Modeling of α-acids and xanthohumol extraction in dry-hopped beers

The practice of dry-hopping has been used by the brewing industry to obtain beers with increased contents of flavor and bitterness compounds. Notwithstanding this, other compounds such as α-acids (AA) and xhanthohumol (XN) are co-extracted influencing the final characteristics of the beer, particularly its beneficial bioactivity. In this context a model for the understanding of AA and XN extraction by dry-hopping is proposed. The varieties Chinook (CHI), East Kent Goldings (EKG) and Tettnanger (TET) were assayed and robust statistical approaches were applied for data interpretation. Concentration of AA in beers post-maturation reached values higher than 20 mg/L using 2.8 g/L of CHI hops and 10 days of maturation. For XN, a similar behavior was verified. The maximum efficiency of AA and XN extraction (transfer rate) were reached at 13.5 days with dose rates of 147 and 13.9 mg/L, respectively.