Saturday, 19 July 2014

Coupage: Brett-Fermented Wit

Today I tried another version of this technique (i.e. cutting fresh beer with older sour beer).  The base beer was something like a belgian wit, fermented with a blend of White Labs brett trois and brett c.  I got the idea to make such a beer from an old article by Chad Yakobson in Zymurgy, in which he gives what I presume is an early version of the recipe for Crooked Stave’s St. Bretta: its a pretty standard wit recipe, with coriander and citrus added to the boil, and a light dry-hop in secondary.  The main point, of course, is that the beer is to have a primary fermentation with brettanomyces alone.

My version turned out ok, but it was a little muddy, and the citrus and coriander were not as bright as I wanted them to be.  I gave it a light dry-hop with motueka, hoping to brighten things up a bit, but the beer still wasn’t where I wanted so my thoughts turned to acidity.  Luckily I was about to transfer the no-boil sour I brewed a month ago to some smaller carboys.  My original intention in brewing this beer was to use some of it for blending, and here I had a good candidate.

Defrosted RaspberriesThe sour, if you don’t want to go back and read the last post, was fermented with the same blend of brett trois and brett c, along with a large dose of lactobacillus.  It already has a nice lemony acidity---not super sharp, but softly assertive, which is how I like it.  Today I transferred three gallons of it onto 1.5lbs of defrosted raspberries from Klug Farm (these were particularly nice berries---brightly fruity, with a tart acidic snap to them).  I divided two of the remaining three gallons into small jugs for future blending, and then transferred the final gallon to my bottling bucket for blending with the wit. 

Pink Sour and small jugsAs a quick aside, I must say that I’m excited to have these smaller jugs ready for future blends.  The biere de coupage I made a few weeks ago seems to have come out pretty well.  Even a small portion of aged beer has given it a pleasant acidity that I think blends nicely with the hops.  With these smaller jugs already separated out, it will be easy for me to blend some of this sour in with future saisons.  What’s more, since it was fermented with two strains of brettanomyces, adding it to a saison at bottling will mean that I am effectively bottle-conditioning with brett.  So I could make a dry saison with a normal sacch strain, then blend this sour in to get some tartness and brett funk in the bottle.

Anyway, I transferred the three gallons of wit onto the sour, giving me a 3:1 blend.  I mixed up a blend in these proportions from my gravity samples, and it tasted promising: as I’d hoped, the lemony acidity of the sour beer helped accentuate some of the flavours in the wit.

Unlike my previous times using this technique, neither beer was completely dry: the wit has been at 1.006 for the past few weeks, and the sour at 1.003 for the past month.  Since they were fermented with the same combination of brettanomyces, I’m hoping there won’t be much additional re-fermentation in the bottle.  But the addition of lactobacillus from the sour beer (or the drop in pH?) could contribute to further fermentation (really, who knows what the brett will decide to do!), so for safety’s sake I put this entire batch into heavy bottles.

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