What is green tea?
Green tea, a shrub or small arbor plant of Camellia in the Camelliaceae family, is made of fresh leaves or buds of the tea tree through the process of green killing, shaping, drying, and retains the natural substance of fresh leaves; The tea is sharp and fine, with smooth surface; White flowers, small, polygonal flowers; The flowering period is from October to February of the next year. Green tea is named because its dry tea is green, the tea soup after brewing is green, and the leaf bottom is emerald green. [9-10]
Green tea is native to China, widely distributed in Henan, Guizhou, Zhejiang and other places in China, and also distributed in Japan, Thailand, North Korea, South Korea and other countries. Green tea likes humid and warm environment, but it is not resistant to sunlight, high temperature and moisture. It is suitable to plant in fertile and loose slightly acidic soil. The propagation methods of green tea mainly include seeding propagation and cutting propagation, which are generally adopted.
According to Lei Gong’s Medicinal Solution, green tea is “slightly cold in nature, bitter and sweet in taste.” Green tea has the effects of astringency, diuresis and refreshing, and is used to treat fatigue and sleepiness, headache and dizziness, thirst, bad urination, alcohol poisoning and other diseases. Green tea is the earliest tea in Chinese history, with a long history of production; During the Tang Dynasty, it was popular in China to make green tea by steaming green tea, which was later introduced into Japan and adopted by many countries; In the Ming Dynasty, fried green tea was invented to make green tea. Green tea has high fragrance, long taste, excellent quality, unique shape and high artistic appreciation value. Green tea is the tea with the highest output in China, and also the tea with the richest varieties and the most famous tea, with rich economic value.
Foreign language name: Green Tea
Taste: fragrance, orchid fragrance
Main raw materials: tea,
Whether the tea bud contains preservatives: No
Main nutrients: tea polyphenols, caffeine
Main edible effects: refreshing, diuretic, fatigue relieving, anti-aging, suitable for people, too many greasy foods, hypertension, poor urination, fever and thirst side effects, excessive drinking may lead to reduced sleep Storage methods: pot storage, plastic bag storage, hot water bottle storage, refrigerator storage of famous varieties Biluochun, West Lake Longjing, Mengding Ganlu, Mount Huangshan Maofeng, etc
From the history of written records, Mengding Mountain is the earliest place in the history of China where there are written records of artificial tea planting. It can be proved that Mengding Mountain in Sichuan Province is the origin of tea planting and tea manufacturing from the existing world’s earliest record of tea, Wang Bao’s Tong Yue and Wu Lizhen’s legend of planting tea in Mengshan. Green tea originated in Badi (today’s northern Sichuan and southern Shaanxi). According to the Records of Huayang State – Records of Ba, when King Wu of Zhou defeated Zhou, the Ba people “offered tea” to reward the army of King Wu of Zhou. The Chronicle of Huayang is a faithful history. It can be concluded that no later than the Western Zhou Dynasty, the Ba people in northern Sichuan (Seven Buddha Tribute Tea) began to cultivate tea in the garden.
Green tea is non-fermented tea. Because of its characteristics, it retains more natural substances in fresh leaves. Among them, tea polyphenols and caffeine retain more than 85% of the fresh leaves, chlorophyll retain about 50%, and vitamin loss is less, thus forming the characteristics of green tea “clear green leaves, strong taste convergence”. It has special effects on anti-aging, anti-cancer, anti-cancer, sterilization, anti-inflammatory, etc., which is inferior to fermented tea.
◆ West Lake Longjing
- Origin: West Lake Longjing belongs to fried green tea, which is produced in the mountains of Shifeng, Wengjiashan, Hupao, Meijiawu, Yunqi and Lingyin of West Lake in Hangzhou, Zhejiang Province. Hangzhou has a long history of tea production, which was recorded in Lu Yu’s Tea Classic in the Tang Dynasty, while Longjing tea was produced in the Song Dynasty.
- Quality characteristics: Longjing tea is famous for its “green color, mellow fragrance, sweet taste and beautiful shape”, known as “national tea”. The finished tea is shaped like a bowl nail. It is flat and straight. The color is a little yellow and “brown rice”. The taste is sweet, fresh and mellow. The aroma is elegant and clear. The color of the soup is green and clear. The bottom of the leaves is tender and blossoming.
- Origin: Dongting Biluochun is produced in Dongting Mountain, the Taihu Lake Lake, Wuxian County, Jiangsu Province. Biluochun was created in the Ming Dynasty. When Qianlong went down to the south of the Yangtze River, he was already famous.
- Quality characteristics: slender strands, curled into snails, covered with hair, silvery white and green, with rich fragrance, fresh and mellow taste, sweet and thick taste, green and clear soup color, light green and bright leaf bottom, known as one tender (tender buds and leaves), three fresh (color, fragrance and taste), is a treasure of China’s famous tea, and is famous at home and abroad for its “beautiful shape, beautiful color, strong fragrance and mellow taste”.
