odd fermentation

DoubleRainbow · Dec 15, 2013

My ciders usually ferment quick. This one has been fermenting for over a month. The recipe as follows, 5 gallons of Kirkland apple juice, 2 cans of concentrate, yeast nutrient and a vial of wlp002 English ale yeast. I did not take a gravity reading before fermentation. It has been held at 68 degrees the entire time. It has what appears to be a thick layer of yeast floating on the top that refuses to drop out. I have never had this " krausen " type layer last more than a few days. Any ideas of what this is. The last reading was 1.015

caseymac91 · Dec 15, 2013

Nothing to worry about here. Looks like a healthy krausen. It should drop when fermentation ends. Yeast strains behave differently, last time I used white labs liquid yeast it looked exactly like that.

DoubleRainbow · Dec 16, 2013

I tasted the gravity sample and it tasted really good. I just thought it was odd that it has stayed on top for this amount of time! Thanks for the reply

jackson09 · Dec 18, 2013

The wlp002 attenuation is only 63-70%. Not knowing your starting gravity it would be hard to say but the yeast might be done. At a 1.070 SG x 70%=1.021. There are a lot of examples of 100% attenuation of ciders but that's achieved with wine/champagne yeasts. I'm no expert but it would strike me that is because those yeasts have adapted to eating simple sugars and have a higher alcohol tolerance.

WilliamSlayer · Dec 18, 2013

Some ciders/fruit wines can take longer due to the yeast strains nature/temps/nutrient lvl/oxygen lvl/presence of adjuncts (etc. etc. ad nauseam). I wish I had an easy answer for this one, but lots of factors contribute.

As for a possible solution to the problem, trying stirring the batch to resuspend the yeast in to the brew. With the gravity so low I would not add nutrient, but that's a possibility for batches at an earlier stage.

Xantus954 · Dec 18, 2013

You should be fine, I used that same yeast in the Cran-Apple cider I just made and it looked the same at first and lasted almost two weeks before it started to calm down.

dlester · Dec 18, 2013

I have the same yeast on Apple Cider now, but need mine to finish quickly. Upon final gravity I'll cool it down to 29° to force the yeast to the bottom. I agree with the others to stir it to force the krausen to mix.