Hi, did a search, but couldn't find a very good answer.
Pitched dregs from a Supplication into a mason jar starter (OG 1.040sh) on Saturday. Monday evening, there's a tremendous amount of acetone/nail polish remover/solvent smell, which I understand to be ethyl acetate.
What conditions would cause the acetobacteria to dominate? What can I do to avoid this? Can I decant the starter and pitch it into a new starter?
This isn't a difficult bottle for me to obtain, but I'd love it if this starter could be salvaged.
brett can produce ethyl acetate as well, it happens when there is a lot of o2 for the bugs to use
I hate to say it as well, but I wouldnt pitch it into a beer, ethyl acetate is horrible stuff, I had a worse experience with a flanders red, I tasted it to see how it was coming along and it was awesome!, then I moved into a new house, disturbed the pellicle (apparently it was done fermenting completely) it dropped and I wasnt able to bottle for ~1week, tasted at bottling and it was an ethyl acetate bomb, the whole batch and 2yrs of time and it was a drain pour
Article about "Common Beer Faults" in latest version of Brew Your Own magazine (March-April). It's fusel alcohol/oil. Usually due to high ferm temp or less than healthy yeast not completing fermentation.
I had a similar problem with a cider that I fermented with wild yeast (cultured yeast from fruit skins from the local greenmarket that I left in some fresh cider and grew a starter of sorts). I let the cider ferment down and it was like drinking nailpolish.... figured I'd give the stuff some time to rest but it never got any better.
__________________ Drinking:Smoked Dunkelweizen; Imperial Nelson Sauvin Pilsner; American Brown Fermenting: Air On Deck: ??
I did an all Brett Lambicus beer (with the White Labs Brett L strain) and the first 2-3 days the nail polish remover smell coming out of the airlock was so bad that I could barely stand putting my head near the carboy to even look into it. Eventually that died down after a few days and the beer was ridiculously sour on tasting a sample. Strangely enough, 4 weeks later there was no trace of acidity in the taste and it was a very well-rounded, smooth tasting beer.
(Actually, is was almost too smooth & non-acidic, so I added 4 lbs of dried cherries, a vial of Brett B, French Oak, and blended in some Pinot Noir. Now, 4 months later the samples are tasting amazing and complex!)
Maybe it's a Clostridium (a probiotic like lactobacillus) infection. I think it's a fairly common bacteria. It dies at a ph<4.2ish. I hate the smell, but it will go away, as it is very volatile. Maybe a few days to a week. I've had it a few times. The faster you can get your pH down (eg. by adding a small amount of acidulated malt) the better chances you have of avoiding enterobacter and clostridium smells. Interesting enough, Apte talks about 100% of the acetic acid character in traditional lambics coming from enterobacter in the first couple of weeks of fermentation. Some think it adds complexity for a better lambic. I'm still not sure. A couple of links: http://www.microbiologyprocedure.com/industrial-microbiology/acetone-butanol-fermentation.htm http://4.bp.blogspot.com/_XYiLrMURRG0/Sl43JJHHRiI/AAAAAAAABvM/bXQxcgp7K-0/s1600-h/Lambic+graph.gif
I doubt Clostridium. It's very oxygen sensitive, and like you mention, low pH sensitive. So that would leave only the tiniest window of time between the yeast consuming all the oxygen, but not yet dropping the pH. It probably isn't Clostridium for the same reason we don't have to worry about botulism (caused by Clostridium botulinum) from homebrew.
Clostridium perfringens is used to leaven some old fashioned bread ("salt rising bread") but wild yeast has to be inhibited by high salt and high starter temperatures before the Clostridium can take over. And Clostridium is supposed to impart cheese-like flavors to the bread, which is not like what the OP describes.
And I wouldn't characterize all clostridium as simply a "probiotic": think botulism, gas gangrene, food poisoning, tetanus, women dying after childbirth, colitis and diarrhea after antibiotics... members of this genus can be pathogens. Good thing we don't have to worry about it in our homebrew.
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Random Fact: Human Immunodeficiency Virus particles have approximately the same density of 1.170 wort. I know because I float them on a sucrose gradient in the lab to purify them for research.
Primary: nada
Drinking: Belgian strong golden, Northern Brown, Porter
Nail polish remover aroma
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