Acetobacter Infection From Bottle Dregs?

Because the microbes have been studied by science. Smart people wearing lab coats and pocket protectors have verified brett, lacto and pedio can produce acetic acid and have written numerous scientific papers about it. However, pedio and lacto make a lot more lactic acid than acetic acid. I don't think sac makes acetic acid, but some strains can make small amounts of lactic acid.

 

I'm not pinning the acetic character solely on lacto. I'm not pinning it on one microbe. Acetobacter is likely present, but there are at least four other microbes producing acetic acid. I can't determine how much acetic acid is being produced by each microbe. If there was zero acetobacter present, it would not be difficult to achieve the same level of acetic acid in Gran Cru. If Gran Cru was excessively acetic, I wouldn't have questioned your original comment.

Drink Cantillion Iris and Hanssens Oudbeitje to see what I mean about excessive acetic acid.

 

I haven't had much success in searching for peer reviewed scientific studies on this, although admittedly I probably don't have access to many decent sources on that. I remembered recently reading someone say that the only two sources of acetic acid in sour beer are Acetobacter and Brett, both requiring oxygen to create acetic acid. Sure enough @OldSock says the two sources of acetic acid are Brett and Acetobacter in American Sour Beer.

 

Nice blog posting about tasting this, as a lambiphile(?) your lambic posts are some of my favorite. The blending session with the Pyles was incredibly helpful as well.

 

Here is one example of lacto making acetic acid under anaerobic conditions.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC92530/

A real lambic can accumulate acetic acid from a wide variety of microbes. For example, Enterobacter can produce acetic acid. Wild oxidative yeasts such as Kloeckera and Pichia can produce a lot of acetic acid.

 

I may have said or inferred earlier that pedio can produce acetic acid, but that isn't true. Sorry.