Acorn beer: Results, discussion

How'd it come out?

I brought some to the PALE ALES holiday party on Jan. 11, 2016, and the bottles were labeled "Acorn beer — Brown ale with acorns." I received many compliments on the beer, but I always asked, "Do you taste anything unusual?" The answer was "No." A few people mentioned that it had a dryness to the finish that they didn't expect. Maybe I hadn't leached all of the tannin out, and that gives that bit of dry mouthfeel. One person said he tasted a hint of something nutty.

I have to agree. It tastes like a pleasant but not terribly remarkable brown ale. It does have terrific head retention, and a strong chill haze. Maybe the acorns contributed protein.

What would I do differently?

So the cereal mash approach I used didn't give noticeable acorn flavor. These acorns are pretty mild, not just in tannin but in other flavor, too. There is one more thing I would try, which I mentioned earlier: Roast them and soak in the secondary. I may do this, if we get another big crop and I feel I have time on my hands for the shelling.

Just to summarize some points:

• Different oak species (and maybe different trees, seasons, other things?) give acorns with different levels of tannin, the bitter astringent chemicals that should be leached out before consuming. The Eastern white oak in my front yard gave acorns so mild, it wasn't obvious that I needed to leach the tannin out. I did it anyway. The pin oak in my back yard had very bitter acorns.
• The oil level of acorns apparently also varies with species, and maybe other things. The Eastern white oak acorns were not oily. The great head retention I got proves that it isn't a problem, at least for these acorns.
• Mashing the acorns doesn't give much flavor to the beer. In fact with the two pounds in the five-gallon batch I made, a number of people couldn't taste them.