Tea - #Oxidation of Tea vol. 1
In the previous article called “Tea - The Exiled Emperor Discovery” we spoke about the history of tea and how it shaped the world we know today. Tea has influenced and changed the world in more ways than we could have imagined, with the aforementioned countries having the biggest influence. In this article, we will look further into the classification and production of our beloved teas.
For the most part, teas are harvested using very similar methods. The main differences in tea production are the amount of oxidation they undergo and how the oxidation process is halted. Oxidation is the second step in tea production (after harvesting) and is the process by which the tea is exposed to oxygen. During oxidation, the tea develops its flavour profile, with deeper flavours and darker teas being produced the longer the oxidation process continues. Tea masters use several different methods to create and control oxidation and these are chosen based on which tea is being created. Methods of controlling oxidation include: rolling, shaping and, or crushing tea leaves to help and speed up the process. Afterward, oxidation is stopped by steaming, firing, and roasting the tea.
Now, let's look at the lightly oxidised teas in more detail:
Green teas go through 2-3 steps, with the first one is drying. Next, they go through a process called fixing or kill-green, which stops oxidation from continuing longer than required. This step is done by heating the leaves to a minimum of 65°/70° Celsius at which the enzymes responsible for oxidation are destroyed.
The Chinese style of green tea is characterised by pan-firing, where tea leaves are heated in a basket, pan, or rotated in a drum. This process might be repeated more than once depending on the style of the product. Firings can be conducted in several different ways including; using a wicker basket, steel wok-like pans, or by utilising metal drums over charcoal, gas flame, electric heat, or hot air. The chosen method is based on the prefered flavour outcome. Chinese green teas are generally pan-fired and the tea takes on a yellowish-green or dark green color with grassy, earthy, roasted flavors.
The green teas originating in Japan are often briefly treated with steam within hours of harvesting. The steaming process brings out the rich green color of both tea leaves as well as a final brewed tea. Steaming creates a unique flavour profile that can be described as sweet, vegetal, or seaweed-like.
Let's have a look into the most popular Japanese green teas;
Sencha - makes up to 80% of the tea produced in Japan and is the most popular tea drunk across the country. Sencha is typically steamed green tea leaves that are rolled into long skinny strands.
Hojicha - is sencha tea roasted over high heat and it produces a roasted, nutty flavour. During the process of roasting the high heat reduces the tea’s caffeine content.
Genmaicha - is a blend of Sencha and roasted popped rice with a toasted flavour profile that works really well with food.
Gyokuro - is Japan’s most treasured tea. The leaves are grown in the shade during the last few weeks before harvest to intensify the color and flavour of the tea.
Matcha - The key tea for Japanese tea ceremonies is shade-grown like Gyokuro, except that the tea leaves that make the matcha are ground into a powder.
White teas are known to be the most delicate, and these are often very minimally processed. White tea is harvested before the tea leaves fully open. At this stage, the leaves have fine white hairs and this is where white tea gets its name from.
As soon as tea buds are harvested, they wither and air dry in the sun or in a carefully controlled indoor/outdoor environment. Since oxidation is not encouraged in the production of this type of tea, it has a much softer, delicate flavour profile than green or black tea.
The white tea we know today was originally commercially produced from the very first plant varieties discovered in China’s Fujian province in the 1700s. A loose-leaf version of white tea was developed from these plants which are known for the production of beautiful tea buds. Today, many countries outside of China are cultivating their own versions of white tea, which we know as;
Silver Needle - originates from Fujian province and is made from large, full buds that are covered with white hairs, which give the tea its name.
White Peony - is a newer variety of white tea and is cultivated in countries around the world including China. It usually includes some buds blended with unfurled or barely opened young tea leaves.
Monkey Picked White Tea - “monkey picked” is a term used in these days to denote a very high quality of Chinese tea made from the buds and young leaves of the tea plant.
Darjeeling White Tea - originates from the Darjeeling region in India, where the processing method is similar to that of the white teas from China, however, the flavour profile is very different.
Yellow tea is the rarest of the six classes of tea and is only produced in China, specifically in the high mountains of Hunan, Zhejiang, and Sichuan provinces. The tea pickers gather only the bud by breaking it from the stem with a twist. It takes 60,000 of these carefully harvested buds to yield just one kilogram of tea, and it is said that only 500 kilograms of this tea are produced per year. Therefore, this product is only drunk by locals. As you can see, the production of yellow tea can come across as difficult and time-consuming and as a result, many tea growers have switched to producing green tea.
In today’s article, we covered Green teas from Japan and China, as well as White and Yellow teas. In the next article, we will discuss Oolong, Black, and Pu’Erh tea.
Recipes & Tips
Take a good quality tea and infuse it with vodka (1:10 ratio) for 5 min.
Strain the infusion, stir and pour it over ice as you would do for a classic martini (using 1 part water to 15 part infused spirit with no vermouth). The tea will provide you with a lovely dry, flavourful martini-style beverage.
Note: Adjust the tea infusion based on your preference, for example, you can infuse the tea 2 to 3 times into different batches and try blending them together.