Basic knowledge of tea review: Tea quality is evaluated by people's senses of smell, taste, vision and touch. And whether the sensory evaluation of tea is correct, in addition to the tea evaluators should have a keen sensory evaluation ability, but also have good environmental conditions, equipment conditions and orderly tea evaluation methods, such as a variety of tea evaluation utensils, tea water quality, tea proportion, tea evaluation steps and methods, etc., have made corresponding provisions, domestic and foreign are unified, objective conditions are unified, and gradually in the understanding, the specific quality of the superiority, in order to achieve subjective understanding of the close, after nearly a hundred years of trade exchanges, especially nearly half a century of scientific exchanges, This special, near-ancient quality assessment method, has been recognized worldwide.
In this chapter, the requirements for the objective conditions of tea evaluation and the steps of tea evaluation are discussed in sections.
First, the equipment and requirements for tea evaluation
Tea evaluation equipment is the basic condition for tea evaluation, and the consistency of equipment and utensils has the identity of tea evaluation results. The evaluation of tea equipment is relatively simple and special, some utensils are professional, basically international, in general, the market is not sold, the need for unified production in the industry, its specifications and requirements, more stringent, so as not to produce artificial error. It can be implemented according to GB/T13063-1992 sensory analysis - general guidelines for the establishment of sensory analysis laboratories, general requirements of laboratories, and layout of laboratories.
(1) Requirements for the evaluation of the tea room:
Sensory evaluation rooms are required to have even, adequate light and avoid direct sunlight. Direct sunlight on the tea soup or leaf bottom, resulting in freckles of light points is prone to error. Tea tasting rooms located in the northern hemisphere should face north and south, with spacious windows and no tinted glass. The light transmitted from the north is more uniform in the morning and evening, and the change is small. There must be no discolored reflections and obstructions that block the light inside and outside the tea room. In order to avoid the interference of the reflected light outside the window, it is advisable to install a black diagonal bucket-shaped black shield with a prominent tilt of 30 ° C along the north window to shield the direct light from outside and other colored interferences outside the window, so that the light shoots from the glass above the inclined bucket, and the light on the tea table surface is soft. The light illumination of the working surface of the dry evaluation table is required to be about 10001x. The moisture rating table has a shine of not less than 7501x, and in order to improve the indoor light, the walls, ceilings and furniture are painted white. Directly above the tea table, a standard fluorescent tube ((4 tubes or 5 tubes side by side) that simulates daylight can be installed for use when natural light is poor. The light should be uniform, soft and without projection, and in the constant temperature evaluation tea room, it is used as the main tea evaluation light source. The tea room requires dry and clean, preferably located upstairs, commonly known as "tea house" in the past, to avoid moisture on the ground and facilitate the preservation of sample tea. Indoors, it is best to have a constant temperature (20 °C 5'C) and constant humidity (relative humidity of 70% 5% 5%). In case of slightly worse conditions, mainly moisture-proof. The tea room is best connected to the tea storage room to avoid the biochemical analysis room, the warehouse of production materials, the canteen, the toilet and other odor places are too close, and it is also far away from the song hall and the downtown. Ensure tranquility, no smoking is allowed indoors, the floor is not waxed, and the tea review staff does not apply fat powder so as not to affect the accuracy of the tea evaluation. In units where conditions permit, lounges, bath rooms and changing rooms may be established near the evaluation rooms. The tea evaluation room is equipped with dry evaluation desk, wet evaluation desk, sample tea cabinet rack and other equipment.
1. Set up a dry evaluation table by the window in the dry evaluation table tea room to place sample tea pots and sample tea trays to review the form and color of the tea shape. The height of the thousand evaluation desk is generally 90-100cm, the width is 50-60cm, the length depends on the evaluation room and the specific needs, the table surface is painted black, and the sample tea cabinet is set under the stage.
2. The wet evaluation table is used to place the evaluation cup and bowl, and brew the inner quality of the review, including the aroma, soup color, taste and leaf bottom of the tea. Generally, the wet evaluation table is 140cm long, 36cm wide, 88cm high, the countertop trim is 5cm high, and a gap should be left at one end of the countertop to facilitate the flow of tea from the countertop and clean the countertop, all brushed with white paint. The wet judging table is set up behind the dry judging booth.
3. The sample tea cabinet shelf evaluation room should be equipped with an appropriate amount of sample tea cabinet or sample tea rack, and the sample tea pots used to store sample tea cans should be placed on both sides of the evaluation room, and the cabinet frame should be painted white. In addition to other evaluation utensils, the decoration of the tea room should be simple and applicable, so that the tea evaluators have a clean and bright feeling.
