Absolute Configuration of Beer′s Bitter Compounds

During the beer brewing process, bitter tasting cis and trans iso-α-acids are generated from the precursor α-acids found in hops. The absolute configurations of the α-acid (−)-humulone and several of its derivatives have now been elucidated by X-ray crystallography, thus resolving decades of confusion over the humulone isomerization mechanism. The science and art of making beer, likely the oldest liquid fermented by humans, stretches over...