The hemp plant is one of the few climbing plants whose tendrils wind clockwise (seen from above). North of the Alps, hops was cultivated in monasteries as a potent seasoning and preservative from the 8th century at the latest. Its breakthrough came with the Bavarian Purity Law of 1516, which ensured that beer could only be preserved with hops. Other beer ingredients, such as the psychoactive henbane, have since become a thing of the past.

Wherever there is a temperate climate in Eurasia and North America, the wild form of the hop can be found in riparian forests and forest edges. Hops are dioecious, i.e. there are male and female plants. The latter form scaly fruit clusters ("hop cones"), which ripen at the end of August and beginning of September. The perennial plant is cultivated in hop gardens; one of the world's largest hop-growing areas is the Bavarian Hallertau, also known as Holledau. There, under optimal conditions, the hops grow up to eight meters in height on wires - up to 30 cm a day.

Hildegard von Bingen wrote about hops: "Its bitterness prevents putrefaction." In fact, its resinous, sticky fruit scales are particularly rich in bitter substances with an antibiotic effect; the bitter acids humulone and lupulone make up the largest proportion. Bitter and tannic substances are also responsible for the appetite-stimulating and digestive properties of hops. Other constituents of hop cones are effective plant pigments (flavonoids). Some newer hop varieties contain fewer bitter substances and more essential oils ("aroma hops").