Tea, like coffee, is stimulating because of its caffeine content. Tea remained unknown to the Western world until the sixteenth century, when European explorers who traveled to China and other Far Eastern countries returned with a host of new foods, spices, and beverages. Very soon a thriving commerce in China teas was established between Europe and the Far East. In 1826 the Dutch established plantations on Java, followed some ten years later by the British, who set up tea estates in India. The production of tea has since spread rapidly to regions in Sri Lanka, Bangladesh, Iran, Japan, and parts of Africa and South America.
Tea is made from the leaves of an evergreen tropical and subtropical plant, Camellia Sinensis. There are three major kinds of finished tea. Black tea, which makes up more than 90 percent of the tea trade, is produced by first allowing tea leaves to wither. The leaves are fed through rolling machines to release the juices. The rolled leaves are then placed in extremely humid rooms and left to ferment. Fermentation is stopped by drying the leaves over fires in pans, trays, or baskets, a process that also seals in their final flavor.
A second variety is oolong or semi-fermented tea which is prepared from a special kind of China tea plant. The leaves are heated before fermentation progresses very far, then they are rolled and dried. Lastly, there are green or unfermented teas made by steaming or heating the leaves to sterilize them and kill the enzymes responsible for fermentation. The leaves are then rolled and roasted until they acquire a blue-green tint. Teas are graded for size, age, and quality, and classified according to leaf size such as orange pekoe, pekoe, and souchong.
Paraguay tea, or mate, which is widely drunk in South America, is made from the leaves of a species of holly.