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Friday, February 13, 2015

Spontaneous by Proxy

The juice beginning fermentation.
A few months back, I mentioned trying an experiment with spontaneous yeast.  I was racking a batch of spontaneously-fermented cider, and when I discovered that lovely yeast cake at the bottom of the carboy, I wished I had some wort to throw on it.  Well, I got another bite at the ... err, another chance.  Kevin Zielinski, who makes some of the best cider in America, set me up with ten gallons of juice from his orchards (a mix of mostly French and some English bittersweet varieties).  He suggested I try one in the English mode, racked once and fermented to dry, and once in the French mode, with multiple rackings to try to get the yeast to exhaust the nutrients in the juice and go dormant (which is how they end up with sweet ciders that don't turn the bottles into bombs).

In any case, this afternoon I finished up a three-gallon batch of wort and transferred it to the barm of one of those ciders.  It smells like a great ferment has begun, with a lovely, fresh juice aroma and the beginnings of that wild yeast funk (and a bit of sulfur, which Kevin says is normal).  If this works, I'm going to call it "spontaneous by proxy" and hope the title catches on.  Of course, if it doesn't work I'll call it "a debacle" and hope everyone forgets quickly and moves along.

I am slightly less sanguine than I was before, though, owing to the lab report Kevin shared with me of the yeast and bacteria found in the juice sample.  It has lots of saccharomyces, which is great, and very little brettanomyces, which is curious.  But it also has tons of acetic acid bacteria, something called Hanseniaspora uvarum, and something else called Pichia membranifaciens.  I can't predict whether these would normally be found in a spontaneously-fermented beer, so who knows what they'll do in my wort.

Whatever happens, never fear--I'll let you know.

Update.  Well that was fast.   The yeast cake went into the wort at about 3pm yesterday, and by 7 this morning it was rocking.  I'd chilled the wort down to 55 so the yeast wouldn't be shocked by warm temps (the apple juice is outside and is probably around 45-48).  I therefore expected a slow ramp-up, but no:

(And to be clear, I don't leave the carboy on the sunny deck to ferment--that was for photographic purposes only.)

1 comment:

  1. it sounds awesome! I'd love to hear how this turns out debacle or not. I'm betting not though. I wouldn't worry about the acetic acid bacteria since it needs oxygen to make acetic acid, in an anaerobic environment it's going to have a bad time.