Why oolong tea needs to be roasted?

Reasons why oolong tea needs to be roasted:

I. To reduce the water content and ensure the quality during storage, just reduce the water content, which is a physical change.

Two, to improve or adjust the color, aroma, taste and shape of the tea. Tea itself is not enough aroma, through the fire to improve the fire aroma, is a chemical change. Especially the tea and match, must borrow the power of the fire to the quality of the delineation, is the soul of the tea merchant.

The quality of tea is changed because the tea leaves are subject to oxygen (acid) relationship, tea contains 5-8 ﹪ of fat, fat exposure in the air soon acidification, oxidation to have enough water to do the media, so the tea must be packaged before the water down to less than 5%, why? We will be a grain of tea leaves enlargement, water content in 3-4% when the water into a single molecule layer, the water in the air can not enter. When the water absorption to more than 5%, there will be free water, free water will bring oxygen into the tea leaves, tea will gradually class change. When the absorption of more than 6% of water will produce condensation (capillary water) in the tea leaves to form a waterway, oxygen circulation fast tea class change accelerated, this is why the tea leaves to dry again.

The tea with insufficient aroma, the tea stored for a period of time or the tea flavor out of shape, in order to participate in competitions or to cater to the taste of customers must use the power of fire to change the color, aroma, taste, shape of the tea, that is, roasting. Tea roasters must understand the chemical composition of tea in the roasting process of chemical changes and the quality of the relationship.

Three, the chemical composition of tea in the baking process of chemical changes in relation to quality

Amino acids: taste sweet, bitter, sour, the more the better. Tea buds young stalks, high sea trekking, spring and winter tea more. Tea production wave Anna produced aroma, roasting and reducing sugar to produce the role called Mena reaction (the most important chemical reaction of tea roasting).

Caffeine: the cause of tea bitterness is not important to the tea-making technology and roasting process, because it is very stable and will not change due to different manufacturing and roasting processes. Caffeine in addition to the bitter outside of the fresh taste, will be combined with catechins to produce the temple, cold temperature when combined, high temperature when separated, known as emulsification. Black tea tea red texture is the most obvious.

Catechin class: catechin plus a class, said there are many kinds, currently divided into six categories, two types, free type with bitter, fat type with bitter astringent, also known as the tea tannin (non-tannic acid) tea broth in the most substances accounted for more than 50 %. Tea production and roasting process are very important, tea fermentation yellow, red, and affect the fatty acids so that the tea aroma of tea flavor and aroma are very important relationship.

Mono and di-Saccharides: Tea contains 2-5% of the baking can be said to rely entirely on it, sugar itself has a sugar flavor, heating has a honey aroma and then caramel aroma, on the taste and aroma are good.

Pectin: very important to the formation of the tea soup, the viscosity of the tea soup (the feeling of fullness), when baking to produce aroma.

Phytochromes: chlorophyll and anthocyanins, green tea and Taiwanese oolong tea to keep, black tea to destroy. When making tea, keep the good ones and remove the bad ones. Chlorophyll, for example, can keep the chlorophyll after frying immediately after the cold to keep the tea leaves green body.