(2) Tea evaluation utensils
Tea evaluation utensils are special products, the quantity is sufficient, the specifications are consistent, the quality is superior, and strive to improve, and minimize the errors generated objectively. The commonly used tea evaluation devices have the following types:
1. The evaluation plate, also known as the sample tea tray or sample plate, is used to evaluate the shape of the tea leaves. Made of hard thin planks. There are two kinds of rectangles and squares, squares are generally 23cm, 23cm, 23cm, 3cm in length, and 25cm, 16cm, 3cm in rectangles, and the wood is odorless and painted white. Make a notch in the upper left of the dish to make it easier to pour the tea leaves. The square plate is convenient for sieving the tea leaves, and the rectangular plate saves the area of the dry evaluation table. The evaluation of Mao tea generally adopts a contemptuous circular sample plaque with a diameter of 50 cm and a side height of 4 cm.
2. The evaluation cup is used to brew tea and evaluate the aroma of tea leaves. Porcelain pure white, the cup lid has a small hole, in the cup handle opposite the cup mouth, there is a row of saw-shaped notches, so that the cup lid rests horizontally on the evaluation bowl, from the serration to filter out the tea juice, the capacity of the evaluation cup is generally 150m1, the international standard evaluation cup specifications are: 65mm high, 62mm inner diameter, 66mm outer diameter, the small gap of the cup handle relative to the cup edge is serrated. The outer diameter of the cup lid is 72mm above and 61mm below, and there is a small hole in the top of the lid. The mao tea review cup used in the evaluation of red and green hair tea in China is different from the fine tea. The capacity of the evaluation cup is 250m1, and the cup is curved along the small gap. The bell-shaped cup for the evaluation of green tea (oolong tea) has a capacity of 110m1, and the evaluation cups are required to be consistent in height, thickness and size.
3. The evaluation bowl is a special wide-mouth white porcelain bowl, which is used to evaluate the color and taste of the soup, and the evaluation bowl used for mao tea has a capacity of 250m1, and the fine tea is 150m1, and the porcelain color is pure white. The international standard evaluation bowl specifications are 95mm outer diameter, 86mm inner diameter and 52mm high.
4, leaf chassis ' review the leaf bottom, wooden leaf chassis has square and rectangular two kinds, square length and width of 10cm, side height of 2cm, rectangle length, width, height of 12cm, 8.5cm, 2cm. Usually painted black. In addition, an appropriate amount of rectangular white enamel plate is configured, and the bottom of the leaf is floated with clean water.
5, sample tea scale for the special copper weighing tea scale, weighing the scale of the lever at one end of the bowl-shaped copper disc, placed with 3g or 5g weight flat round copper piece piece, the other end with a sharp mouth oval copper plate, used to hold sample tea. If there is no scale, a small coarse balance (1/10g sensitivity) is also available.
6, sand timepiece or fixed clock sand timepiece for special products, used to time, generally using a fixed clock, 5min bell to tell the time.
7. The mesh spoon is made of fine copper wire mesh to remove the tea residue fragments in the tea bowl.
8: Teaspoon porcelain pure white, 5m1 capacity, for the soup to evaluate the taste.
9: Put a teaspoon and a net spoon in the soup cup, and boil the water when used.
10. Spit tea canister The bottom of the tea soup used to spit tea and install sweeping during the evaluation. There are two kinds of cylindrical or semi-circular, round height 80cm, diameter 35cm, bee waist diameter 20cm, two sections, the upper section of the bottom of the sieve hole, to filter tea residue, the lower section of tea soup water.
11. Kettle electric kettle (aluminum or stainless copper can be), or use the general kettle to configure electric stove or liquefied gas burner.
Second, the tea leaves are sampled
Sampling is also known as sampling. Sampling or sampling is to extract the minimum number of sample tea that can represent the quality of this batch of tea leaves from a batch of tea leaves, as the basis for reviewing and inspecting the quality of quality and physical and chemical indicators, whether the sample is correct and whether it is representative, is the primary key to ensuring the accuracy of the results of the audit face.
(1) The meaning of the sample
The objects of tea review are generally said to be wool tea, refined, reprocessed tea and deep processed tea. Each type of tea is composed of individuals with multiple forms and different forms, and the quality is composed of many factors that make up the quality, and the relationship is very complicated. Even in the same batch of tea leaves, there are differences in size, length, thickness, elasticity, roundness, and whole pieces in shape, there are differences in the texture of old tenderness, bud leaves, and milli-stemmed, and there are differences in the number of components contained in it, proportion and quality. Moreover, there are many differences in region, variety, processing conditions and process technology, and there are many differences in appearance and endoplasm. Even blended with fine tea. There is also a phenomenon of diametrically different quality in the upper, middle and lower sections: the upper section of the tea cord is longer and slightly loose, the middle section of the tea is fine and heavy, and the difference between the short and broken tea of the lower section; the taste of the inner soup is light, mellow and strong, and the aroma is slightly lower, higher and peaceful; the upper part of the leaf bottom tea is complete, the lower part of the tea is short and dark, and the middle part of the tea is more tender and soft. It is precisely because the tea leaves are uneven, and it is necessary to take representative samples, which requires more careful and meticulous. Sampling from a large number of teas should be accurate, and sampling should also be accurate when reviewing and inspecting Yi. The number of samples required for the evaluation of the soup is only 3-5g. It is more strict, and the evaluation results of this 3g tea are objectively and correctly identified for a region, a tea or a whole batch of products, which is related to the overall situation. Therefore, without the representativeness of the sample, there is no correctness of the results of the evaluation test. From the perspective of acquisition and acceptance, sample tea determines the quality grade and economic value of a batch of tea. It is the physical basis for embodying the price according to quality. From the perspective of production and scientific research, sample tea is the basis for reflecting the level of tea production and guiding the improvement of production technology, and correctly reflecting the results of scientific research. From the perspective of tea export, sample tea reflects whether the quality specifications of tea are consistent, which is related to the national reputation. In short, sample work is by no means an insignificant technical task, and directly or indirectly involves implementation.
