It's easy for anyone to distinguish the difference between a black and green tea just based on the colour. But that can't be said for black and oolong teas. Even more confusing, we recently received an email from a beginning tea drinker asking: "Is oolong tea a black tea or green tea? One other tea drinker asked: "Does oolong tea have black tea in it?" The fact is that oolong is a category in itself, and it differs in production method, appearance and taste.
Black tea is the most familiar tea in the West, as it was the earliest type introduced to the West hundreds of years ago. The Dutchman Jan Huygen van Linschoten was the first who successfully bring tea to Portugal. Then green tea started to become popular since around 20 years ago due to the media frequently mentioning its health benefits.
In contrast, oolong tea is a relatively new tea that became popular in the recent years. It's therefore not surprising that many people can't really distinguish between the two. Let's take a look at the differences between these tea types in the below discussion.
Oolong Tea versus Black Tea/Green Tea Production
What is oolong tea made of?
A lot of people believe that a dark oolong tea is a type of black tea. This isn't true. Like all teas, oolong is also made from the Camellia Sinenses tea plant. However, each tea type is processed in a different way. The processing methods used for black teas result in fully oxidised leaves.
Green teas are minimally oxidized maintaining its green colour. When leaves are picked, they are dried in the shade and directly roasted in a pan to stop the oxidation.
Oolong teas have oxidations levels between that of green and black tea. Hence, they're also known as 'semi oxidised' teas.
However, the term 'semi oxidised' is perhaps not fully correct. As different oolongs can have different levels of oxidation, the term 'partially oxidised' is a more suitable term as it takes into account the different levels of oxidation.
Appearance Differences
From a raw material point of view, black teas that consist of small buds are generally considered more premium. Teas like Lapsang Souchong or Keemun all consists of small leaves or buds. Black teas are even more expensive, if they consist of a lot of golden buds, which is the case for teas like Yunnan Gold or Jin Jun Mei. Also for green teas, the younger and more tender buds are preferred.
In contrast, oolong teas are less about small buds and leaves. In fact, they often consists of larger leaves, which are more suitable for the intense processing steps they undergo. With oolongs, the edges of the leaves are brushed when the teas are rolled, resulting in complex aromas. This is especially the case with Tie Guan Yin.
Besides the size of the leaves, oolongs also have a wide range of colours. Take for example a Tie Guan Yin, which is very lightly oxidised, and thus maintaining a green colour. Therefore, it's not strange that many people wrongly think that Tieguanyin is a green tea.
Other oolong teas such as Dan Cong and Da Hong Pao have a darker colour. These dark oolong teas have oxidation levels that are closer to a black tea, though they still belong to the oolong category.
The wide range of colours is due to the fact that oolongs can have different oxidation levels, resulting in also a wider range of flavour possibilities.
Taste Differences
While black and dark oolong teas may appear to have a similar colour, the taste is completely different. Black teas often have honey, caramel or smokey notes. Some of these notes may also appear in dark oolong teas. However, dark oolong such as Da Hong Pao have the rock mineral base that you won't easily find in black teas.
Then you have light oolong teas such as Tie Guan Yin, wihch often taste more like green tea with flowery notes. Yet, green teas are generally more vegetal and grassy, while light oolongs have more smooth and rounded flavours due to oxidation. For first time tea drinkers, a light oolong is often more accessible in taste relative to a grassy green tea.
When to drink oolong tea?
The timing of drinking oolong tea isn't much different from black tea. The most proper time is about 30 minutes after breakfast and lunch. It helps you avoid the mental dips after a meal and it aids digestion. For more info you may also read: When to drink oolong tea
Caffeine levels
Caffeine in tea is a very complex topic, depending on brewing methods, teaware used, steeping time and temperature and tea-to-water ratios applied. Thus, it's not possible to simply tell you what the exact caffeine level of a cup of black versus oolong tea is. To learn more about the factors behind caffeine levels you may read our Tea Caffeine Guide.
Conclusion
To sum up, black tea and oolong teas are really different tea classes. There differences in processing methods result in different levels of oxidation. Good black teas often use small leaves, while this matters less for oolong tea. The difference in processing and raw material selection result in different flavours. While we've attempted to try our best to explain the differences, we highly recommend you to experience the difference yourself. Several years ago, cheap oolong was at first introduced as a weight loss tea in the West. Today, there's a wide offering of excellent artisan oolongs directly available in our Teasenz online store.