Abstract: A hopping material useful as a kettle additive in preparing anactinic malt beverages is prepared by a method which includes first forming an aqueous suspension of crude hops, containing alpha acids and cellulosic material and alkali hydroxide and an alkali borohydride. The suspension, which has a pH above about 10.5, is heated to isomerize and reduce the alpha acids initially present in the hops. The pH is lowered to about 2 to convert the reduced iso-alpha acids to their free acid forms so that they are adsorbed on cellulosic hop material in the reaction mixture. The cellulosic material which now contains the free isomerized and reduced alpha acids is isolated and is useful as an anactinic kettle additive which can be stored for prolonged periods with no decomposition.