Oolong Tea: What is it and why do we love it?

In the world of pure tea, especially when it comes to Chinese teas, there are 6 main categories – White, Yellow, Green, Oolong, Black and Dark teas. All true tea comes from the same plant – Camellia Sinensis – and the differences lay mainly in the way each type of tea is processed. There are also other factors such as varietals and cultivars, terroir etc but that’s a topic for another discussion. In this article, we explore the what, the how and the why of Oolong tea.

WHAT IS OOLONG TEA?

Simply put, Oolong tea is a semi-oxidised tea that sits between a green and a black tea. With green tea, there is very little, close to zero percent oxidation and with black tea, the leaves are fully oxidised. Oolong tea sits somewhere in between, with some types leaning closer to the green side, sitting at around 10 – 20% oxidation, and others leaning more to the black tea side at 70 – 80% oxidation. These varying levels of oxidation is one of the reasons why there are so many different varieties of Oolong teas, each with their own unique flavour profiles. This makes it one of the most interesting and exciting types of teas to experience and explore for us tea nerds.

DIFFERENT TYPES OF OOLONG TEAS

The best way to explain the different types of Oolong teas available is through the key regions that have historically produced Oolong teas: Southern Fujian (home of Tie Guan Yin aka Iron Goddess), Northern Fujian (Rock Tea), Guangdong (Dancong) and Taiwan.

Southern Fujian Oolong

The Southern Fujian region is the home of Tie Guan Yin, one of the "Top ten teas of China." It’s perhaps the most widely available and well-known type of Oolong tea around and is a ball-rolled type of Oolong. Flavour-wise, it’s generally quite floral and the levels of oxidation range from light at 20% to medium at 50%. The most popular versions around the world tend to be the greener types with a light roast.

The Southern Fujian region however produces more than just Tie Guan Yin Oolongs. Other varieties such as Huang Jin Gui (aka Golden Osmanthus) and Bai Ya Qi Lan are also becoming increasingly popular with tea lovers worldwide. Bai Ya Qi Lan in particular is a wonderfully complex, floral and aromatic tea that looks very similar to Tie Guan Yin in that it’s also a ball-rolled Oolong, but has a different flavour profile and full yet soft mouthfeel.

Northern Fujian Oolong (aka Rock Teas)

The northern Fujian region produces a distinct type of Oolong tea known as “Rock Tea”, with the best types coming from the Wuyi Mountains. These are long, strip types of Oolong teas that have a distinct “rocky” or mineral-like characteristic that links them all together, otherwise known as Yán Yùn (岩韵), which literally translates to “rock rhyme”. The most expensive tea in the world ever sold was a Rock Tea known as Da Hong Pao, or Big Red Robe. It’s a type of tea that’s taken on a legendary, almost mythical status, with this particular one being processed from a blend of leaves picked from the 6 original mother trees.

The 6 original Da Hong Pao mother trees

20g of this tea was sold at auction in 2002 for ¥180,000RMB – that’s over $28,000USD for just 20g of tea! And since 2006, in order to preserve and protect the 6 original mother trees, picking leaves and producing tea from these trees is prohibited, with the last 20 grams of tea produced from these trees donated to the China National Museum in Beijing. So as a super rare, collectors item, it may just be worth the price.

Da Hong Pao is now a widely available type of Rock tea, but obviously, not in the same league as this one of legends. Rou Gui, Shui Xian and Bai Ji Guan are some other well-known Rock teas. Check out our YouTube channel for more on Wuyi Rock tea and Da Hong Pao.

Guangdong Dancong Oolong

In the neighbouring province of Guangdong, the Chao Zhou region produces Dancong Oolong teas. Another strip type of Oolong, Dancong teas are most well-known for the intense aromas and the wide variety of different aroma types. There are said to be over 100 different sub-varieties of Dancong, broken up into roughly 10 different main aroma categories, each with their own unique taste and flavour profiles. The word "Dancong" literally means "single stem." If you look at an actual Dancong tea plant, you'll see it differs from your standard tea plant in that they're all single trunk trees as opposed to being long interconnected tea bushes.

Dancong tea trees in the Phoenix Mountains of Chao Zhou

All varieties of Dancong Oolong tea stem from a series of "mother trees" that had cuttings taken from them and gradually cultivated over time to arrive at the many different aroma varieties that we have today. Honey Orchid (Mi Lan Xiang), Duck Poop (Ya Shi Xiang), Almond Fragrance (Xin Ren Xiang) are some of the more popular cultivars of Dancong Oolong tea.

