Technological importance of individual hop components
The most important component of hops for beer are α-acids, and among them humulon. They are the most soluble in the wort and most easily transform into the isomerized form. Isomerized α-acids are relatively stable and remain mostly in this form in beer, if they are protected against oxidation during beer technology.
When using fresh hops 2/3 the strength of bitterness in beer is imparted by α-acids, while 1/3 β-acids (β-fraction). The quality of bitterness, so its "nobility" is mainly shaped by bitter β-acids.
In hops grown in our country, the ratio of the α-fraction to the bitter β-fraction is at the level of 1 :1,5.
Bitter β-acids are very sparingly soluble in the wort, and their utilization rate is low. For this reason, they are of less technological importance than α-acids.
γ-acids are not of significant technological importance, because they are practically insoluble in wort and beer. They are formed as a result of the oxidation of α and β-bitter acids (soft resins). The increase in the content of γ-acids proves the old hops, or about poor conditions of its care during storage. Under normal conditions, the amount of γ-acids is 1-1,5% dry hop mass.
Garbniki, whose amount in hops is 3-5%, have a positive impact on the technology and quality of beer. They are more easily oxidized than barley-derived tannins and react more easily with medium molecular weight proteins when boiling the wort. High molecular weight proteins do not react with tannins, however, they contribute to the formation of foam and shaping the flavor characteristics of beer.
Tannin-protein complex compounds formed in beer have a stabilizing - beneficial effect on bitter substances.
Hops oil is a mixture of essential oils, which evaporate in 85% while boiling the wort with hops. WITH 20 known ingredients of hops oil, it is most abundant in terpenes, humulenu and myrcenu, which, in their oxidized form, can give the beer a different aroma. Myrcen is most susceptible to oxidation. It evaporates easily. This ingredient is "responsible" for the pungent smell of the beer. For this reason, a batch of hops of a higher grade is used to impart a pleasant hop aroma to the beer, with a lower myrcene content and stored under the right conditions.
Among other compounds contained in hops, pectins deserve attention, whose content is 12-14%. Of this amount, only a small part passes into the beer and acts as a protective colloid.