help identifying aftertaste in porters

[silvery37]

Twice now I have found an aftertaste in porters that i am sure is simple but I can't identify. The first was a vanilla porter I brewed and the second is a coconut porter from Maui Brewing.

I would describe the taste as more tart and acidic than standard hop bitterness. It is kind of like the ending taste of Guinness but more subdued. I know my beer didn't have lactic acid and I dont think Maui adds any to their beer. Is this a specific type of hop bitterness or something from a type of grain?

 

[TopherM]

Tart and acidic ending taste makes me think carbonic acid. Have you noticed that this batch is highly carbonated?

Also, did you happen to use a high AA hop or hop this one so the IBUs are out of style on the high side?

 

[zebbielm12]

It's probably just acidity. Highly kilned grains make for a more acidic beer. You need to counter it with bicarbonate or some such.

 

[brycelarson]

What's your gain bill?

Dark roasted grains - especially rye can give some acidic / peppery edge to your beers. I've backed down on Rye and moved to some debittered chocolate malts for my sweeter porters / stouts.