(2) Sample method
The number and method of samples vary according to the requirements of the review and inspection, and can be implemented in accordance with the provisions of gb8302-1987 of the national sample retrieval standard. For example, there is no standard provision for the purchase of mao tea samples, and it is generally subject to the extraction of representative tea samples and the availability of tea evaluation and pricing. Before the sample, you should first check the number of pieces of raw tea per ticket, distinguish the tickets, make a good mark, and then take a handful from the top, middle, bottom and surrounding of each tea, first see whether the appearance color, thickness and dry smell aroma are consistent, if inconsistent, then pour out of the bag and take it from the pile. Sometimes samples need to be taken from a large tea pile, and great care must be taken to re-evenly stack the samples if necessary. If the number of pieces is too large, you can also take a number of bags to re-pile and then pick up the sample. Each sample of tea taken is mixed as a large sample, and 500g of small samples are taken from the large sample using the diagonal sampling method for review and inspection (diagonal sampling method: it is to fully mix and flatten a certain thickness of the sample tea, and then use the sub-sample to draw an "X" shaped groove diagonally, divide the tea into independent 4 parts, take 1, 3 parts, discard 2, 4 parts, and divide it repeatedly until the required quantity). One vote of tea, take a sample, such as the number of pieces of raw tea in one vote, the sampling method is taken, but generally not less than 1/3. When picking samples, it is necessary to pay attention to the dryness degree and dry aroma of the tea leaves, such as the water content is too high or the dry incense has a different odor, which should be treated separately according to the specific situation and in accordance with the regulations. Policy issues. Great attention should be paid. For the sample of Mao Tea transfer and acceptance, it is usually handled by the purchasing unit of Mao Tea and the refining and operation department of Mao Tea. The acceptance of Mao tea transfer is to re-check whether the level of sample repurchase meets the standards and whether there is any deterioration in quality, so as to clarify and strengthen the responsibility of both parties in and out of the transfer. In order to make the acceptance correct, it is necessary to record the batch, grade, quantity, and purchase unit price of the shipping note for the delivery of raw tea, and compare the incoming goods.
The sample of fine tea in the tea refining factory is the key to the implementation of the product factory responsibility system. Generally, after the pile is evenly stacked, it is picked up before packing. Samples are taken in various parts of the tea pile several times, and the sample tea is mixed into a small conical pile, and then the required samples are taken from different parts of the upper, middle and lower parts of the tea pile for evaluation and inspection. Large-scale tea factory, operation machinery assembly, processing continuity, uniform stacking boxing also implements continuity and automation, sample is in the uniform pile operation assembly line, timing and segmentation. The reprocessed pressed tea is ready to be sampled at any time during the drying process. Just like brick tea, tight tea, cake tea, etc. are sampled from different parts of the baking room. Basket loose teas such as Liupao tea, Xiangjian tea, square bag tea, etc. are selected to sample the tea at the waist or lower layer of each piece. Tuo tea sampling, take 1 piece (about 100g) in the total number of obtained, randomly select 6-10 as an average sample, divided into 2 tea sample cans or bags for inspection. Brick tea, cake tea, square tea sampling, random sampling of the specified number of pieces, open one by one, from different positions in each piece, take out 1-2 pieces. In the total number of blocks obtained, 2 pieces with a single weight of more than 500g are retained, and 4 pieces are retained for 500g and below 500g, which are packed in 2 bags for inspection.
