Abstract: A concentrated single phase aqueous alkaline solution of tetrahydroiso-.alpha.-acids having greater than 10% to about 45% w/w tetrahydroiso-.alpha.-acids is disclosed. A method of hydrogenating and formulating a starting solution of iso-.alpha.-acids to obtain such concentrated solutions of tetrahydroiso-.alpha.-acids is also disclosed.

Abstract: A method of making a light stable, hop flavored, fermented beverage of less bitterness having a comparable hop flavor to one prepared using whole hops consists of adding to a wort as the sole hopping material a solid hop residue obtained by extracting whole hops with liquid carbon dioxide, boiling the solid hop residue and wort mixture, removing the solids from the fermented mixture and fermenting the remaining liquid to obtain the beverage.

Abstract: Tetrahydroiso-.alpha.-acids are prepared from iso-.alpha.-acids metal salts by hydrogenating the salts in a reaction solvent of a lower alkanol containing about 5% to about 20% w/w water and in the presence of up to about 5-50 psig hydrogen and a hydrogenation catalyst at about 30.degree.-50.degree. C. to form tetrahydroiso-.alpha.-acids.

Abstract: Tetrahydroisohumulones are prepared from isohumulones by hydrogenating the isohumulones in a reaction solvent of ethanol containing up to about 15% water in the presence of about 1 to about 40 psig of hydrogen and a hydrogenation catalyst to form tetrahydroisohumulones.

Abstract: A method of inhibiting Listeria in a medium comprises adding to the medium an effective amount of tetrahydroisohumulone or hexahydrocolupulone or mixtures or salts thereof to inhibit any Listeria.

Abstract: A method of preparing anactinic hop extracts comprising three stages: pre-purification of a liquid CO.sub.2 hop extract using liquid-liquid extraction to isolate pure humulones or alpha acids; isomerization/reduction of the humulones to obtain a mixture consisting of reduced isohumulones and non-isohumulone light unstable products (NILUPS); then adding alkali and water to the mixture of reduced isohumulones and NILUPS, heating and stirring to extract the reduced isohumulones into an aqueous phase and to leave the NILUPS in an oil phase. The aqueous phase is an anactinic hop extract which can be used to prepare light stable malt beverages.

Abstract: Tetrahydroisohumulones are prepared from beta-acids without using objectionable organic solvents by treating the beta-acids to form desoxytetrahydrohumulones which are dissolved in an aqueous alcoholic caustic solution and then oxidized and isomerized with an oxygen-containing gas in the presence of metallic ion to form the desired tetrahydroisohumulones.

Abstract: Beta-acids are separated from alpha-acids in a hop extract without using organic solvents by bubbling CO.sub.2 through an aqueous hop extract having a pH of about 9.6 to about 13 to lower the pH to about 8.5 to about 9.5 to precipitate the beta-acids and leave the alpha-acids in the extract.