Potential House Acetobacter bug

I'm not one to write a thread freaking out that my beer is infected and ruined. On the other hand, in a few recent brews, I've been noticing a disturbing trend. I brewed a tripel 2-3 months ago, which I fermented on a temperature ramp pitching at 65, and getting up to 82 over the next week. After a total of ten days, it hit the secondary for a month. When I bottled it, it had reached an apparent attenuation of 100%, but the hydrometer sample was delicious. It had apple overtones to it, but not overwhelming. After being in the bottle, this intensified. More recently, I made a batch of Ed Wort's Haus Pale. I recall the sample tasting fine. It reached a FG of 1.010. After force carbonating in the keg, I tried one last night, and it was bigtime apple on both the nose and in the taste. This put together with some bottles of porter that I had stored away for 9 months that went totally sour makes me worry. I have made kombucha before in this house. I live in the Santa Barbara area, and I worry that geography, or the kombucha culture, or some other factor could be leading to me getting aceto infections. I've made several other beers in this same time period without these problems, so I'm really not sure what to think. I recall talking to a winemaker at one of the local wineries, and he was telling me that the facility that they took over had a really bad malolactic bug problem from the previous winery, so they have to try really hard whenever they're making something they don't want to undergo malolactic fermentation, so it seems likely that any one particular local might be more likely to different types of bacterial/wild yeast problems. Does anyone have thoughts, or does any have experience with consistently getting a particular infection? I should add that I'm confident that my sanitation procedures are good, and I'm fermenting in glass and not plastic.

AFAIK, acetobacter would give you a vinegar, not apple, flavor.

Denny said:

AFAIK, acetobacter would give you a vinegar, not apple, flavor.

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Very true. I had kegs turn to vinegar from an acetobacter infection. I didn't really get apple smells from it, though.

This old post of mine has a link that might be helpful.

I alternate sanitizers now, since my own infection issue last summer. I don't use the same sanitizer thorought the entire batch...if I use starsan on brewday I use iodophor at bottling, and vice versa...

Even Chris Colby as an aside in a BB podcast mentioned switching sanitizers, a "house" bug can mutate to become accustomed (like with pennicilin) to your sanitiziation regimen. So switching, at least temporarily will knock it for a loop.

Honestly, it ain't a big deal, it happens to us on occasion.....On Craftbrewer radio they said it usually happens around the 10th, the 30th and the 50th batch...even the pro's deal with it (the Brewer at New Glarus said in an interview on Basic Brewing once, that a commercial brewery operation gets a 3 year grace period before their first infection)

It's called a house germ...and it develops over time...
The hosts of the podcast in Australia have 60 years of brewing experience...This is a very good discussion on infection and infection control.

They talk about the "timeframe" of infections, and how it is less likely for a first batch to be infected...it tends to occur around the 10th batch and the 50th...When the equipment gets more used up, and "house germs" start to build up. They used the term "house mouth" in the discussion, how we may not even notice, because we're sort of used to the taste of our beers, it's usually NOT a regular drinker of our beers that notices it.

December#2,2006

“What is sour mashing?” I hear you ask. So said our brewmaster as he guides you thru this most interesting of ways of making a beer. In a nice compact show, we also cover feedback, Kit and Kilo infections, our beer superhero turns “gay”, and a faviourite beer song is requested yet again. Not enough, well also hear about WHO stuffed up his brew day.

http://radio.craftbrewer.org/shows/December2-06.mp3

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It's a pretty good discussion.

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Hope you find the section in the aussie podcast helpful.

Denny said:

AFAIK, acetobacter would give you a vinegar, not apple, flavor.

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Thanks Denny. I was just going off of what John Palmer says for off flavors in his book. It had been my understanding that acetobacter would make acetaldehyde as an intermediate to acetic acid, which would give an apple flavor before the full on souring.

Revvy said:

This old post of mine has a link that might be helpful.



Hope you find the section in the aussie podcast helpful.

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Thanks Revvy, seems like a very interesting discussion. I will listen to it tonight. Perhaps I will have to switch from StarSan to Iodine for a while.

acetaldehyde is also one of the primary indicators of oxidation. could that be a possibility?

brewgrl said:

acetaldehyde is also one of the primary indicators of oxidation. could that be a possibility?

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I don't think so, especially since one of the examples was kegged, purged and force carbonated.