Last year I thought I was so smart and creative to replace yellow corn in my two flanders beers with purple peruvian corn. The taste at the beginning was great, and they had a very cool color. I tasted the oude bruin through the fermentation from time to time and it weirdly seemed to be getting MORE bitter. I took my first taste of the flanders red I brewed six or so months ago and it's super bitter.
So I started researching a possible cause of it, and was lead to wine bitterness taint.
Glycerol is reduced by the bacteria in the beer ultimately to acrolein. Acrolein is not bitter on its own but when combined with anthocyanins you end up with a rather bitter combination. These beers taste as if I added a butt load of red grape skins or something they're strong of tannin characteristic.
So hopefully this flavor ages out in a year or so for this one in the bottle. As for the other 6 gal of flanders red, I will be making about 15 gal more very soon (sans purple corn!) and will see if I can blend this into the batch to reduce or make the bitterness drop below perceptible limits.
So I started researching a possible cause of it, and was lead to wine bitterness taint.
Glycerol is reduced by the bacteria in the beer ultimately to acrolein. Acrolein is not bitter on its own but when combined with anthocyanins you end up with a rather bitter combination. These beers taste as if I added a butt load of red grape skins or something they're strong of tannin characteristic.
So hopefully this flavor ages out in a year or so for this one in the bottle. As for the other 6 gal of flanders red, I will be making about 15 gal more very soon (sans purple corn!) and will see if I can blend this into the batch to reduce or make the bitterness drop below perceptible limits.