39466Re: strong yeast odor after fermentation
- Oct 15, 2010BC,
It's just a guess, but one from a fair amount of experience. I think what you observed with the sulfur (hydrogen sulfide, probably) smell was a great lesson in yeast nutrition. With insufficient/incorrect nutrients, you tend toward bad flavors and smells. Fix that and you fixed the smells.
Of course, some yeast and worts generate some off smells/tastes in a healthy situation, and this is what lagers and lagering is all about.
When a still wash sits, especially when hot, dissociation can form acids, which react with the alcohol to form esters, which are flavor and smell elements of the spirit. The bicarb just raises the pH, and (more or less) stops those acids from forming, and so retards ester formation. If you're making "brown" booze, with ester profiles that you've worked hard to get, bicarb will flush your efforts down the toilet.
Bicarb is mostly for vodka runs, and only for the second-or-more (low wines) runs. In many cases raising your pH in a stripping run, with yeast nutrient present, will give you the dreaded "blue ookies", blue copper compounds (Schweizer's reagent) in your spirit.
Zymurgy Bob, a simple potstiller
--- In email@example.com, "Becool Stayslinky" <becoolstayslinky@...> wrote:
> Mr. ZB,
> You have mentioned a couple of things that I have some curiosity about.
> I have been doing all wheat mashes for vodka with some fair success lately. I'm ending up with a clean tasting vodka, and am getting between 7-8 percent at 2 pounds grain/gallon of water. I recently started using EC-1118 (last two batches), and about 4 days into the fermentation, both batches got a significant sulphur smell. I read on the Lallemand site that EC-1118 produces a lot of suplhur under low nutrient conditions, so I added a little DAP to each batch and the sulphur smell went right away and didn't come back. Do you think that the sulphur was due to low nutrient, or some other stressor? Mash temp was around 80 degrees at the time of the sulphur smell. Fermentation took 6 days, and ended at 1.006
> Has anyone ever tried Lalvin DV10 yeast?
> The other question is about the bicarb (I'm assuming sodium bicarbonate) in the spirit run: How much do you use and what exactly does it do?
> Thanks in advance,
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