Photo credit: Terroir Tea Merchant

Oolong teas are semi-oxidized, falling between unoxidized green teas, and fully oxidized black teas. Oolong is one of the most complex teas to learn about, due to the vast array of tea styles, processing techniques, oxidation levels and flavor profiles. Literally translated, oolong means "black dragon" or “dark dragon”. Oolong was originally created in China, and now many of the most famous and exquisite oolongs come from China and Taiwan. Oolong processing requires true artisan mastership, as it is one of the most time consuming and demanding tea types to create.


Many of the names for different types of oolong teas are tied to ancient myths and legends, including the name “oolong” itself. Some believe that the Chinese bestowed the name “wulong” or “dark dragon” upon these tea leaves, which traditionally were heavily oxidized and twisted to resemble the mystical dragon, a highly auspicious and revered symbol in China.

Another story tells a tale of the accidental discovery of oolong by a tea farmer named Wu Liang. After one long day of tea picking, he became distracted and forgot to dry his tea. When he remembered the tea and returned to it, he discovered the leaves had changed color. He was worried it had spoiled, but didn’t want to be wasteful, so he continued to dry it and made a cup to try. He was pleasantly surprised by the smooth taste and aromatic fragrance, and gave some to his neighbors. The tea spread throughout the province, and became known as Wu Long tea.

Tea was first produced from oolong cultivars during the Song Dynasty (960-1279AD), when it was officially a tribute tea in China. The process of semi-oxidizing tea didn’t become widespread until the Ming Dynasty (1368-1644AD), around the time that the famous Yixing clay teapot gained popularity – this small, porous teapot is thought to be the most suitable vessel for preparing oolong.

It is believed that oolong was first produced in the Wuyi Mountains in Fujian Province, and it then spread to the Anxi area, and Guangdong province, and also to Taiwan. These are the most famous Oolong producing regions to this day, although you can also find oolongs from various parts of the world, such as Sri Lanka, Japan, Thailand, Nepal, Vietnam, New Zealand and India.


Oolong tea is similar to wine – there are so many different varieties, based on growing region, processing type, and plant variety. A naming system was developed in Taiwan to create consumer-friendly categories that apply to both Taiwanese and Chinese oolongs:

  1. Baozhong: Translates to "wrapped kind", also called Pouchong or Green Oolong. These are the most lightly oxidized and similar to green tea in flavor, while also exhibiting the complex and floral notes typical of oolongs. The leaves are generally twisted instead of rolled.
  2. Jade: Lightly oxidized with floral characteristics and a light green liquor color. Examples include Dong Ding (or Tung Ding – “Frozen Summit”) and Green Dragon oolong.
  3. Amber: Medium oxidation level with an optional baking after the final firing process. The liquor color is usually amber. Examples include Tie Guan Yin (Iron Goddess of Mercy), Phoenix Mountain, and Wuyi Rock oolongs. These are more traditional oolongs that are typically from China.
  4. Champagne: These have the highest level of oxidation. The leaves are generally colorful, with some golden tips, and the flavor is rich with honey notes. Examples include Bai Hao / Formosa, Oriental Beauty and Gui Fei (Royal Courtesan).
  5. Aged: That’s right – some teas can get better with age! Certain oolongs develop a smooth and rich texture and flavor from years of controlled storage and periodic firings. Fun fact: aged and roasted oolongs are lower in caffeine!


Oolongs can come in a variety of different flavors, from light and floral to creamy to toasty and dark. The tea that ends up in your cup depends on many factors, including the tea plant variety or cultivar, the terroir (the characteristics of the geography, climate and culture where it’s grown), and how the tea leaves are processed after they are harvested.

The flow of oolong tea processing looks something like this:


The leaves that are plucked to make oolong tea need to be relatively large and durable to withstand the long processing. Oolong leaves at lower elevations may be plucked up to 6 times a year, whereas high mountain oolongs can only be harvested 2-3 times because the cooler climate slows the growth of the tea plant.


After they are plucked, leaves are spread on a flat surface to wither, which decreases their moisture content. This can be done in sunlight, partial shade, or indoor Withering softens the tea leaves, making them flexible and supple so they won’t break during the rolling and shaping step. It also promotes chemical changes in the leaf that develops aromatic compounds (for example, UV exposure during withering helps to bring out that lovely fragrance typical in high mountain oolongs). Next, the leaves are placed in air-controlled withering houses where they are often shaken to bruise the leaves, accelerating the oxidation process. The leaves lose up to 30% of their moisture in the entire withering stage.