◆ Anji white tea
- Origin: Anji white tea is roasted green tea, produced in Anji County, Zhejiang Province. Anji County, located in the north of Zhejiang Province, is a famous hometown of bamboo in China with beautiful mountains and rivers and flowing green water. Anji white tea, a rising star of China’s famous tea, is one of the top ten names in Zhejiang Province. White tea is one of the six categories of tea, but Anji white tea is made by green tea processing technology and belongs to the green tea category. Its white is because its processing material is taken from a tea tree with white tender leaves.
- Quality characteristics: Anji white tea sticks show straight buds, strong and even; The color is light green, fresh and golden, and the shape is like cymbidium; It’s very pleasant. After brewing, the fragrance is high and lasting. The taste is light and fresh. After drinking, the lips and teeth retain fragrance, and the aftertaste is sweet and produces saliva. The bottom of the leaves is light green and bright, and the buds and leaves are distinguishable.
◆ Mount Huangshan Maofeng
- Origin: Mount Huangshan Maofeng is a roasted green tea, which is produced in Mount Huangshan, Anhui Province. The history of tea production in Mount Huangshan can be traced back to the Jiayou period of the Song Dynasty. By the reign of Longqing in the Ming Dynasty, Mount Huangshan tea had become very famous. Mount Huangshan Maofeng was founded in the Guangxu period of the Qing Dynasty.
- Quality characteristics: The super Mount Huangshan Maofeng is the best Maofeng in China. It looks like a sparrow tongue, uniform and sturdy, and the peak is exposed without hair. Its color is like ivory, and the fish leaves are golden. The fragrance is clear and long. The soup is clear and bright, and the taste is fresh, mellow, sweet, and the bottom of the leaves is yellow and blossoming. “Gold flakes” and “ivory color” are the two characteristics of Mount Huangshan Maofeng. 
◆ Yuyao Waterfall Xianming
Yuyao Waterfall Xianming, a specialty of Yuyao City, Zhejiang Province, is a national geographical indication of agricultural products.
Yuyao Waterfall Xianming Tea is produced in Taoshi Mountain, Siming Mountain, Yuyao Province, and belongs to the green tea category. Taoist Mountain is located on the hillside of the waterfall ridge, with an altitude of more than 400 meters. The tea garden is surrounded by lush trees and bamboos, and the streams are crisscrossed. The tea trees are immersed in the clouds all year round, forming a unique natural quality. Lu Yu of the Tang Dynasty said in the “Tea Classic” that the tea made by Yuyao from the buds and leaves of the big tea tree is of excellent quality and has become famous in the Tang Dynasty. Lu Yu praised it as “immortal tea”, so it is called “immortal tea of Yuyao Falls”.
◆ Taiping Houkui
- Origin: Taiping Houkui is produced in Houkeng Village, Taiping County, Anhui Province. Taiping Houkui is the best of sharp tea and has long enjoyed a high reputation. Taiping is the name of the county, and its tea production can be traced back to the Ming Dynasty. Taiping Houkui was founded in the late Qing Dynasty.
- Quality characteristics: two leaves embrace one bud, flat and straight, naturally stretched, and pekoe is concealed. It is known as “the monkey’s head is pointed, not scattered, not warped, not curled”. The leaves are pale green and moist, and the veins are green and reddish, commonly known as “red silk thread”. The flower fragrance is high and refreshing, the taste is sweet and mellow, and the fragrance has a unique “monkey charm”. The soup is clear and green, the bottom of the leaves is green and bright, and the buds and leaves are plump and plump. When drinking, “the first bubble has a strong flavor, the second bubble has a strong flavor, and the third bubble and the fourth bubble have a lingering fragrance”.
Green tea is known as “national drink”. A large number of studies in modern science have confirmed that tea does contain biochemical ingredients closely related to human health. Tea not only has pharmacological effects such as refreshing and clearing the heart, clearing heat and heat, eliminating food and phlegm, removing fat and losing weight, clearing the heart and removing annoyance, detoxifying and sobering up alcohol, producing saliva and thirst, reducing fire and brightening the eyes, stopping dysentery and dehumidifying, but also has certain pharmacological effects on modern diseases, such as radiation disease, cardio-cerebrovascular disease, cancer and other diseases. The main ingredients of tea with pharmacological effects are tea polyphenols, caffeine, lipopolysaccharide, theanine, etc. Specific functions include:
It helps to delay aging. Tea polyphenols have strong antioxidant and physiological activity, and are scavengers of free radicals in human body. Research has proved that 1 mg of tea polyphenol has the effect of removing excessive free radicals harmful to human body equivalent to 9 micrograms of superoxide dismutase, which is much higher than other similar substances. Tea polyphenols can block lipid peroxidation and eliminate active enzymes. According to the results of the test conducted by Takuyo Oda in Japan, it is confirmed that the anti-aging effect of tea polyphenols is 18 times stronger than that of vitamin E.
