Hi
I just bought a fermentausaurus to try do a lager a room temperature. I have 2 questions.
Can you use any yeast to ferment under pressure ?
Would there be any adverse effect if i ferment an ale yeast under pressure?
I already have my grains for my next few recipe and they're all ales. I would like to try this asap.
JF
I do pressurized lager fermentation (in a 10 gallon corny in my case) with my current house yeast, WLP833. Even though White Labs sells a "high pressure lager yeast," note that Chris White himself used 833 for all his own pressure fermentation experiments. Not that there's anything special about that one either. Kind of a coincidence I settled on it. I'm not aware that commercial German brewers using the method use any special yeast. So AFAIK there's no reason not to use any yeast you like.
I have tried a couple of ales under pressure, in my case with S-04. I wouldn't do it again. I found it does what you want it to do with a lager: suppress esters and other fermentation products. Makes for an un-ale-like ale, IMO.
Note that because you are fermenting at ale temperatures, lagers will finish as fast as ales, and because they are so clean after pressure fermentation, they're ready to crash, clear and package as fast as an ale. Since ales are already going quickly, I don't see any practical advantage to using pressure fermentation on them.
But hey, try what you want and see how you like it. And maybe different ale yeasts will perform differently, or you want clean fermentation characteristics in a particular style. Play around with it and report the results!
(BTW my pressure fermented lagers are equal if not superior in every way, IMO, to the traditionally made ones I was doing for a couple decades. Wish I'd tried it sooner. You'll love it.)