Background:

Tea cultivation is a carefully controlled process, with every step executed perfectly to ensure the best flavor possible upon brewing. The two primary types of tea are true teas (oolong, white, green, yellow, black, pu’er, etc.), which are made from the Camellia sinensis tea plant, and herbal teas (peppermint, ginger, hibiscus, chamomile, etc.), which do not contain the tea plant. Although true teas are all made from the same plant, they all taste very different due to their specific cultivation process.

Harvesting:

High-quality tea is harvested by hand to prevent damage to the leaves. Tea plants reach maturity after three years of growth, and harvests occur twice a year. Plucked tea leaves are taken to a processing center, where they complete the following steps to a certain extent unique to the type of tea plant.

a - Withering leaves:

A tea leaf starts to wither the instant it is picked. Many production facilities choose to harness this by placing leaves on outdoor mats either in direct sun or in the shade for an extended period of time. Most plants undergo daily cycles where their stomata open and close to let out and keep in moisture. The tea leaves’ stomata open and lose moisture, but the stomata cannot close because of the sun. As a result, abscisic acid is released as a sealant for the stomata, which gives the tea leaves a unique floral flavor.

b- Rolling:

The rolling process consists of breaking and damaging the cell walls of tea leaves to release juices and distribute moisture evenly across the leaves. This can be executed in several different ways - mechanical rolling, rotorvane rolling, and hand rolling all produce very different results that determine the durability of the leaves in a tea bag.

c - Oxidation:

Oxidation is a process by which tea leaves darken after exposure to the sun. The time at which a tea leaf’s oxidation is halted determines the color it will take on when brewed and the exact flavors it will release. For example, the oxidation for white tea leaves is stopped soon after picking, which produces brews with a light yellow color and sweet and delicate flavors. Meanwhile, the oxidation for black tea leaves is stopped much later, producing brews of dark red and orange colors and bold and rich flavors.

d - Drying:

Once tea leaves have reached the desired level of oxidation, they are taken onto trays of tea leaves and dried by being sent through hot air dryers. This reduces their moisture content to around three percent and makes them ready to pack and sell.

Bonus: CTC Method

During World War II, the CTC (or cut, tear, and curl) method was used to make tea that could be packaged in greater quantities due to its low weight. In this method, withered tea leaves are sent through a roller covered in sharp spikes that curl and tear the leaves into many tiny pieces suitable for bagging. The tea leaves are then oxidized and dried.