Tea polyphenols, which help to inhibit cardiovascular diseases, play an important role in human fat metabolism. The content of cholesterol, triglycerides, etc. in human body is high, the fat deposits on the inner wall of blood vessels, and vascular smooth muscle cells proliferate to form atherosclerotic plaques and other cardiovascular diseases. Tea polyphenols, especially the catechin ECG and EGC in tea polyphenols and their oxidation products, such as theaflavin, help to inhibit this macular proliferation, reduce the fibrinogen that forms enhanced blood coagulation viscosity, and clear blood coagulation, thus inhibiting atherosclerosis.
Helps prevent and fight cancer. Tea polyphenols can block the synthesis of various carcinogens such as ammonium nitrite in the body, and have the effect of directly killing cancer cells and improving the immunity of the body. According to relevant data, tea polyphenols in tea are beneficial to the prevention and adjuvant treatment of various cancers such as gastric cancer and colon cancer.
Tea polyphenols have strong astringent effect, obvious inhibition and killing effect on pathogenic bacteria and viruses, and obvious effect on anti-inflammation and anti-diarrhea. Many medical institutions in China have used tea preparations to treat acute and chronic dysentery, amebic dysentery and influenza, with a cure rate of about 90%.
Beauty and skin care
Tea polyphenols are water-soluble substances. Washing your face with it can remove the greasy, astringent pores, disinfect, sterilize, resist skin aging, and reduce the damage to skin caused by ultraviolet radiation in the sun.
Awakening and refreshing
Caffeine in tea can stimulate the central nervous system of the human body, enhance the excitation process of the cerebral cortex, and play a refreshing and refreshing effect. It also has certain effect on relieving migraine.
Diuretic and antipyretic
It is helpful to diuresis and relieve fatigue. Caffeine in tea can stimulate the kidney, promote the rapid excretion of urine from the body, improve the filtration rate of the kidney, and reduce the retention time of harmful substances in the kidney. Caffeine can also eliminate excessive lactic acid in urine, which helps to eliminate fatigue as soon as possible.
Green tea contains powerful antioxidants and vitamin C, which can not only eliminate free radicals in the body, but also secrete hormones that fight against stress. The small amount of caffeine contained in green tea can stimulate the central nervous system and stimulate the spirit. Because of this, we recommend drinking green tea in the morning to avoid affecting sleep.
Protect your teeth and eyes
It is helpful to protect teeth and eyes. The content of fluorine in tea is high. The content of fluorine in every 100 grams of dry tea is 10 mg – 15 mg, and 80% is water-soluble. If each person drinks 10 grams of tea every day, they can absorb 1 milligram to 1.5 milligrams of water-soluble fluoride. Moreover, tea is an alkaline drink, which can inhibit the reduction of calcium in the human body, which is beneficial to the prevention of dental caries, tooth protection and hard teeth. The experiment of “tea treatment and mouthwash after drinking” among primary school students can reduce the caries rate by 80%. 28.6% of cataract patients have the habit of drinking tea; 71.4% had no habit of drinking tea. This is because vitamin C and other ingredients in tea can reduce the opacity of eye crystals. Drinking tea regularly has a positive effect on reducing eye diseases and protecting the eyes.
It is helpful to reduce fat and help digestion. There is a record of the effect of tea in the Tang Dynasty’s “Herbal Collection”, which is “thin after eating for a long time”. There is a saying among the ethnic minorities in the border areas of China that “one cannot have no tea in one day”. Because tea has the important effect of helping digestion and reducing fat. In modern fashion language, it is helpful to “lose weight”. This is because caffeine in tea can increase the secretion of gastric juice and help digestion. In addition, green tea is rich in catechins, which can help reduce abdominal fat.
The Chinese scientific research team found that a natural small molecule in green tea can become a “manipulator” of cells, allowing some customized cells to “obey”, so as to release therapeutic drugs in a timely and quantitative manner. The research team recently published a paper in the US journal Science · Translational Medicine, saying that they designed and synthesized a transgenic expression control system using the secondary metabolite protocatechuic acid of green tea, which can be regulated by protocatechuic acid like a “switch”. The researchers installed this control system in human cells and encoded a specific gene segment in the cells, which can generate and release insulin and other drugs under the control of protocatechuic acid. When such cells are implanted into the human body, it is expected that people can only drink customized concentrated green tea.
The researchers also combined gene editing technology to use green tea as the regulatory switch of gene editing to control gene expression and editing. Research has confirmed that this control system can also perform complex logic operations and is expected to be used in biological computers in the future.
