means of temperature control) I'm not too concerned about the beer being too sour.

Anyway, the more I read about pH and brewing, the more I come across all sorts of potential issues I can't control and/or don't understand (let's just say water chemistry isn't my strong suit). For now, I'll just wait to see what happens. Barring something totally unexpected, I'll bring the soured wort back down to the garage on Monday morning, bring it to a boil, and add the hops, coriander and salt. Then I'll pitch onto the yeast cake from my Altbier (fermented with WLP 320 American Hefe yeast). Look for a wrap-up of the rest of the process Monday evening.

UPDATE: Just under 24 hours later, it's still at 96°F. Good to see those blankets are doing a pretty good job of insulating!

UPDATE 2: At roughly a day and a half, the wort is at 91°F. I took a sample and immediately noticed the wort is starting to smell funky. The wort has dropped to 3.95 and has a tang to it but is not what I would describe as particularly sour. That being said, it's already down to the pH that Christoph Bhenke recommended and, given how much the pH typically drops during fermentation I would assume we'll definitely get into the 3.2-3.6 pH range recommended by the brewer at Bayerischer Bahnhof. It'll be interesting to see how much further it drops by tomorrow.

UPDATE 3: For a recap of the second brew day, click here.

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