Export tea samples, the number of samples, in accordance with the tea output into the interim standards of the sample method, divided into two kinds of samples before packing and after packing, before packing the sample is in the uniform stacking of boxes in accordance with the provisions of the number of picks, from each box to extract a small shovel, into the sample box, and then the sample of tea in the sample box through the sample divider sample, take 500g of tea cans two cans. After packing the sample, it is carried out after the packaging is completed and the brush mark is added, and the sample clerk is carried out according to the number of pieces listed in the inspection list, the name, the mark, the number or batch, the manufacturing plant, the storage location, etc. after the proofreading is correct, the number of pieces that should be picked is opened and the lid of the box is opened, the tea leaves in the box are poured into the bamboo tray, the sample is taken in each part of the sample, and each can (with a capacity of about 500m1) is poured on the canvas, and after all the samples are taken, the samples are fully mixed, and two cans of samples are taken by the sample divider for review and inspection. In order to simplify the procedures and reduce consumption, the pre-packing sample method is now mainly adopted. Tea samples for sensory evaluation, poured out from the sample jar, take 200-250g into the sample tea tray, and after evening, use the index finger, thumb and middle finger to grasp the review tea sample, each cup of sample should be grasped once, it is better to have the remaining tea in the hand, it is not advisable to grab the tea multiple times to increase, as for the physical and chemical test sample tea, mix it evenly according to the prescribed quantity. The action of taking tea samples should be light, and try to avoid scratching the tea leaves and causing inspection errors.
(3) The water temperature of the tea
The temperature of the water used for tea should be boiling and foaming, and the water temperature standard is 100 °C. Boiling water that is too boiling or boiling water that is less than 100 ° C is used to make tea cannot achieve a good effect of tea evaluation. Lu Yu's "Tea Classic" Yun: "Its boiling, such as the eyes of the fish, the slight sound, is a boil; The edges are like gushing springs, which are two boils; Tengbo drum wave is three boiling; The above water is old and inedible also. Ming Xu ci "Tea Shu" Cloud: "As soon as the water enters the chole, it needs to be boiled urgently, and when there is a sound of loosening, it is to cover it to signal its oldness." After the crab eye, the water has a slight wave, which is for the time. The great waves are boiling and swirling until they are silent, for the sake of obsolescence, and the soup is old and fragrant, and it is absolutely useless."
The above is the historical record of the ancients on boiling water to boil tea for reference. Commenting on the boiling water of tea should reach the degree of boiling and boiling, so that the water brewing tea leaves can make the aroma of the soup play out more, and the water leaching matter is also dissolved more. The water boils for too long, so that the air dissolved in the water can be expelled and become non-irritating. Brewing tea with this kind of boiling water will inevitably lose the fresh taste that a tea soup should have with fresh boiling water. Commonly known as thousand boiling water is not drinkable. If the water does not boil and the tea is brewed, the tea extract cannot be brewed to the maximum.
Water leaching is all the soluble substances that can be detected after tea is brewed, and the content of water leaching reflects the quality of tea to a certain extent. The water leachable from boiling water at 100 °C is 100%, the amount of water leached out of hot water at 80 °C is 80%, and the amount of bubble out of warm water at 60 °C is only 45%. The content of water leachables after boiling water and warm water brewing is more than doubled, and the solubility of free amino acids and polyphenols is completely positively correlated with the brewing water temperature. Secondly, green tea is rich in vitamin C, and its leaching amount also increases with the increase of water temperature.
From the above analysis, with a sample of tea 3g, injected 150m1 water brewing for 5min, to boil moderate 100 ° C boiling water, you can get a more ideal tea soup quality. In addition, the hot and cold of the tea cup also has an impact on the quality evaluation of the tea, according to the test of the cold tea cup after the boiling water is flushed down, the water temperature drops to 82.2 °C (1800 °F), and after 5min it is reduced to 67.71 °C (1540 °F). So the ancients had a cupping procedure for making tea. At present, when reviewing or tasting oolong tea, it is usually first boiled in boiling water to facilitate accurate evaluation of its aroma. Therefore, the evaluation of the quality of other tea leaves is prudent, and it is often often necessary to blanch the tea cup with boiling water first, so that the water temperature only drops to 78.8 °C (1740 °F) after brewing for half a minute, which can achieve good results in the review. As for brewing delicate and tender tea, from the perspective of appreciation, keep the soup clear leaves green, and some of them pour boiling water into the cup and then add the tea leaves. Japan's high-grade Gyokuro tea is brewed with boiling water of about 50 °C, medium sencha is brewed with boiling water at 60-80 °C, and general fragrant tea is brewed with boiled water at 100 °C.
(4) The time to brew tea
The shades of tea soup color and the thick and refreshing soup flavor are closely related to the amount of water extract in tea, especially the amount and brewing rate of the main flavored substances. According to Nakagawa Zhizhi's 1970 test data, take 3g of superior sencha, put it into a small teapot, pour into boiling water 180m1, brew 2min, pour out the tea soup for measurement, the first brewed tea is then flushed with 180m1 boiling water, the same tea soup is poured out after 2min to be tested, and the third brewed tea soup repeats the same operation.
