Hi. I wanted to boost the ABV of a beer for some specialty reasons. I was going to add Champagne yeast near the end of initial fermentation; however, I learned about FermFast and used that. I added it on day 4 after pitching the initial yeast and fermentation has pretty much stalled. The grains were pretty much 8# US 2-row, 8#Maris, some oats, Centennial and Citra, and a Giga yeast to start. I oxygenated the crap out of it before pitching the Giga yeast (hoping some would still be in there for the FermFast) and fermented in the mid 60s. On day 4 I tasted a sample (it was great), then poured in the FermFast, swirled it (purging with CO2 the whole time), and over the span of several days brought the temp up to 70-ish. However, fermentation has pretty much come to a standstill. I just drew out a small taste. The nose is great; however, it has the taste of yeasty bread dough. Any thoughts or suggestions? I was expecting a very vigorous fermentation and am feeling quite underwhelmed and concerned that nothing more is going to happen (this was a pricey batch). Thanks.
More info: Mash was thick (about 1 qt/pound), and in low 150s. I added yeast nutrient near the end of the boil. There’s 5-6 oz of hops in it.
Champagne yeast would not attenuate anything that whatever ale yeast you used wouldn't. So it's good you skipped that one. I'm not too familiar with FermFast Turbo yeast, but which one did you use? I suspect that's important. In order for it to attenuate your wort beyond what your ale strain would have, the Turbo yeast would have to be able to ferment carbs that the ale yeast wouldn't, and/or any enzymes added to the Turbo yeast would have to break down otherwise unfermentable carbs into something fermentable.
I clicked “post” too early. I’ll “digest” the rest of your info tomorrow when I’m more awake. I do have some enzymes for GF brews, I wonder if either of those would work? Though it’s probably too late to add the enzymes. I wonder if I should have just started with the turbo yeast?
Again, I'm not a Fermfast Turbo Yeast expert, but I believe the 48 Hour version is intended for fermenting Sugar Washes, i.e. simple sugars. I wouldn't be surprised if it was much less attenuative with a beer wort than ale strains would be. What are the enzymes? My guess is that would have been even worse.
Here’s a link to a profile summary of the FermFast 48 Hour Turbo Yeast. 13 lbs sucrose in 6.6 gallons water will produce 14.5% ABV in 48 hours.
Yes, it's probably a sugar issue. I think I'll wait a day or two, add a couple pounds of sugar dissolved in water and see what happens. It probably wouldn't have worked even if I skipped the Giga yeast.
I suspect either/both of these would make what's left of your wort more fermentable. You could certainly do this (though I'm not sure why you'd wait a day or two), i.e. it should give you more alcohol. Flavor-wise, I've read many warnings against using distiller's turbo yeasts in beer, with flavor being one of the concerns. Good luck with this! ETA: Did you go with the turbo yeast due to claims about 20% (or whatever) ABV? That's really a function of having the sugars available to ferment and a high alcohol tolerance, not AFAIK any ability to get more attenuation from a given wort.
One final thought...you might need to use these enzymes at mash temperatures for them to be effective.
I'll be the one that says that I think you went about this the wrong way....if you knew during the recipe design stage that you were looking to boost ABV without a supplemental body boost, you should have added sugar. Enzymes, like both those you listed, into the mash could have also been used. As Vikeman pointed out, most wine (and distillers?) yeast aren't going to ferment any beer's sugars that beer yeast aren't already going to eat. Not really familiar with distiller's yeast, but most champagne yeast I'm familiar with (wine yeasts in general) are POF+, so you better be ready for phenolics to come omto the scene if you add champagne/wine yeast in the mix. Also not sure about the "Killer" status of these yeast, but there is also that factor to consider. Enzymes (especially the amyl) into the fermenter are a gamble, and one I don't usually recommend unless you're willing to accept that it may become a bone dry beer...I don't think the alpha amylase is going to do that though, actually don't think the alpha will do much at all. I think it's best to let it run it's course cause it seems like a solid recipe as it stood from the get go. Seems to me you're trying to fix a perfectly good car...but obviously you had a direction you wanted to try and can't blame you for experimenting. Best of luck with the GeeL.
Circling back to this...I can't seem to find technical data on the strain you used, but see that a few distillers yeasts indeed have the k2 killer factor...you may have killed off your brewer's yeast and the distiller's yeast can't ferment maltotriose, so you may be at a dead end there. Am interested to hear if anything kicks back up though.
