You may know that tea comes from the Camellia sinensis plant, but do you know how are tea leaves processed? Read this article to find out.
Tea processing involves four steps: withering, rolling, oxidation, and drying. Those four steps are known as the ‘orthodox method’ in tea production.
This article will explain how the leaves of a plant grown in large quantities in China, India, Kenya, and Sri Lanka are processed into the base ingredient for hundreds of different types of tea.
One of the joys of this drink is the variety of options available, and naturally, there are different processing methods associated with different types of tea. However, the process for all teas that come from Camellia sinensis starts with removing leaves (which is also known as ‘plucking’).
Plucking Of Tea Leaves
Before the tea leaves are processed, they have to be harvested, and this is done by plucking the buds and leaves from the tree plant. Plucking is either done by hand or by machine. There are different methods associated with both manual and mechanized plucking.
The time of year that tea harvesting takes place depends on the climate of the country in question. For instance, Northern India and China’s primary harvesting season occurs between spring and autumn. In Kenya, plucking takes place year-round because of the consistently warm weather.
Read our guide to matcha powder vs leaves.
Manual Plucking Methods
There are several different methods used while manually harvesting tea leaves. They include the following:
Two Leaves and a Bud
This plucking method involves two leaves and a bud being carefully removed from the top of the tea plant. It is considered the gold tea plucking standard but inefficient, labor-intensive, and time-consuming. Thus, it is a method that is more closely associated with high-quality premium teas rather than general commercial tea production.
Clutch and Tear
Also known as the CTC method, this is less intricate than ‘two leaves and a bud,’ and because of that, CTC tea isn’t as sought after.
However, it is a more efficient way of doing things. It involves the harvester wrapping their hand down the base of the twig and pulling it upwards to remove the leaves into the palm of their hand. This method is closely associated with areas within the Shiga Prefecture in Japan.
All Of The Twig
Where the clutch and tear method leaves the twig behind, another method takes the leaves with the twig, separating them from the leaves at a later stage of the process.
Using Small Tools
Different areas will have different types of tools for harvesting teas. Amongst the most popular manual plucking are harvesting scissors, sharp moon-shaped plyers, and other types of traditional equipment.
Mechanized Harvesting
Harvesting is changing, and some commercial farms have invested in mechanized systems that allow them to collect tea leaves at a much quicker and more efficient rate than would be possible by hand.
Portable hand-held harvesters allow the tea to be harvested from rugged terrain, whereas tractor-harvester vehicles are also popular in certain areas. However, those vehicles require a straight harvesting surfaces and can damage the soil due to their weight, so they are not ideal for all tea farms.
Withering of Tea Leaves
The withering process sees the tea leaves become flaccid and lose moisture. This helps with the rolling and drying of the leaves, which are processing steps further down the line.
Withering is important for many reasons, not least that a tea leaf that is too wet and gunky has the potential to damage the machinery that is used to dry the leaves. During it, the tea leaves are often laid out over tarps or indoors in troughs, with heated air sometimes pumped through to quicken the process.
The process is completed when the tea leaves lose the desired amount of moisture. You can recognize when this happens by the change in weight, flaccidity, or aroma of the leaves. A tea master monitors the withering process and decides when to move the leaves on to the next stage.
Chemically, chlorophyll degrades in the leaves during withering, while caffeine levels rise, and the flavor and aroma of the leaves develop. The leaves also lose carbohydrates, and the process of oxidation begins.
Rolling of Tea Leaves
The next stage of the process after withering is the rolling of the tea leaves. This happens after withering as the leaves are more soft, pliable, and, thus, easier to roll.
This has traditionally been done manually, with hand-rolling considered a treasured skill in tea-producing countries, but more contemporary production methods have seen mechanized rolling machines come to the fore.
Rolling involves breaking the tea leaves’ cell walls, which allows the cell sap to be exposed to the oxygen in the atmosphere and begin oxidizing. Essential oils are also released during this process, affecting the aroma of the rolled broken leaves.
The rolling usually takes between 30 and 90 minutes, with several rolls often taking place. The longer the tea leaves are rolled, the finer the grade of tea produced, with tea that is only rolled for a short period often sold as whole-leaf tea.
Oxidation Process for Tea
Oxidization occurs when rolled tea leaves are laid out on tables or put in troughs in a warm area (usually about 26°C) and allowed to react to the oxygen in the atmosphere. This step determines the tea’s color, strength, and taste.
During the oxidization process, the enzymes inside the leaves react with the atmosphere, changing the color of the leaves from their original green hue to beige, then to a deep brown, and then to a blackish color.
The color of the leaves indicates how oxidized they are and what flavor will come from them. Although people might use the terms’ oxidization’ and ‘fermentation’ interchangeably, they are not the same thing.
Where oxidization is the drying and darkening in color of the leaves due to their exposure to oxygen, fermentation involves microbial activity from when the leaves are decomposing. Puerh tea is an excellent example of an aged, fermented tea.