The amount of brewing after each brew of green tea is mainly flavored: the head brews the most, and then plummets sharply. The leaching rate of each ingredient varies from fast to slow. For example, the amino acids with a fresh sweet taste and the caffeine with a bitter taste are the most easily leached, and the brewing rate of the first bubble for 2 minutes accounts for almost 2/3 of the total bubble output, and the total leaching capacity of the first bubble for 4 minutes is more than 90%; The astringent catechin leaching is slower, the head bubble out rate is 52%, the second bubble is about 30%, the head bubble two bubble is about 80% of the total leaching, of which the taste alcohol and the free catechin with strong astringency are also different from the leaching speed, and the leaching speed of free catechin is faster, and the first bubble two bubble can leach 87% for 4 minutes, while the vinegar catechin brew is 76%. According to the test data of Wang Yuegen of the Tea Research Institute of the Chinese Academy of Agricultural Sciences, 3g of Longjing tea is brewed with 150m1 water for 3min, 5min, 10min, and the amount of its main ingredients is different.
Within 10 minutes, as the brewing time is extended, the amount of brewing increases. Among them, the free amino acids are easier to leach, and the amount of leaching in 3min and 10min is very small. Compared with 10 min, although the brewing time of polyphenol compounds is doubled, the leaching amount is increased by less than 1/5. The leaching after brewing for 5 minutes is mainly an ester catechin component with a heavier astringency residual polyphenol compound, which is an unfavorable ingredient in taste quality. Good taste, on the basis of appropriate concentration, the harmony between the composition of astringent catechins, umami amino acids, bitter caffeine, sweet sugars and other flavored components is the most important. Practice has proved that brewing is less than 5min, the soup color is light, the taste is light, and the black tea soup color lacks brightness, because the leaching rate of theaflavin is slower than that of theareume. More than 5min, the soup color is deep, the astringent polyphenol compounds, especially the ester catechin, have a large amount of leaching and poor taste. In particular, the high temperature of the soaking water and the long brewing time cause the strengthening of the automatic oxidation and condensation of chemical components such as polyphenols, resulting in the yellowing of the green tea soup and the darkening of the black tea soup.
It is assumed that the moisture content of tea is 3.3%, the caffeine content is 2.4%, and the polyphenol content is 11. 0%, then 3g of tea samples, containing caffeine 0. 07g, polyphenols 0. 32g。 In the 150m1 tea soup, the polyphenol content is less than 0. The taste of 182g is light, more is stronger, too much and becomes astringent. The content of polyphenols and caffeine in the leaching must be a certain ratio, 3:1 is appropriate. In summary, the tea brewing time of red and green tea is generally set at home and abroad as 5min, which has a certain scientific basis.
(5) The proportion of tea and water
The amount of tea used and the amount of water brewed in the evaluation are very related to the thickness of the soup and the thickness of the liquid layer. The amount of tea used is more and the water is less, the leaves are difficult to brew, and they are too thick. On the contrary, if there is less tea and more water, the soup flavor will be too thin. The same amount of tea sample, the brewing water consumption is different, or the water consumption is the same, the amount of tea used is different, will affect the difference in tea aroma and soup taste or the deviation in the evaluation. The amount of tea used is the same, the brewing time is the same, and the water leachable that can be leached out is different due to the different amount of water used. More water, the amount of water leachables that can be brewed in the tea leaves is more; With less water, less water can be leached out. If the water is 200 m1, 34.10% can be leached out, while 20 m1 can only leach 22.90%.
Review tea quality is often a variety of tea samples at the same time brewing comparison and identification, water consumption must be the same, international review of red and green tea, the general proportion of 3g tea with 150m1 water brewing. If the capacity of the Mao tea review cup is 250m1, it should be called 5g of tea samples, and the tea-water ratio is 1:50. But review rock tea. Tieguanyin and other green teas, due to quality requirements focus on aroma and attach importance to the number of bubbles, with a special bell-shaped tea turn to evaluate, its capacity is 110m1, put into the tea sample 5g, tea water ratio of 1:22.
Third, the tea evaluation procedure
The quality of tea, the division of grades, and the level of value are mainly determined by sensory evaluation according to the shape, aroma, taste, soup color, leaf bottom and other items of tea.
Sensory review scores are dry tea review and open soup review, commonly known as dry look and wet look, that is, dry review and wet review. Generally speaking, the results of sensory evaluation quality should be based on wet evaluation of endoplasm, but due to different production and marketing requirements, there are also dry evaluation appearances as the main evaluation results. Moreover, the imbalance of the endoplasm imbalance of the same kind of tea is a common phenomenon, if the endoplasm is good. The appearance is not good, or the appearance is good, the color and fragrance may not be all good, so the evaluation of tea quality should be both appearance and internal quality.
Tea sensory evaluation is carried out in the order of appearance, aroma, soup color, taste and leaf bottom, and the general evaluation tea operation procedure is now divided
It is described below:
(a) Put the plate
The handle plate, commonly known as the sample plaque or sample plate, is the first step in the evaluation of the shape of dry tea.
