I love sour beers and I love homebrewing. Makes sense that I’d combine the two and brew some sour beers, right? It sounded so simple.
The third beer I ever brewed was a sour beer. I brewed it in the summer of 2011 and bottled it in February of 2013. I had pretty much no idea what I was doing. Over that time I’ve done many things: I brewed a bunch of other beers (sours included), read almost 100 books, my wife and I renovated our first house, we had a beautiful baby girl, and I learned many, many things about what to do and not to do while brewing sour beers. I actually just bottled my second sour (a sour blonde with Sauvignon Blanc grapes added during aging) and I figured this was about as good a time as any to put some of this stuff down on paper. It isn’t exhaustive or anything; just stuff that has been bouncing around in my head.
FYI: A much more exhaustive and knowledgeable brain dump on sours is found at The Mad Fermentationist. That site has been the single most useful source of information regarding brewing sours that I have come upon.
1. Be patient – Brewing a sour is different than brewing pretty much anything else, at least in terms of the time commitment. You’re looking at a year plus before you have something even remotely close to bottle. Leave your beer alone and don’t take gravity/tasting samples every week or even every month. You won’t be able to tell much of a difference between these samples if they’re too frequent, plus you introduce unnecessary and vinegar-inducing oxygen. In the early stages, it’s probably going to taste horrible anyways and you’re going to get freaked out. Just leave it alone. My rule now is to leave a new batch alone for 6 months before testing gravity and tasting. At that point you should get a good idea as to what you’re getting into and what you’d like to add in terms of bottle dregs, fruit, oak, etc.
2. Keep your airlocks topped off – Oxygen allows acetobacter to turn beer into vinegar. You don’t want to find out that the beer you waited on for a year isn’t drinkable just because you did something silly like not keep your airlock full of fluid.
3. Commercial cultures are only a base to build upon – Wyeast and White Labs both carry a number of cultures which contain everything you need to brew a sour beer. Wyeast Lambic blend, for instance, contains a Belgian style ale strain, two Brettanomyces strains, a sherry strain, and all the other bacteria typically needed to brew sour beer are all included in one package. These cultures will create a perfectly acceptable sour beer, but one without a ton of complexity or variation. The fun in brewing sours is the use of bottle dregs. By adding the dregs of a few of your favorite sours during fermentation, you can add an “oomph” in terms of both additional sourness and complexity. With my first sour, I added dregs from pretty much everything under the sun. With my second, I maintained a tad bit more discipline and kept it to two: Cantillon Fou Foune and Cantillon Rose de Gambrinus. I liked the characteristics of both of those beers and wanted them, and only them, in mine.
4. Get a cycle going – A year is a long time, yes, but it seems like less if you know you don’t have to wait another year to bottle another batch. By brewing a new sour every 3-4 months, once that first year is over, you should have a pretty solid backlog of beers going. You also have the added bonus of being able to pitch a new batch onto the cake of a freshly-bottled batch to make things simpler/cheaper. I’m still working on this one.
5. Re-yeast at bottling – Traditional unblending lambics are mostly uncarbonated, but I don’t care for my sours this way (and I don’t brew traditional lambics anyways), so I carbonate mine. After at least a year of fermenting and aging, almost all, if not all, of the ale yeast initially pitched in the blend will be inactive, so you’re not going to get much in terms of post-bottling carbonation without adding new yeast, even if you do add priming sugar. I’ve used wine or champagne yeast in the past because it’s cheap (about a $1 per pack), it doesn’t impart any flavor, and it can work in an acidic environment. I’ve used both Red Star Champagne Yeast and Lalvin EC-1118 with luck
Just a note: I don’t purport to be an expert on brewing sours or even claim to mostly know what I’m doing. I’m still learning all the time, like any good homebrewer should. The world of homebrewing sours is still a very new thing, relative to homebrewing in general and there are, to quote an infamous U.S. Secretary of Defense, many “unknown uknowns”. Maybe the above will help at least one person getting into brewing sours, and that’s good enough for me.