This is infected. What is the microbe?

[tennesseean_87]

This cropped up on a Dubbel. It sort of looks like brett pellicle with the bubbles deflated. Is that a possibility? If not, what is it?

 

[Gavin C]

This cropped up on a Dubbel. It sort of looks like brett pellicle with the bubbles deflated. Is that a possibility? If not, what is it?

Impossible to differentially identify a microbe from a picture, macro or micro.

Given the massive oxygen rich headspace, it's likely a lactobacilli or an aceterobacter dominant biofilm.

 

[tennesseean_87]

Thanks. I guess if either of those is it I won't dump. A sour dubbel would be good, I think, as would malt vinegar made from a dubbel.

Did you see the enlarged image? If it helps, it smells somewhere between light acetone and bananas (1214 yeast used).

 

[BugHunter]

Impossible to differentially identify a microbe from a picture, macro or micro.

Given the massive oxygen rich headspace, it's likely a lactobacilli or an aceterobacter dominant biofilm.

With that amount of oxygen available to it my bet would be on an acetobacter infection. Without doing a genomic or biochemical test it's hard to tell the difference between the two though; they look similar at both the macro and micrograph level.

 

[tennesseean_87]

So it just tasted thin and bland. No sour. I'll probably dump it.

 

[IslandLizard]

So it just tasted thin and bland. No sour. I'll probably dump it.

If it's not sour it could well be Brett or just a very young sour starting to develop. The pellicle forms under oxygen (air) to shield the beer from other competing micro-organisms. I'm surprised it's thin and bland tasting.