In our prequel piece, we laid the groundwork for what makes a particular libation truly “tea.” If you need a recap on all of the basics of Camellia sinensis and the processes that produce the subcategories of white, green, black tea, etc. click here.
As we mentioned in The Real Tea Part I, there are certain steps that are still essential to the processing of tea leaves (i.e. it must be plucked to get from a plantation to your cup). But now we’d like to dive deeper into that “boundless potential within the process,” fertile for exciting experimentation and expansive variations to flavor. One avenue that has proved to be ripe with diversity is the chemical process of oxidation.
Let’s think of oxidation as the plant absorbing oxygen and as a result (and with time), browning. If you want to get down to the nitty gritty, oxidation is an enzymatic reaction that begins when tea leaves are damaged (the moment they are torn from the body of the plant) and continues as the leaves' cellular contents are being sloshed around and exposed to the air. Rolling, tearing and crushing leaves are different modalities used to accomplish the same reaction, with their subtle distinctions ultimately influencing the resulting taste. The aftermath of the enzymes’ work is the degradation or conversion of various compounds into new ones which is reflected from our point of view in the changes that we experience in color (green to brown or any amber-like color in between) and flavor (i.e. “vegetal” to “malty”).
When it comes to experimenting with oxidation in the realm of tea, there is no better illustration than our dear oolong. In fact, the distinction of (partial) oxidation is what distinguishes whether or not a tea leaf can be considered a part of the oolong family. The spectrum is wide-ranging, but oxidation levels can roughly span from 8-85% to be qualified within this particular class of tea. Translation: this range means that the leaf will land somewhere between more oxidized than green teas but less than black teas.
Once the process has concluded per the tea master’s wishes, the leaves are heated to fix them in their desired state. There are a variety of methods that can be used such as pan firing, steaming and roasting which will ultimately factor into the taste as well. SILK & JADE's oolong tea leaves are fixed using a high temperature tumbler, creating a delicate red edge with a naturally green center still intact. While the variety and room for possibility seem to be almost infinite, we will attempt to briefly break down this mysterious world of oolong into subgenres of light, medium, and heavy oxidation levels.
Light oxidation: Jade Oolong
Lightly oxidized oolongs often resemble green teas and also tend to taste similar. However, the defining oxidation step can lend to a more full bodied mouthfeel and deeper, more rounded flavor rather than the typical light and bright taste of green tea. Oftentimes these “green oolongs” carry a floral personality like that of our Jade Oolong, which exhibits notes reminiscent of osmanthus followed by a buttery finish. The light oxidation preserves this soft quality, while the twisting of its leaves further amplifies and releases its flowery essence. S&J’s Jade Oolong is pure and never tumbled with flowers or added flavoring agents, but the unique vibrance of the terroir and minimal processing makes these notes exceptionally palpable.
Medium oxidation: Silk Oolong
More heavily oxidized leaves tend to move towards resembling a black tea while the precision of the oolong's processing offers a more dynamic personality than a predictable English Breakfast or Assam. Silk & Jade's Amber Oolong undergoes heavy oxidation after it is harvested during a meticulously defined window in the summer season when the leaf hopper insect can be found in the tea shrubs. In addition to the influences of oxidation, the chemistry of the plant's response to small tearing bites from seasonal leaf hoppers comes together to present a round, honeyed aftertaste.
The term oolong (pronounced “wūlong”) can be interpreted as “black dragon.” With such an elusive identity, constantly mutating and shifting, it seems the enigmatic title is quite fitting for Taiwan’s preferred drink of choice. The country’s subtropical climates, precise machinery and artisanal technique have provided the grounds for, dare we say, “perfecting” the craft of oolong tea. Beyond its quality and diversity in taste, people on the island consider it suitable for all-day consumption due to its ability to balance heat and cold in the body.
