Abstract: A method for the production of an isomerized hop preparation comprises mixing together hop extract with a solid alkaline or alkaline earth metal salt, and subjecting the resulting mixture to a temperature of at least 80.degree. C. for a time sufficient to effect conversion of .alpha.-acid to iso-.alpha.-acid. The method may be a stage in a process for brewing beer or the isomerized hop preparation may be further processed to produce high purity isomerized extracts.

Abstract: A barrier cross-flow separation method is used to separate wort from mash in beermaking. The separator medium is preferably a cylindrical element with an internal diameter of at least 20 mm and a pore size in a range of from 10 .mu.m to 100 .mu.m. High gravity wort is obtainable from a four-step separation process which can handle mash free of husk and including large amounts of cereal adjunct. The wort may be clarified in a subsequent filtering step.

Abstract: A method for the production of isomerized hop preparations comprising admixing whole or powdered hops with a solid or aqueous alkali or alkaline earth metal salt. The invention provides that the resultant admixture is simultaneously subjected to a pressure of at least 2 Kg/cm.sup.2 and at a temperature of at least 80.degree. C. in a closed vessel, thereby to form a hop preparation high in iso-.alpha.-acids and with substantially undegraded hop oils. The closed vessel is preferably an extrusion cooker.

Abstract: Hop extract containing a high proportion of a desired constituent, hop oil, .alpha.-acids or .beta.-acids, is formed by extracting hops with pressurized fluid carbon dioxide, collecting separate fractions of the extract obtained at different times, and selecting the fraction having a high proportion of the desired constituent. Fractions containing (a) at least 70% of the available hop oil at at least 10% concentration, and (b) at least 25% of the available .alpha.-acids at at least 55% concentration, may be obtained in a single process by extracting initially at a lower temperature in the range 0.degree. C. to -57.degree. C. and subsequently at a higher temperature in the range -5.degree. C. to 31.degree. C.

Abstract: A method of preparing a hop extract is described in which liquid carbon dioxide is passed at a temperature of from -5.degree. C. to +15.degree. C. through a column of hop material to extract .alpha.-acids contained therein. The method gives a primary extract which is of much higher purity than has been previously described particularly in comparison to presently commercially available solvent extracts.