The analysis of resin fractions provides hop extract processing plants with information regarding their yield during operational testing and enables inferences to be made regarding how processing affects the quality of the final product. Resin fraction analysis provides the industry not only with a value for the amount of the bitter substances in the product but also information about the hop variety from which the extract was produced, its provenance and age, in addition to information about the product type. However, measuring hop additions based solely on the conductometer value can, in some cases, lead to substantial differences in the bitterness of beer produced using them.
Hop extract 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.