The hops used for brewing are the female inflorescences of Humulus lupulus. On the inside of the cone scales is a cup-shaped gland containing substances valuable for brewing: essential oil, resin, tannic acid and other bitter substances.
The essential oil and the bitter substance give it a flavor and the resin has an antiseptic effect, especially the growth of lactic and putrefactive bacteria.
The purpose of cooking with hops is to precipitate proteins, concentrate and sterilize the whey.
Boil the mash with the hops for 1 to 1.5 hours.