Review the shape of dry tea and identify it by visual touch. Because of the type of tea. The decor is different, the external shape. The color is not the same. Therefore, when reviewing, you should first check the sample tea, identify the tea type, flower color, name, place of origin, etc., and then take a representative sample of tea, the evaluation of mao tea needs 250-500g, fine tea needs 200-250g.
The shape of the evaluation of mao tea is generally to put the sample tea into the sample plaque made of contempt, hold the edge of the sample plaque in both hands, use gestures to rotate back and forth, so that the tea leaves in the sample plaque are evenly distributed in different orders such as weight, size, length, thickness, etc., and then the hair tea evenly distributed in the sample plaque is concentrated into a steamed bun shape by reversing and retracting, so that the "sieve" and "collection" actions of the shaking plaque make the mao tea divided into upper, middle and lower levels. Generally speaking, the relatively thick and light floating tea leaves float on the surface, called noodle tea, or called upper section tea; The tight and heavy concentrated in the middle layer, called mid-section tea, commonly known as waist stall or belly goods; Small crushed tea and flakes are deposited on the bottom layer, called lower body tea, or lower section tea. When evaluating the shape of Mao Tea, compare the standard sample, first look at the face dress, then look at the middle section, and then look at the lower body. After reading the noodles and loading the tea, pull out the noodles to put the tea and put it on the edge of the sample plaque, look at the middle section of the tea, and then use your hands to put it aside, and then look at the lower body tea. When looking at the three-stage tea, when determining the grade according to the analysis of the factors of the sample tea according to the appearance review, it is necessary to pay attention to the proportion of the tea in each section and analyze the quality of the three-layer tea. If there is too much tea on the surface, it means that there are many coarse old tea leaves, poor body bones, generally in the middle of the tea is better, if the lower body tea is too much, pay attention to whether it belongs to the end of the tea, strip tea or round fried green in the following section of the tea fragments content more, indicating that there is a problem with workmanship and quality.
When evaluating the shape of round fried green, in addition to the same "sieving" and "closing" actions, there are also "cutting" (cutting) or "grasping" operations. That is, with the palm of your hand along the steamed bun-shaped tea pile surface gently like peeling", peeling off layer by layer, peeling off one layer, evaluating one layer, generally cutting three or four times until the bottom layer. When operating, the fingers should be straight, and the gestures should be light to prevent the levels from getting messed up. Finally, there is a "bump" action, before the dust, first flatten the shaved layers of hair tea to the left and right, be careful not to pull randomly, and then gently move the sample plaque up and down 3 times, so that the sample tea is evenly spread in the sample plaque from front to back according to the size of the particles. Synthesize the various factors of appearance and evaluate the quality of dry tea. In addition, when reviewing the appearance of various types of raw tea, you should also grasp a handful of dry tea to smell dry fragrance and measure the moisture content by hand.
The shape of the refined tea is generally to pour the sample tea into the wooden review plate, hold the diagonal edge of the evaluation plate with both hands, hold the small gap of the poured tea of the sample plate with one hand, and also use the method of rotary sieve to divide the tea leaves on the plate into three layers. Generally look at the face and lower body first, and then look at the middle of the tea. When looking at the middle section of tea, gently grasp the sieved fine tea into your hand, and then flip your palm to see the quality of the middle section of tea, and weigh the weight of the body. Look at the general requirements of the shape of fine tea, whether the blending ratio of the upper, middle and lower three grades of tea is appropriate and consistent, and whether it is flat and even. Although the red crushed tea cannot be strictly divided into three stages of tea, but after the sample tea tray is sieved, the thickness, uniformity and clarity of the sample should be evaluated, and a handful of tea should be grabbed and spread out in the plate, so that the weight and uniform clarity of granular crushed tea are more easily distinguished. When reviewing the shape of fine tea, the capacity of each plate of tea should be roughly the same, which is convenient for evaluation.
(2) Open the soup
Opening soup, commonly known as making tea or tea, is an important step in wet evaluation of endoplasm. Before opening the soup, the evaluation cups and bowls should be washed and dried in the order of numbers on the wet evaluation table. General red, green, yellow, white loose tea, called sampling tea 3g into the evaluation cup (mao tea such as with a 200m1 capacity of the evaluation cup is called sampling tea 4g, the cup lid should be put into the evaluation bowl, and then boiling moderate boiling water at a slow and slow speed to brew the cup, the amount of water should be consistent with the cup mouth. When brewing, the first cup should be remembered, and from the low-grade tea brewing, with the cup lid, the lid hole towards the cup handle, 5min according to the brewing order of the cup of tea soup into the evaluation bowl, when pouring tea soup, the cup should lie on the bowl mouth, the cup should be completely filtered.
In Japan, in order to keep the leaching time and leaching concentration consistent, so that the color and taste of the soup are reasonably evaluated, the evaluation bowls are arranged in a row, from right to left, and filled in two parts, the first to 70% and the second to full.
