There are many factors that affect the taste of the tea we drink: the type of plants Camellia sinensis (i.e. the tea plant) from which the leaves are collected, the state of the leaves, the harvesting period, the processing. In China and other East Asian countries, where tea is very important both from a cultural and economic point of view, the focus on tea harvesting and production methods is comparable to that in European countries such as Italy. and France is there for wine. Scientific research on tea is quite lively, and has led to remarkable discoveries: even if in Europe the teas we drink are more or less always the same, in Asia in the past decades numerous new variants have been created, which have had commercial success. often exceptional.
This somewhat unknown world of tea in the West recently got excited about research published by the Journal of Agricultural and Food Chemistry and taken fromEconomist, the content of which can be summarized as follows: a large part of the taste of unfermented teas derives from fermentation. This makes little sense, but in practice it means that the scientists who conducted the research may have discovered a way to create teas with new and particular flavors, impossible to find in nature.
Tea falls into numerous categories, with two of the best known divisions being that between fermented and unfermented teas. Non-fermented teas are the most common in Europe, such as black tea or green tea, while fermented teas are drunk mainly in Asia and are more valuable, because they are subjected to a fermentation process that is often very long, which allows bacteria and to the fungi present on the surface of the leaves to alter their flavor and other characteristics. The most famous of fermented teas is pu’er, which is aged like whiskey, and which usually becomes sweeter and more viscous as it matures.
Pu’ers aged for decades are considered delicacies, and in Asia they are sold at prohibitive prices. Kombucha, a drink that has become very popular in recent years, is also a fermented tea, which however matures in a couple of weeks and not decades, thanks to the addition of leavening agents and bacteria from the outside.
Until now it was thought that the taste of these two types of teas had therefore two different origins: teas not fermented by processing (which involves various stages of cooking, rolling, drying), teas fermented by the action of fungi and bacteria.
Ali Inayat Mallano and Jeffrey Bennetzen, two researchers from Anhui Agricultural University in China, have shown that fungi and bacteria actually play an essential role in defining the taste of even unfermented teas. To do this, they compared normal processed black tea samples with other sterilized tea samples so that most of the fungi and bacteria present were eliminated from the surface. They analyzed the leaves, and saw that while the caffeine and theine content between the two samples did not vary, in the sterilized one, the content of catechins and theanine, which are two of the most important compounds in establishing the quality of the tea, drastically decreased. .
In practice, the study, which involved the infusion of a considerable amount of cups of tea, showed that the good taste of black tea is largely attributable to the presence and action of fungi and bacteria on the leaves, exactly as it happens. with fermented teas.
This news has created some enthusiasm in the tea market because Mallano and Bennetzen are convinced that it is possible to modify the microorganisms present on the leaves to change the flavor of unfermented teas, especially black tea. As he wrote theEconomist, the two scientists have already begun work on a new study to identify which of the various microorganisms commonly found on the leaves are responsible for altering the flavor of tea.
The two scholars hope that at that point, by manipulating bacteria and fungi, it will be possible to obtain new varieties of tea with a taste never heard before, reducing the need for long and complex processing and without the need to resort to aromas to make them sweeter or more fragrant. as is the case now with many popular varieties in the West (Earl Gray, for example, is a black tea flavored with bergamot).
Tea is by far the most popular drink in the world, after drinking water. Each day, he estimated theEconomist, around two billion cups are consumed, and the global tea market is worth around $ 200 billion.