I was asked a question yesterday that I could not answer. Certainly not the first time. I was talking to a chemist about alpha acids as relating to the hop shortage and he asked me what kind of acids are alpha acids. Hmmmm, well, umpf umpf they are.... I don't know. So I looked in the Fix book and the alpha acid shown is not an acid. It has no carboxyl group. So what acids are they. Just a curious question. Thanks. Happy New Year. Why am I here today?
There are hundreds of compounds that make up hop resin and oil.
..."Alpha acids consist of more than 50% of the soft resins"
..."alpha-acids are a class of compounds known as humulones. They consist of a complex hexagonal molecule with several side chains, with ketone and alcohol groups. Examples include humulone, cohumulone, adhumulone, posthumulone, and prehumulone..."
This and more in a nice write up in BYO by Steve Parkes (March 2002):