First of all, watch
Deactivating is to destroy the tissue of fresh leaves by high temperature, so that the contents of fresh leaves can be quickly transformed. Fixing green tea is the first process of green tea, and it is the key to achieve the quality of green leaves in green tea soup. It can destroy the enzyme activity in fresh leaves, prevent the enzymatic oxidation of polyphenols, prevent the leaves from turning red, and lay a foundation for maintaining the quality characteristics of green tea broth. 2. Evaporate some water in the leaves, enhance the toughness of the leaves, and create conditions for twisting into strips. 3. It is the volatilization of low-boiling aromatic substances in the leaves and the exposure of high-boiling aromatic substances that enhance the tea fragrance.
The technical factors of water fixation include pot temperature, leaf quantity, time and method. These factors restrict and promote each other, and affect the immobilized quality of the enzyme.
(1), the pot temperature generally requires that the temperature of the fixed pot be between 260℃ and 320℃ to achieve the purpose of inactivating the enzyme. If the pot temperature is too high, the water loss of the water-removing leaves is too fast, which is easy to produce burnt leaves and burnt taste. If the pot temperature is too low, it is easy to produce red stems and leaves, which will affect the quality of finished products.
(2) The amount of leaves cast varies with the equipment, tender water removal and pot temperature. Under the same pot temperature, the empirical formula of blade input is:
Leaf quantity = (150-5k) r? Kg/can
In the formula, k is the old and tender grade of fresh leaves, and r is the radius of the water-removing pot.
(3) Generally, the water fixation time is 5- 10 minute. The length of time is related to the pot temperature and the amount of leaves thrown. The water locking time is too long, and the water locking leaves lose too much water, which is not conducive to shaping; According to the news from China Tea House, the time of enzyme fixation is too short, and the hydrolysis and transformation of tea polyphenols, protein and other components in fresh leaves are not sufficient, and the finished product is green and heavy. Generally, it is advisable to master the principle of "young leaves are old and old leaves are young".
(4) Methods The principle of "combination of vibration and boring, more vibration and less boring" should be mastered in pot enzyme fixation. Shake is to hold the leaves high, which is conducive to the loss of water, the volatilization of grass gas, the fragrance of leaves, and prevent the leaves from turning yellow. Smoothing means not to lift the leaf cover, so that the hot steam stays in the leaf for a short time and the leaf harvest is quickly improved? Did you burn apples in the ditch and make curtains? Hey? Is it true?/You don't say. Did you have a good time? Hey? Do you want to talk to me? A ton of plutonium? Cover up and knock? 0-50 is the strongest. If the temperature continues to rise, the enzyme activity begins to be passivated, and when the leaf temperature rises to 70, the enzyme activity is destroyed. Therefore, if the leaf temperature can be quickly increased to 70 meridian in the early stage of water fixation, red stems and red leaves can be effectively prevented. But what if you are tired of time? Buds and leaves are easy to turn yellow, and they are sulking when cooked, which does not meet the quality requirements of tea.
Fresh leaves turn over in the pot. When the leaves turn from bright green to green, the leaves lose their luster, and they are huddled, slightly elastic, soft, and the stems are constantly broken and fragrant. Take the pot out, spread it out and roll it.
At present, in addition to tank-type water fixation, drum-type water fixation machine is widely used in production. The drum cleaner has the advantages of convenient operation, low labor intensity, high working efficiency, fuel saving, continuous operation, etc. However, due to the short residence time in the drum, it is easy to produce green odor, and because of the uneven distribution of water vapor in the drum, it is easy to stick leaves in the drum and the drum mouth to produce smoke odor.
Second, knead
Kneading is an important process for frying green tea into strips. Kneading is the use of mechanical force to make the water-fixing blade in the kneading barrel subject to the interaction of various forces such as pushing, pressing, twisting and friction to form a tight knot. Kneading also broke the cell tissue of leaves, promoted the oxidation of phenols, reduced the bitterness of roasted green tea and increased the rich alcohol flavor. Except for a few manual twists, they are all machine twists.
There are many kinds of rolling machines for machine-made green tea, with different models and different performances. In production practice, it is not suitable to use barrel kneader to make fried green tea. Large-scale leaves are thrown for a long time, and the leaf temperature is high when they are twisted, which is easy to cause yellowing. Kneaders with barrel diameters of 45 cm and 55 cm are generally selected, and a kneader with a diameter of 65 cm can also be used when the capacity is large. The quantity, pressure and rolling time of leaves depend on the type of tea and the tenderness of leaves. Master the principles of "gently kneading young leaves and re-kneading old leaves", "light-heavy-light" and "combination of shaking and kneading" to operate. Green tea is generally rubbed once, and young leaves generally need to be rubbed for 20-25 minutes. Old leaves are rubbed under heavy pressure for a long time, screened in blocks and rubbed several times, but the total time is generally less than 50 minutes. The rate of high-grade tea strips is above 85%, and the cell breakage rate is above 45%. The peeling rate of low-grade green tea is above 60%, and the cell breakage rate is above 65, which is a sign of the completion of kneading.
Thirdly, drying.
Drying is an important process for shaping tea, fixing tea quality and developing tea fragrance. Because of the different machines used, the drying process can be divided into: full frying method, full rolling method and rolling frying method. Due to different processes, the quality of the products produced is also different. Taking the rolling frying method as an example, the drying is divided into three parts, namely, second green, third green and? Fuck.
The purpose of "Liangqing" and "Liangqing" is to evaporate some water, reduce viscosity, improve the plasticity of bud leaves and facilitate molding. The moisture content of twisted leaves is about 60%. A roller water-removing machine can be used, and the method is that the roller temperature is 70-80℃, the amount of leaves is 15 kg, and the time is 15 minutes. The appropriate standard of Qing Er leaves is: weight loss rate 30%, water content 35%-40%; Hand-held tea leaves are elastic and not easy to loosen; The leaves are soft, sticky, green, smokeless and stuffy.
China Teahouse,
Three greens are divided into two times, namely, initial frying and re-frying. The initial temperature of the wok is 70- 100℃, the dosage of leaves is about 13 kg, the time is 30-40 minutes, and the water content is 20%-25%. After airing for 20-30 minutes, sieve with No.5 sieve. Stir-fried sieve leaves. Stir-fried leaves and tea with sieve bottom are rolled to dry feet respectively. The temperature of the frying pan is 60-80℃, the dosage of leaves is 65438±08kg, the time is 40-60min, and the water content is about 65438 02%.
The drying temperature should be controlled between 50-60℃, first high and then low. Stir-fry until the water content is about 5%, knead it into powder by hand, then take it out of the pot, spread it out and package it.