The detail in processing, along with brewing method, allow for oolong to be enjoyed through multiple steepings. As mentioned in our previous piece, rolling and/or twisting of the tea leaves is often more pronounced and visible in oolongs, which decreases its surface area, or exposure to the water. Using the gongfu method of brewing involves much more tea (plant matter), less water and a shorter steep time than the common Western approach. Each small cup reveals a new quality about the tea as the leaves continue to unfold and the experience is more robust on the palate due to the concentrated, almost espresso-like style of brewing. We encourage you to experience the profound complexity of oolong tea gongfu style with our interactive Fundamentals of Tea Workshop.
This gongfu method is also a perfect way to prepare a rich, layered tea like puerh. Puerh is produced solely in the Yunnan province of China and gets its name from the town in which its production originated. Also known as “dark tea,” puerh serves as a great example for demystifying the age-old confusion between oxidation and fermentation. Oftentimes when the concept of oxidation is discussed in the realm of tea, the term is used interchangeably with “fermentation.” We believe this may be due to some differing interpretations of the terms in the Chinese language and its crossover (or lack thereof) in English. However, these chemical processes are quite different - oxidation being a relatively constant part of the tea making process, while fermentation is reserved for only a select group of specialty teas like the aforementioned puerh as well as yellow tea or "huángchá."
Fermentation is a complex chemical reaction that fosters microbial growth - meaning it stimulates that good bacteria that is healthy for our guts. There are two primary methods of feeding this reaction - one being a newer, accelerated version of the traditionally lengthy process. Both work by feeding small amounts of moisture to the dried tea leaves and allowing nature to do the rest. The moistened tea is either steamed and immediately pressed (Sheng) or subjected to controlled, hot steam for up to two months (Shou) and eventually squeezed into a compressed tea “cake” form.
Keep in mind that prior to fermentation, the puerh leaves have also undergone oxidation when they were picked and rolled, damaging the leaves’ cell walls. Once the dried leaves are subjected to moisture for this added fermenting step, oxidation can begin again. So both processes can occur simultaneously!
Once purchased, puerh can be steeped and consumed immediately or left to age for years and even decades! Consider this group like the fine wine of teas - the longer it ages, the better! The accelerated or “Shou'' version mimics the aging process that occurs over years with raw or “Sheng” puerh. Imagine buying a Sheng puerh cake today and letting it age in your cellar for 20 years.
These fermented subgroups are often even more prized than oolongs in cultures of the east. Both puerh and yellow tea essentially begin as green tea that, with additional steps, are melded into an entirely new persona. Like oolong, puerh has a wide range of potential for taste with the added tweak of aging to further amplify the possibilities. It would be an injustice to condense the boundless diversity in flavor within the world of puerhs into just a few words, but the process of fermentation is said to generally mellow some of the biting tannic quality and bitterness that we tend to experience more commonly with black and green teas.
The gentle, sometimes sweet, divergence (from it’s close green relative) is the hallmark characteristic of yellow tea. Offered as what was known as a “tribute tea” to ancient emperors and the elite as a gesture of honor, this is a rare tea that seems to only be cultivated in limited amounts within China. The yellow tea leaves are also subjected to moisture like puerh but through a different process of being wrapped in a wet cloth immediately after the drying/heating process, which creates steam. The sequence of these “sealings” can continue for up to three days to slightly ferment the leaves. This process is a delicate and tedious one that a limited number of tea masters still practice today, making yellow tea a scarce commodity.
Oolongs may be the dragons of the bunch, but the tea plant as a whole exhibits a chameleon-like capacity to be transmuted into an intricate repertoire of characters. Every detail counts and adjustments to a number of factors within production affect the color, properties and taste that the tea exudes starting from its placement on the farm all the way to your cup. The cultivation of camellia sinensis can lead to a personality far beyond a familiar Lipton or Bigelow sachet and is worthy of the same adulation that Westerners give to aged spirits and even coffee beans nowadays. Silk & Jade is excited to share in the realization of all of tea’s plant magic and provide supreme selections for an immersive experience on our ever-expanding tea journey.
Article written by Mariah Monet J.