Mi az az oolong tea, és miért szeretem?

What is oolong tea and why do I love it?

When I introduce Calm Tea to people less familiar with the world of tea, their first question after reading the product label is almost always the same: "what is oolong tea?"

Since I often talk at length about these teas, I thought it was time to put those words into a blog post so that I could cover this frequently-recurring topic as comprehensively as possible.

If I want to give the shortest answer to the question what is  oolong tea, I usually say the following:

"Oolong is a tea whose character and processing lies somewhere halfway between green teas and black teas."

Or that:

"Oolong is an umbrella term for teas whose oxidation has been deliberately stopped somewhere during processing."

These two statements are almost one and the same, but to understand what they mean exactly, we should first familiarize ourselves with the process of tea production.

Tea processing and differentiating teas 101

Teas can be grouped in many ways: growing area (Chinese, Japanese, Indian, African, etc.), condition of the finished tea leaves (whole-leaf, CTC or cut-tear-curl, powdered, etc.), caffeine content and processing -- these are just some of the many options.

Although many people are not aware of it, the most common grouping of teas (green, black, white, etc.) actually indicates not only the color of the tea, but also the processing of the tea leaves. Here, of course, there is a relationship between the color of the processed tea leaves and/or the brew (green leaves in the case of green tea, black-ish leaves in the case of black tea) and the name; the reason for this is the most basic process of tea production:


Oxidation is a natural biochemical process that surrounds us in all areas of life. If you cut an apple in half and the white inside starts to turn brown, it's oxidation. If a leaf falls from a tree and begins to turn brown, that is also oxidation; and I could go on with the examples.

If we group teas according to processing, we distinguish the following main categories:

  • green tea
  • white tea
  • oolong tea
  • black tea (often referred to as red tea)
  • pu'er tea (or fermented, post-fermented tea)

If we look at oxidation in the three most common types of tea, we can observe the following:

  • green tea: not oxidized
  • oolong tea: partially oxidized
  • black tea: oxidized

Green and black tea give a good indication of oxidation just by their looks. This nicely illustrates the concept of oxidation in tea processing:

  • When making green tea, the goal is to preserve the freshness and green character of the tea. The lack of oxidation shows up in a bright green color, freshness, and vegetable character. This is achieved by heating the freshly harvested tea leaves by baking or steaming them.
  • During the processing of black tea, the goal is to create a longer-lasting, more complex tasting, stronger tea. The longer processing process allows the oxidation to fully unfold, which results in black/brown leaves, a dark brew, and more pronounced, full flavors.

Oolong teas are located on a scale between these two extremes.

Tea feldolgozás - angol nyelvűSource: www.teaepicure.com


Oolong tea

"Oolong" (or wulong, 乌龙) is a Chinese word meaning "black dragon". The origin of the name is probably connected to the oldest red oolong teas, whose dark-colored, twisted dry leaves evoke a black dragon motif. Their appearance in Chinese history is dated to the Song Dynasty (960-1279) at the earliest, and it is believed that they really began to spread during the Ming Dynasty (1368-1644).

Like tea in general, oolong can be grouped in many ways, too. The following two parameters are most common here:

  • based on oxidation: green oolong and red oolong, depending on whether the batch is more like green tea or black tea;
  • by origin: North Fujian Province, South Fujian Province, Guangdong Province, Taiwan, other.

The oxidation level of oolong tea is usually between 10-80%, which means that there can be huge differences between oolong and oolong.

Green oolong teas are usually lighter in color, have a more flowery, fresh fruity taste, and somewhat resemble green teas - such is the "Goddess of Mercy" (Tieguanyin) tea used in the production of Calm Tea. Red oolong teas are more pronounced, give a dark brew, and are characterized by rocky, mature, dried fruit, wilder flavors. For those who are less experienced tea drinkers, it is easy to confuse the latter with black tea.

Oolong teas are predominantly made in China and Taiwan, but we increasingly see oolongs from India, Vietnam, or even African countries. Like black and green teas, they contain many vitamins, minerals and antioxidants.


The "Goddess of Mercy"

My first serious oolong tea experience dates back to 2016, when I studied at university in Hangzhou, China. A tea-loving friend of mine there introduced me to the world of Chinese teas and to the most well-known of them: Xihu Longjing green tea, Da Hong Pao ("big red robe") rock oolong tea, Lapsang Souchong black tea; and last but not least, the Goddess of Mercy, among others.

Goddess of Mercy, or Tie Guan Yin (often abbreviated TGY, 铁观音) is one of the most popular Chinese teas. It originates from Anxi, the southern part of Fujian province on the east coast, with humid, mild climate. Processing of this tea is lengthy and complex and requires high quality, mature, large tea leaves. The smell of the processed, finished tea is floral and inviting; its flavor is reminiscent of peach and jasmine.

Why was she named the Goddess of Mercy? According to legend, a Buddhist farmer in Anxi took it upon himself to maintain the ran-down local Goddess of Mercy (Guan Yin, 观音) temple. He put it in order, kept it clean, took care of the shrine every day, until one night in his dream the goddess Guan Yin appeared to him: "tomorrow go to the garden of the temple, and there you will find a gift for your hard work," she said to the farmer.

The next day, the peasant entered the temple yard, where he found a tea bush. He plucked a branch from the shrub, grew it into a vine in his own garden, then into a tree, and made tea from the harvested leaves. The smell and aroma of the tea was so special that the farmer decided to pay tribute to the goddess and name it after her.


Oolong tea plantation in Anxi -- August 2018 

How does this fit into Calm Tea?

I fell in love with the Goddess of Mercy tea almost "at first sight", because I thought it was an aromatic, fragrant and exciting tea. I particularly liked the fact that even after longer tea sessions, it barely gives off bitter flavors, and its round, fruity, floral character remained.
This green oolong tea turned out to be very interesting with cold brewing as well. Its caffeine content is not negligible, but its theanine content - which is responsible for the tea's calming and meditation-promoting effect - is higher compared to green and black teas. For this reason, it can be made into a pleasant, balanced, stimulating, but not insanely invigorating tea drink.
I think the Goddess of Mercy was a good choice as the refreshing backbone of the first Calm Tea. It is easy to like, it is balanced, and confidently represents the uniqueness of Chinese tea culture.

Goddess of Mercy tea used during the production of Calm Tea

Recommended reading

Should you be interested in reading further in the topic of oolong tea, below are some suggestions:

Serious Eats: A Beginner's Guide to Drinking Better Oolong Tea

Steeped App: Oolong Tea

Teatulia: What is Oolong Tea?

Flying Bird: Az oolong  vagy wulong tea fajtái, ízvilága és kedvező élettani hatásai

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