After being allowed to rest for several hours, the leaves are rolled or shaped by hand or with machines. This process helps the tea leaves develop their unique appearance and flavor profile. As the leaves’ cell walls are broken, enzymes and essential oils are released, altering the flavor of the leaves and further accelerating oxidation. There are many ways that oolongs can be rolled/shaped, depending on the style that’s being made – for example, Tie Guan Yin oolong leaves are tightly packed in cloth and rolled, then removed and fired at low heat, then packed and rolled again (this can be repeated up to 32 times).


Oxidation is a chemical reaction that occurs when the compounds in the cells of tea leaves are exposed to oxygen, altering the flavor of the tea leaves and helping the tea develop its ultimate appearance and color. Black tea is allowed to fully oxidize during processing, and green tea is barely oxidized at all, oolong tea falls somewhere in between and is often described as a partially oxidized, or semi-oxidized tea. Oolong oxidation levels can range from 5% to 85% depending on the type and the production style of the tea master - which is why the flavor profile of some oolongs may lean more toward a fresh green tea (less oxidized) and others toward a malty black tea (more oxidized).


The application of heat is used to stop the oxidation process. It also lends important flavor characteristics to the final oolong tea.


Some oolongs undergo an additional baking step – traditionally done in bamboo baskets or over charcoal. Many variations in time and temperature are used.


If an oolong is aged, it will be stored in a large pot in a dry, cool area and will be allowed to breathe. Unlike pu-erh, oolongs are kept dry and free of fermentation as they age. Most often, the oolong will be taken out of storage every couple of years and baked, which reduces the moisture content and protects the quality of the tea, extends its freshness, enhances the fragrance, and also reduces caffeine content. In Traditional Chinese Medicine, it is believed that aging tea enhances the cooling (yin) property of the tea.


There are a wide variety of oolong types - the leaves can be rolled or twisted, lightly oxidized or heavily oxidized, roasted or unroasted. Here are just a few of the most famous oolong types:

tie guan yin
alishan oolong
jin xuan

Left: Tie Guan Yin (Iron Goddess of Mercy) by Teabook | Middle: Alishan by Melanie Mock| Right: Golden Lily (Jin Xuan) by Rishi Tea


Tie Guan Yin (also spelled “Tie Kuan Yin”) is one of the most widespread and popular oolongs for everyday drinking in China. It is a rolled oolong whose cultivar originated in Anxi county in Fujian province. Tie Guan Yin is one of the most complex oolongs to make. Traditionally it was heavily oxidized and roasted to create a robust, rich tea with an intense aroma. But in recent years, the trend has been towards lighter, greener Tie Guan Yins with less baking.


Oriental Beauty can also be called White Tip oolong, Formosa Silver Tip, or Bai Hao in China. This tea is curled and twisted (not rolled), and is tippy (the leaves frequently have white or golden tips), with natural fruity aromas, a bright red appearance, and a sweet taste. It’s famously known as “bug-bitten” tea – grown with no pesticides, this particular cultivar attracts leafhopper insects, which bite the tea leaves and trigger a unique oxidation that gives a unique sweet flavor to the tea. It is generally highly oxidized (60-75%) and unroasted. We love this Oriental Beauty from Zhi Tea.


Jin Xuan, which translates to Golden Lily, comes from Taiwan and is known around the world as "Milk Oolong" because of its creamy, smooth, and easy taste. Some Jin Xuan tea leaves naturally produce lactones, a compound also found in milk that creates a creamy texture. Milk oolongs have no actual milk in them, but some companies are adding things like milk powder or steaming the leaves over milk to imitate the real thing – so make sure you know what you’re buying! Golden Lily oolongs are generally lightly oxidized (20-30%) and lightly roasted.


Oolong that is grown in the Wuyi Mountains of Fujian, China are sometimes known as "rock teas" because of their distinct terroir - they are grown on mountainsides with rocky, mineral-rich soil, making them highly prized. Da Hong Pao is one of the most famous cultivars of Wuyi rock oolongs teas from Fujian, China. Its name – Big Red Robe – may be in reference to a scarlet blanket sent by a Tang Dynasty Emperor to clothe the tea bushes that cured his mother of a serious disease. It is known for being one of the most expensive teas in the world – costing more than 30 times its weight in gold. This is because genuine Da Hong Pao originates with a cutting from a single group of mother trees, of which there are hardly any left. Genuine aged or antique versions are extremely valuable due to their rarity. Here is another type of a Wuyi oolong from white2tea.


