Bad sour batch?

[j4ustin]

I've had this batch aging for about 7 months now and noticed that it's started looking odd compared to where it was a few months back. Can any more experienced members on here let me know what's going on with this batch? There's a white layer that looks different than the initial pellicle, and it seems to be creeping up the walls of the fermenter.

The beer is rare barrel gold base, w/ the east coast yeast sour country blend. Aged for 7 months in a 3g glass ferm. I've opened it 3 times to sample but have purged w/ c02 each time.

 

[mashpaddled]

Pellicles will change appearance, texture and thickness over time. They can be flakey, filmy, powdery, bubbly, wavy, thin, thick, white, off-white, tan, etc. Changing appearance by itself isn't usually a reason for concern.

That said, you usually don't see a lot of growth up the sides of the container. It looks like you have quite a bit of headspace and it looks like there is a lot of moisture on the walls. It could be that in a slightly pressurized environment, especially if you are keeping the beer warm, that you are getting high humidity in the headspace and you're getting pellicle growth on some of the beer that is clinging to the walls in the headspace. I would also be slightly concerned that there is mold growth but that looks a lot more like pellicle than mold. Can you get some clearer pictures?

Generally that much headspace is undesirable for aging sour beer. Not only do you create opportunity for mold growth but eventually air gets in and you have more opportunity for oxidative reactions like forming acetic acid. It looks like you have about two gallons in the three gallon vessel. I would rack the beer into two one gallon jugs and simply eliminate all of these problems.

 

[j4ustin]

I've posted some close up pictures of the beer top below. It does kinda look like a pellicle now that I'm looking closer. The reason why it may be up the walls is how I purged co2 last time I sampled. I sprayed c02 into the vessel which likely sprayed beer up the walls.

Next weekend I'm brewing a top up batch and will fill this container with already fermented beer from another vessel and be sure to go nearly to the top so to remove as much o2 as possible. This is a leg of a 3 - 3 gallon solera project. The other two have far less headspace, I just had a bunch of stuff go wrong during brewday on this batch and ended up with less than half of my intended volume that day.