The Best Black Tea vs. Oolong Tea Comparison

Jill Caren

Black tea is very popular in the West. Oolong tea is not so popular in the West but is one of the favorites among tea …

Categories Black Tea

Black tea is very popular in the West. Oolong tea is not so popular in the West but is one of the favorites among tea drinkers. Both kinds of tea, properly brewed, make delicious and healthy beverages.

Black vs. oolong tea: it is so hard to say which one is better, but I can definitely show you their differences and you’ll decide which one to choose.

Black Tea vs. Oolong Tea

Before I show you the main differences between black and oolong tea, I consider it essential to understand the fundamentals of these two popular types of tea.

Black Tea: The Unique Qualities

Dry black tea loose leaf
Dry black tea, loose leaf

Black tea is made from the Camellia sinensis plant. All true teas (green, white, black, oolong, and pu-erh) come from this plant, and they develop unique characteristics depending on the production process and other factors.

I mentioned the production process because it has a significant impact on the final appearance of the leaves as well as the benefits of the tea.

So, the main characteristic of black tea is that it is more oxidized than other teas. To be more clear, here is a little comparison: Green tea is not oxidized (or only minimally), black tea is fully oxidized, and oolong tea is semi-oxidized.

The length of the oxidation process has a significant influence on the flavor and appearance of the tea. As a result, black tea has a stronger flavor and a darker color than other teas.

There are very different types of black tea, which are characterized by where they are harvested, and black tea blends, which are very popular around the world.

The following are the most popular types of black tea:

  • Chinese
    • Lapsang Souchong
    • Keemun tea
    • Yunnan tea
  • Indian
    • Assam tea
    • Darjeeling
    • Nilgiri tea
  • Sri Lankan
    • Ceylon tea

The most popular black tea blends in the world are Earl Grey, English Breakfast Tea, and Masala Chai.

Oolong Tea: The Unique Qualities

Oolong tea, loose leaf
Loose-leaf oolong tea

Oolong tea is a semi-oxidized tea, which means it falls somewhere between green and black tea. Darker leaves and a reddish tea brew imply higher oxidation. The major feature that separates oolong from other true teas is its shape. Oolong tea leaves are twisted or rolled into balls.

This is nearly exclusively Chinese tea, which is different from black tea, which may originate from a range of countries.

Also known by the name Black Dragon Tea, depending on the levels of oxidation, oolongs are mainly classified as green oolongs (10-30% oxidation) with fragrant floral notes and dark oolongs (40-80% oxidation) with more subtle fruity and woody overtones.

Since oolong tea is not fully oxidized, many of the natural polyphenols are kept. While black tea contains mainly theaflavins and green tea has the highest levels of catechins (particularly EGCG), oolong tea includes both catechins and theaflavins.

These polyphenols are major elements that make tea a healthy beverage. They act as antioxidants.

Depending on the oxidation level, origin, climate, soil, and other production variables, there are many types of oolong tea. The most popular ones are:

  • Iron Goddess of Mercy (Tie Guan Yin)
  • Wuyi Oolong Tea (Da Hong Pao)
  • Phoenix Tea (Dan Cong)
  • Milk Oolong Tea (Jin Xuan Tea)
  • High Mountain Oolong Tea (Gaoshan)

Black vs. Oolong Tea: The Main Differences

Black TeaOolong Tea
Leaf Colordark, with shades of dark brownbrown to dark brown with shades of red or green spots
Leaf Shapewhole uniform leavesformed into balls by twisting or rolling
Flavorrobust, earthy, slightly bittervariation of sweet and floral, rich and roasty
Caffeine40-80 mg per cup15-55 mg per cup
Water Temp. 190°F-212°F185°F-208°F
Steeping Time5 min.3 min.
Black Tea vs. Oolong Tea: The Main Differences

Leaf Color and Shape

Black tea leaves are typically a uniformly dark color, with some types showing varying shades of dark brown. A brewed black tea can range in color from amber to dark brown.

If the black tea is of high quality, the leaves should be uniform in color and shape. If you find broken leaves or a mix of different leaves in your tea package, in most cases, this means that your tea is not of high quality.

Oolong tea leaves are typically brown to dark brown with red or green spots. They are formed into balls by twisting or rolling them. Oolong tea leaves with higher oxidation levels are usually darker brown, and those with lower levels of oxidation are brownish red.

Depending on the oolong, the color of the brew can range from green to golden to brown.


As I mentioned before, there are many different types of black tea, each with its own unique flavor profile. In general, black tea has a robust, earthy, and slightly bitter flavor. This is why many people enjoy their black tea with sugar or milk.

