Yunnan black tea is famous across the world; the Assamica varietal used makes it very different from the other Chinese black teas. It offers both fragrance and good mouthfeel. Here is an example of what Yunnan tea leaves become when put into expert's hands.
Mrs. Pu Jin Jing runs a small tea factory in Lincang County, in the Western part of Yunnan province. Her village is Matai, it's not a very famous area, but it is certainly a hidden jewel, overshadowed by the more heavily branded Fengqing black teas.
This tea has all the charm it takes to make your mind wander across the tea mountains of Yunnan. The tea gardens of Mrs. Pu are located at a high altitude (1400m to 1600m) and were established over half a century ago, in the hills above the village. They are managed in an extensive way, the density of plantation is low, which allows the tea trees to grow a large root network and reduces the need for fertilization.
We visited Mrs. Pu in 2013; she is genuinely passionate about tea and her dedication can be felt in the cup. We have offered her black tea since 2012 and the quality has always enchanted us.
This black tea has both complex fragrance and thick mouthfeel, which is quite hard to achieve and results in the mastery of the rolling and oxidation processes. It takes a long time to learn the art of black tea-making and Mrs. Pu has been an expert for years.
Yunnan black tea, also called Dian Hong, is made in four steps: withering, rolling, oxidation and drying. Each step will have an influence on the final taste of the black tea.
The purpose of withering is to soften the leaves. For Yunnan black tea, it usually takes 24 hours, but it depends on temperature and the thickness of the fresh tea leaves layer. The fragrance of the withering leaves changes as they soften, when the tea is ready, the aroma reminds of Yunnan Moonlight White.
Once the leaves are soft enough, they are put into a rolling machine: a rotating cylinder with several edges on the bottom plate. In this machine, the leaves are turned upside down and crushed with moderate strength. In the case of black tea, the purpose is to break the cell walls to release the tea juices. Those juices are rich in polyphenols: the molecules responsible for the fragrance and mouthfeel of tea. Once they are released, a reaction happens with oxygen, and the tea leaves will turn red. A long rolling is required to ensure that enough water is extracted from the leaves and that enough cells have released their content. The rolling process takes between one and two hours.
After having been rolled, the leaves look like more like finished tea, but they are still green. Polyphenol oxidation takes several hours to complete, just like withering, the actual speed strongly depends on temperature. In the large factories, the oxidation room has a controlled temperature, but in the case of smallholder tea farmers, the oxidation time is adjusted. As time goes, the leaves will turn darker and their fragrance will change. In typical conditions, it takes around six hours to obtain the desired level of oxidation. Although it is said black teas are fully oxidized, this is not entirely accurate; some producers decide to stop oxidation early in order to get a different profile. In the cup, this translates into a yellower tea soup and red leaves instead of brown. This Matai tea is heavily oxidized.
-Sun drying is made by spreading the tea leaves thinly on bamboo or cloth mats. When the sun is shining, the tea leaves take about four hours to dry. Things get complicated when the weather is cloudy; the tea doesn't dry much, and if it is left over two days, it will turn terrible and will have to be discarded. Sun-dried tea has a long shelf life, it can be kept for years and can even improve with aging, the downside is that the fragrances are not as brilliant as the second method.
-Drying leaves in a dedicated dryer is the most common method used to make Yunnan black tea; this allows running the production even during cloudy weather, which makes a big difference in Summer. In the most common dryer, the black tea leaves are laid on multiple layers in a special closet and hot air is blown through it. This allows tea to be dried in a couple of minutes, but the tea maker should control the air temperature and make sure it's not too hot.
If the tea leaves are dried quickly, they will develop a toasted aroma. Within certain limits, these roasted notes can enhance the tasting profile, but too much could easily ruin the tea. This is very similar to tea roasting, the limit between enhancing and ruining a tea is easily crossed and the tea makers who take this risk literally play with fire. Mrs. Pu is surely one of them, but her black tea stays well within the boundaries of fine tea.