If you’re a tea lover, you may already know that all tea is made from the leaves of the Camellia sinensis plant. But if you’re new to the world of tea, this concept may seem mind-boggling. How can one leaf be transformed into such a variety of flavors? What steps does that leaf need to go through in order to produce the incredible infusions we know and love?
In China, tea crafters have been refining the answer to this question for millennia. In each region, people have developed unique methods for growing and crafting tea. Variation in local taste and techniques has driven tea innovation through the ages.
Today, we are able to source and learn from a wide range of diverse areas. With this perspective, it is possible to distill the tea-making process into just a few essential steps, described here in their broadest terms.
Camellia sinensis plants must be grown and harvested as the first step in making tea. Growing conditions and harvesting methods can have a huge impact in the flavor of the finished tea. So while this step is probably the most ubiquitous, it can also produce the most variation.
The terroir (or growing environment) of the tea can be one of the most fundamental sources of a tea’s flavor. Just as a wine grape grown in California will taste different than the same type of grape grown in France, the character of a tea leaf can vary based on the location of the plant. Changes in climate, soil, or even surrounding vegetation can subtly change the leaf, and it’s resulting flavor in the cup.
Farmers can also manually change the growing conditions of the plant to exert control over the tea’s chemical composition. Planting tea in rocky soil or at varying elevations can change the character of the harvested leaves. Another example of this occurs in production of high quality Japanese green teas. As they grow, they are shaded with constructed awnings to promote creation of chlorophyll and theanine.
Finally, the method of harvesting the leaves is another way of creating variation at this early stage. Premium tea leaves are plucked by hand to preserve natural sweetness, but mass producers harvest by machine. The leaves are sheared from the top of the plant and chopped in the process. Though this process does speed production, it also exposes more surface area of the leaf. When steeped, the chopped leaves quickly release bold, dark flavors. By contrast, whole leaves often do not release their fullest flavors until they have been brewed more than once.
The first processing step after the leaves are harvested is a very basic one. Since Camellia sinensis leaves are thick and waxy on the plant, they must be softened, or withered, to make them pliable for crafting.
The leaves are laid out on fabric or bamboo mats, and left to wilt. Modern tea farmers control the variables in this process with great precision. Humidity and temperature are monitored and controlled, and racks of leaves are carefully rotated to ensure each layer receives proper airflow.
Though this step sounds similar to oxidation (step #4), it is a required process for even white and green teas. The withering process reduces the water content of the leaves by as much as half. Without withering, subsequent heating steps would produce something akin to cooked vegetables, rather than dried tea leaves.
After the leaves are withered, crafting methods for different styles start to diverge. Oolong teas, black teas, and pu-erh teas usually undergo some sort of bruising process. This means the leaves are rolled, twisted, or otherwise crushed. The purpose of this step is to break down cell walls in the leaf, and facilitate the next step: oxidation.
Manually bruising a large batch of tea leaves was once the most demanding step in processing tea. Leaves must be thoroughly and evenly bruised to produce a consistent batch of tea. Some dark teas, with high levels of oxidation, must go through through multiple rounds of bruising and oxidation. It’s really no wonder that black tea producers began chopping leaves to speed up the process for the mass market.
Today, many small scale producers have found a happy medium, using machines that replicate the traditional bruising processes, and don't break the leaf. When used as a component of artisanal crafting, these machines increase the consistency of quality and keep the production process clean.
After bruising, leaves intended for oolong or black teas are left to oxidize, or turn brown. Again, the leaves are laid out and left to wither. Now that the cell walls have been broken, an enzymatic reaction turns the leaves brown, just like a cut apple.
Leaves must be carefully monitored during this process. For oolongs, in particular, missing the correct moment can mean ruining the tea, or crafting something entirely different than what was intended. Again, heat and humidity are carefully controlled, and trays are rotated to ensure even oxidation.
This browning process is the primary differentiating factor between different styles of tea. Green tea crafting skips these steps entirely, creating a tea that is by definition, unoxidized, and therefore still green in color. A black tea is defined as fully oxidized, without any green color left to the leaf. Pu-erh, or “post-fermented” tea, lies outside this spectrum. Pu-erh teas usually undergo bruising, but skip the wilting that creates oxidation.
To stop the oxidation process, the tea leaf is heated. Just like baking an apple, the application of heat denatures the enzymes responsible for oxidation and stops the leaf from continuing to turn brown.
This step is applied to all tea styles except black tea, where the final drying step is used to slowly halt oxidation instead. This fixing step is sometimes called the kill green, but it actually serves to preserve whatever green color is still left in the leaf at this stage.
Variations in the method of heating the leaves create some differences between regional styles. Leaves that are steamed (like Japanese green teas) will taste wildly different from leaves that are roasted (like Chinese green teas). Frying the leaves in a wok creates a different flavor profile than roasting them in a rotating drum. In this way, styles of crafting can create endless variety, even within a category.
Finally, all tea must be dried to remove any residual moisture and create a shelf-stable leaf. Again, the method of heating can dramatically change the flavor of the tea. This effect is most commonly seen with charcoal roasting, which imparts a distinctly rich quality to the flavor during this step.
By contrast, the drying process can also be very gentle, to avoid imparting any flavor changes. White tea, for example, is usually given a very gradual bake, which replicates traditional sun-drying.
After it’s dried, the tea is ready to be packaged and shipped all over the world. Using variations on these steps, a single leaf can be crafted into any type of tea. By remixing these steps in nontraditional ways, modern crafters are still coming up with new ways to make interesting teas with unique flavors.
To try a variety of flavors and experience the difference in crafting styles for yourself, we recommend trying one of our collections, which offer a selected variety of samples for you to explore. Get started on your tea journey with our Discovery Collection, or dig a little deeper with the complex flavors in our Premium Collection.
Sign up for our newsletter to get blog updates in your inbox!