Tips for brewing
There are two ways to brew green tea: the first is the upcast method, which is suitable for high-grade famous green tea with tight shape, that is, first pour hot water of 75-85 ℃ into the cup. The second is the downward pouring method, which is suitable for ordinary green tea.
Drinking green tea correctly can make it taste better and drink healthier. There are certain requirements for tea making, especially the water temperature.
General green tea brewing methods and precautions:
When brewing green tea, the water temperature should be controlled at about 80 ℃~90 ℃. If you want to brew green tea powder, brew it with warm water at 40 ℃~60 ℃. The portion is 2 grams of green tea powder with 450 ml of boiled water.
Don’t drink the first brew of tea. Shake it with hot water and then pour it out.
Green tea powder should not be soaked too thick, otherwise it will affect the secretion of gastric juice. It is best not to drink it on an empty stomach.
Tea tasting in porcelain cup:
Porcelain cup green tea is suitable for brewing and drinking medium and high grade green tea, such as first and second grade fried green tea, pearl tea green tea, baked green tea, sun-cured green tea, etc., focusing on palatability, taste or thirst quenching. Generally, observe the color, aroma and shape of tea before pouring it into a cup. It is advisable to use the “middle pouring method” or “lower pouring method”, brew with 95-100 ℃ initially opened boiling water, cover the cup lid to prevent the fragrance from escaping, maintain the water temperature, facilitate the development of the tea body, accelerate the sinking of the cup bottom, open the lid after 3-5 minutes, smell the tea aroma, taste the tea taste, and drink it to three openings depending on the degree of the tea soup. This method is more convenient for guests to offer tea and drink tea during office hours.
The ratio of tea to water in the cup method depends on people’s taste. Generally, it is appropriate to brew 3 grams of tea in 200 ml of water. Those who prefer strong drinks can add a little more tea, while those who prefer light drinks can add a little less tea.
Make tea in a teapot
Generally, it is not suitable to brew and drink delicate and precious green tea. Because there is too much water, it is not easy to cool down, and it will suffocate the green tea leaves, making the green tea leaves lose their fresh flavor. Potting method is suitable for brewing middle and low grade green tea. This kind of tea is rich in cellulose, resistant to brewing, and has strong taste. When making tea, wash the pot first, take green tea into the pot, brew it with 100 ℃ boiling water until it is full, and then drink it into the cup after 3-5 minutes. When there are many tea drinkers, it is better to use the pot brewing method. Because they are not appreciating the tea interest, they are quenching their thirst, drinking tea to talk, or eating Dim sum to chat about tea friendship.
It is the common etiquette of the people of all ethnic groups in China to offer tea to guests. Generally, the cup method is more solemn. The method of making green tea in pot is relatively vulgar. In some areas, in order to show respect for guests, sugar is also added to green tea to show sweetness.
Tea tasting by glass:
Green tea in a glass is suitable for drinking delicate and precious green tea, and it is convenient to fully appreciate the appearance and inner quality of famous tea.
Before drinking, enjoy the color, fragrance and shape of dry green tea. Take a cup of tea, put it on a white paper without peculiar smell, and watch the shape of tea. The shape of famous tea, due to different varieties, or bar, or flat, or snail, or needle… appreciate the green tea production process, observe the color of green tea, or green, or dark green, or yellow green, or more than a milligram… then dry smell the aroma of green tea, or cream, or chestnut, or pan fried, or indescribable fresh tea… fully appreciate the regional natural charm of various famous tea, called “tea appreciation”. Then enter the bubble.
The transparent glass is used to soak and drink delicate and famous green tea, which is convenient to observe the slow stretching, swimming and changing process of tea in the water. People call it “green tea dance”. The specific operation of brewing green tea can be seen from the different tightness of the green tea bar. Two brewing methods are adopted respectively. One is to brew famous tea with tight and solid shape, such as Longjing Green Tea, Biluochun Green Tea, Duyun Maojian Green Tea, Mengding Ganlu Green Tea, Lushan Yunwu Green Tea, Fujian Lianxin Green Tea, Lingyun Baihao Green Tea, Yongxi Huoqing Green Tea, Gaoqiao Yinfeng Green Tea, Cangshan Snow Green Tea, etc., which can be used as “green tea upcast method”. That is, after washing the tea cup, first pour the boiling water at 85-90 ℃ into the cup, and then take the green tea and put it into the cup. Generally, the green tea leaves will automatically sink slowly without capping, but some will sink first and then, some will sink straight, some will hover slowly, some will float up and down and then fall to the bottom of the cup; Dry green tea absorbs water and gradually unfolds its leaves, showing one bud, one leaf, two leaves, single bud and single leaf in their original colors, with buds like guns, swords and leaves like flags; The water vapor of Noodles in soup mixed with tea aroma rises continuously, such as rising clouds, smelling the aroma of tea while it is hot, making people relaxed and happy; Observe the color of the tea soup, or yellow, green and clear, or milky white and slightly green, or light green and slightly yellow… Through the perspective of the sun across the cup, you can also see that there are thin and fluffy hairs swimming in the soup, glittering and starry spots. Green tea leaves are more delicate and more scattered, which is the characteristic of green tea. This process is called wet viewing and appreciation.
