EFFICIENT ONE-STEP PREPARATION OF THE BEER ADDITIVE TETRAHYDROISO ALPHA-ACIDS

alpha-Acids from hop extracts are simultaneously isomerized and hydrogenated to yield tetrahydroiso alpha-acids, an important additive in beer. The alpha-acids can also be sequentially isomerized and hydrogenated to tetrahydroiso alpha-acids, provided the hydrogenation is done between pH 6.0 and pH 11.0. The process is ideally suitable to scale-up and is more cost effective than any other route. The product has a higher purity than material produced by use of other reported methods. Hexahydroiso alpha-acids, a related beer additive, are also prepared in one step from alpha-acids.