En Purpetuum – Solera
A few of us HomeBrew buddies had a great idea a while back: What if several of us pitched in (no pun intended) and brewed 5-10 gallons each and combined the finished, fermented brews into a single 60 gallon oak barrel that we sourced from a local winery. Then inoculated it with the dregs of a few well known and at least one not so well known commercial sour ales and..well…see what happened. The theory then, would be that every 6 months or year, we “harvest” 5-10 gallons, bottle it and replace that part with a fresh batch of “new” beer. Thus continuing the cycle..En Purpetuum..ad infinitum..ad nauseum… etc…
So, in the early Spring of 2011, that’s what we did. We all agreed to make a similar recipe of a pale Belgian ale, I made a 10G batch as my contribution, and by late February we had the barrel filled. Several weeks later, a peek in the bung hole confirmed that a pellicle had formed and after a few more months, several gallons were racked off and some of that was separated and fruit was added. A “fresh” batch of beer was then added to replace the amount that had been removed.
The samples I got as part of my participation were pretty good. The ones that had the apricot or raspberry were very good, but the plain ones were a little off. I’ve managed to go through the 12-15 12oz bottles that were my share already, making some of them last for over a year and enjoyed all of them, even the so-so ones.
A few of them (the fruited ones) were so highly carbonated that after opening them, the carbonation action would stir up the sediment at the bottom so vigorously that you had to open and pour quickly before the remaining beer in the bottle just turned into a self fueled murky foamy mess. This got me only 8-9 ounces out of each of those. They were the tastiest ones though. I think the sugar in the fruit contributed to some unanticipated additional bottle conditioning.
Documentation of the project went by the wayside a bit, but it is still going. The idea is that this is an ongoing project, and every 6 months or year, 5-10 gallons are racked off and bottled, with some of those bottles possibly being saved and aged. I’ve been thinking of doing one for myself but these barrels are typically 60Gallons or so and I can only make 10G at a time with my current setup. My basement would be the perfect place to store one of these though. I can just see it sitting there…souring away when I close my eyes…mmm sourness…
The Mad Fermentationist documented his Solera project here, it’s an interesting read and he goes into a lot of detail.