So I've tried using about 30oz of cold brewed medium roast Ethiopian into the bottling bucket of a 5 gallon batch, and the flavor was minimal, and I'm wondering if it's what killed the head retention. So I'm debating on using a dark roast espresso to being out the flavor more, but would this be ok? Do the oils kill head retention? What do you guys use?
When cold steeping, the type of coffee you use is really important. I've made two coffee stouts to date by adding cold steeped coffee. One came out pretty great and the other was bland and underwhelming.
The great one had a really dark, robust coffee (I think it was a Mexican roast) with lots of roasty flavors. The bland one used beans (Sumatran, I think) that had less roasty characters and more acidity and fruity qualities. You could definitely taste the acidity, but it wasn't really the roasty-ness I was hoping for that compliments a oatmeal stout (though I could see it potentially being interesting in a Foreign stout). I spoke with some local baristas about making cold brewed coffee just for drinking in the morning, and most said you should definitely opt for the darker, more robust roasts when cold steeping since less flavor is extracted than a hot brew. I made cold steep coffee out of the rest of the acidic beans mentioned above, and I didn't even really enjoy that on it's own, never mind in a beer, though it's my go-to hot coffee.
Oh...and espresso sounds like it would be delicious, too!!