The Harney & Sons Guide to Tea - Michael Harney [30]
Bred of the same preference for sweeter teas that has led to bud-sweetened Chinese white and green teas, Chinese black teas are loaded with glucose-laden buds. The light green buds turn gold during oxidation, the process that turns tea black. Thus many Chinese black teas have the word Golden in their names.
As with Chinese green teas, the buds do not give the teas a particularly pronounced sweetness. Their honeyed notes are subtler, like those of roasted carrots or even a baked but unsweetened peach. What helps amplify the dulcet quality of Chinese black teas is the way the teas darken. Generally speaking, Chinese black teas are oxidized very, very slowly, creating chemical compounds that result in a mild, soft brew that doesn’t need milk to soften it.
After harvesting the tea leaves, black-tea makers do not fix their teas to preserve the green chlorophyll as green-tea makers do. Instead they allow the leaves to darken. The same reaction causes avocados and bananas to brown when their flesh is cut open and exposed to the air. During oxidation in tea, an enzyme in the leaves reacts with oxygen to create new brown-colored compounds called “flavonoids.”
For more on this reaction, I encourage you to consult the more scientific appendix “From Tree to Tea” (page 193). For our tasting purposes, it’s important to know that the levels of these flavonoids not only determine the tea’s color, they also influence its flavors and body. As oxidation begins, the first flavonoid to emerge is called “theaflavin,” which makes the tea golden but also quite brisk and puckery. If oxidation continues, milder flavonoids called “thearubigins” emerge and give the tea a rounded, gentler body and a darker brown color. The slower the oxidation, the more thearubigins, the mellower the tea.
Generally speaking, Chinese black teas consist mostly of thearubigins, since Chinese tea makers slow down oxidation as much as possible. First they roll the leaves very gently, keeping the leaves as whole as possible. Macerating the leaves only very lightly slows down oxidation by preventing the enzymes from breaking out of the leaf cells into the air. Then the tea makers pack the leaves into deep, finely woven bamboo baskets that limit access to oxygen. The leaves remain in the baskets for several hours, where they oxidize very slowly. Loaded up with thearubigins, the teas taste delightfully rounded and gentle.
Chinese black teas weren’t always so sweet. Until the late 1800s, most of them were quite dark, like Keemun and Lapsang Souchong, brisker versions made for a larger British audience. Black tea was exclusively a Chinese product until the mid-nineteenth century, when the British began to grow their own tea in their colonies of India and Sri Lanka. These new tea gardens employed industrialized methods to make a remarkably brisk, uniform drink I call British Legacy Tea (see “British Legacy Black Teas,” page 121). While a much diminished British market for Keemun and Lapsang did endure, the sales of Chinese black teas plummeted. The embattled Chinese sent envoys to India to learn from the new “experts,” but luckily for us, the knowledge did not stick. About the only new technique the Chinese adopted from the British was the use of mechanical rolling machines (hand rolling is hard work). Unlike British Legacy Teas, which look uncannily alike (all formed on identical rolling machines, even today), Chinese teas are made using a variety of machines in myriad ways to create a panoply of shapes and flavors.
Recent innovations have made some Chinese black teas even more enticing, with the incorporation of extra buds, the