Author Topic: Spontaneous Fermentation and Mold  (Read 732 times)

Offline wakeele

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Spontaneous Fermentation and Mold
« on: February 18, 2015, 07:49:46 AM »
So I had a bunch of old grain I needed to get through, and it pretty much worked out to make a Scottish-type Ale (has some peat malt too).  I put 12 gal into my conical, and had 8 gal to play around with.  I boiled a few gallons as an experiment in proper boiling hardware ;)  The rest I left in a bucket in my basement and because of time, nothing became of it, so I'd see what happens.  I'm in Montana, so my basement doesn't get above 60ºF in winter.  It started fermenting pretty quickly (2-3 days) and was a slow lager-like ferment.  Looked like a fairly regular ferment. 

I brought it upstairs to get it a little warmer to continue fermenting.  I never set my thermostat more than 62º.  After a few days, mold started forming.  Before too long I had a nice mold pellicel.  Being a completely what-the-heck experiment, I thought, well, lets see where this goes.  Before the mold took over, the SG was ~1.015.  I put it outside on the porch a few days ago to chill it down and get ready to either dump it or whatever.  Just check the gravity and it's ~0.97.  The OG was ~1.066. 

Of course I have a spigot or I would have dumped it as soon as the mold formed on top.  I thought there may be a chance that towards the bottom might be safe considering the ABV and it started without any mold involved.

It has a nice subtle smoky nose with strong hint of moldy dirt.  Oh yay.  Well I'm calling this one a wash.  Any thoughts folks?

Here's a photo of my beautiful mold city:
--WAK

Offline reverseapachemaster

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Re: Spontaneous Fermentation and Mold
« Reply #1 on: February 18, 2015, 07:07:18 PM »
A pellicle is not the same as mold floating on top of the beer. A pellicle is a biofilm that regulates oxygen and keeps other organisms out of the beer. Mold is the actual organism's colony floating on top.
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Offline wakeele

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Re: Spontaneous Fermentation and Mold
« Reply #2 on: February 18, 2015, 10:45:38 PM »
A pellicle is not the same as mold floating on top of the beer. A pellicle is a biofilm that regulates oxygen and keeps other organisms out of the beer. Mold is the actual organism's colony floating on top.

I'm well aware of that--it was a bit of a joke and a way to describe how it looked before I decided to just add a photo.

I'm mostly interested in discussing mold growth during spontaneous fermentations.
--WAK