The Harney & Sons Guide to Tea - Michael Harney [53]
In summer, the plants slow their growth, digging in for the heat and the assault of late-season insects. Japanese Banchas plucked in May and June taste grassy and thin compared with early-spring Senchas because they have about a third fewer amino acids and a much higher proportion of EC to EGCG. Second Flush Darjeelings and later-season oolongs like Bai Hao have far less glucose and fewer amino acids than their earlier-season equivalents. Makers of both teas compensate for the nutrient loss by allowing insects to attack them before harvesting. The plant reacts by producing a defensive compound with a lovely fruity aroma evocative of Muscat grapes.
To ensure the most flavors, tea makers have also developed a dizzying number of tea varietals, each with differing levels of the six chemical compounds. Almost all the pure teas in this book have been bred from two parent varietals: Camellia sinensis var. sinensis, a small-leafed variety indigenous to China; and Camellia sinensis var. assamica, a larger-leafed type native to Assam. From these two, tea makers have developed hundreds of cultivars. The exquisite Chinese breed Da Bai (“big white”) produces extra-large, glucose-packed buds, perfect for white teas and tippy black teas. The Japanese cultivar yabukita grows in 90 percent of that country’s tea gardens, because of its above-average levels of amino acids and relatively low levels of polyphenols. The black teas Keemun (China) and New Vithanakande (Sri Lanka) both get their chocolaty flavors in part from cultivars with extra amino acids.
After choosing the tea cultivar and the timing of the harvest, tea makers can also control the levels of compounds in tea—and therefore the tea’s flavor—by gathering the leaves by hand. The finest teas also come from the very youngest leaves. Tea plants grow by sending out buds—incipient leaves shaped like spears that unfurl into young leaves, then mature. The youngest leaves on the plant are called “leafsets,” consisting of a bud and its adjoining two leaves. These leafsets are loaded with nutrients to feed and protect the sprouts as they grow. Fully mature leaves contain comparatively few nutrients, since they send whatever they photosynthesize into the roots for storage. Mechanical harvesters cannot distinguish between leafsets and mature leaves; like crude hedge clippers, they merely shear the bushes of their outer layer. As a result, machine-harvested teas often taste dull and insipid. Most of the teas in this book were gathered by hand. It is meticulous work. Harvesters often wear gloves affixed with razor blades to snip off the leafsets one at a time, their fingers flying from branch to branch as they work their way down the bushes, gently storing the cut leaves in straw hampers as they work.
WITHERING
For all the work involved in harvesting it, freshly plucked tea tastes like bitter grass. Its hundreds of flavors don’t begin to emerge until tea makers go to work to draw them out. As I’ve said, these flavors exist in the plant to defend it against attack. The first line of defense emerges right after the leaves have been plucked. Cut off from the roots, the leaves begin to lose moisture and nutrients. In an effort to feed themselves, the leaves break down starches into glucose and proteins into amino acids. In what scientists believe is an attempt to alert the rest of the plant that they are in distress, the leaves also transform fatty acids into aromatic compounds. These alerts are the first flavors to emerge, in this process called “withering,” or dehydration, as tea makers let the leaves go limp.
The longer the leaves wither, the more aromas the final tea yields. Green teas wither only over the short trip between the field and the factory, just long enough