When the green tea soup is cool and palatable, taste the taste of the tea soup, sip it and swallow it slowly, let the tea soup fully contact with the tongue taste buds, and appreciate the charm of famous green tea. At this time, the tongue and nose can be used together to taste the aroma of green tea and tender tea from the tea soup. This is called the first open tea, which focuses on the taste of the first open taste and the aroma of green tea. When the green tea soup in the cup has a third of the water left (it is not appropriate to drink all the water in the first open), and then add boiling water, it is called the second open green tea. If you brew and drink the famous green tea with strong tea leaves, the second open green tea will be thick, and the tongue will be sweet after drinking, and the aftertaste will be endless, and the teeth and cheeks will remain fragrant, and the body and mind will be comfortable. When you drink it three times, the taste of tea is generally weak. If you drink it again with water, it will become weak and tasteless.
The second is to brew famous green tea with loose tea strips, such as Lu’an Gua Pian green tea, Mount Huangshan Maofeng green tea, Taiping Houkui green tea, Shucheng Orchid green tea, etc. If the “up casting method” is used, green tea leaves will float on Noodles in soup and will not sink easily. The “middle throw method” can be used, that is, after the dry green tea is appreciated, take the green tea into the cup, pour 90 ℃ boiling water to one-third of the cup capacity, pause for two minutes, wait for the dry tea to absorb water and stretch, and then flush the water to the full. At this time, the green tea leaves either hover and float, or swim between the ups and downs, and observe the dynamic shape of its tea, which is very interesting. Enjoy other items and drink as before.
To brew and drink delicate and famous green tea, if you use an opaque white porcelain cup, of course, you can also, but you can’t see the whole picture of green tea in the cup, and you can’t fully appreciate the tea taste in green tea soup, which is a deficiency.
- It is suitable for hypertension, hyperlipidemia, coronary heart disease, arteriosclerosis, diabetes, people who eat too much greasy food, and people who are drunk.
- Those who smoke and drink too much for a long time, have fever, thirst, headache and dizziness, have bad urination and eat too much milk food should also eat.
Taboo of drinking tea
- Don’t drink tea for the first time: because tea is polluted by pesticides and other harmful substances during cultivation and processing, there is always some residue on the surface of tea.
- Avoid drinking tea on an empty stomach: drinking tea on an empty stomach can dilute gastric juice, reduce digestive function, cause a large amount of undesirable ingredients in tea to enter the blood, and cause dizziness, palpitation, limb weakness and other symptoms.
- Drink less new tea: because the new tea has a short storage time, it contains more non-oxidized polyphenols, aldehydes, alcohols and other substances, which has a strong stimulating effect on human gastrointestinal mucosa and is easy to induce stomach disease. New tea stored for less than half a month should be avoided.
- People with cold stomach should not drink too much. Excessive drinking will cause gastrointestinal discomfort. People with neurasthenia and insomnia should not drink tea before going to bed. Women who are breastfeeding should also drink less tea. Tea has a astringent effect on milk.
- Avoid taking medicine with green tea and drinking overnight tea. Tannic acid in green tea will combine with many drugs to produce precipitation, hinder absorption and affect the efficacy.
matters needing attention
The skin care and beauty effect of green tea is mainly caused by one of the substances called tea polyphenols, which has antioxidant effect and can supplement moisture and compact skin in combination with vitamins B and E. However, it should be noted that tea polyphenols, as the general name of phenolic substances or their derivatives, are easy to volatilize in the air and lose their antioxidant effect. Therefore, the new tea products of the year are the best for such skin care products, especially facial mask.
Green tea contains a certain amount of caffeine. When coexisting with tea polyphenols, it can stop the effect of caffeine in the stomach, avoid stimulating the secretion of gastric acid, and make the disadvantages of caffeine not play in the body, but promote the function of central nervous system, heart and liver. Aromatic compounds in green tea can also dissolve fat and prevent fat from accumulating in the body. Caffeine can also promote the secretion of gastric juice and help digestion and fat elimination, but women should not drink more during menstruation. Because green tea contains more tannic acid, it will combine with iron molecules in food to form a large amount of sediment, which will hinder the absorption of iron molecules by intestinal mucosa. The thicker the green tea, the greater the blocking effect on iron absorption, especially after drinking tea. Therefore, women and people with anemia should drink less strong tea even at ordinary times.
