Why green tea is green! The secret of steaming explained

Introduction

Sencha is green because the leaves are steamed immediately after picking to prevent oxidation.

This steaming process is called "steaming," and it prevents the tea leaves from discoloring by stopping the action of the enzymes in the tea leaves.

This allows Sencha to maintain its beautiful green color.

In addition, since the picked tea leaves begin to oxidize even in the short time before they are steamed, measures are taken to delay the oxidation as much as possible by exposing them to air and adjusting the humidity.

Tea manufacturing: Withering and fermentation

When making oolong tea or black tea, the tea leaves are not used as is after they have been freshly picked; instead, they are first allowed to wilt.

This process is called "withering."

In the case of oolong tea, the picked tea leaves are allowed to wilt in the sun, then brought indoors and rocked to allow oxidation to proceed, and finally roasted in a high-temperature pot to stop the oxidation.

Black tea, on the other hand, is left indoors overnight to wilt, then rolled and placed in a warm, humid room to oxidize again.

In this way, the flavor and color of the tea can change significantly depending on whether the oxidation of the tea leaves is stopped halfway through or allowed to continue until the end.

Tea is broadly classified into four types depending on the method of oxidation.

Four classifications based on the degree of fermentation of tea

Tea is broadly classified into four types depending on the degree of fermentation during the manufacturing process.

Sencha, which is barely fermented, is called "non-fermented tea," oolong tea, where fermentation is stopped halfway, is called "semi-fermented tea," black tea, which is fermented completely, is called "fermented tea," and pu-erh tea, which is fermented using microorganisms, is called "post-fermented tea."

A manufacturing method that makes the most of the individual characteristics of the tea leaves

Each tea leaf has different characteristics depending on the variety and place of origin, and the optimal manufacturing method is selected to bring out these characteristics to the fullest.

For example, the Assam variety, which has a high catechin content and a strong astringent taste, is more suitable for black tea than green tea, while the Chinese variety, which has a high amino acid content and a sweeter taste, is more suitable for green tea.

In this way, countless types of tea are created by combining different tea leaf varieties and processing methods.