What gives a good cup of green tea its vegetal, grassy flavor? What makes oolong fruity or woodsy? And how can we learn to appreciate the subtle notes of flavor in our tea?
Black, white, green, or oolong It’s all from the same plant! All true tea is made from the leaves of Camellia sinensis, the tea plant. Other plants in the genus Camellia are sometimes used, but very rarely do these teas make it to the United States and on to store shelves. The differences between the types of teas we drink are all in the growing and processing of the plant.
How tea is processed? After tea has been harvested it is left to wither. The leaves are laid out to lose water content so they do not break while being rolled. Rolling tea leaves by twisting and pressing them damages the cell walls, releasing the liquid stored in the cells and speeding up the oxidation of the leaves. The rolling process also releases volatile organic compounds, natural chemicals that give tea its distinctive aromas. In the past, most tea was rolled by hand, but today, it’s done by mechanical rolling plates. White tea is the most minimally processed and is dried naturally. Delicate white tea leaves are dried, either in the sun or indoors, and not rolled or crushed A tea leaf will continue to oxidize after being picked and rolled, so the process must be halted to achieve the desired level of oxidation for the type of tea being produced. This is done by heating the leaves to denature the enzymes responsible for oxidation, a process called “fixation” stops the chemical reaction. Fixation is done by steaming or heating the leaves. Green teas, for example, are either steamed or pan fired after a short withering period to stop the oxidation. Black tea leaves are fully oxidized turning the leaves black. Oolong is semi oxidized. During oxidation, the chlorophyll in the leaves is broken down by those enzymes we mentioned earlier, which creates tannins, the bitter compounds that are also found in red wine. These tannins cause the puckery mouth feel you get from a sip of wine or a bite of persimmon, and they, along with phenolic compounds, are vital to giving black and oolong teas their flavor.
How does oxidation change a teas flavor? Typically, the more oxidation in your tea, the more robust and full the flavor and aroma. Other factors that influence the chemical composition of your cup of tea, and thus the flavor and color, include the season when the tea was picked and the growing region, just like with wine! Even whether or not the tea plant was bitten by bugs while it was growing can affect the flavor, as in the case with white-tip oolong, a highly sought after tea with a honey-like flavor.
Getting the most out of your tea In order to really appreciate the subtle flavors and complex bouquets of your tea, whether white, green, black, or oolong, or even herbal tisanes, flavored teas, and yaupon, we recommend finding a flavor wheel to tease out the complexities of your brew, just as you’d do for a fine wine. A flavor wheel can help you put words to the subtle variations in taste and scent in every cup of tea. This makes you a more conscious, thoughtful connoisseur of flavor.