The identification methods of green tea can be divided into mechanical identification and visual perception identification. The quality identification of green tea mainly includes the following aspects:
(1) Shape: including the thickness, length, weight, size of the tea, the tightness of the rope, the breaking, evenness, and cleanness of the tea, whether there are inclusions and adulterations, whether there are old leaf hard pieces, as well as the lower plate, the degree of dryness and wetness, and the weight of the body and bone. The shape of green tea varies with the type of tea. For example, the eyebrow tea has a tight and thin rope, which is as thin as that of a fish fisherman, and the bending part is appropriate at one-third. The upper part is blunt, the body bone is heavy, the lower part is small, the rope is uniform, and the rope is clean without inclusion and old leaf hard pieces. Longjing is flat and straight, the tip is not bent, and the body bone is delicate. The top of the hair peak is slender and slightly curved. Japanese jade dew is as thin as a needle, but not bent. The bead tea is round like bead, and very small. It can also identify the origin of tea from its shape. It comes from the origin, such as Mount Huangshan Maofeng, Shifeng Longjing, Lu’an Gua Pian, which are extremely valuable. However, shape alone cannot absolutely determine the correctness of the way. We must also look at the characteristics of fragrance to avoid mistakes.
(2) Color: including the depth, dry, bright and dark, uniform, and whether there is abnormal color, bad discoloration, etc. The color of green tea also varies with the type of tea. For example, the brightness and whiteness of the eyebrow tea bead tea are gray and green. Maofeng takes dark green and brownish ones as the top, and Longjing Yulu melon slices take emerald green as the top. In short, the color should be deep and fresh, and the moist and uniform one is the best. Dark and dry, shallow and uneven, or even with abnormal color, poor discoloration, blistering, and spots are all inferior products. In particular, the bending part of the tea bar must also be uniform and moderate before it can be considered as top grade. When identifying the shape and color, it is necessary to mix the tea evenly, look up and down more, and make the light contrast before and after itself. The positions of the two plates of tea must also be exchanged at any time for comparison.
(3) Aroma: including high and low, clear and turbid, pure and pure: sharp and blunt, and whether there is grass gas, and smoke, odor and sour gas. The aroma of green tea also varies with the origin and type of tea. For example, green tea for export has a special kettle fragrance, Longjing has a special fragrance, Maofeng has a generous chestnut fragrance, melon slices have a thick and pure fragrance, and jade dew has a special covering fragrance. In short, the aroma of green tea is high and clear, pure and sharp. Those with low and turbid aroma, blunt and miscellaneous aroma, or even the smell of green grass, smoke, stink and sour mildew are inferior. There are two methods to identify aroma: dry aroma and wet aroma.
(4) Taste: including sweet, light, clear and turbid, mellow, astringent and bitter, heat, and whether there is bad smell such as deterioration, acid decay, charred smoke and mildew. The taste of green tea, like the aroma, varies with the origin and tea category. Generally speaking, they are sweet and clear, thick and mellow. Those with light taste, bitter and stimulating taste are not top grade. Some green tea, although slightly bitter, must also be bitter and sweet. It has the taste of green grass, smoke, stink, acid, mildew and scorch. Or bitter and heavy numb tongue and throat prick, are not top grade. When identifying the taste, the tea soup should not be too much in the mouth. The tea soup must be rotated from time to time so that the circumference reaches above the tongue, down, left, right and back. The tip of the tongue feels sweet and spicy, the sides of the tongue feel sour, the root of the tongue feels bitter, and the whole tongue feels salty. You must understand the whole tongue before you can distinguish all the tastes of tea.
(5) Water color: including light, clear and turbid, bright and dark, and free matter and sediment. No matter what kind of green tea, it is green and clear, and the water color is thick. Those with yellow, turbid, light and dark, or free sediment are not good products. But sometimes in order to meet the needs of consumers, the water color should be yellow but not green, which is another matter. When identifying the color of water, the cup should be tilted slightly from time to time, and attention should be paid to whether there are free substances.
(6) Leaf base: including bright and dark color, uniform and clean, rough and tender leaf buds, curling or unfolding? And whether there are cracks, scorches, green leaves, black leaves, false leaves, old leaves, and bronze, purple, yellow-brown and other abnormal colors. In a word, the bottom of any green tea leaves is green, the buds are tender and even, the color is bright, and the leaves are unfolded. The leaves with dark and dull color, different aging, cracking, curling, astringent but without fuzz, or mixed with green and black flakes, or with irregular color, dry but not moist and blistering, are inferior.
