The Process of Tea 'Fermentation'
At Food85, we love tea for a many reasons.
Not only is a hot cup of tea beautifully comforting, and a long-standing way of connecting and sharing with others, it's also 'fermented', slowly produced and a wonderful way of being mindful.
There are five different types of tea, yet they all come from the same plant - the Camellia sinensis. The different flavours and qualities of the teas comes from the 'fermentation' process of the leaves.
Yet the fermentation of tea isn't the fermentation we've come to know and love (unless, it's the tea used in kombucha). It's in fact, the process of enzymatic oxidation (which is also the cause of food turning brown). Fermentation also results in the chlorophyll in the leaves breaking down, which is why the they turn brown and release tannins (which is responsible for the bitterness in tea). This process causes the leaves to dry; which can be stopped earlier in the process, to create various teas. It's a slow process of drying, which can take 10 hours, and with some teas, even years, as explained below:
White Tea - White tea is very lightly fermented, in fact, the leaves are withered rather than dried, which helps the leaves retain their fresh, subtle flavours.
Green Tea - Green teas can be non-fermented and lightly fermented, again these teas hold their original flavour and are lighter in colour due to the chlorophyll still being largely intact.
Oolong Tea - Oolong tea falls under the category of semi-fermented. It often has a brown or yellow colour and can be lightly fragrant.
Black Tea - Black tea, the tea that has become a staple in British society, is fully fermented. They're much darker in colour, have more tannins and are usually stronger in flavour.
Pu'erh Tea - Pu'erh tea is perhaps one you may not have heard of, but may just be our favourite. Like a good cheese or wine, these teas can be 'fermented' for years. The tea will be fermented until the leaves are completely dried out, the process will be stopped, but will then commence again; this method is known as post-fermentation and is often a complex, gradual process.
The process of teas can vary, even within these categories, and the ways in which tea is used in various cultures is another area to explore in future posts. These careful and deliberate processes are an incredible way of demonstrating the art of slow food, and how a gradual process can so dramatically change the end result, in the case of pu'erh tea.
For more reading on the journey behind tea, we suggest: