Black tea, the most common variety of tea consumed in the west, is named for the dark, almost black color of the leaves that results from a combination of the oxidization and drying/firing process. In China, black tea is usually called red tea, named after the color of the steeped tea liquid, which generally has a red-brown color. In China, if you request a black tea, they will serve you Pu’erh tea, which is a fermented variety of tea, with a vastly different flavor.
Like all teas, black tea is unique due to it’s processing methods. The actual flavor of black tea widely varies based on nuances in the processing and location and growing conditions of the tea bush. The oxidation and firing gives most black teas a very bold taste, often with a woody or charcoal flavor that is a result of the roasting.
The processing of black tea follows four steps, withering, rolling, oxidizing, and finally a firing/drying stage. The withering step comes first - if weather conditions allow for it, tea producers will let the harvest wither in the sun, on bamboo woven mats or large sheets. To accelerate the process and insure consistency, some outfits will use a blower to directly apply air to the leaves. The purpose of this first stage is to soften the leaves to allow for them to be manually manipulated, and remove some of the water content. The withering stage of tea processing can take up to 18 hours.
Following withering, the leaves are shaped. There are two primary methods of shaping black tea leaves, the /Orthodox/ method and the /CTC (cut-tear-curl)/ method. Orthodox method leads to full or nearly full loose leaf tea, while CTC creates much smaller, but consistent leaf pieces, which are particular useful for teabags, by allowing more surface are of the leaf to be exposed to the water while constrained within the teabag. The rolling or manual manipulation of the leaves actually kicks off the next stage in processing, oxidation, by breaking down the cell walls in the leaves, and releasing the enzymes and chemicals that cause the leaf to oxidize.
After withering and rolling are sufficiently completed, the batch of leaves moves onto oxidation, where the chemical process is assisted by maintaining the leaves in specific humidity and temperature controlled environments. The leaves are left to oxidize nearly completely turning into a rich dark color as a result. The oxidation process, depending on how the leaves were rolled, can be as short as 20 minutes.
Drying is the final step of black tea processing. With oxidation completed, the leaves must dried or fired in order to remove all water content and halt any further oxidation. The presence of water would result in the tea continuing to degrade, mold, and other undesirable conditions. To dry, the batch of leaves is placed in a large automated drying machine which simply enough, blows hot air on the leaves, until the water content is sufficiently reduced.
Due to the processing, black tea can be brewed at a higher temperature than it’s green or white tea counterparts. Using water at 200 degrees Fahrenheit and an initial steep time of 60 seconds is advisable. Black teas typically will have higher caffeine content due to processing, steeping temperatures, and steeping times, but caffeine content can vary widely from batch to batch. Due to it’s more robust flavors, many people take their black tea with milk and sugar, enhancing their beverage to their personal preference.
Where will you enjoy your next cup?