When evaluating Wuyi rock tea, it is often encountered that the green taste of the first mao tea, or the refined tea taste of the green taste.
Why? How to stop it?
The first is that the fresh leaves of the tea plant contain a class of aromatic substances with low boiling point, of which cis-3-hexenol (also known as cyanol) has the highest content, accounting for about 60% of the fresh leaf aromatic oil. High concentrations of green leaf alcohol have a strong grass gas;
Secondly, the tea processing process is improperly mastered, such as rain green or dew green and other fresh leaves with more water content of tea green, in the initial production process, insufficient withering, impermeable green, insufficient fermentation, low temperature of greening, insufficient distribution of water to cause impenetrable greening, low baking temperature or thick spreading of green, raw tea dryness is not enough;
The roasting is not thorough enough during refining or the temperature is high at the beginning of baking (rapid fire), so that the internal moisture of the tea strip has not evaporated and is wrapped in it;
There are also moisture returns in the storage and transportation process...
In order to prevent the "green taste" of Wuyi rock tea, it is necessary to grasp the following links in the process of tea processing and storage:
01, withering
Withering can promote the reduction of evaporation of aromatic substances with low boiling point and grassy gas, promote the formation or exposure of floral components with high boiling point, and improve aroma.
During the Wuyi Mountain Spring Tea Period, it is often rainy and rainy, especially the water content of rain or dew tea green is more. After this kind of tea green enters the factory, if there is no condition to dry the green, it will use the heating withering tank withering, the hot air temperature is 30-35 degrees, every 30 minutes or so to flip, the thickness of the spread leaves is about 20cm. After the withering is over, leave the green room for about 1 hour and shake the green.
Comprehensive green machine withering, hot air temperature in 30-32 degrees is appropriate, every 10-15 minutes to flip a few turns, the total duration of no water blue is 1.5-2.5 hours, rain blue (should first be used cold air to dry the leaf surface moisture and then blow hot air) for about 3-4 hours. The weight loss rate of withering can reach about 10%, when the first and second leaves of fresh leaves droop, the leaf color darkens, the green qi decreases, and the aroma is revealed when the withering is moderate.
02, do green
Making green is the most important process for forming the quality of oolong tea, which is carried out alternately by shaking green and drying green. This step not only increases the aroma of the tea leaves, but also improves the sweetness and mellowness of the tea soup.
The green room should have facilities such as heating, dehumidification, exhaust ventilation and so on. Keep 18 °C -26 °C, the relative humidity is about 75%, the temperature and humidity of the greening process requires low and then high, so that the tea green water is smooth.
Rain or dew tea green should be appropriately extended to do green time. In the early stage of doing green, it is necessary to shake the beach more coolly, or blow more wind and shake less.
Do green technical requirements, the first time to shake the green to green gas slightly exposed, the leaf state slightly tense for moderate, commonly known as "shake evenly".
The second green is more exposed to the green qi, showing a more obvious tension, and the leaf margin is slightly reddish, which is moderate, commonly known as "shaking live".
The third shaking of green is based on the appearance of strong green qi and the red dots of the leaf margin are still obvious; commonly known as "shaking red". The third time to dry the green to the leaves are slightly spoon-shaped, the leaf surface is green and yellow, the leaf edge is rolled, the red dots are bright, the hand is slightly prickly, the green qi subsides, and the fragrance is slightly dewy.
The fourth green shake is characterized by a slight green qi and obvious red dots at the leaf margin. The fourth time, the leaf surface is slightly yellower and brighter, the red spots at the leaf edge are more obvious, and the floral fragrance is moderate. The fifth shake is yellow and shiny in the foliage, the spoon-like features are prominent, the hand is like cotton, and the floral and fruit aroma is revealed as moderate.
Cool for 1-2 hours after one shake, cool for 2-3 hours after two shakes, cool for 3 hours after three shakes, and cool for 3 hours after four shakes. After that, it is flexible to grasp the changes in green leaves, and it is necessary to pile green for 2-3 hours before killing.
The traditional process of doing qingqing lasts 10-12 hours, and the whole process of doing greening in the air-conditioned environment lasts more than 16 hours.