I enjoy the flavor of black tea as it is, without sweeteners, and if you brew it at the proper temperature and use high-quality tea, I’m confident you will as well.

The flavor of oolong tea can also vary depending on the type.

Greener (less oxidized) oolongs will have a sweet and floral flavor, whereas more oxidized oolongs will have a rich and toasty flavor.

Oolong tea has a more complex flavor than black tea, and personally, I like the flavor of good oolong more than the flavor of black tea.

Caffeine Levels

Black tea usually has more caffeine than oolong tea. This is not always the case. Different types of black and oolong tea have different caffeine levels. Furthermore, if you brew a stronger cup of oolong tea, it will have more caffeine than a regular cup of black tea.

An 8 fl oz (237 ml) cup of black tea typically contains between 40 and 80 mg of caffeine, or approximately 47.4 mg per cup.

In comparison, an 8 fl oz (237 ml) cup of oolong tea has between 15 and 55 mg, or around 37 mg of caffeine.

The caffeine levels of black and oolong tea may vary depending on the tea type, steeping time, brewing temperature, etc.

The caffeine content of oolong tea is somewhere between green and black tea. If you prefer tea with higher caffeine levels, opt for black tea.

Furthermore, the caffeine levels of black tea and the same for oolongs vary by type, so it is always good to read the label or ask your tea provider about the caffeine levels in your tea.

Water Temperature and Steeping Time

  • Oolong Tea
    • Water Temperature: 185°F-208°F (85°C-98°C)
    • Steeping Time: 3 minutes
  • Black Tea
    • Water Temperature: 190°F-212°F (88°C-100°C)
    • Steeping Time: 5 minutes

As you can see, there is a little difference between black and oolong tea when it comes to brewing temperature and steeping time. Generally, oolongs require lower water temperatures and less steeping time compared to black tea.

Note: Please keep in mind that these numbers for water temperature and steeping duration are only estimates.

Different types of oolong tea and black tea have different water temperatures for brewing and steeping. Sometimes, depending on the type, they may be higher or lower. Always follow the brewing instructions on the label.

Oolong or Black Tea: Which One Should I Drink?

If your question is which one to choose: black or oolong tea, my answer will be to try both of them and pick the one that you’ll like more. If you like some guidelines, both teas have their own advantages.

The Advantages of Black Tea

Black tea contains more caffeine than oolong tea, and many people drink it as a substitute for coffee. Among high-caffeine teas, black tea is the most popular worldwide. Not just because of its higher caffeine levels, but also because, like the other true teas, it contains the amino acid L-theanine.

A combination of L-theanine and caffeine, as found in tea, has been shown to enhance attention, focus, and concentration. Tea’s caffeine provides a longer-lasting energy boost without the jitters and energy collapse associated with coffee’s caffeine.

Due to its higher caffeine levels, it is not recommended to drink black tea late at night because caffeine can interfere with your sleep. To learn more about this, visit my detailed article about the best time of day to drink black tea.

The Advantages of Oolong Tea

Oolong tea is more tea to enjoy with every sip. Almost all oolongs offer a rich, deep flavor, which is why I personally love this tea. Despite accounting for just around 2% of all tea produced and consumed globally, oolong tea is a favorite beverage among tea drinkers worldwide.

Because it’s lower in caffeine compared to black tea, it’s said to have a calming effect on the nervous system and may help you boost your mood and de-stress. Oolong’s flavor, aroma, and beautiful liquid color will certainly relax you and clear your mind.

This tea is so great that one of the Chinese oolong teas named Da Hong Pao, also known as Big Red Robe Tea from the Wuji Mountains of China, is one of the most expensive teas in the world often reserved for welcoming elite guests.

Closing Point on Black vs. Oolong Tea

Now you know the main differences between black and oolong tea, such as their flavor, caffeine content, leaf color and shape, brewing temperature, and steeping time. These contrasts may help you choose the right tea for you.

My advice is that if you want a good replacement for coffee that is rich in caffeine for better focus and concentration, opt for black tea. When you want to enjoy your cup of tea and have a tea with beautiful color and a wonderful taste that will help you relax and clear your mind, opt for oolong tea.

Both oolong and black tea are great beverages, and I’m sure that you’ll like both of them. It’s best to try both of these teas and decide which one is best for you.

In the end, I just want to remind you to always use high-quality loose-leaf tea. When possible, avoid using tea bags and follow the brewing instructions to always get a cup of tea with the right flavor.