The Riddle of Bitterness

Scientists long ago figured out the mechanism through which hops turn beer bitter: the alpha acids in the lupulin glands become isomerized over the boil–a process that allows the bittering compounds to become soluble. There’s a mathematical curve that demonstrates the process, and the amount of bitterness is a direct function of alpha acids plus boiling time. This all beer geeks know.

But

from Beervana http://beervana.blogspot.com/2017/03/the-riddle-of-bitterness.html