03. Kill the green
Oolong tea is to accelerate the volatilization of aromatic substances with low boiling point and high boiling point aromatic substances in fresh leaves under the action of high temperature and high temperature, as well as the transformation of chlorophyll, protein and amino acids, sugars and tea polyphenols and other contained substances, forming a large number of new color, aroma and taste substances. In addition, the water can be evaporated in an appropriate amount, so that the leaves are soft and easy to knead and shape.
Now use more 110 type drum killing machine, barrel temperature above 260 ° C, rain or dew tea green pot temperature can be slightly higher, green leaf pot to have a beeping sound, to kill through the killing evenly, the amount of leaves 20-40 kg, frying time 6-9 minutes.
Frying the green process, when a large amount of water vapor overflows the cylinder mouth, exhaust, fry until the aroma is pure, the leaf color changes from green to dark green, the stem folds continuously, the leaves are wrinkled, and the hand rubbing is moderately sticky.
04. Kneading
Using oolong tea kneading machine, the principle of kneading is "hot, small amount, heavy pressure, fast, short time". Ask to knead out the tea leaves and roll them into tea strips. After kneading, untie the block and bake it in time to avoid smouldering yellowing.
05. Initial baking
Initial baking can further volatilize the low boiling point grass odor, intensify and retain high boiling point aromatic substances. Tighten the tea strips, fix the shape, evaporate the water, and keep dry to prevent mildew.
Now the initial baking of large-scale Wuyi rock tea adopts automatic dryer, the gross fire temperature is 120-150 °C, the thickness of the spread leaves is 2 cm, and it lasts 10-15 minutes.
The moisture content of the hairy fire leaf is 20%-25%, and it is about 70% dry.
After the hair fire, after 1-6h of drying, the foot fire is carried out.
The foot fire temperature is 100-120 °C, the thickness of the spread leaves is 5-6 cm, it lasts 15-17 min, and the moisture content of mao tea is less than 6%.
06. Refined stew
Wuyi Rock Tea's unique roasting process has formed its high aroma, strong taste, bubble resistance and unique tea soup taste charm. The process of stewing should master the principle of "low temperature slow simmering".
At present, the main ways of baking are: dryer baking, oven baking, baking cage charcoal baking and so on.
Automatic dryer stewing temperature 130 ~ 140 °C, lasted 1.5 ~ 2.0h, spread leaf thickness 5 ~ 6 cm; oven stew temperature 120 ~ 130 ° C, time 7h, spread leaf thickness 4 ~ 5 cm; charcoal baking temperature 80-120 °C, time 8 ~ 12h, spread leaf thickness up to 80% of the cage, each cage of spread leaves up to 4 ~ 5 kg.
Refined stew should "look at the tea roasted tea", and flexibly grasp the temperature, time, and thickness of the leaves to control the fire.
Different degree of green rock tea stew to make light green or rain dew water tea green rock tea, the temperature should be slightly higher when stewing, spread the leaves slightly thinner, appropriately extend the baking time, roast through the roasting foot, in order to improve the fire power to completely remove the green gas and bitter taste.
To make rock tea with a heavy degree of greenness, the fire power should be low to prevent the aroma from being low. To make green moderate rock tea fire work, it is necessary to grasp the moderate, so that the product color, aroma and taste are complete, and the quality characteristics of "mellow and smooth" are achieved. In particular, the use of traditional charcoal roasting and stewing can achieve the unique quality flavor of Wuyi rock tea "fragrant, clear, sweet and alive".
07. Tea storage
The main points of tea storage are: low temperature, drying, oxygenation and light avoidance.
The storage of large quantities of tea should be built into special warehouses.
In the process of storage, the higher the general temperature, the faster the quality deterioration. The economically suitable temperature for tea storage is 0 °C-5 °C.
Tea is easy to absorb moisture, so the environmental conditions of the tea packaging and storage process must be dry, and the relative humidity should be kept below 50%. The higher the water content of the tea leaves, the faster the tea leaves will age and deteriorate. The water content of tea must be maintained within 6%, and it is best to control it at 3%-5%.
During storage, the active ingredients in the tea will slowly oxidize, so it is best to isolate the air when the tea is stored.
Light will promote the oxidation of the pigment and lipids of tea leaves, and tea leaves are stored under direct light, which not only yellows in color, but also produces bad odors. Therefore, the storage of tea leaves should use opaque packaging materials and containers. Tea leaves are very good at absorbing odors, and the storage environment should be clean and odorless.
Photography / Zhou Ang, "Tea Ceremony" photo gallery