Technological aspects of the use of hop preparations.
Hop powders and extracts were analyzed and replacement ratios to whole hops were calculated from alpha acid contents but with old preparations or those with high alpha acid, replacement rate was derived from boiling tests giving a "Universal Bitter Value" similar to "Total Realizable Bitterness". Worts were boiled with hops and with hop preparations and fermented. Worts and beers were analyzed for N, coagulable N, anthocycanogens, bitters, head retention, taste and stability. Beers made with hop powder were preferred to beers brewed with whole hops but concentrated hop powder gave insipid taste and best results were obtained by boiling with two thirds replacement of hop powder followed by the remaining one third as concentrated hop powder. Standard hop extract gave a balanced bitterness when bitter content was less than 30 mg/litre. Beer stability and foam capacity was better than beers brewed with whole hops. Again best values were obtained by a first addition of standard extract followed by resin extract of low tannin content. The use of hop preparations gives little financial economy over whole hops but the brewing process can be more easily standardized to give good beers and real process economies are secured. For example no hop strainer is needed and good whirlpool separation or trub can be achieved. Whole hop powders give too great a mass of trub but when combined with concentrated hop powder or low tannin hop extract the mass of trub can be reduced to manageable amount. The myrcene content of hop powder can be reduced by vacuum extraction and extracts from hops high in myrcene should be added at the start of wort boiling.
Keywords: brewing hopping hop product survey