Today in 2004, US Patent 6748849 B2 was issued, an invention of Richard J. H. Wilson and Robert J. Smith, assigned to S.S. Steiner, Inc., for their “Bittering Of Beer.” Here’s the Abstract:

Iso-α-acids and reduced iso-α-acids in their free acids states are converted into mobile resins by the addition of concentrated solutions of alkali metal hydroxides. The products may be used in brewing for the bittering of beer and are most effectively used in an apparatus that automatically blends the product with water and injects the resultant, aqueous solution into beer.