How is Tea Made? The Processing and Production of True Teas

Whether you enjoy a refreshing, cold glass of iced tea or a warmed mug of hot tea, the production of this beverage makes all the difference when it comes to flavors and aromas. From harvest to drying, tea leaves undergo changes that can mean the difference between a delicate, sweet white tea and a robust, powerful black tea. The flavors and aromas you enjoy aren't due to different leaves or plants; in fact, these unique tea characteristics arise from the processing methods of the same tea leaves.

The tale of tea is a fascinating one, including proven health benefits, traditional uses in ceremonial practices, and a production process that exemplifies skill and artistry. Starting as a tiny seedling, the flavors and aromas of these tea leaves are affected by the region they are grown in, the amount of sunshine they receive and the careful eye of a storied tea master. Harvested by hand and skillfully manufactured in a multi-step process, the story of tea leaves has multiple outcomes, depending on which true tea type you prefer the most.

What is Tea?

Tea is one of the most popular drinks in the world, second only to water. With thousands of different flavors and aromas ranging from cool, fresh and herbaceous to floral and spicy, there is a flavor for just about everyone. Offering an extensive array of health benefits, drinking tea is a great way to boost your health while enjoying a delicious beverage.

Originating in China, tea has been used for centuries by ancient societies such as the Romans and Greek and in traditional medicine including Ayurveda. Long heralded as an important part of social life, the Chinese and Japanese have consumed tea as part of religious and cultural ceremonies since its discovery. Tea made its way from Asia to the Western world during the 16th century when it was discovered by travelling Portuguese priests and traders. It wasn't until the 17th century during British colonial rule that tea became popular in Great Britain and was integrated into social engagements.

Tea derives its aromatic scent and wide range of flavor profiles from the production process of tea leaves. True teas such as green tea, white tea, oolong tea, black tea and pu-erh tea are harvested from the tea plant known as Camellia sinensis. Herbal infusions or tisanes are produced using as array of spices and flower parts including unopened buds and stem. Herbal teas are produced and categorized differently from true teas since they don't actually contain any tea leaves from the tea plant.

How is Tea Made?

We've broken down the process from harvest to production so you can understand how tea leaves get from rolling green hillsides to your piping hot cup. For the purpose of simplicity and accuracy, this guide focuses on the two methods of production for true teas. Read on to learn how tea is made and learn about the process that takes leaves from the same plant and turns them into incredibly different flavors and aromas.

Cultivation of Tea Plants

The first stage of tea production is the cultivation of the tea plant. The Camellia sinensis plant is an evergreen bush that thrives in tropical and subtropical climates. This plant prefers acidic soil and a significant amount of rainfall for the best growing conditions. Grown as far north as England and as far south as New Zealand, the tea plant is cultivated all across the world. Tea plants grown at higher altitudes tend to have a more potent flavor.

In general, it takes about three years before a tea plant produces leaves suitable for tea making.  Tea plants are categorized into three different groups based on their size (1). Assam leaves are the largest, followed by Cambodian, which are medium sized and China type leaves, which are the smallest. While the tea plant can grow up to 50 feet tall, most plants for tea harvesting are kept to waist height in order to make it easier to pluck the young, fresh leaves at the top of the plant. Shorter plants also tend to produce more shoots and leaves, thus increasing production capacity.

Harvest of Tea Leaves

Tea leaves are harvested from the tea plant and then transported to a nearby tea factory for production. During the harvest, leaves are only plucked from the top one to two inches of the tea plant. Known as flushes, these tea leaves are produced every 7 to 15 days during harvest season (1).

Tea leaves are generally hand-plucked from the tea garden or tea plantation and placed into large wicker baskets. Once a basket is full, it is brought to a tea master where leaves are inspected and weighed to ensure quality. Broken leaves are typically discarded as are ones that shown signs of sun or water damage. For every 100 kilograms of fresh tea leaves, only about 25 kilograms are sent on to the next tea production step (2).

During the Harvest and sorting stage, tea leaves are examined based on size, type and appearance. In many countries, tea leaves are classified based on the region in which they were cultivated as well as the methods used for harvesting. Each individual tea leaf is also inspected and sorted into white, green, black, pu-erh and oolong categories for the next processing step.

Processing the Tea Leaves

As mentioned, all true teas are derived using the same leaves—the difference in color, aroma and flavor arises from the ways in which they are processed following harvest. Leaves can be withered, dried, oxidized, fired and shaped depending on the desired tea type. For example, leaves for green and white teas are not oxidized at all—leaves are simply dried in the sun, pan-fired or steamed and then shaped into pellets or small twigs. Green tea leaves can also be ground to create matcha green tea powder.

