Today in 1975, US Patent 3923897 A was issued, an invention of Leonard R. Worden, assigned to the Kalamazoo Spice Extract Co., for his “Production of Hoplike Beverage Bittering Materials.” If the Kalamazoo Spice Extract Co. sounds familiar, that’s where Firestone Walker brewmaster Matt Brynildson worked as in intern in college and then as his first job afterwards, as a hop chemist. Here’s the Abstract:

Production of hoplike beverage bittering materials by the peracid oxidation of 3′,5′-dialkyl-2′,4′,6′-trihydroxyacylphenones to 6-acyl-2,4-dialkyl-2-hydroxycyclohexane-1,3,5-triones (tetrahydrohumulones or tetrahydro-alpha acids) and isomerization thereof to 2,4-diacyl-5-alkyl-4-hydroxycyclopentane-1,3-diones (tetrahydroisohumulones or tetrahydroiso-alpha acids).