When I ask people to name their favourite tea, most opt for green. There are several possible reasons for this. It may be because the word "green" is associated with things that are fresh, natural and light; but more likely it's that much research has been done on the health benefits of green tea, and that news of this put about by advertising companies - and financed by big brands - has boosted the image of the variety. Green is the oldest of the teas, having been drunk for 5,000 years. Back then it was recorded as being a bitter drink that had medicinal effects. "Green" refers to the colour of the leaves, not that they are freshly picked from the shrub. There are different ways of keeping the leaves green, including steaming and frying. The popular Japanese green tea, matcha, is derived from a processing method developed during the Song dynasty (960-1279) by which the leaves are steamed and dried, then ground into powder. To prepare this tea, one or two teaspoonfuls of powder are put into the centre of a big bowl, hot water is poured in and the liquid is stirred with a bamboo whisk for a minute or so. The well-known Longjing, or Dragon Well, green tea from West Lake, Hangzhou, Zhejiang province, is processed using a hand-frying technique. Small batches of fresh leaves are thrown into a wok-like pan and fried multiple times, during which a master roaster stirs and presses the leaves with his bare hands. The leaves end up being sword-like in shape. There is also the lesser known, but ancient, method of sun-drying, whereby fresh leaves are laid in thin layers to dry and are not pressed or rolled, so they retain a natural form. No matter which method is employed, the idea is to use heat to stop the oxidation of fresh leaves. Green tea contains a variety of enzymes, amino acids, carbohydrates, lipids, sterols, polyphenols, carotenoids, vitamins, phytochemicals and dietary minerals. Of those, polyphenols are discussed the most, due to their antioxi-dant properties, which detoxify cell-damaging free radicals in the body. The most antioxidant polyphenol, a catechin called epigallocatechin-3 gallate, which may contribute to the reduction of cardiovascular disease and prevention of diabetes, is plentiful in green tea and largely responsible for its bitter taste. To minimise the bitterness, brew the tea using a lower temperature range, say 65 to 85 degrees Celsius, rather than at boiling point. Although green teas are full of health benefits, they are "cooling" in traditional Chinese medicine terms, so might not be suitable for everyone. Try not to drink green tea on an empty stomach as it will bring down blood sugar content very quickly and you may experience dizziness. If that happens, try eating milk candy, such as a White Rabbit sweet or two. There is a general perception that the lighter the tea, the lesser the caffeine. An average cup of green tea has about 40mg of caffeine, much less than the average cup of brewed coffee, which contains 100mg. However, if you are sensitive to caffeine, it would be wise to avoid both. Vivian Mak is the founder and owner of the MingCha tea company www.mingcha.com.hk.