Taiwanese Oolong

Finally, we have Taiwanese Oolongs. Tea plants in Taiwan were originally brought over from Fujian in the late 18th Century and have since developed unique characteristics of their own. Not surprisingly, many Taiwanese Oolongs share similar characteristics with Southern Fujian Oolongs such as Tie Guan Yin, but others, like the summertime “Oriental Beauty” is unique to Taiwan. What makes the “Oriental Beauty” Oolong unique is that it requires the leaves be bitten by leafhopper insects, which causes the tea leaves to release certain enzymes to defend themselves against these bugs. As a result, the releasing of these enzymes helps to give the tea its unique flavour and characteristic.

HOW IS OOLONG TEA MADE?

Once the tea leaves have been picked, there are 6 general steps in the production of Oolong tea: Withering, Shaking, Fixing, Rolling/Twisting, Drying and Baking. While there are slight regional variations depending on the type of Oolong tea being produced, here’s a short explanation of each step in general.

Withering

 
Tea leaves withering indoors

After picking, tea leaves are left out to “wither.” During this stage, the cell walls in the leaves start to break down, the tea leaves soften and become pliable, ready for further processing. This withering  can be done outdoors or indoors but the key is for the leaves to be lightly exposed to sunlight. Best conditions for this are generally slightly overcast days where the light is softer and the sun isn’t too harsh. This stage is very much dependent on the weather, with farmers and producers having to determine the best time to begin tea processing. Sometimes it’s morning, other times it’s late afternoon.

Tea leaves withering outdoors

Once the withering begins however, the processing of the tea can’t really be stopped until closer to the end, lest they wish to throw out this entire batch. This means, if withering began late in the afternoon, tea producers need to stay up till the early hours of the morning to ensure the best quality tea.

Shaking

 
Shaken, not stirred – withered tea leaves getting shaken in large bamboo rollers

A key step that’s unique to the production of Oolong tea is Shaking. After withering, traditionally, tea leaves are then placed onto large bamboo trays, or into big bamboo rolling machines and “shaken up.” The shaking slightly bruises the leaves, which causes the leaves to begin gently releasing their internal tea juices. The juices then come into contact with oxygen in the air, and a chemical reaction known as “oxidation” begins. The level of desired oxidation in the leaves varies depending on the type of Oolong tea and from producer to producer as well, and this will determine how much and how often they will shake the leaves.

Hand shaking withered Oolong tea leaves 

Typically though, tea producers would shake once every 1.5 – 2 hours, for between 5  – 10mins, with the process repeating 5 – 6 times. With the tea juices come aromas as well, which are also released into the air during this stage. The smell of the room during this stage of tea processing is incredibly fresh and intoxicating.

Fixing

Fixing aka "sha qing" aka "Killing the green" in an old-school hot air tumbler

After several hours, once the shaking is done and the desired level of oxidation has been reached, the tea leaves then undergo a heating where this level of oxidation in the leaves becomes “fixed.” This can either be done in large hot air tumblers or by hand in big, wok-like vessels. This stage is also known as “Sha-qing”, which literally translates to “killing the green” and more or less determines the eventual colour of the finished tea leaves.

Fixing the green in wok-like vessels (Photo credit Easy Tour China)

Rolling / Twisting

 
Machine used to twist Oolong tea leaves

Depending on the type of Oolong tea and the region it’s produced in, the next stage is shaping the tea, which either means the leaves get twisted into long strips (e.g. Phoenix Dancong or Wuyi Rock teas) or, as is the case with teas such as Tie Guan Yin or Bai Ya Qi Lan, twisted then rolled and shaped into tiny balls. This is either done manually, by hand (or in the old days, feet – yes, feet) or, in most cases for modern producers, it’s done through machines. Producers need to be careful during this stage to apply the correct amount of pressure to be able to get the desired shape, but also not ripping or tearing up the tea leaves.

Additional step of rolling the tea leaves for Southern Fujian and Taiwanese Oolong teas

Loosening clumped tea leaves

Once shaping is complete, tea producers need to then loosen up the clumped tea leaves and place them on to large bamboo trays, ready for the drying stage.
 