After opening the soup, you should first smell the aroma, quickly look at the soup color, then taste the taste, and then evaluate the bottom of the leaf, and sometimes review the green tea and sometimes look at the soup color first. However, the tea collection station reviews the endoplasm of mao tea, in addition to special tea, it is generally based on the bottom of the leaf, and the aromatic soup color is used as a reference, and generally only normal is required.
(3) Smell the aroma
Aroma is distinguished by the sense of smell. The aroma of tea is evaluated by brewing tea to make the aromatic substances contained in it volatilize, and the airflow of volatile substances stimulates the olfactory nerves in the nasal cavity, and different types of tea aromas appear to varying degrees. Olfactory receptors are very sensitive, and it is the olfactory cells in olfactory cells that directly feel the sense of smell. The surface of the olfactory cell is moistened by the secretion of water, commonly known as the nasal membrane glaze, the surface of the olfactory cell is negatively charged, when the volatile substance molecules are adsorbed to the surface of the olfactory cell, the partial charge on the surface is changed and an electric current is generated, so that the ends of the olfactory nerve are stimulated and excited, and transmitted to the olfactory area of the brain to produce a sense of smell of incense.
The smell should be held in one hand of the evaluation cup that has been poured out of the tea soup, and the lid of the cup should be opened with the other hand, close to the cup to follow the nose to sniff lightly or deeply, and also to deepen the entire nose into the cup close to the bottom of the leaf to increase the sense of smell. In order to correctly determine the type of aroma. High and low and long, when sniffing should be repeated once or twice, but the time of each sniff should not be too long, because the sense of smell is easy to fatigue, smell for too long, the sense of smell loses sensitivity, generally about 3s. In addition, when the number of cups is large, the smell time is prolonged, and the degree of heat and cold is different, which is difficult to evaluate. Each time you sniff the bottom of the leaf of the cup, the bottom of the leaf of the cup is shaken over, and the lid of the cup must not be opened until the aroma is evaluated.
The smell should be a combination of hot sniffing, warm sniffing and cold sniffing. The focus of hot sniffing is to distinguish whether the aroma is normal or not and the type and height of the aroma, but because the tea soup has just been poured out, the steam molecules in the cup are moving very strongly, the olfactory nerve is stimulated by the heat, and the sensitivity is affected to a certain extent. Therefore, it is better to distinguish the superiority of the aroma, or to smell warmly, and the accuracy is greater. Cold sniffing is mainly to understand the durability of the tea aroma, or in the evaluation, there are two kinds of tea aromas that are comparable in temperature smell, which can be distinguished according to the degree of afterscent of cold smell. The most suitable leaf bottom temperature for evaluating tea aroma is about 55 °C. When it exceeds 65 ° C, it feels hot nose, and when it is below 30 ° C, the tea aroma is low, especially for tea stained with smoke and wood gas and other exotic gases that volatilize with heat. When reviewing the aroma of several cups of tea at a time, in order to distinguish the aroma of each cup of tea, after sniffing and evaluating, the aroma is divided, the evaluation cup is moved back and forth, generally the good aroma is pushed forward, the second swing is reversed, this operation is called aroma queuing, and the evaluation aroma should not be carried out at the same time as red and green tea. When evaluating aroma, it is also necessary to avoid the interference of external factors, such as smoking, wiping balsam, washing hands with soap, etc. will affect the accuracy of identifying aroma.
Tea collection stations across China evaluate the aroma of Mao tea, sometimes using bamboo chopsticks to take soaked leaves from the bowl and put them close to the nostrils to smell the incense. When evaluating aroma in Japan, tea leaves are also taken by structure, close to the nostrils to identify the aroma, and it is believed that the defects of the tea are checked at high temperatures, and then its characteristics are checked after the temperature is reduced. It is also considered to be the best aroma in countries such as India and Sri Lanka. The heat sniff can clearly distinguish the special high aroma of Darjeeling and Sri Lankan alpine tea, and at the same time, all kinds of strange gases produced by improper manufacturing can be smelled hot on the bottom of the leaf.
(4) Look at the soup color
Soup color relies on visual review. After the tea leaves are opened, the color presented by the solution in which the ingredients in the tea leaves are dissolved in boiling water is called soup color, also known as water color, commonly known as soup door or water bowl. The evaluation of the soup color should be timely, because the ingredients in the tea soup are easy to change after contact with the air, so some people put the soup color before smelling the aroma. The soup color is susceptible to light intensity. Tea bowl specifications. Capacity. Arrange positions. How much sediment. The influence of various external factors such as the length of brewing time. In winter, the soup color gradually becomes darker as the soup temperature decreases; If at the same temperature and time, the color of black tea becomes greater than that of green tea, the large leaf species are greater than the small leaf species, the young tea is greater than the old tea, and the new tea is greater than the old tea, sufficient attention should be paid to the review. If the level of tea soup in each bowl is different, it should be adjusted. If the tea soup is mixed with the residue leaves of the tea residue, it should be fished out with a mesh spoon, and a circle should be made in the bowl with a teaspoon, so that the sediment is rotated in the center of the bowl, and then the evaluation begins, according to the nature of the soup color and the depth, light and shade, turbidity and other evaluations.
