The Hot & Cold of Tea

After water, tea is the most widely consumed beverage in the world. And for that, I think it deserves a post. This may come as a surprise to most Americans (United Staters?), because it doesn’t make the top five in the country. Our eating and drinking habits vary quite significantly from those in other nations, but I’ll go more in-depth into that at a later time. There are definitely some of you tea drinkers out there, and I hope you find this insightful. If you’re not a regular tea drinker, well maybe you’ll be inspired to pick up a cup after reading.

Tea refers to the steeped beverage coming from the leaves and buds of the plant Camellia sinensis. Different varieties of this plant are used to grow commercial tea, but the most common are C. sinensis sinensis and C. sinensis assamica. Tea plants are grown in many areas of the world, but the top producing countries are China, India, Kenya, Sri Lanka, and Turkey. When evaluating tea, it can be helpful to think of it like connoisseurs think of wine. The region, environment, soil, and every step of processing contributes to a tea’s composition, quality, and flavor profile. The more you know about it, the more likely you are to find ones that suit your taste and appreciate the flavors and health benefits.

The different types of tea (black, green, oolong, etc.) come from different processing methods rather than different plant varieties. It might seem strange to think of tea as processed, especially because there can be a negative connotation to that word, but not all processing is inherently bad or uses additives. Sometimes it just refers to cleaning or mechanical processes that make a product usable. Below are different processing steps for tea leaves:

Three women harvesting tea leaves in a field

Harvesting. Picking the buds and leaves off the plant can be done by hand or by machine. You can probably guess that more premium teas are hand-picked (pictured left), while mass produced teas are machine-picked.

Withering. This exposes the leaves to air and helps soften the thick, waxy leaves to be more pliable. The leaves lose moisture and begin absorbing oxygen. The time, airflow, temperature, and humidity may be controlled by the processor. This can take place using bamboo mats in the sun, or in large metal troughs in a production facility (pictured below).

Maceration. This is the process of breaking the leaves, and may also be called bruising. The degree to which it is done varies significantly according to the type of tea being produced. Black tea, Oolong, and Pu’er are crushed or twisted to break down cell walls and promote oxidation. White, yellow, and green teas are produced without bruising. If you see tea labeled as CTC, it stands for crush, tear, and curl. This is a very intensive form of machine maceration intended to reduce the amount of tea needed to brew.

Tea leaves withering in a large container in a factory

Rolling. This process shapes tea leaves into how they look when sold. There may be different shapes, such as pearls or needles. Rolling may cause some amount of breakage, but it is a much more gentle process that maceration or bruising. Typically, yellow, green, and some oolong teas undergo rolling. It can be done by hand or by machine.

Oxidation. This step allows an enzymatic reaction to take place that turns the green leaves brown and creates new flavor compounds (pictured below). The speed and amount can be controlled by temperature and humidity, and a number of compounds can be tested to determine an endpoint. Black teas are 100% oxidized, while oolongs are anywhere from 20-70%. Yellow teas undergo a very light oxidation, while green and white teas are unoxidized.

Employee sorting oxidized tea leaves

Firing. This process exposes the leaves to heat for a short period of time, halting oxidation and enzymatic activity. This may be done by baking, steaming, or pan-frying. Depending on the style of tea production, it may take place more than once at different stages.

Drying. This removes the excess moisture content of the leaf to produce a shelf-stable tea. It can be done to impart more flavor with roasting, or it can be a gentle process like sun-drying that preserves the natural qualities of the leaf.

Sorting. Before the tea is sent out, it is sorted by size or grade and packaged into a final product.

Phew! That was a lot. And keep in mind that this is just a broad overview of the steps it takes to process tea. You can see that there is a huge amount of variation possible, even though most teas come from the same plant. Modern tea producers can follow traditional methods or mix the steps up, allowing for a new level of creativity and unique offerings.

Aside from the flavors and complexity of tea, its numerous health benefits are another reason that people love it. Tea is high in cancer-fighting antioxidants and flavonoids that lower cholesterol. Shout-out for the second link…my dad was a co-author on that paper. I found it online and noticed the name after I already linked it. I guess we all drink from the same cup.

I also want to say thanks to Great Tea Street for providing the pictures used in this post. Stay tuned for another one, where I’ll go more in-depth into different styles, as well as specialty processes like fermentation and GABA. In the meantime, enjoy some quaran-tea!

Featured Image by: Alice Pasqual

 

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