Lactobacillus? Acetobacter?

While sniffing the airlock on a bubbling primary of pale ale (one of the more enjoyable aspects of brewing) I noticed a film of viscous liquid on top of the airlock that was VERY acidic. I touched it with my finger and then touched my finger to my tongue and it was like battery acid.

I'm actually pretty comfortable with our sanitation regimen. Everything that touches wort is always cleaned and sanitized with OxiClean and StarSan, the airlock is filled with sanitizer, and I have not lost a batch to infection since the early 90's. But it appears obvious that my house harbors bad beasties that COULD easily ruin a batch.

My questions:

1. What am I dealing with here? My guess is Acetobacter and that it is airborne.
2. Can I minimize the levels of this bug in my home?

Thanks.

Can't imagine how such a bug could live in an air-lock filled with sanitizer. What sanitizer are you filling the air-lock with? Starsan?

It's a standard clear plastic 3 piece airlock filled with StarSan solution. The sour coating of liquid is outside of the airlock, on top of the airlock cover. I trust the fermenting wort inside the bucket is doing fine and tastes nothing like the substance on the top of the airlock. However, as the wort was fermenting vigorously, bubbles came up through airlock, bubbled up through the StarSan solution, and foamed up through the tiny holes in the airlock cover. I would imagine when these bubbles popped on top of the airlock cover, it left a thin film of partially fermented wort outside the airlock that was then victimized by some sort of aerosolized bug that floats around on dust motes in the air in my house. In the 5 days since the fermenter has been doing its job, I theorized that said alleged bug has feasted on the partially fermented wort on top of the airlock, and has turned it to vinegar. Hence my suspicion of Acetobacter.

I was just curious if anyone had a similar experience, and if so, how they dealt with it.

You are tasting the StarSan. When the airlock foams through the vent, it takes some of the StarSan solution with it. Taste a little StarSan (it's safe) and you will see.

helibrewer said:

You are tasting the StarSan. When the airlock foams through the vent, it takes some of the StarSan solution with it. Taste a little StarSan (it's safe) and you will see.

Click to expand...

This. Except taste DILUTED starsan.

Thanks for the reply.

Of course, I had to run downstairs and lick a spoon filled with StarSan solution. And it DOES have a bit of an acidic bite to it. So, I would say it is plausible that the goop on top of the airlock was StarSan, maybe concentrated through evaporation?

I'll try to worry less now.

And Blizzard...

Thanks for the warning.

I put on my telescopic glasses once and read all the fine print on the side of the StarSan bottle. You'd think it was plutonium or something from all the scary precautionary verbiage.

Yep. Exactly what I had to say...I use starsan and came across the same thing out of the airlock when I started brewing. An acidic bitterness is the best I can describe the taste. Beer was fine.
There was one time after kegging a cider, I apparently didn't flush my serving line of starsan solution and I tell you what, that was one memorable swig of cider haha. Im figurin' a person will only do that once. Note to mothers out there- your kid has a potty mouth? Don't waste your time with soap....use starsan. Bet Jr. won't say that no more!