On the other hand, robust, darker teas such as oolong tea and black tea are created through an oxidation process. During this stage, leaves are withered and rolled in order to encourage enzymes within the leaves to react with oxygen. This process results in darker tea leaves and more potent flavors than those characterized by delicate true teas such as green tea and white tea. The oxidation process is comprised of two methods, the orthodox method, which is most common and the CTC method.

Orthodox Method

For the orthodox method, tea leaves are subjected to a 4-step process that includes withering, rolling, oxidation and drying. During the production, each step helps to produce the flavor profiles associated with darker true teas.

Withering

Tea leaves are transported from the fields to the tea factory within hours after plucking and sorting. Leaves destined to become black or oolong teas are withered in order to reduce moisture content so that leaves can be rolled without flaking. Harvested tea leaves typically have a high water content—around 75%—which is reduced to about 45% for rolling and oxidation. The water content is removed by laying leaves on a flat mesh surface or a bamboo tray. During the drying process, the leaves are subjected to cool air, for anywhere from 8 to 18 hours.

Rolling

Once the leaves are withered, they are rolled in order to promote oxidation. In traditional production methods, leaves are hand rolled although in modern times, many manufacturers use rolling machines to expedite the process. As the withered leaves are rolled, internal cell structures are broken down, releasing essential oils that react with oxygen to develop flavor and aroma.

Oxidation

After the leaves are rolled, they undergo a process of oxidation, also known as fermentation, which determines the strength and flavor of tea. The interaction between enzymes and oxygen breaks down chlorophyll and releases tannins, which causes leaves to turn darker. The process of oxidation is controlled by tea producers who maintain a warm, moist environment.

Temperatures are kept between 80 to 85 F and the length of the oxidation process leads to the different types of true tea. As mentioned, non-oxidized teas such as green tea and white tea maintain a green color and vegetal flavor. Semi-oxidized tea, which are teas that are oxidized only for a short period of time such as oolong tea, are generally light brown or yellow in color and offer a more mild flavor. Fully oxidized teas such as black tea are reddish brown in color and offer bold, robust flavors.

Drying

To stop the oxidation process, tea leaves are subjected to methods of drying. Depending on tradition and tea producer preference, tea leaves can be dried by pan-firing, sun drying or baking. The leaves are subjected to hot temperatures over 100 F to stop the oxidation process and reduce the moisture content to just 2-3%.

CTC Method

Known as the crush-tear-curl method, the CTC production process results in shredded tea leaves and granular pellets. CTC tea leaves undergo the same withering, oxidation and drying methods as orthodox teas. The main difference between the orthodox and CTC method occurs during the rolling stage. During CTC production, tea leaves are rolled in machines that contain hundreds or small, sharp teeth. These sharp points break down the tea leaves into smaller pieces, which are generally used for teas in tea bags.

Production Variations for White, Green and Pu-erh Tea

These production steps are typical for leaves that are to become black or oolong teas. For different teas such as white tea and green tea, a few steps of the production process are eliminated. White teas are made entirely by hand, without any machines and undergo only on stage of the production process—drying. Considered the least processed of the true teas and referred to as an organic tea, these leaves are hand rolled and naturally dried in sunlight.

Green tea is also not oxidized, but still undergoes several steps of the production process. Instead of withering, green tea leaves are immediately dried after harvest through pan firing or steaming. The leaves are then rolled and dried again in a process that can occur several times over before being shaped and styled.

Pu-erh tea is considered a post-fermented tea that is similar in production to fine wines. Pu-erh teas are allowed to oxidize for years, with the best tasting teas generally being the ones that are aged the longest. Raw pu-erh teas can be aged for 50 years while ripened pu-erh teas can be aged for 10 to 15 years.

Enjoy Knowing Where Your Tea Came From

Next time you enjoy a cup of tea, relish knowing exactly how the flavors you're sipping came to be thanks to centuries old production processes practiced around the globe. Whether you like loose tea or tea bags, black tea or white tea, tea is best enjoyed when you understand the effort and finesse put into creating each delectable cup. Tea drinking is a replete with nuances—little minute details that make all the difference when it comes to producing and enjoying the varying flavor profiles of true teas. Pour yourself a cup and cheers to centuries of tea production and thousands of flavors.

Sources:

1. https://hort.purdue.edu/newcrop/duke_energy/Camellia_sinensis.html

2. https://www.schooloftea.org/module/manufacturer-of-traditional-leaf-tea.html