Brewed 11 gallons of this recipe and for some reason it has a nutty and bitter aftertaste that almost makes it undrinkable. I have poured out the last few ounces of the last 2 pints I had! I bottled conditioned for 3 weeks @ 70F.
Mashed at 157F
IBU target of 24
I am always careful on sanitation, never had an issue on 15 batches I've done so far.
I used S04 dry yeast with a 2 Liter starter and pitched the thick yeast slurry from the starter (1/2 cup to each 5.5 gallon fermenter).
I aerated by shaking the fermenter vigorously before and after adding the yeast slurry.
I sanitize using star san and soak anything that will contact my beer in a tub of Starsan.
I really don't think contamination is to blame.
I ferment in a chest freezer using a digital temperature control and the beer temp was in the mid 60's for the entire 21 day fermentation and I didn't bottle until day 28 in primary.
I have no idea what happened or why it tastes like this. I can't really describe the taste but all I can think is that it is very "nutty" and "bitter" with an aftertaste but it is NOT sour at all.
I have 105 bottles of this stuff left and the only thing I can think to do is let it sit in the basement at 70F for another couple months and hope it becomes at least drinkable. I wish I could let an experienced brewer try a taste of this to give an opinion on what it could be.
My recipe was:
66% 2-Row pale
11% flaked corn
4% Pale Chocolate malt
Target Hops @ 60 min and EKG hops @ 15 for 24 IBU based on my calculator for boil volumes.
S-04 yeast with starter