(7) Others: about the degree of dryness. The pricking of the hand with the hand is a clear proof of the dryness. If you press it with your finger, it will break, and if the tea stem breaks, it will be more clear. If the color is uniform, that is, the curved part is also gray white, it is dry and intact. If it is soft and does not prick the hands, the water content must be high. If it is analyzed mechanically, the water content should be more clear. The weight of the body bone can be compared on the hand. For the identification of the lower plate, you can read the bottom of the tea plate or sieve it, or pick the green tea stem to weigh it. As for the identification of the origin, it is necessary to observe its shape, color, fragrance, water color and leaf bottom in detail, and pay attention to its characteristics without special experience.
(8) Coloring and pasting: the refined green tea for export to North Africa must be colored. However, it is better not to color the tea. The stems of the colored tea are very unnatural, and the color is also dry. When soaking in water, there is oily light or floating matter on the water surface. When the cup is tilted, there is a circle on the edge of the cup. Rub it with your fingers, and the leaf bottom also has colored marks. The color of the tea sprayed with paste is dead and withered, and it is not allowed to shine. Put it on the palm, and then press it with the other palm, and it will attach to the palm. If viewed with an enlarged mirror, there are granular starch. The water color is muddy and greasy. The water surface is sticky and foam. The leaf bottom is broken and coarse, and it is very easy to become rancid and smelly.
(9) Deteriorated tea: mouldy tea has dull color, bitter and heavy taste at the root of the tongue, and both the fragrance and taste are mouldy, and the water is not easy to expand. Sour tea has a light taste, low aroma, sour taste in both aroma and taste, and a purple color at the bottom of the leaves. The smell and taste of the burnt tea are scorched, the bottom of the leaves is broken, and there are bubbles and spots, and the taste is bitter and precipitated. The smoky tea smells like smoke, and the food stings the throat, which makes people cough. The color of the old tea is dry and not moist, and there is old gas. The water is yellow and turbid, and the water is not easy to expand. The color of Huilong tea is light and colorless, and it is extremely light. Chewing it is light and tasteless, and it is not bitter and astringent. It spreads quickly when soaking in water. The flavor of fermented tea is not positive, the water color is yellow, turbid or red, and the leaf bottom is red. The smell and taste of rancid tea are both rancid, and the leaf bottom is purple, dark and colorless, and the water is yellow and turbid.
(10) Fake tea and mixed tea: When the price of tea is high, there are some unscrupulous people who mixed it with fake tea such as holly, willow leaves, peach leaves, camellia oleifera, Manchurian green, or mixed with impurities such as sand. The fake tea stems are square and flat, with different lengths, different soft and hard strings, different colors, shapes, and flavors. The water is soaked slowly, the bottom of the leaves is narrow and long, the serrations are large and thick, and the veins are not raised. They are broken by rubbing them with hands, dry and astringent without fuzz. The color of tea mixed with sand is dark and dull. It feels heavy when you let it go. When you press it with force, there will be a sound of sand. The water color is turbid and there are many precipitates. The bottom of the leaves will rub like fine sand.
In addition, the quality of green tea varies greatly, which can be identified according to the appearance of green tea and the tea soup and leaf bottom.
Fresh green tea and old green tea:
The appearance of fresh green tea is bright green, shiny, and has a strong smell of tea; The tea soup brewed is green in color, with fragrance, orchid fragrance, ripe chestnut fragrance, etc. It tastes sweet and refreshing, and the leaves are bright green.
The appearance of old green tea is yellow, dark, dull, and its aroma is low. For example, if you blow hot air into the tea, the leaves in wet places are yellow and dry, and you can smell cold; The brewed tea soup is dark yellow in color, mellow in taste but not refreshing, and the leaves are yellow and not bright.
Spring tea, summer tea and autumn tea:
Spring tea has strong and plump buds and leaves, dark green and moist, with tight and thick cords; The brewed tea soup is strong, sweet and refreshing, with strong fragrance and soft and bright leaves.
The shape of summer tea is thick and loose, with mixed colors and distinct wood buds; The brewed tea soup tastes astringent, the bottom of the leaves is hard, the veins of the leaves are exposed, mixed with copper-green leaves.
The shape of autumn tea is tight and thin, with many silk tendons, light and green; The brewed tea soup is light in color, mild in taste, slightly sweet, light in aroma, soft at the bottom of the leaves, and mostly copper-colored single pieces.
Alpine green tea and flatland green tea
Alpine green tea is thick, green and glossy; The tea soup brewed is green and bright in color, with lasting fragrance, strong taste, bright bottom and soft leaves.
The flat green tea is thin and thin in shape, with exposed tendons, light and yellow green in color; The tea soup brewed is light in color, light in aroma, mellow in taste, hard in leaf texture and exposed in vein.
