I've posted before about the group barrel projects I've been taking part in since last fall. It is finally time to drain our initial barrel of its contents, a sour Belgian Imperial Stout. We'll also be emptying our Rye Porter from the Zinfandel barrel it has been aging in.
In place of these beers the plan is to ferment a lambic-like beer in the barrels. Barrel #1 already has more than enough yeast and bugs from the 5 gallons of starter I inoculated it with last year. It was fermented half on Roselare and half on Bugfarm from East Coast Yeast. Barrel #2, which we've dubbed 'Rosie' probably doesn't have enough living in it to do the job of primary fermentation though. It has a mild brett strain living in it, but doesn't exhibit enough brett character (or any sourness) to make me think that there is enough population or variety of bugs for lambic fermentation. That being the case, I brewed a 10 gallon starter batch into which I pitched Wyeast Lambic Blend. I also mixed together dregs from bottles of Hansen's, Cantillon, and Boon Gueuze which some friends and I polished off while I was brewing.
For the starter batch I used the following recipe:
Lambic Solera Bug Starter
batch size: 10 gallons
brewed on: 7/3/11
IBUs: 0 IBUs (?)
mash temp: 158F
expected color: 3.6 SRM
90 minute mash
90 minute boil
10 lbs German pils malt
5 lbs German wheat malt
2 lbs flaked oats
4 oz debittered Crystal & Willamette whole leaf
WY Lambic blend, dregs from Cantillon Gueuze, Boon Gueuze, Hansen's Gueuze, and Lindeman's Cuvee Rene
We'll be filling the barrels each half-way with wort brewed on 7-17-11. Six of us will provide wort that day. One week later, the rest of the group will be brewing the rest and topping the barrels up. We'll then rack off 5 gallons from each barrel to allow for headspace during primary fermentation. Once that has calmed down, the beer will be racked back to the barrels to top them up.
I've ordered debittered, aged hops for use in this project. Since they aren't here yet though, I experimented with quickly oven-aging them. I started at 170F, the lowest my oven will go, and slowly raised the temp up to around 190F over the course of 4 hours. The house smelled really cheesy and stale by the time I was done. It took a couple days to air out.
For the rest of the batches, we'll be using the following grist:
12 lbs pils
3 lbs wheat malt
2 lbs unmalted wheat
2 lbs flaked oats
Rather than doing a ridiculously long, but traditional turbid mash, we're mashing at 158F to provide some more complex sugars for the secondary fermentation, along with everything the unmalted wheat and oats will be adding. I amended the recipe after brewing my batch with 10 lbs of pils to help raise the gravity a bit. I realized it was a bit on the low side!
The plan is to use these 2 barrels 'solera' style, and draw off half every 8 or 12 months, replacing that with 5 gallons per brewer of fresh wort. This will keep the batch going and simulate the blending of older beer with younger in traditional gueuze. While not as refined as the traditional blending process, it seems like a fun starting place for our further exploration of sour barrel aged beers by the Barrel Of Monkeys Brewers!