Hop extract intended for use in beer brewing or elsewhere in the food industry
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
Hop constituents are distributed between an aqueous acidic methanolic phase and diethyl ether. Hop bitter substances extracted with ether are subsequently separated according to their different solubility properties in cold methanol and hexane into fractions: total resins, soft resins and hard resins. The soft resins are further separated according to their capacity to form complexes with lead salts into α-acids (conductometer value) and a β-fraction.
This method describes how to determine the hard resin fraction in hops and hop products; for the procedure, refer to the MEBAK method R-300.03.901 [2016-03].
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
The hard resins are calculated by subtracting the soft resins from the total resins. This yields the hard resin content as a percentage of the total resins.
Applicable for all (laboratory) worts
Medium and high molecular weight proteins are precipitated by phosphomolybdic acid. The nitrogen is determined in the filtrate. Therefore, the results express the amount of low molecular weight proteins.