According to the different objects and green tea ownership and storage quantity, the storage and storage methods of green tea are mainly divided into two categories: professional and family. Professional storage mainly refers to the storage of tea products by tea merchants, and family mainly refers to the storage of a small amount of green tea. Among them, there are three professional storage methods of green tea:
First, lime block preservation method. Quicklime blocks are packed in bags made of white muslin. Put green tea into white cotton paper bag, coat it with kraft paper bag, then wash and dry the small-mouth pottery jar, place the green tea bag in the small-mouth pottery jar with white paper under it, and embed one or two lime bags in the middle. Seal the jar mouth with several layers of grass, and finally compact it with bricks or thick wood plates to reduce air exchange. After that, the storage condition shall be checked frequently, and the lime shall be replaced in time after deliquescence.
The second is carbon storage method. The operation method is basically the same as the lime block preservation method. The materials used are only charcoal after burning out, and the tea utensils can be replaced by clay pots or small iron buckets. The capacity of charcoal bag and green tea bag can increase or decrease depending on the size of the container.
The third is the cold storage method of green tea. Dry the tea with water vapor, and the water content is between 3-5%, not more than 6%. The green tea leaves are put into aluminized composite bags and sealed with heat. The air in the bags is pumped out with a breathing extractor, and nitrogen is poured into the bags at the same time. The green tea leaves are sealed with a sealing sticker, placed in the tea box, and then sent to the low-temperature cold storage for storage. This method is the best tea preservation method under the condition of scientific and technological level. Large storage capacity and long time.
There are generally five ways to preserve green tea at home:
The method of storing tea in earthen pots has existed in ancient times. Feng Mengzhen of the Ming Dynasty (1368-1644) said: “The big vat of tea is solid, with the bottom of the vat of Ruo, and the bottom of the vat of Ruo, and the bottom of the vat is sealed upside down, so that it will not be yellow in the summer, and its gas will not leak out.” The water content of the tea can not exceed 6%. It can be dehumidified with quicklime. The specific operation method is the same as the lime block preservation method
Canning method. The containers are metal cans, boxes, cans, boxes, or iron or aluminum, or paper or paper products, or square or round, flat or irregular. The important thing is that the tea should be dry and the bag mouth sealed. This method is simple and convenient
The method of storing tea in plastic bags. Select food packaging bags with high density, high pressure, thick, good strength and no peculiar smell. The tea can be wrapped in soft clean paper in advance, then placed in the food bag and sealed
Hot water bottles can be used to store tea. Hot water bottles that are discarded due to poor heat preservation can be filled with dry green tea. The bottle stopper shall be closed and sealed with wax
Refrigerator preservation method. Green tea is packed into food packaging bags with high density, high pressure, thick, strong and odorless, and then placed in the refrigerator freezer or freezer. This method has a long storage time and good effect, but the bag mouth must be sealed tightly, or it will regain moisture or taste, which will damage the quality of green tea.
- Taboo of preservation
First, avoid dampness: green tea is a loose and porous hydrophilic material, so it has strong hygroscopic and hygroscopic properties. When storing green tea, the relative humidity is more appropriate at 60%, and more than 70% will cause mildew due to moisture absorption, and then acidification and deterioration.
Second, avoid high temperature: the best storage temperature of green tea is 0-5 ℃. If the temperature is too high, the amino acids, sugars, vitamins and aromatic substances in tea will be decomposed and destroyed, which will reduce the quality, aroma and taste.
Three taboos: sunlight will promote the oxidation of green tea pigments and esters, and can decompose chlorophyll into demagnesified chlorophyll. Green tea leaves are stored in glass containers or transparent plastic bags. After being exposed to sunlight, their internal substances will react chemically, which will deteriorate the quality of green tea leaves.
Four taboos of oxygen: chlorophyll, aldehydes, esters, vitamin C, etc. in green tea are easy to combine with oxygen in the air. Oxidized green tea leaves will make the green tea tea soup red and dark, and greatly reduce the nutritional value.
Five taboos: green tea contains macromolecular palmatase and terpene compounds. This kind of material is extremely unstable and can absorb odor widely. Therefore, when tea is mixed with articles with peculiar smell for storage, it will absorb the peculiar smell and cannot be removed.
Does green tea contain caffeine?
Although it contains caffeine, green tea contains less caffeine than coffee. In fact, a cup of green tea has about half the caffeine content of a cup of coffee. Therefore, if you are looking for a gentler way to get caffeine, green tea is a good choice.
Which of black tea and green tea has higher caffeine content? Let experts tell you:
Black tea and green tea all come from the same plant, but why are the caffeine content, color and taste different? In fact, the reason lies in the “fermentation method”. If you are sensitive to caffeine, it is recommended to choose green tea with low caffeine content.
Many people who drink tea care more about the caffeine content of tea than other things. In general, black tea has more caffeine than green tea.
Specifically, each cup of black tea contains about 47 mg of caffeine, while each cup of green tea contains about 28 mg of caffeine. In other words, if you want to drink tea in the afternoon, you can choose to drink green tea to avoid affecting your sleep at night.