We’ve tried to brew sour beer before, but with little success.  Which is unfortunate, since sours are the main style we like that we can’t easily find in shops.  So we were excited to hear about some alternate methods for souring beers that don’t involve waiting for years for traditional barrel-souring to work its magic.  We read the Mad Fermentationist blog post about a faster souring process,  and then found a really good breakdown of the various souring options.

We decided to go with the sour-kettling technique, which boils down to taking a break between collecting wort and doing the boil to sour the wort with Lactobacillus.  We used the same recipe we usually use for our Saison Bruxellensis, and left the wort in the kettle (bundled up with towels to keep in as much of the heat as possible).

We added pure Lactobacillus culture from White Labs, and let it sour for a few days, watching the pellicle formation and checking the pH with color-change test strips.

This is where we hit our first complication: the pH strips were not nearly sensitive enough to reflect the small changes in pH we were seeing.  So we mostly relied on taste to monitor the souring process.  It was a little hard to judge the sourness, because the unfermented wort has a bunch of sugar in it.  We reasoned that the fermentation would convert the sugar and make it seem more sour, so we stopped when the sourness was noticeable but not dramatic.  As it turns out, the final beer was no more sour, so next time we might let it go a little longer.

We did the boil and fermentation as usual with both saison yeast and Brett Bruxellensis in primary.  The fermentation proceeded normally, the gravity stabilized, and we bottled with priming sugar as usual.  But I think we were too hasty in bottling, because when we opened the first bottle about a week later, it was badly over-carbonated.  Shortly after that, the caps began to swell.  We put as many of the bottles as we could fit in our kegerator, and luckily we haven’t had any bottles explode.

So, there are a few kinks to work out in the process, but overall it seems very manageable.  It does add a few days between the mash and the boil — though that’s probably not a bad thing, since it naturally splits the brew day, and each half fits into an evening instead of taking up an entire day of our weekend.

The final results are very nice, if we do say so ourselves.  A very drinkable sour saison, with a little body, a little funk, and a mild sourness.  It’s not gueuze, but it’s much better than our (basically non-existent) previous sour options.