The Ginger Plant (Adrak) is native to India and China, and is used in many forms. The part which is used is commonly called ginger root although technically it is the rhizome that is used; this is an underground stem from which roots and shoots grow (you can actually grow your own from a piece of this rhizome and many Indians do).
It comes from the same family of plants as cardamom and turmeric. It has a quite sweet, pungent smell and the taste is distinctly fiery. The chemical which makes it hot is called (wait for it) gingerol and is a relative of capsaisin which is what makes chillis hot.
Oil can also be extracted from the rhizome; for this the ginger plant is generally grown longer than if growing for cullinary use as the oils build up more.
The botanical name Zingiber officinale takes it name from a sanskrit word meaning 'like an antler' although nowadays you buy a 'hand'.
The first uses of the ginger plant were medicinal - by the Indians and Chinese more than 5000 years ago when it was considered to be a cure for pretty much everything. It was certainly known to the Romans and, since it is mentioned in the Koran, must have been known to the Arabs of about 650AD.
It was traded by the Arabs as early as the 13th century and was, like most spices, a valuable commodity (it was said that one pound of ginger was worth one sheep). It was probably known of in England before 1066 - brought here by the Romans and was certainly known to Tudor England - there is a story (probably an urban myth) that Queen Elizabeth I invented gingerbread men.
The ginger plant made its way to the Caribbean in the 16th century and as it spread around the world it was cultivated wherever conditions permitted (it can actually grow in lots of places but a sub tropical climate is best); in no time at all Jamaica was exporting it back to Europe.
It is only relatively recently that it has been used as a common spice rather than as a medicinal herb.
It comes in many forms. What we normally refer to as 'fresh ginger', the stuff you get at the local supermarket is part of the mature rhizome, this is the type you will find in most kitchens. There are some oriental groceries where you can buy really fresh root which is immature and a pale green colour, this has a really fresh zingy taste but is quite rare. Fresh ginger is peeled and usually cut into very small dice or thin strips; you can also pound it in a mortar and pestle with a little water to make a paste (or you can say to hell with tradition and use a blender or grinder!).
When buying you should look for smooth firm pieces that don't bend and it can be kept for about a month in the fridge, at room temperature it will start to lose it freshness after about a week. I'm not sure why you would do this but ginger also freezes well and keeps almost indefinitely (perhaps if you were offered a job lot under some weird circumstances)
The other main form that ginger is used is powdered. To produce this the rhizome is boiled, scraped and dried then ground into powder. This is then used in curry powders and individually in many Indian dishes including pickles and chutneys; it is very good with lentil dishes .
The ginger plant also provides other forms such as 'stem ginger (boiled and in a heavy, sugary syrup), crystallized (like stem but then dried and coated in sugar), and pickled (like you get with sushi). You can also buy it dried but I never have so I can't tell you much about it.
Not huge in the vitamin department but has a lot of Vitamin E, some B6 and other B vitamins. It also has loads of manganese as well as potassium, iron, calcium and selenium. The roots have lots of dietary fibre and is good for a range of amino acids.
Medicinally the ginger plant has been used for a whole load of things. Most notable is its use in digestive remedies; it helps with stomach cramps, diarrhoea and indigestion, it has also been recommended for morning sickness and motion sickness. There is probably a lot of truth in most of this as it is very anti-inflammatory and is known to increase saliva and gastric juice production and therefore helps breakdown fatty acids and proteins.
The anti-inflammatory properties are also useful in treating arthritis, rheumatism and fevers. (I make a sort of tea with strips of ginger, lemon and hot water when I have a cold).
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