Post-fermented tea

A very old Chinese specialty is heicha, literally "black tea". Due to the risk of confusion with Hongcha - ‘red tea’, which we call black tea - Heicha is called post-fermented tea (or dark tea) in the West. Heicha are processed according to a certain basic scheme; however, the exact procedure can vary quite a bit. The picked leaves are withered and fired with hot air or in a wok and then formed in rotating drums, sometimes rolled and finally dried in the sun or hot air. This semi-finished tea is called Mao Cha ("hairy/unfinished tea"). Fermentation and oxidation only take place after processing - hence post-fermented. Many of these teas are fermented before they are finally dried. For this purpose, the tea is processed and aged using man-made, artificial post-fermentation, known as Rengong Houfajiao. The Mao Cha is stacked in piles, left in the resulting heat and moisture and shifted from time to time. This process takes up to three months and is a fermentation induced by natural microorganisms - primarily bacteria, certain types of yeast and other fungi present in the air - which completely changes the chemical structure of the tea leaves. At the same time, oxidation with atmospheric oxygen always takes place. Finally, they are dried, sometimes heavily roasted. Depending on the strength of this post-fermentation, these teas are yellow-brown to very dark red-black in the leaf and cup and are therefore called Heicha. Pu Er teas are also processed as Sheng Cha, i.e. as ‘raw/living tea’ - i.e. in their green state, which then ferment with age due to microorganisms present in the air, oxidise with atmospheric oxygen and thus become darker, i.e. strictly speaking they are only heicha after a certain age. In the same way, stored oolong teas and stored white teas are sometimes called heicha.The historical origins of heicha are not clear, but it is probably the oldest form of tea processing still in existence today.

Pressed forms

Tuocha, zhuancha and bingcha are different pressed forms. The classic Bingcha, ‘tea cake’, weighs 7 Liang, which today corresponds to 350-375g; however, there are also smaller cakes. Tuocha, ‘tear tea’, are 100g, 250g or even heavier tea hemispheres. Zhuancha, ‘brick tea’, are produced in various sizes. The quantity is first weighed for pressing. This portion is then made smooth with steam and formed by hand in a jute sack, after which the sack is placed in a mold. Then a very heavy stone is placed on top for some time. Finally, a press is used to briefly press the tea, then the tea is left to dry and wrapped in paper. For storage, the teas need air, reasonably warm temperatures and a little humidity.