The Great Souring Experiment

The first Friday of every month marks “The Session” when participating beer bloggers all post their take on single topic.  Getting bloggers to write about the same thing is a great way to promote discussion and the exchange of ideas. I’ve never joined in before (I tend to be anti-blogger-social), but with August’s sour beer topic it seemed like a good time to give it a shot. This blog delves into brewing sour beers more than occasionally, so I was torn on exactly what to write about.  An overview of brewing sours didn't seem interesting or specific enough (not to mention that I've already posted one).  While homebrew bloggers participate in The Session, it is predominantly bloggers who focus on craft beer, so I wanted to do something that even people who don't brew would find interesting.

While stripping labels from a few cases of bottles, I started thinking about how much beer I have to bottle over the next few weeks and what I’ll be brewing to fill all of those emptied carboys.  While working on my book I've researched all of the different techniques that brewers have come up with to turn beers acidic, but I've had a hard time comparing the results because each brewery sticks to just one (or at most two) methods.  Comparing results between breweries has its own problems because of the large variation in microbe selection, aging temperature, grist, aging vessel etc...  So I dreamed up:

The Great Souring Experiment!

Concept: 
Produce a series of sour beers using different methods, while controlling for as many variables as possible by using the same ingredients, microbes, and equipment to isolate the character that each method imparts. 

Methods:
1. Inspired by Russian River (Temptation): single infusion mash, ferment with a Belgian ale strain, fine and crash cool to remove the yeast, pitch Brettanomyces, followed a few weeks later by Lactobacillus and Pediococcus.

2. My standard: same wort as #1, but pitching all of the yeast and bacteria into the wort at the same time.

3. Inspired by The Bruery (Marrón Acidifié): same wort as #1, but with 100% Brett/Lacto/Pedio fermentation (no brewer's yeast).

4. Inspired by Ithaca (Brute): replace ~14% of the malt with acid malt, ferment with an English ale strain, followed by secondary with Brett.

5. Inspired by Pizza Port (Mo' Betta Bretta): Sour the wort pre-boil with Lactobacillus, followed by fermentation with 100% Brett.

6. Inspired by Cambridge Brewing (Cerise Cassée): Sour mash in a carbon dioxide flushed mash tun, primary fermentation with an ale strain, and finally secondary with all of the microbes.

Almost all American breweries that publicly discuss their method use some variation on one of these six. Trying all of these methods would provide new tools for making sour beers, as well as insight into how the same microbes behave under a variety of conditions.

Variables:
I'd suggest using a pale base beer to let the microbes' character shine. The recipe could be as simple as 80% pilsner, 20% flaked wheat to 1.050 with ~15 IBUs of noble hops added near the start of the 90 minute boil.  To avoid variations due to microbe selection/viability use the same pure cultured microbes for each batch (avoiding the variability of bottle dregs).  I'm thinking of using Wyeast Lactobacillus and Pediococcus for sourness and their Brett bruxellensis and Brett lambicus for funk.  All of the batches should be aged at the same temperature and in the same type of fermenter.  At packaging they should each receive the same amount of carbonation.

Final Thoughts:
I'd be interested to hear if anyone has other methods to suggest for comparison.  I did not include spontaneous fermentation (even though it is gaining in popularity, and my first American Lambic tastes great after just four months) since it wouldn't be the same microbes.  Including a duplicate of one of the first three methods, switching the single infusion to a turbid mash to show what it actually adds to the final character.  Using one gallon jugs for fermentation would allow for splitting the wort from one mash in several ways to reduce the amount of brewing required.

Ideally, brew all of the batches in quick succession so they have similar ages for the more accurate comparison. After 12-18 months bottle some of the beer straight and use the rest to find how the characters meld and mesh. I'm not sure whether I'll have the time or effort to pull this off, and even if I do it will be a few months before I can fit them into my schedule.  Interested to hear if other people think it would be worth the effort, or if anyone has tried something similar.