Where does the aroma of tea come from?
Did you know that the same leaf, after different processing techniques, can also produce a variety of different fragrances? The bean aroma of green tea, the medicinal aroma of white tea, the orchid aroma of green tea, the potato aroma of black tea, and the aged aroma of Pu'er...... So where does the aroma of tea come from?
The formation of tea aroma, the variety and leaf shape are the fundamental influencing factors, which are the internal factors. The regional ecology shapes it for the first time, the finished tea will have regional fragrance and seasonal fragrance, and processing is the finishing touch of aroma formation, and various teas are shaped by processing to create completely different aroma styles and characteristics.
In fact, aromatic substances generally only account for 0.02% of the total dry matter of tea, and the important components that determine the aroma of tea are only dozens of them.
Cyanofol
It smells like grass, which is a volatile smell in fresh tea leaves. As the name suggests, incense smells like grass and belongs to aromatic substances with a low boiling point. It is the most important volatile odor in fresh tea leaves, accounting for 60% of the total volatile substances. In the finishing step of green tea, pu-erh tea and other teas, the heat and enzymatic action will cause a part of green leaf alcohol to volatilize.
linalool
The olfactory sense is the aroma of lilies and orchids, and this kind of aroma is the most obvious in Yunnan large-leaf tea, which belongs to aromatic substances with high boiling point. Compared with the small and medium-leaf teas in Fujian and other places, the large-leaf teas in Yunnan have more agarol and its oxides. In the same soil, under high altitude conditions, tea plants can form more agarwood alcohol. Coupled with the low temperature in the mountainous areas, the growth of tea trees is slow, which provides favorable conditions for the formation of tea aroma.
sugar
The sugars in tea contain monosaccharides, disaccharides, polysaccharides and a small amount of other sugars, and monosaccharides and disaccharides are the main components of soluble sugars, which are one of the sources of soup taste and craft aroma. Amino compounds and sugars will form a large number of pyrazine, pyrrole and furan components under the action of heat, which has a baking aroma. For example, when green tea is dried, there is a saying that "the fire is fragrant".
Aromatic alcohol
It has aromas such as apple, rose, daffodil, etc., and promotes its formation in large quantities during rolling and fermentation. It is an alcohol with a benzene ring attached to the carbon chain in the molecule, such as benzyl alcohol. The smell will have aromas such as apple, rose, daffodil, etc. Aromatic alcohols are present in fresh leaves and all kinds of teas, and their formation will be promoted by rolling and fermentation, and their content will increase with the increase of tenderness.
Varieties fragrant
Each tea tree variety is born with its own innate, unique aroma. In fact, it is the composition of the substances contained in the tea, that is, the aromatic substances in the tea.
For example, the daffodil variety, native to Dahu Village, Xiaohu Town, Jianyang, in Jianyang, Jian'ou planted in northern Fujian daffodils have a unique floral fragrance, transplanted to the north to Wuyi Mountain, the unique landscape is more dense to add to the charm of Wuyi daffodil aroma, in Wuyi Mountain is carried forward, transplanted to the south to Zhangping of Longyan, made into a unique block oolong tea, is also a unique charm.
Regional incense
The geographical environment of each tea tree is different, and the unique aroma formed, such as the rock tea of Wuyi Mountain and the West Lake Longjing of Hangzhou, can be called regional fragrance.
It is mainly determined by factors such as ecological environment, altitude, and soil, forming different regional incense and seasonal incense. The aroma of green tea in the mountains at a certain altitude is particularly rich, which is very different from the flat tea garden, showing the unique aroma of high mountain tea. The aroma substances of green tea in mountainous areas at a certain altitude are rich in aroma components with high boiling point, while those at low altitude are mainly at low boiling point.
Craft incense
During the tea making process, the unique aroma is produced. The craft fragrance generally comes from the two main processes of tea finishing and fermentation. The tea fragrance we often talk about is actually a craft fragrance. With good ecology and good raw materials, there must be a good process to make a good cup of tea, tea aromatic substances, some of which are original in fresh leaves, but most of them are formed in the process of making tea. The content of aromatic substances in fresh tea leaves is 0.02%-0.05%, and there are about 60 kinds of ingredients, including more than 260 kinds in green tea and more than 400 kinds in black tea, indicating that the aroma formation of tea is mainly produced in the process of tea making.
▼【Black Tea】—— Sweet potato fragrance
The aromatic substances in withered and fermented fresh leaves are largely transformed or volatilized by enzyme pro-oxidation and moisture. Floral and fruity aromatic substances are formed during the drying process.
The floral and fruity aroma is a significant feature of Wuyi rock tea, and the maturity is slightly higher than that of the tea with a high floral aroma during processing, and the aroma is more stable. At the same time, it is slowly roasted at low temperature through charcoal fire, so that it has an intoxicating charcoal incense.
Source: Xianqitang