Why do black tea and green tea change their flavor after a long time?

Tea polyphenols, polyphenols, vitamin C and carotene in tea are highly oxidized, so ambient temperature, relative humidity, odor, light, air and microorganisms will affect the quality of tea. In order to keep it from deteriorating, it must be careful to avoid high temperature, high humidity, light and oxygen.

The materials used to preserve tea in daily life are aluminum-platinum composite bags, utensils, and a combination of the two. Tin pots are preferred, but other clay pots, metal boxes, etc. are also acceptable. It is best to put an appropriate amount of tea preservative in the packaging bag to preserve the tea leaves in a composite bag.

Of all the tea leaves, green tea is best stored in the refrigerator. If the storage time is short and you need to drink it at any time, you can put the green tea in the refrigerator and adjust the temperature of the refrigerator to about 5 degrees Celsius; However, if it is an unopened tea leaf and you want to keep it for more than a year, you should put it in the freezer. In addition, in order to prevent tea from becoming the "deodorant" of the refrigerator, the tea should be sealed and packaged before being put into the refrigerator, and a sufficient amount of special preservative should be filled into the packaging bag, and the packaging material should be preferably an aluminum foil composite bag.

It should be noted that after taking out the tea leaves from the refrigerator, do not open the package immediately, the correct way is: take out the tea leaves in the refrigerator and let it slowly heat up, and after it rises to room temperature (usually every other day), open the packaging bag, and then brew and drink. And it is best to drink it in half a month.

Compared to green tea, oolong tea, black tea, and jasmine tea do not have to be stored in the refrigerator. Due to the relatively low content of polyphenols in oolong tea and black tea, the aging and deterioration rate is slower and easy to store. Flower tea has a strong floral aroma, and storage at low temperature will inhibit its aroma and reduce the freshness and concentration of the aroma. Therefore, as long as it is placed in a dry, airtight, light-proof container and odor-free container, it can be stored for a long time.

Pu-erh tea is best stored at room temperature and does not need to use desiccant.

It's not impossible to put it in the refrigerator, it's just don't rumor, the shelf life of black tea is generally three years, but as long as it is not moldy and does not deteriorate, it can generally be drunk, but. For example, green tea, green tea should be drunk and bought at the time, but some green tea should be left for a period of time before it tastes good.

The longer black and green tea are left out, the better it tastes, and red wine is. And so on.

That's not sealed well, and if it's sealed, it generally won't smell.

Green tea boiled red can be drunk, green tea is not fermented tea leaves, under normal circumstances, the color of the gas soup is emerald green or tender green, and after boiling the tea for a long time, the tea soup is oxidized, thus turning red, and secondly, when the pH value of the water used for boiling tea is greater than 7 (weak alkaline), the color of the tea soup will also turn red, but it is a normal phenomenon to drink, just pay more attention to it.

After the red phenomenon, if the quality of the tea soup is normal, there is no obvious change, you can drink, if it is left for too long, the tea soup appears to change the taste, rancid taste, etc., you can no longer continue to drink.

Whether it is boiling tea or making tea, green tea is not easy to soak for a long time, because green tea itself pays attention to the fresh taste, and long-term soaking will lead to a thick tea soup, so that you can't really taste the taste of tea.

Secondly, long-term soaking will also cause the substances in the tea soup to be oxidized, which will make the tea soup tend to be red. When the pH value of the water used to make tea is greater than 7, that is, it is weakly alkaline, and the color of the tea soup is easy to become dark and red. Because colorless tea polyphenols are easily converted into theaflavins or thearubigins in weakly alkaline water, this phenomenon is more obvious in teas with lighter soup color.

The above content refers to People's Daily Online-9 major effects Drinking green tea often has many benefits.

People's Daily Online-Expired green tea can't make black tea.

Green tea will not turn into black tea after a long time. Green tea is a non-fermented tea.

Black tea is a fully fermented tea, and there are many differences between the two. Green tea is a product made of fresh leaves as raw materials, through killing, rolling, drying and other processes, which is generally divided into four categories: fried green tea, roasted green tea, dried green tea and steamed green tea.

Black tea is a product made of fresh leaves as raw materials, withering, rolling, fermentation, drying and other processes, mainly including black broken tea, kung fu black tea and small black tea. In other words, the raw materials of both are fresh leaves, and there is a big difference in the production process. Therefore, it is impossible to make black tea from green tea that has expired.

Green tea will not turn into black tea after a long time.

Green tea is one of the main types of tea in China, which refers to the product made from new leaves or buds of tea trees, unfermented, and made by typical processes such as finishing, shaping, and drying. The color of the finished product, after brewing, the tea soup preserves the green main tone of fresh tea leaves. Drinking green tea regularly can prevent cancer, lower blood lipids and **.

Nicotine damage is reduced for smokers.

Green tea is a tea made without fermentation, which retains the natural substances of fresh leaves, and contains more nutrients such as tea polyphenols, catechins, chlorophyll, caffeine, amino acids, and vitamins. These natural nutrients in green tea have special effects on anti-aging, anti-cancer, anti-cancer, anti-bacterial, anti-inflammatory, etc., which are unmatched by other teas. Green tea is a tea made from the new shoots of suitable tea trees through typical processes such as killing, rolling, and drying.

The color of its dry tea and the tea soup after brewing, and the bottom of the leaves are mainly green, so it is called green tea. Green tea is the fresh leaves picked by high temperature first, killing various oxidases, keeping the tea green, and then rolled and dried, clear soup green leaves are the common characteristics of green tea quality. The scope of green tea production in China is extremely extensive, Henan, Guizhou, Jiangxi, Anhui, Zhejiang, Jiangsu, Sichuan, Shaanxi (southern Shaanxi), Hunan, Hubei, Guangxi, Fujian are the main green tea producing provinces in China.

Because green tea has been left for a long time, an oxidation reaction has occurred, and generally the tea will precipitate after a long time, and the color will become darker.

Unfermented is green tea, fully fermented is black tea, and semi-fermented is oolong tea. Green tea is left for a long time, and when it is fermented, it becomes black tea.

Yes. Otherwise, what to do with tea eggs. It's going to be boiled red. Add soy sauce as well.