The half century or so following the Opium Wars saw much competition in the China trade, and, with a Western public convinced that the fresher the tea the better, speed in transport became critical. For a few romantic decades, that speed was supplied by the famous clipper ships, which could rush tea from China to London or New York in 90 to 120 days instead of the earlier 6 to 9 months - effectively cutting the sailing time in half.

Tea reached the height of its popularity in the 1880s, but subsequent events served to sustain demand for the beverage. One was the introduction of iced tea to a thirsty crowd at the St. Louis World's Fair of 1904, which, although hardly constituting the invention of the drink (as has been claimed), certainly did help to popularize it. Another such event was the inadvertent invention of the "tea bag" by Thomas Sullivan in 1908. Sullivan was a tea merchant who began distributing his samples in hand-sewn silk bags rather than in tin boxes and was suddenly swamped with orders by customers who had discovered that they could brew the tea right in the bag.

It has been said that there are more kinds of tea in China than there are wines in France. To this is might be added that the classification of teas is every bit as complicated as that of wines. All tea starts as "green," and it must be rolled, withered, fired, and dried to deactivate an enzyme present in the leaves. If, however, the rolled and cut leaves are permitted to stand (and ferment) for one to three hours before heating, the tea becomes "black." If the leaves are semifermented, the tea is called "Oolong." Tea grading is by leaf size. Young, soft shoots make the best tea, and thus only the bud and the top leaves are plucked from the bush. With black tea, the leaf bud is called "pekoe tip"; the youngest fully opened leaf is "orange pekoe"; the next leaf is "pekoe," then "pekoe souchong"; and finally there is "souchong" - the largest leaves that are used. The corresponding green tea grades are "twanky" for the bud, then "gunpowder," "imperial," "young hyson," and "hyson." The very small pieces, called "dust," generally go into tea bags.

The most famous of China's black teas is Keemun (or Keemum), known for its winelike quality. Darjeeling tea, from the foothills of the Himalayas, is one of India's contributions to the ranks of rare and prestigious black teas. Assam tea (from the same region but a lower elevation) is another. The Ceylon teas, from Sri Lanka, run the gamut - from the mild Flowery Orange Pekoe to the full-bodied Broken Orange Pekoe Fannings. The highest-grade Oolongs and the smoky Lapsung Souchongs come mostly from Taiwan.

In truth, however, most commercial teas are blends of several of these individual teas. Green teas are consumed mostly in Japan and some of the Arab countries, whereas black teas constitute the overwhelming bulk of the tea drunk in the West.