EVALUATION OF HOPS: IX. FLAVOUR OF HOP OIL CONSTITUENTS

The presence of whole hop oil in water is detectable by taste at a concentration of 1-0 p.p.m. In beer, a concentration of the whole oil of 3 p.p.m. but not I p.p.m. is recognizable. The oxygenated compounds present in the oil affect the flavour of beer when only 0–3 p.p.m. is present, while 0–1 p.p.m. of the volatile fraction of this material in water is sufficient to be noticed by tasters. Work using steamed hops suggests that the main flavouring effect of dry hopping is due to the essential oils.