Hops are the flowers of the hop plant Humulus lupulus, a member of the Cannabaceae family of flowering plants. They are used primarily as a bittering, flavouring, and stability agent in beer, to which, in addition to bitterness, they impart floral, fruity, or citrus flavours and aromas. Hops are also used for various purposes in other beverages and herbal medicine. The hops plants have separate female and male plants, and only female plants are used for commercial production. The hop plant is a vigorous, climbing, herbaceous perennial, usually trained to grow up strings in a field called a hopfield, hop garden, or hop yard when grown commercially. Many different varieties of hops are grown by farmers around the world, with different types used for particular styles of beer.
Humulus lupulus, the common hop or hops, is a species of flowering plant in the hemp family Cannabinaceae, native to West Asia, Europe and North America. It is a perennial, herbaceous climbing plant which sends up new shoots in early spring and dies back to a cold-hardy rhizome in autumn. It is dioecious.
Myrcene, or β-myrcene, is a monoterpene. A colorless oil, it occurs widely in essential oils. It is produced mainly semi-synthetically from Myrcia, from which it gets its name. It is an intermediate in the production of several fragrances. α-Myrcene is the name for the isomer 2-methyl-6-methylene-1,7-octadiene, which has not been found in nature.
Humulene, also known as α-humulene or α-caryophyllene, is a naturally occurring monocyclic sesquiterpene (C15H24), containing an 11-membered ring and consisting of 3 isoprene units containing three nonconjugated C=C double bonds, two of them being triply substituted and one being doubly substituted. It was first found in the essential oils of Humulus lupulus (hops), from which it derives its name. Humulene is an isomer of β-caryophyllene, and the two are often found together as a mixture in many aromatic plants.
Ocimenes are a group of isomeric hydrocarbons. The ocimenes are monoterpenes found within a variety of plants and fruits. α-Ocimene and the two β-ocimenes differ in the position of the isolated double bond: it is terminal in the alpha isomer. α-Ocimene is cis-3,7-dimethyl-1,3,7-octatriene. β-Ocimene is trans-3,7-dimethyl-1,3,6-octatriene. β-Ocimene exists in two stereoisomeric forms, cis and trans, with respect to the central double bond. The ocimenes are often found naturally as mixtures of the various forms. The mixture, as well as the pure compounds, are oils with a pleasant odor. They are used in perfumery for their sweet herbal scent, and are believed to act as plant defense and have anti-fungal properties. Like the related acyclic terpene myrcene, ocimenes are unstable in air. Like other terpenes, the ocimenes are nearly insoluble in water, but soluble in common organic solvents.
β-Pinene is a monoterpene, an organic compound found in plants. It is one of the two isomers of pinene, the other being α-pinene. It is colorless liquid soluble in alcohol, but not water. It has a woody-green pine-like smell.
Humulus japonicus, known as Japanese hops, is an ornamental plant in the family Cannabaceae. Some authorities have it as a synonym of Humulus scandens.
Alpha acids are a class of chemical compounds primarily of importance to the production of beer. They are found in the resin glands of the flowers of the hop plant and are the source of hop bitterness.
Cannabaceae is a small family of flowering plants, known as the hemp family. As now circumscribed, the family includes about 170 species grouped in about 11 genera, including Cannabis (hemp), Humulus (hops) and Celtis (hackberries). Celtis is by far the largest genus, containing about 100 species.
Prenylated flavonoids or prenylflavonoids are a sub-class of flavonoids. They are widely distributed throughout the plant kingdom. Some are known to have phytoestrogenic or antioxidant properties. They are given in the list of adaptogens in herbalism. Chemically they have a prenyl group attached to their flavonoid backbone. It is usually assumed that the addition of hydrophobic prenyl groups facilitate attachment to cell membranes. Prenylation may increase the potential activity of its original flavonoid.
Xanthohumol is a natural product found in the female inflorescences of Humulus lupulus, also known as hops. This compound is also found in beer and belongs to a class of compounds that contribute to the bitterness and flavor of hops. Xanthohumol is a prenylated chalconoid, biosynthesized by a type III polyketide synthase (PKS) and subsequent modifying enzymes.
When drinking beer, there are many factors to be considered. Principal among them are bitterness, the variety of flavours present in the beverage and their intensity, alcohol content, and colour. Standards for those characteristics allow a more objective and uniform determination to be made on the overall qualities of any beer.
Humulone, a vinylogous type of organic acid, is a bitter-tasting chemical compound found in the resin of mature hops. Humulone is a prevalent member of the class of compounds known as alpha acids, which collectively give hopped beer its characteristic bitter flavor.
8-Prenylnaringenin (8-PN; also known as flavaprenin, (S)-8-dimethylallylnaringenin, hopein, or sophoraflavanone B) is a prenylflavonoid phytoestrogen. It is reported to be the most estrogenic phytoestrogen known. The compound is equipotent at the two forms of estrogen receptors, ERα and ERβ, and it acts as a full agonist of ERα. Its effects are similar to those of estradiol, but it is considerably less potent in comparison.
Isoxanthohumol is a prenylflavonoid, and it is a phytoestrogen. It is abbreviated as IX or IXN.
Lupulone is an organic chemical compound with the molecular formula C26H38O4 and an appearance of a yellow powder which was historically used in beer brewing. However, recent studies have revealed numerous antibacterial and anti-cancer abilities of lupulone.
The chemical compounds in beer give it a distinctive taste, smell and appearance. The majority of compounds in beer come from the metabolic activities of plants and yeast and so are covered by the fields of biochemistry and organic chemistry. The main exception is that beer contains over 90% water and the mineral ions in the water (hardness) can have a significant effect upon the taste.
Research has shown that Humulus lupulus and Cannabis sativa are closely related, and it may be possible to create novel cultivars of hops that express valuable chemicals similar to commercial hemp. Both hops and cannabis contain terpenes and terpenoids; tetrahydrocannabinol (THC) is a terpenoid. Hops lack the enzyme that could convert cannabigerolic acid into THC or CBD, but it could be inserted using genetic engineering as was done in 2019 for yeast.
The United States of America is the world's largest producer of hops, the flowers of female Humulus lupulus plants. The primary use of hops grown in the United States is in brewing. In 2019, the U.S. accounted for 40% of world hop production and 39% of world hop acreage.
