Hops are an herb mostly known for their use in flavouring beer. They provide both bitterness and aroma. Beer made without hops will taste "fruitier."
Hops are also a preservative. They allow weaker alcohol content beers to have a longer storage life.
Hops are a member of the hemp family: they are related to marijuana and stinging nettles. They grow on perennial vines that die back to the ground each year. Underground, the plants have rhizomes and a crown.
The vines don't have tendrils, like peas. They have to be trained, and they need support to grow on early or they may stop growing. When happy, they can grow as much as two feet (60 cm) a week. They are often grown up 18 foot (5 1/2 metres) trellises.
By the end of June, as daylight hours start to shorten, they'll stop growing upward and start to branch out. The stems have sharp hairs that can irritate the skin. The branches (called "bracts") bear the flowers. A Hops vine won't produce many flowers in the first year of growth, as the plant is establishing its root system. It starts being productive in its second year.
The flowers can be 1 to 2 inches (2 1/2 to 5 cm) long, and 1/2 inch to 1 inch (1 to 2 1/2 cm) wide. They are pine-cone shaped, and hang down in clusters. They have green scales on it ripening to yellowish. They have a papery feel when ready to harvest.
There are male and female Hop plants; it's the flowers from female plants that are harvested. A Hop vine is usually grown from cuttings from their rhizomes, so that growers can be sure to be planting lots of female plants. Hops will grow from seed, but it's a crap shoot as to how many of the plants will be female and how many male.
The flowers are usually seedless, because male plants (needed for pollination) are not planted.
At the bottom of each scale on the flowers are small yellow glands that look like pollen dust. These glands contain the flavouring ability of Hops, which is alpha acids, aka a-acids or "humulones", which give most of the bitterness in Hops. There are also beta acids (aka ß-acids or "lupulones") which also add some bitterness. Analysing the acids in hops is done by High Pressure Liquid Chromatography in labs. There are also tannins and oils in the flowers. The oils give aroma; the tannins along with the beta acids help act as a preservative. The balance of these four items -- alpha acids, beta acids, tannins and oils -- in hops depends on the variety of hops being grown.
There are many different cultivars of Hops. Some give more aroma, some give more bitter. Hops used for bitterness are boiled with the wort; hops for aroma are added towards the end of simmering. These aroma hops are also called "finishing hops."
For use in brewing, the flowers are dried, and often pressed into one of two types of shapes:
- Plugs: dried hops are loosely pressed into a shape, generally weighing about 1/2 oz / 15 g. When boiled, they come apart into loose flowers again;
- Pellets: Hops are ground to a fine powder, then pressed into pellets.
Hop shoots are edible. They are available for about three weeks in the spring. Efforts are now being made to revive their use as a vegetable (see History below.) Aroma hops are less bitter to eat.
The centre of hops production in America is the Pacific Northwest. On the eastern coast, Hop crops are susceptible to a downy mildew.
- Aroma Hops: Backa, Bramling Cross, Cascade, Challenger, Columbia, Crystal, East Kent Golding, Eastwell Golding, Elsasser, Ultra, Elsasser, Fuggles, Hallertau (all varieties), Hersbrucker, Liberty, Lublin, Mount Hood, Progress, Saazer, Spalter, Strisselspalt, Styrian Golding, Tettnang, Willamette (sic)
- Bittering Hops: Brewer's Gold, Bullion, Centennial, Chinook, Cluster, Eroica, Galena, Northern Brewer, Nugget, Perle, Pride of Ringwood
- All-Purpose Hops: Aquila, Banner, Blue Northern Brewer, Northdown, Olympic, Saxon.
The Romans grew Hops in England, but they disappeared from England after the Romans.
Hops were being used in a few places in beer by the 1100s. Previously, "gruit" was the normal thing to flavour beer with. In some places, the Church had the rights to produce gruit, and so resisted the introduction of Hops.
Hops started to supplant gruit in the 1300s. The first Hops since Roman times were planted in England in 1428. Henry VIII tried to stamp out their usage in 1524. By 1536, though, Edward VI, abandoned his predecessor's attempt to discourage their use.
Hops were introduced into America in 1629 by the Massachusetts Company.
Literature & Lore
Hildegard (16 September 1098 – 17 September 1179) was a Benedictine nun who lived in St Ruprechtsberg, near Bingen. She is perhaps more properly known as "Hildegard of Bingen", as she was never officially designated an Abbess by the Church. Her name in German was actually "Hildegard" or "Hildegard von Bingen" (without the "e"). Though, because she lived in Latin, she was also referred to as Hildegardis Bingensis. She is sometimes referred to as a Saint, but though she was beatified, she was never canonized.
In any event, the error concerning Hildegard and Hops may have begun with the book "Hops—A Millennium Review"  by Michael Moir. Moir writes:
"Corran , however, in his classic history of brewing, believes that hops were not used in brewing for over 200 years after that first garden was established in the Hallertau, stating that not until 1079 do we hear of hops being used to make beer. This is, in fact, a reference to a passage written by Abbess Hildegarde of St. Ruprechtsberg, near Bingen, in her Physica Sacia, which mentions a vat of beer being boiled with grug, and also with myrtle berries, ash leaves, and hops."
Hildegard, though, never wrote a book called "Physica Sacia."  And she wouldn't have been making beer with hops in 1079 -- 21 years before she was born.
She does, however, mention hops in her book "Physica, sive Subtilitatum" (written between 1151 and 1158.) She talks about its preservative powers: "putredines prohibet in amaritudine sua" (spoilage is inhibited by its bitterness.) Later in the same book, she mentions "if you want to make beer from oats without using hops...", which implies that hops were being used in beer at the time.
If you see a reference to Hildegard and "Physica Sacia", it is people quoting this Moir reference (or each other) without stopping to check a bibliography of Hildegard's actual works.
 Moir, Michael. "Hops—A Millennium Review". Scottish Courage Brewing Limited. 2000.
 Corran, H. S. A History of Brewing. David & Charles, Newton Abbott, England, 1975.] [Ed.** He attributes his source for this to Patton, J. Additives, Adulterants and Contaminants in Beer. Patton Publications, Barnstaple, England, 1989.]
 Among the many books she wrote, she wrote one called "Physica, sive Subtilitatum diversarum naturarum creaturarum libri novem" (written between 1151 and 1158), and one called "Scivias seu Visiones."
HerbsAngelica; Angostura Bark; Bay Leaf; Borage; Chamomile; Chervil; Chives; Comfrey; Curry Leaves; Dill; Dried Herbs; Epazote; Filé; Folium Indicum; Garlic Greens; Green Garlic; Gruit; Herbes Salées; Herbs; Hops; Jacob's Ladder; Lady's Bedstraw; Lavender; Loroco; Lovage; Marjoram; Mexican Tarragon; Mint; Mugwort Powder; Oregano; Pennywort; Potherbs; Rolling Mincer; Rosemary; Rue; Sachet Bags; Sage; Salad Burnet; Sarsaparilla; Sassafrass; Savoury; Screw Pine Leaves; Shiso Leaves; Silphium; Sorrel; Stevia; Sweet Cicely; Tarragon; Thyme; Trefoil; Valerian; Wild Garlic; Winter Purslane; Wormwood; Yarrow; Yomogi
Please share this information with your friends. They may love it.