HOP

Humulus Lupulus

Hemp Family [Cannabaceae]

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flower
flower8green
 
inner
inner8yellow
 
petals
petalsZ10
 
stem
stem8angular
 
smell
smell8aromat
aromatic

24th Sept 2009, Swinton, Gtr M/cr. Photo: © RWD
The Hop cones form from the female flower after the separate male and female flowers (on the same plant) have flowered. The stem winds clockwise around any support.


24th Sept 2009 Swinton, Gtr M/cr. Photo: © RWD
The light-green cones hang downwards, each on their own stem. The leaves are coracle toothed.


24th Sept 2009 Swinton, Gtr M/cr. Photo: © RWD
The cones have several faint lighter-coloured veins.


24th Sept 2009 Swinton, Gtr M/cr. Photo: © RWD
There are four sepals behind the cones.


24th Sept 2009 Swinton, Gtr M/cr. Photo: © RWD
The inside of the cone is fairly secret.


24th Sept 2009 Swinton, Gtr M/cr. Photo: © RWD
The leaves, which may be either palmate, or nettle-shaped, come off a main stem in pairs at right-angles, the underside much lighter than the dark upper surface of the leaves.


24th Sept 2009 Swinton, Gtr M/cr. Photo: © RWD
The dark-green stems are angular, with reddish ridges which accommodate very short spines all pointing backwards to help it climb.


24th Sept 2009 Swinton, Gtr M/cr. Photo: © RWD
The upper surface of the dark-green leaves also has a rough one-way tactile texture.


17th May 2009, Bury, Gtr M/cr. Photo: © RWD
Goldings hops have light-green leaves. Neither flowers nor hop cones have yet grown. The number of lobes on a leaf of Humulus Lupulus varies from one, three, or five on the same plant, the larger leaves having five. (Humulus Japonica has five to seven-lobed leaves)


Uniquely identifiable characteristics

Distinguishing Feature : The aromatic light-green cones that hang downwards after flowering.

Hop is a climber without tendrils, it climbs by wrapping itself clockwise around a supporting branch or stem of any other plants nearby aided by the stiff short backwardsly directed spines on the stems. This mode of climbing is represented by the word bine; therefore it should be known as Hop bine, rather than Hop vine. Vines climb by the use of tendrils and suckers, which Hop bines lack.

The stems are angled, with very short rough spines facing one way which helps it to cling on to whatever stems it is climbing up.

Hops are used as the main aromatic flavouring element in ales, beers, lagers, stouts, entires, porters and some other alcoholic drinks. It is hops which impart the bitterness to bitter. Fresh green cones are usually used for the best beers. There are many varieties grown commercially, especially in Kent, but also in other parts of the world especially for lagers.

The following is a list of all hop varieties grown commercially for the brewing trade: Czech Saaz, US Saaz, Tettnanger, German Tettnanger, Cluster. Styrian Gold, Suoper Styrian, Strisslespalt, Spalt Select, US Spalt, German Spalt, Kent Golding, US Hallertau, Perle, Progress, Liberty, US Hersbruck, German Hersbruck, Lublin, US Fuggle, British Fuggle, German Mittelfruh, Galena, Mt. Hood, Cascade, German Tradition, Huller, Willamate, Crystal, Challenger, Target, Pacific Gem, Brewer's Gold, Pride of Ringwood, Northern Brewer, Northern Brewer Hallertau, Columbus, Centennial, Nugget, Eroica, Chinook and Bullion. All have differing proportions of the main flavour components, both good and bad, many of which are shown below.

Along with Hemp, Hop is the only (UK) member of the Hemp Family.


Myrcene is an olefin monoterpene that is contained in plants of Genus Myrcia (with no representation in the UK), Verbena, Hop, Hemp and Bay Laurel. It has a pleasant odour and is used in perfumery. Although myrcene has a high presence in hops, up to 30%, it is highly volatile and does not usually survive in the finished beer, although its degradation and oxidation products such as linalool, geraniol and geranyl isobutyrate do. Linalool is a terpene alcohol with a floral slightly spicy smell found in many plants including the peel of citrus fruits and especially in Lavender and used as a scent in perfumery, soap and toiletries, and as an insecticide for fleas and cockroaches. Farnesene is a green sesquiterpene found in the skin of Apples and is responsible for their greenness and odour. Damage to the fruit results in the release of Farnesene contained within cells, the subsequent oxidization of which turns the fruit brown. It acts both as an insect repellent and pheromone. Potatoes and other similar species synthesize Farnesene as an insect repellent. Farnesene is also volatile and degrades into innumerable other compounds during brewing. All three are present in Hop and Hemp.