(5) Taste the taste
Taste is distinguished by the organs of taste. Tea is a flavor drink, different types of tea or the same tea and different origins have their own unique flavor or taste characteristics, a good sense of taste is one of the important factors constituting the quality of tea. The different taste sensations of tea leaves vary due to the fact that the number and composition ratio of the flavored substances of the tea leaves do not vary. The taste is sweet, sour, bitter, spicy, fresh, astringent, salty, alkali and metallic. Taste receptors are the taste buds on the surface of the tongue, after the taste buds come into contact with the tea soup, the stimulated excitement waves are immediately transmitted through the afferent nerve to the central nervous system, and after comprehensive analysis by the brain, there are different tastes. The taste buds of each part of the tongue have different ability to feel different taste sensations. For example, the tip of the tongue is most easily excited by sweetness, the front part of the tongue on both sides is most likely to feel salty and the back of both sides is excited by sour taste, the tongue is the most sensitive to umami and astringency, and the near base of the tongue is easily excited by bitterness.
The evaluation taste should be carried out immediately after the evaluation of the soup color, the tea soup temperature should be appropriate, generally about 50 ° C is more suitable for the evaluation of taste requirements, such as tea soup is too hot when the taste is evaluated, the taste is strongly stimulated and numb, affecting the normal evaluation, such as the tea soup temperature is low, the taste is affected by two factors, one is the low taste of the tea soup sensitivity, the second is that the taste-related substances in the tea soup are dissolved in the hot soup and coordinated, and as the soup temperature decreases, the substances originally dissolved in the hot soup are gradually precipitated, and the soup flavor changes from coordination to incongruity. When evaluating the taste of tea, use a porcelain spoon to take a light spoon from the evaluation bowl to suck in the mouth, because different parts of the tongue have different feelings of taste, the tea soup entrance is circulated on the tongue to correctly and comprehensively distinguish the taste. After tasting the tea soup is generally not suitable for swallowing, when tasting the second bowl, the residual tea liquid in the spoon should be poured out or rinsed in the boiled water soup, so as not to affect each other. The taste of the evaluation is mainly based on intensity. Strength. Fresh stagnation and pure heterogeneity are evaluated as superior. In foreign countries, it is believed that the fragrance tasted in the mouth is the highest manifestation of the aroma of tea. In order to evaluate the taste correctly, it is best not to eat foods with strong irritating taste before the review, such as peppers, onions, garlic, candy, etc., and should not smoke to maintain the sensitivity of taste and smell.
(6) Evaluate the bottom of the leaf
The evaluation of the leaf bottom mainly relies on visual and tactile sense to judge, according to the leaf bottom of the old tender, homogeneous, whole crushed, color and development or not to evaluate the merit, but also should pay attention to whether there is other adulteration. The bottom of the leaf is to pour the tea brewed in the cup into the leaf bottom or put into the reverse of the evaluation cover, there are also put into the white enamel drifting plate, when pouring, pay attention to the finely chopped tea leaves stuck to the bottom of the cup wall and the cup lid, pour clean, use the leaf bottom or cup lid to mix the leaves well, spread out, flatten, observe its tenderness, uniformity and color. If you feel that it is not obvious enough, you can add tea soup to the plate to flatten, and then slowly pour out the tea soup, so that the bottom of the leaf is flat or flipped to see, or the leaf bottom is thrown back on the table for observation. Use a floating tray to see the leaves with water, so that the leaves are floated in the water for observation and analysis. When evaluating the bottom of the leaf, it is necessary to give full play to the role of the eyes and fingers, and the fingers should press the softness, hardness, thickness and so on of the bottom of the leaf. Look at the difference between bud head and young leaf content, leaf roll spread, light and roughness, color and uniformity.
Tea quality evaluation generally through the comprehensive observation of the above dry tea appearance and soup color, aroma, taste, and leaf bottom five items, in order to correctly assess the quality and grade price. Practice has proved that the evaluation of each project cannot reflect the entire quality alone, but the various quality projects of tea are not formed and isolated, and there is a close correlation between them. Therefore, when synthesizing the results of the review, careful comparisons should be made between each review project before drawing conclusions. For tea samples that are comparable or difficult, sometimes a double cup should be brewed for evaluation to obtain the correct evaluation results. In short, when evaluating tea, it is necessary to grasp it according to different situations and requirements, some select key projects for review, and some should be comprehensively reviewed. All sensory reviews should be carried out in strict accordance with the operating procedures and rules of tea evaluation in order to achieve correct results.