There are many varieties of hops used in the brewing of beer. This article discusses some of the differences between different hop varieties, and the articles listed below give more details about particular varieties.
 What is a hop variety?
There are two factors that can affect a hop's use in beer: genetics and the environment. Traditionally, hops were referred to by names that gave information about both factors.
 Hop cultivars
Like most other cultivated plants, the hop plant is available in many different cultivars, or cultivated varieties. These cultivars have specific genetic traits that affect the hop cones and growth. The cultivar is the most important determinant of the hop's alpha acid content and basic flavor characteristics.
 Terroir and landrace hops
The growing environment, including the length of the season, the temperature and weather conditions, and the composition of the soil and water, also affect hops, as they do most other plants. As in wine making, the combination of these unchangeable factors associated with a specific growing region is known as terroir.
A hop which has, through a long history of cultivation in a particular area, become particularly well suited to that area, is known as a landrace. Landrace hops are older, open pollinated varieties, since the natural selection process requires time and some genetic variation to gradually suit the hop to the terroir.
While any hop's character will be affected by terroir, landrace hops are considered especially sensitive to changes in growing conditions, and they often are thought to display their prized characteristics only in their native soil.
 Hop variety nomenclature
Because the cultivar and the terroir are both critical to the character of the hop, especially with traditional landrace hops, traditional hop names include both elements.
This section is a stub.
 Hop variety categories and attributes
Hops can also be divided into categories based on attributes other than cultivar and terroir. These include the way they are used by brewers; their genetic heritage and fertility; and the height to which they grow.
 Bittering and aroma hops
Hops are commonly referred to as falling into one of three categories, bittering, aroma or finishing, or dual-purpose, based on the way they are commonly used by brewers.
Hops contribute three elements to beer: bitterness, hop flavor and hop aroma. Most brewers prefer to add hop bitterness from hops high in alpha acid. This requires buying fewer hops, which saves money. Using fewer hops in the boil also which reduces the amount of wort absorbed by the hops and the amount of trub. Some brewers also feel that high alpha acid hops also give a cleaner bitternessto the finished beer. On the other hand, in finishing applications, alpha acid level is much less important, and the flavor and aroma characteristics of a particular hop depend more on its levels of hydroocarbons, especially myrcene, humulene, caryophyllene and farnesene.
If a hop has sufficiently high alpha acids to be practically used in bittering applications and a pleasant flavor and aroma suitable for late hop additions and dry hopping, it is referred to as "dual-purpose" or "dual-use" hop. Hops which have a coarse or harsh character when used in late additions, as many high-alpha hops do, are referred to as "bittering" hops. Hops which are not suited for use in bittering, because of their low alpha acid levels, unpleasant bittering character, expense, or some other factor, are referred to as "aroma" or "finishing" hops.
However, this distinction is to some extent a creation of the modern brewing industry. Many traditional beer styles use only a single hop variety for bittering and aroma, usually a variety now considered and "aroma" hop, such as Czech Saaz in Bohemian pilsener, and some hops which were once considered "bittering" hops were discovered to have interesting and distinctive characters when used in late additions, such as Pride of Ringwood. A homebrewer should not let the label on a hop deter him or her from experimentation.
 Pollination and polyploidy
This section is a stub.
 Full-size and hedgerow
Traditional hop bines can grow as high as thirty feet high, and hops grow best when allowed to grow almost straight up. This means that extensive scaffolding must be prepared, and special ladders and equipment must be used to harvest them.
Recently, British hop growers have begun experimenting with hops bred to be shorter, known as hedgerow hops or dwarf hops. These hops grow to heights of 10 feet or less, but produce the same hop yield as conventional plants. This allows them to be grown, harvested and processed more cheaply and easily and with more automation.
Originally known as "dwarf hops", British growers are now attempting to rebrand these varieties as "hedgerow hops". They have quickly been adopted by many English growers, and hop products and, in the case of Summit, rhizomes, are beginning to be available to homebrewers. Many in the industry feel that because of the superior economics for growers, hedgerow hops will replace a significant amount of current hop production.
 Specific hop varieties and subcategories
The hop variety pages below contain more information on specific hop varieties, including their history, genetic heritage, chemical composition, and use in brewing. The subcategory pages include links to hops which share a particular origin or characteristic.
For a complete list of hop varieties, including those with no entry in the Home Brewing Wiki, see the List of hop varieties by country of origin.
This category has the following 21 subcategories, out of 21 total.
Pages in category "Hop varieties"
The following 99 pages are in this category, out of 99 total.