How is Tea Made?

From assam to earl grey, oolong to darjeeling, there’s a huge variety of teas produced all over the world. The question is, how is tea made? Read on to immerse yourself in the subject of how tea is manufactured.

Engineering How It’s Made
15 October 2022

How is tea made? It’s the kind of question that can cause a tempest in a teapot. How long do you brew? What colour should it be? As for whether milk or sugar should be involved, well, that’s a topic worthy of a book. In other words, people feel very strongly about tea. Especially about weak tea.

Fortunately, we’re not discussing the process of brewing tea. We’re answering the questions ‘how is tea produced’ and ‘how tea is manufactured’. From harvesting the tea leaves to processing and packaging, we’ll examine every step of making this globally beloved beverage. Along the way, we’ll look at how tea is made in different varieties, including, how is decaf tea made? But first, a bit of background.

A Short History of Tea

Tea is one of the oldest and most beloved beverages in the world. But where did it come from? And how did it achieve its iconic status?

It’s believed that tea was first harvested in China, possibly as far back as the 3rd millennium BC. It eventually spread to other parts of Asia, and from there, the world.

It made its way to Europe in the 16th century and quickly became a fashionable drink among the upper classes. However, it wasn’t until the 19th century that tea really took off in Europe, becoming the ubiquitous drink it is today.

With that in mind, how is tea produced?

How Tea is Made: A Step-by-Step Guide

Women picking tea leaves in Vietnam (Photo: HAIPIANO NGUYEN` via Getty Images)

A whizz around the local supermarket would leave you spoilt for choice when it comes to tea. The options seem endless. Do you go for mild and citrusy Earl Grey? Smoky Lapsang Souchong? Or a classic builder’s brew?

Therefore, it might come as a surprise to learn that almost all tea comes from the same plant: a small evergreen shrub called camellia sinensis that is native to Asia. This is, in turn, available in two main varieties. The main one is camellia sinensis sinensis and the second is camellia sinensis assamica. What’s more, there are only five basic varieties of tea:

  • Black: the most common type of tea, especially for blends such as English Breakfast.
  • Green: light and delicate
  • Oolong: fruity and fresh
  • Pu-erh: short for post-fermented tea, this type is dark, rich and full bodied
  • White: sweet and mild

So, how is it that teas come in so many flavours and forms? It’s all in how tea is manufactured.


When it comes to tea production, everything begins with the harvesting. The part of the tea plant that is harvested is usually either just the bud or the bud and the top two leaves. Having said this, harvesting tea at different stages or harvesting different parts of the leaf will result in different teas.

Tea can be harvested either by hand or mechanically. The mechanical method is far quicker and more economical. In fact, a mechanical power plucker is approximately 25 times faster than hand picking on average. However, the quality of tea is usually higher with the hand plucking method.

The sooner the picked tea is processed, the better. In fact, tea makers tend to have tea packaged up and ready to go within 24 hours of picking. The process of how tea is made described below is known as the orthodox method.


Tea withering is the process of removing moisture from tea leaves. From a practical perspective, this lengthens their freshness and makes them easier to roll. Chemically, this is where proteins and carbohydrates break down into simpler amino acids and sugars.

The orthodox method of how tea is made entails spreading the leaves out on a flat surface and blowing them with hot air. The surface might be a coarse fabric known as tats or on wire mesh within troughs. Depending on the conditions and method used, this can take anything from 12 to 20 hours. Historically, this was done in the open air or in a mix of in and outdoor, but nowadays it is mostly done in temperature controlled rooms.


Tea rolling releases essential oils in the leaves and enhances the flavour and colour of the tea. Historically, all tea rolling was done by hand. Today, most tea rolling employs a mechanical rolling machine. The leaves are placed in a round tray with a ribbed metal surface, above which there is an agitator. The agitator rotates horizontally against the leaves in a stirring motion, crushing and tearing them against the bumpy surface.


Oxidation, also called fermentation, is the process by which the enzymes in the tea leaves react with oxygen. This not only darkens their colour, but intensifies their taste and strength. For this, the leaves are once again splayed out on a surface like a table or trough. Then it’s a matter of waiting. Traditionally, times for oxidation are between two and four hours. The longer the leaves are left to oxidise, the darker and stronger they become. For example:

  • Black: fully oxidised to a brownish-black colour
  • Oolong: a middle ground between green and black tea
  • Pu-erh: undergoes a second oxidation after fixation
  • White: limited oxidation
  • Green: minimal or zero oxidation


Tea fixation is a term used to describe the process of drying tea leaves, usually by passing them through a heated dryer for 10 to 15 minutes. The heat halts the oxidation process and ‘fixes’ it at the desired level. They are then quickly cooled to avoid overdrying. At this point, their moisture content has reduced to between three and five percent.

Cut, Tear and Curl (CTC)

CTC is sometimes classified as a separate method to the orthodox, but is more like an additional step between withering and oxidation. It’s essentially a method of granulating the tea and is almost exclusively used for the black tea variety. The withered leaves are placed in a CTC machine, in which they are passed through a series of corkscrew rollers. A multitude of tiny sharp teeth cut, tear and curl the leaves.

How is Tea Made? Variations

A cup of green tea (Photo: ATU Images via Getty Images)

In terms of how tea is made, the methods described above are often varied. Sometimes this means steps are skipped for particular types of tea. For example, green tea is not oxidised. In other cases, the variation is down to different ways of completing the same steps.

Where tea undergoes CTC, its fermentation stage time can be reduced by as much as half. Generally, the more mechanised the process, the faster and more economical, but almost invariably at the expense of quality.

How is Decaf Tea Made?

Brewing tea (Photo: Roberta Lazar / 500px via Getty Images)

Tea naturally contains caffeine. In terms of ‘how is decaf tea made’, caffeine can be removed by numerous methods, most commonly:

Ethyl Acetate: tea leaves are soaked in ethyl acetate, a chemical which is naturally found in tea. Caffeine molecules bond to the ethyl acetate.

Carbon Dioxide (CO2): the tea is pressure cooked with CO2, during which the gas becomes a solvent and attracts the caffeine molecules. It’s said this method is best for retaining all the original benefits of tea.

Herbal or Infused Teas

Fresh hot water for herbal tea ( Photo: Guido Mieth via Getty Images)

A quick note about herbal teas. Sometimes known as infused teas, these are not technically teas at all. That’s because they do not contain any tea plant leaves. Instead, they’re made with other plants, fruits and herbs.

Explaining how Tea is Produced

Woman with cup of tea relaxing (Photo: Westend61 via Getty Images)

So now you know how tea is made. Whether it’s piping hot or cold brewed, milky or on its own, there is a tea for everyone. As explained above, the real key to making all these different types is in how the tea itself is manufactured.

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