Black Tea Oxidation
Black teas undergo the entire oxidation process, allowing the leaves to darken, losing their green color entirely. This results in a rich, flavorful tea with more caffeine than other types. The robust flavor of these teas means that they often pair excellently with milk and sweetener.
Popular black teas include Earl Grey and English Breakfast.
Oolong Tea Oxidation
Oolong teas are the middle ground between fully oxidized black tea and green tea without oxidation. These bruised and partially oxidized leaves offer a smoky flavor that isn’t as malty as black tea but not as floral as green tea. There is a large variation between different types of oolong tea, with dark oolong closer to black tea and light oolong closer to green tea in flavor.
Green Tea Oxidation
Green teas don’t go through the oxidation process, often skipping straight to the drying stage after rolling. Green tea leaves are sometimes pan-fired after harvest to halt the oxidation process. The heating of these tea leaves to prevent oxidation is known as ‘kill-green.’
Green teas offer a mellow, floral taste profile to the palette. Popular green teas include sencha and the ever-popular Japanese green tea, matcha.
White Tea Oxidation
White teas comprise the youngest part of the tea plant, the unopened buds, and do not undergo oxidation. However, they can oxidize slightly when exposed to air during drying. White teas are low in caffeine and offer a mild, bright taste.
Drying of Tea Leaves
When the leaves are oxidized to the desired amount, they are passed through hot air dryers, which reduces their moisture content even further. Traditionally, reducing the water content of tea leaves has also been done by setting them out on perforated trays or shallow baskets and allowing them to dry naturally.
The drying process is a vital step during tea processing. It is generally done to make tea shelf-stable, but it can also be conducted to enhance the flavor of the tea.
By reducing the moisture content by 2-3 percent, you slow the oxidative process to an almost stop. This makes the tea shelf-stable and ensures it is ready for sorting, grading, and packaging.
Drying for flavor is usually done via finish-firing or roasting. Finish-firing involves the low-temperature heating of tea leaves for several hours, after which they are immediately packaged and shipped. In comparison, roasting refers to heating dried tea leaves, where toasty burnt notes are deliberately added.
Sorting and Grading of Tea Leaves
After the tea leaves are dried, they arrive at the tea factory, where they are sorted and graded. This is where impurities, damaged tea, seeds, and stems are removed. Sieves are often used to ensure consistency of size and shape, while dust is cleaned off the tea.
Fannings are small pieces of tea that are left over after this stage. Traditionally, these pieces were viewed as rejects. However, fannings of high-quality teas can now be purchased and brewed, and they are often cheaper than the whole leaves they came from.
Purchasing the fannings can be cheaper to try premium teas that would otherwise be out of your budget.
Tea Packaging
Tea packaging is done after the processing steps are complete. Packaging’s primary job is to protect processed tea from being damaged before it goes to market. Good packaging protects the aroma, flavor, and freshness of the tea.
For loose-leaf packaging, the processed tea is put in a machine that carefully measures the right amount into each packet before sealing it and weighing it as a final check. When automated, this process is done in seconds.
Tea bags are done similarly, with hundreds of teabags filled by automated machines each minute. These tea bags are then packed into cartons. On average, a teabag weighs about 2.27 grams.
Specialty tea producers can differ, with smaller producers packaging their own processed teas. There has been a conscious effort in recent years for tea companies to consider environmental factors when packaging tea.
The Future Of Tea Processing
It’s difficult to comprehend that tea makers can take a leaf from the Camellia sinensis plant, put it through the stages of tea production and produce a magical substance that transforms when it touches hot water.
Your cup of tea goes through an epic production process that is uniquely traditional but also contemporary and innovative. Hopefully, the above article helps you realize the hard work that goes into every cup and encourages you to try new types of tea.
The tea industry has come a long way over the years, becoming more industrialized with the use of machinery. With the growth of the drink, it isn’t easy to envisage what the future might bring. However, there will always be a market for traditional, hand-processed tea, with that element of processing a vital part of the tea culture.
If you like this article, check out our guide to the best black tea brands.
FAQ
What is the difference between green tea and black tea?
Green tea and black tea come from the same tea plant, but they differ because black tea goes through the oxidation process in contrast to green tea, which skips that processing step. Because black tea goes through oxidation, it has a stronger flavor and color than mellow and floral green tea. Green tea has traditionally been more popular in Eastern countries, whereas certain black teas, such as Earl Grey and English Breakfast, are mainstays in Western countries.
What is the first process done to the tea leaves?
The first process done to tea leaves after harvesting is known as withering. This is where the tea leaves moisture levels are reduced, and they go flaccid, allowing for easy rolling in the next stage of the process. It happens after the tea leaves are harvested.
How are green tea leaves processed?
Green leaves first go through the withering process before they are rolled. However, at this point, they do not go through oxidation like their black tea counterpart. Instead, they go straight to the drying process before being sent for grading and sorting.