Thursday, January 3, 2008

Brewing With Bugs

My first experience with a sour Flanders Red Ale was at The National Geographic Museum in DC. Michael Jackson was our host and he had arranged for Rodenbach Foederbier to be on the menu for the evening. At the time, I didn't realize how lucky we were. Foederbier is only available at De Zalm, the brewery's cafe in Roeselare, West Flanders, dispensed by hand-pump. What I did realize was that these are incredible beers. Since that night I've been fascinated with the idea of trying to replicate one at home.

It was last spring that I came across several presentations by Raj Apte. In them he discusses, among other things, the oxygen permeability of various materials and comparisons of surface area exposure in various barrel sizes. One of his conclusions is that the small (5, 10, 15 gal) wood barrels used by homebrewers expose way too much surface area to the wood, relative to barrel volume. He set out to replicate, as closely as possible, the exposure experienced while aging in a 10,000 to 60,000 liter tun. His method? A toasted oak stopper.


So, there it is in all it's lumpy, fuzzy, glory. The fuzz is the pellicle from the bacteria and yes, it's supposed to do that. Yummy. The grain bill is primarily Pilsner malt built up with Vienna, Munich, and various Belgian malts. Traditionally, stale hops are used to impart the natural preservative nature, but none of the bittering qualities of the flower. I used a small quantity of low aa% hops that should get lost in the other flavors of the beer. I started fermentation with a very neutral yeast, then added Wyeast Roeselare Ale blend (#3763) which, as I understand it, is a combination of yeasts, including brettanomyces, and a blend of lambic bacteria cultures. It's been sitting there since August and will continue to sit until February or until it's oaky enough. Then the stopper comes out and I affix a regular airlock, and it sits until next August, or until it's sour enough, before bottling.

Cheers!