Trying to identify flavor in Goose Island Fleur

Ingredients
1

I had a bottle of Fleur last week and it has a mild bitter aftertaste that I believe is unrelated to the hops.

I recognize this flavor from a batch of Belgian I made that went very wrong.  In my case, I cultured some yeast from a couple bottles of Orval and made a big starter.  The final beer, while beautifully golden in color with a nice rocky head, was undrinkable due to an overwhelming bitter aftertaste.  I poured it out with tears in my eyes.

Does this sort of flavor come from the brett?

Does anyone know if Goose Island uses brett at all in Fleur?  It does not say on their website.

I know it’s hard/impossible to identify a flavor on-line, but perhaps someone can help.  It would be nice to put to rest what went wrong with that ol’ batch of mine.

FTR - I have no real experience using brett, so wouldn’t know what to expect.

2

I’m not sure but it’s possible.  Are you sure you mean bitter?  I didn’t think Fleur was bitter at all?

3

It’s something in the aftertaste.  I perceived it as bitter.

I have another bottle that I’ll taste perhaps later today.  I suppose I should go get some Orval and taste that, too.

4

I doubt it could be from Brett (if it’s even in there), but it’s hard to tell based on your description. Could it be an ester or phenol that you’re perceiving as bitter? Brett will kick off plenty of those.

Keep in mind that while Orval has a class Brett profile, it’s also quite hoppy, both in bittering and late additions.

I just looked up the beer on their website, and it says that it has Kombucha in it. Could it be tannins or lactic acid from that?

5

has to be the kumbucha that they put in it.