Barrel aged off flavor?

[scottcd]

Hey all,

Our brewery is fairly new to barrel aging and I think we're having an issue with one of our beers. So we aged an Imperial Stout in a bourbon barrel which came out pretty good with no off flavors and was received very well. We got two rum barrels from a local distillery and I'm having trouble identifying some of the flavors I'm tasting. It's a coconut porter aged in a rum barrel. I get a strong rum flavor, the coconut got totally lost, and I'm picking up almost a tart/brett character. We left it in the barrel too long and I'm not sure if I'm confusing the oak character with brett or some wild yeast. We haven't tapped it yet but I'd like to see if I can figure out whats going on.

We do have a really crappy microscope and I've put a few barrel aged beers under it to see if I can spot an infection, but I'm not sure what I see. I've included a few pictures and I would really appreciate if anyone could take a look and help me out.

This is our BA Imperial Stout that we release in bottles and had no off flavors.


This is a Barleywine that we put in a bourbon barrel about two weeks ago.


This is the Coconut Porter in the rum barrel.


None of them look super different from each other. I'm not sure if the strands are just debris from the barrel or lacto infection and this is as far as my microscope will zoom.

Thanks again for any help that can be offered.

[UnFermentable]

I have no idea what magnification this is, but I am guessing 100x-150x. And it looks like a slide with cover slip and not a hemocytometer. Not enough to determine much. 400x is best for counting cells and beginning to identify bacteria presence, and a hemocytometer is of great value especially for a magnification reference. Most bacteria is hard to identify without even more magnification. Like 600x-1200x is much better. Methylene blue would be helpful to accentuate the color and make it easier to see.

You should also consider investing in a gram stain kit to help identify bacteria, if you are going down that road. Usually high magnification is enough to see what you need though. It's possible your last example shows something. Differentiating between wild yeast can be more challenging. It's fairly simple to purchase wild yeast media on petri's and swab and incubate for further clarification without a microscope.

Cheap doesn't mean bad, it just needs to have the proper range. See if you can borrow one, or take a sample into a local college and ask a kid/teacher who likes beer. They probably have or will do plates as well. Beer buys a lot of friends!