Ali Shan is an area in Taiwan famous for its mist-shrouded peaks and exquisite high mountain oolongs. Alishan oolong is grown at an elevation of 1,000 to 1,400 meters, where there is plenty of fog and low temperatures which are ideal for developing complex floral and fruity flavors in the tea. It is typically lightly oxidized and produces a light golden yellow liquor, though you can also find Alishan oolong that is more oxidized, like this one from Terroir Tea Merchant.


The primary difference between GABA and other types of teas is the way it’s processed: during oxidation, GABA is exposed to a nitrogen-rich environment (as opposed to the typical exposure to oxygen). Japanese researchers discovered a few decades ago that this process enhances naturally-occurring GABA in the tea. It has a deep fruitiness of flavor, with notes of Japanese plum, cinnamon and molasses – delicious and easy to drink. What is GABA? GABA is short for gamma-aminobutyric acid – a naturally occurring amino acid utilized by the human nervous system. It primarily acts as an inhibitory neurotransmitter in the function of adult nervous systems. GABA is also used in supplemental form to encourage anti-anxiety and relaxation. Because of its calming and soothing effects, GABA also lowers blood pressure, helps control hypoglycemia, prevents anxiety and promotes restful sleep. It also may regulate appetite, helping to maintain an optimal weight.


Pictured: Wild GABA Oolong by Terroir Tea Merchant (left) and Da Hong Pao by Harney & Sons (right)


    Because of the wide variety of flavor profiles, processing methods, terroirs and leaf styles, oolong can be one of the most interesting tea types to taste, and is often a favorite of tea enthusiasts and connoisseurs. Flavors can range from light to full bodied, floral to creamy, and sweet to toasty (and may more). Therefore, if you try one oolong and don’t like it, that doesn’t mean you won’t like oolong in general! Try experimenting with a range of oolong types to get a sense of which ones appeal to you most.


    Several factors determine caffeine levels of any tea, including the plant variety and region it was grown, processing style and brewing method. It is believed that oolong tea falls somewhere between a black tea and a green tea in terms of caffeine. A lightly oxidized oolong may have lower caffeine levels and a highly oxidized oolong may have higher caffeine levels. However, if an oolong is aged and roasted multiple times, the caffeine content may decrease. In short, all oolong contains some caffeine, but we can’t make an easy generalization about the exact amount! Read more about caffeine in tea with Lesson 109.


    In order to ensure that your oolong remains fresh, you should store it properly to avoid loss of flavor. Try to store it in a cool, dark place and in an opaque, airtight container away from light, moisture and pantry items like coffee and spices that can leach flavor into the tea leaves. Also, more oxidized oolongs will generally last longer than less oxidized oolongs (similarly, black teas last longer than green teas). Typically, oolongs can last 6 months to 2 years before going stale (although aged, roasted oolongs can last longer in a controlled environment


    Because oolong teas can have a wide range of oxidation levels and leaf styles, their ideal brewing temperatures and steeping times can vary. It’s best to check with your tea vendor or look on the package for steeping instructions if they are available. If not, here are a few general brewing techniques for oolong:



    • Water Kettle or Pot to Heat Water
    • Tea Leaves / Sachets / Bags
    • Teapot with Filter / Teacup / Personal Mug and Filter


    • 195℉-208℉ // Just under boil

    The exact temperature depends on the oolong type and on your own preference (when in doubt, try making a new oolong with different water temperatures to see what works best for you)

    Pro Tip: Use filtered water for the best tasting cup!


    • About 2 grams (1 tsp for rolled oolongs, 2 tsp for loosely twisted oolongs) per 8 oz. (1 cup) of water

    Pro Tip: Add tea leaves to an infuser that lets them open fully, or you can put them straight into the teapot and use a strainer when you're pouring a cup!


    • 1-3 minutes

    Pro Tip: Don't let your tea steep for too long! It's best to take the leaves/sachet/bag out when the time's up so you aren't left with a bitter cup. Taste your tea after the recommended steeping time and then decide if you’d like it to steep a little longer.

    Pro Tip: Cover your tea while it steeps to keep all the heat and aroma in the steeping vessel.

    Additions: To appreciate the artful production and flavor complexity of an oolong tea, you should always try it plain with no additives like milk or sweeteners.


    Note: Cold brewing is another way to bring out the complex flavors of oolongs in a refreshing glass of cold tea. Check out how to cold brew tea here.

    Check out this short video on how to prepare oolong tea:

    how to steep oolong tea


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    Written By: Melanie Mock




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