Humulene otherwise known as alpha-Humulene, is a caryophyllene, this time a mono-cyclic sesquiterpene. It is present in Hop and Hemp, contributing to their aroma, taste and bitterness. humulene has a greater percentage in noble hops than myrcene, but it too degrades during the boiling process in beer production, the oxidation products of which survive, imparting several desirable characteristic flavours to the finished beer. Caryophyllene, otherwise known as beta-caryophyllene is a bi-cyclic sesquiterpene found in Hop, Hemp, Rosemary, Cloves, Caraway, Origano and also contributes to the spiciness of Black Pepper. Amounting to between 5% and 15% in hops, caryophyllenes oxidation products contribute to the herbal spicy flavour of beer.

All four of the above compounds, humulene, carophyllene, farnesene and myrcene are present to various percentages in hops and contribute to desirable flavours, aromas and sensations in ales. These compounds constitute the major constituents of the essential oils of hops, of which there are over 300, including the terpene alcohol linalool at 1%.

Related to Humulene and Farnesene are the Alpha-acids which is why Humulene is sometimes referred to as Alpha-humulene, whereas the Beta-acids are related to Caryophyllene, sometimes called Beta-caryophyllene for much the same reason. The alpha- and beta-acids are the resins in hops, as opposed to the essential oils mentioned above.


Alpha-acids

Beta-acids
The alpha-acids humulone, cohumulone and adhumulone are present in hops. They are not very soluble in water, but during the wort boiling phase of brewing are and are converted to the much more soluble and bitter compounds cis-isohumulone and trans-isohumulone. The cis- and trans- forms of isohumulone are in chemical equilibrium and contribute much to the bitterness of beers. The beta-acids lupulone, colupulone and adlupulone are also present in hops but are much less bitter than their alpha-equivalents, tend to precipitate out in the wort and are partially oxidised in the brewing process to become delta-acids (hulupones). The products of oxidation of beta-acids do influence the taste and aroma of beer but to a much lesser extent, and are not present in hops themselves so have no representation here.

Prehumulone, Posthumulone, prelupulone and postlupulone are also acids found in hops. All the acids are fairly weak acids, having a pH of around 5.

minor Alpha-acids

minor Beta-acids
Prehumulone and Posthumulone are minor-constituent alpha-acids that still contribute towards the taste of ales. Prelupulone and Postlupulone are minor-constituent beta-acids.

The sesquiterpenes Cardinene, Muurolene and Selinene, which are present in hops, may also contribute to the flavour of beer in ways not fully understood.

AROMA & TASTE PROFILES OF ALES

The aroma profile of beers is multi-dimensional and attempts to measure the various proportions (on a sliding 0-4 scale) of the following: Alcohol/Solvent, DiMethylSulphoxide (DMS), Other Sulphur, Cereal/Grainy, Malty, Woody, Fresh Hop, Grassy, Herbal, Spicy, Floral/Scented, Pear/Apple, Citrus Fruits, Soft Fruits and Tropical Fruits aromas.

The taste profile of beers is also multi-dimensional, attempting to determine the various proportions (on a sliding 0-6 scale) of the following tastes: Alcohol/Solvent, DiMethylSulphoxide (DMS), Other Sulphur, Cereal/Grainy, Malty, Woody, Fresh Hop, Grassy, Herbal, Spicy, Floral/Scented, Pear/Apple, Citrus Fruits, Soft Fruits, Tropical Fruits as well as extra items not in the aroma profile: Linger, Body, Astringent, Mouthcoating, Sour, Bitter and Sweet.

Various characteristics are undesirable, such as 'DMS' or 'Other Sulphur' smells. Woody I like! Some beers taste a little like oak-matured whisky. Excellent! Strange no mention of Peaty. I like peaty too!

ANY TEXT GOES HERE


Distribution
 family8Hemp family8Cannabaceae
BSBI maps
genus8Humulus
Humulus

HOP

Humulus Lupulus

Hemp Family [Cannabaceae]