Influence of the drying process of Cascade hop and the dry-hopping technique on the chemical, aromatic and sensory quality of the beer

Drying techniques are important for hop storage and quality. The stage of hop addition in beer is another important issue. This study focuses the impact of two drying techniques [freeze-dryer (F) and hot-stove (H)] of Cascade hop, on the chemical, aromatic and sensory quality of beer, comparing beers produced without (BF and BH) and with dry-hopping technique (BFDH and BHDH). Dry-hopping with H significantly increased the bitterness index and reduced the titratable acidity. Isoamyl acetate (450.60 mu g/L) and ethyl caprylate (313.60 mu g/L) were in high content especially in BH while, ethyl-n-caproate (359.37 mu g/L) had the highest content in BF. The beers made with dry-hopping technique, had a significantly higher content in terpenes especially in BFDH (1006.18 mu g/L). Sensory evaluation indicated difference preferences, with freeze-dried hop beers generally favored. In conclusion, depending on the type of beer desired, hops dried in different way and a specific hopping technique can be chosen.