Drying

Tea leaves drying

Once the leaves have been shaped to its desired form and loosened, the tea leaves undergo its first firing or drying, which is generally done in large, temperature controlled oven-like devices, specifically made for tea production. Once done, the tea is now at the “Mao cha”, or rough tea stage. From here, producers begin sorting the tea leaves, picking out the stems and any undesirable bits from the batch. This can be sorted by machines, but for many small producers, this is still done by hand.

Picking out stems and sorting the dried tea leaves

After this, the tea producer can rest a little as the tea will generally hold its flavour and characteristics whilst in the Mao cha stage. It’s also at this point that buyers would come in and begin tasting varieties of Mao cha and make judgement calls on whether or not they wish to buy this particular batch of tea. Mao cha would display most of the flavours and characteristics of the final tea but the final baking would bring these out even further and add further complexity to the tea. For greener types of Oolong teas however, the tea leaves go through the drying stage twice but not a final bake.

Baking

Tea leaves being charcoal fired in bamboo baskets

The last stage of tea production for darker and heavier types of Oolong teas is a final firing or baking of the Mao Cha. The baking adds extra flavour complexities and depth to the tea, as well as allowing for better long term storage. Flavours can be adjusted based on the Bake levels, with buyers able to request a lighter or heavier bake depending on their taste preferences. Heavier bakes can also serve to mask mistakes made in previous steps during the tea’s production or, in some cases, mask undesirable characteristics of lower quality teas. In most cases, the final bake are done in the same oven-like machines as the Drying stage but with adjusted settings; occasionally, and usually for higher quality tea leaves, the final bake is done through a charcoal firing process.

Charcoal firing is a labour intensive process that's done by hand, takes several hours of care and monitoring to ensure the correct amount of heat is applied consistently throughout the entire time. Small mistakes, for example, if a few tiny tea leaves accidentally drop into the charcoal, smoke is created, it covers the tea leaves and what was once highly prized, expensive tea becomes over smoked and much less valuable now. Charcoal firing tea leaves is a process that's generally reserved for higher grade tea.   

HEALTH BENEFITS OF OOLONG TEA

There’s a lot of talk about the perceived health benefits, not just of Oolong tea but tea in general. Some would say drinking Oolong tea regularly will prevent heart disease, diabetes and cancer, lowers blood pressure, treats osteoporosis, promotes weight loss etc. Whilst drinking tea regularly is going to be healthier than drinking soft drinks and alcohol regularly, and as wonderful as all of these miracle benefits sound, please, PLEASE, don’t believe all the hype.

On one of our tea trips, we got a chance to meet a bona fide tea master, Mr. Wang of the Wuyi Mountains, the former caretaker of the legendary Da Hong Pao Mother Trees. He believes that when talking about tea, it’s irresponsible to talk about all these health benefits and that we should leave discussions like this to doctors and medical professionals who actually know what they’re talking about. Tea should simply be enjoyed for what it is – a complex and tasty beverage. This is a sentiment that we wholeheartedly believe in.

WHY DO WE LOVE OOLONG TEA?

From personal experience, I’ve found Oolong tea – particularly a Honey Orchid Dancong or Rising Dawn (aka Bai Ya Qi Lan) – to be my go-to teas to keep me going throughout the day. They are strong enough in flavour to give my palate a bit of kick and, I have found that they also keep me sufficiently alert when needed. Oolong tea, like all other pure teas contains caffeine, but they – and the same goes for teas in general – also contain an amino acid called l-theanine, which has been found to promote relaxation. So the combination of caffeine and l-theanine means that unlike coffee, where you get a spike in alertness, followed by a crash afterwards, with Oolong tea, it’s more like a gentle lift, followed by a gentle decline.

Tea set at work

We also love the flavour variety that Oolong teas provide. With all the different varietals and cultivars out there, combined with varying levels of oxidation and roasting, the regional styles and all the different types within those regions, when you begin diving into the world of Oolong teas, there’s just so much to discover and explore that it never gets old or boring. And we haven’t even mentioned the terroir and how even within the same region, growing the same varietal or cultivar of tea, different mountain ranges and different locations will impart different characteristics into these teas.

From the very beginning, when we started Tea Angle, we’ve focused quite heavily on Oolong teas and trying to understand as much as we can about this amazing style of tea. The deeper we go, the more we learn, discover and try to understand, the more we realise how little we know and how much further we still have to go in order to understand this wonderfully complex category of tea.

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Tea Angle are based in Sydney Australia. We are purveyors of fine Chinese teas and the teas that we source are single origin and have no added flavourings. Click here to see our tea collection