Polyphenols in tea are wetted by water, and slowly differentiate at a certain temperature, which can reduce the astringency of tea blank. Part of protein, which was originally insoluble in water, is decomposed into amino acids, which makes the soup of the product turn dark and yellow, and the taste is fresh and mellow. This is also the reason why high-grade jasmine tea tastes better and more mellow than green tea of the same variety and grade. The scenting process of jasmine tea;
First, tea blank processing.
1, special tea is blank. Refers to round, flat, curved, melon seeds, needles, butterflies, earrings, bunches (flower-shaped, spherical, plum-shaped, etc.) and other tea varieties. ) is made of strong and tender bud leaves of Fuding Dabai tea and Fuding Dahao tea (other tea varieties with rich buds can also be used). Different varieties of tea blanks are required to be clean and uniform in appearance, without other inclusions, and the water content is required to reach 8%, which meets the requirements of soaking water in wet blanks. The hygienic index of tea should at least meet the national standards for pollution-free green tea products. Higher requirements should be checked according to the needs of customers and corresponding health indicators. After entering the factory, tea should be classified and put into storage according to varieties and different health indicators. Products with odor, mildew, red stalks and burning edges should be handled in another pile.
2. High-grade tea blank. Such as Dabaihuo, Dalong, Yin Hao, Maojian, Chunhao, and White Haired Monkey. , are baked green, green, according to the different grades of tea for recycling and refining. Remove non-tea contents, stems and fragments. The quality requirements of tea blank shall meet the standards specified in this grade. The hygienic index of tea is the same as that of special tea blank.
Second, flower processing.
Jasmine for making high-quality jasmine tea is usually processed and produced between summer solstice and high temperature in summer. Due to the high temperature and strong sunshine, jasmine has the best quality and high yield. Use buds picked after three o'clock in the afternoon (commonly known as flower buds of the day). There are three main signs of flowers at maturity: first, the color of flower buds changes from bluish white to white; Second, the buds are full and the corolla tube has been pulled out; Thirdly, due to the extraction of corolla tube, calyx and corolla are slightly separated, that is, calyx does not touch corolla. There are two main technical links in jasmine flower treatment: waiting for flowers and screening flowers.
1, flowers. The purpose of waiting for flowers is to maintain the quality of flowers and promote uniform after-ripening and fragrance opening. After the jasmine flower buds enter the factory, the thickness is 5- 10 cm, so as to give off the sultry and grassy smell during shipment and remove the moisture on the surface of the flower buds. When the flower temperature is close to room temperature or higher room temperature 1-3 degrees, pile flowers 40-60 cm thick to promote temperature rise and keep warm. When the temperature of the stack rises to 38-40 degrees, turn the stack over to cool and dissipate heat. Repeat this for 3-5 times, and the flower pile will be high first and then low. Usually, the flowering temperature is high, and it is mainly spread cold, and the interval between spreading cold is generally about 30 minutes. The purpose of repeated spreading and stacking is to make the buds open evenly at a certain temperature and sufficient oxygen. The optimum conditions of jasmine fragrance release are room temperature 30-33 degrees, relative humidity 80%, wind speed 5-6 ml/min, flower pile height 10- 15 cm, and oxygen content in flower pile 17-20%.
2. Screen flowers. When the opening rate (the ratio of the number of flower buds to the total number) reaches about 70% and the opening degree (the angle of petal formation after a flower bud opens) reaches about 50-60 degrees, "screening flowers" is carried out. The main function of flower screening is to screen the net flowers and classify them (large, medium and small flowers) so as to facilitate the collocation of camellia according to the grade; The second is to play an oscillating role and promote the opening of jasmine; The third is to remove impurities, screen out fallen calyx, flower buds, pests and other impurities. The aperture of the screen is 12,10,8 and mm, the first flower is a big flower, the second flower is a medium flower, and the third flower is a small flower. The No.1 flower is used for scenting high-grade tea or scented tea, the No.2 flower is used for scenting low-grade tea, and the No.3 flower is generally used for scenting sliced tea and finished tea. After classification, the net flowers are weighed, and when the opening rate of jasmine reaches over 90% and the opening degree reaches about 90 degrees (referring to the opening angle of petals), it is the appropriate standard for harvesting.
Third, camellia is mixed.
According to the appearance and quality standards of different varieties of special (high-grade) jasmine tea, the number of jasmine flowers needed this time is calculated. The method of wet-green joint scenting is adopted. When preparing camellia, attention should be paid to ensuring the integrity of the shape of special jasmine tea, and it should be prepared by hand as far as possible. If tea leaves (such as green peony, etc. ) It is easy to be damaged by hand stirring, so you can cover the tea leaves with a special wooden frame, which can avoid turning the tea leaves and reduce the crushing rate. Whether the camellia is mixed or layered, it is required that the camellia is evenly distributed. When the openness and openness of jasmine meet the technical standards, the mixing operation is completed within 30 minutes to 60 minutes to avoid a large amount of volatile loss of jasmine essential oil. The pile height is generally between 25-35cm, and the tea with high density (such as pearls and silver beads) can reduce the pile height and avoid the pile temperature from rising too fast.
Fourth, let the flowers grow.
Camellia are mixed and put into a standing pit, and a small batch of tea leaves can be left in a box. Technically, it is called box pit, the pile of tea left on the board is called pile pit, and the pile left in the machine is called machine pit. Due to the method of wet green continuous scenting, in the whole process of the first scenting, the standing time generally lasts 12- 14 hours. With the increase of scenting times, the standing time can be gradually reduced, and generally the middle is not spent. Adjust the reactor height according to the reactor temperature in the morning. Generally, the reactor temperature is 38-42 degrees. If the pile temperature is too high, the bottom can be properly adjusted, and if the pile temperature is lower than 38 degrees, it can be appropriately raised to create an environment suitable for jasmine to smell normally.
Five, flowers.
Flowering, also known as flowering, is to screen out the flower residue of brewed tea and make camellia mixed and separated. After camellia is mixed, let it stand for a period of time, and the respiration of jasmine will be weakened and its vitality will be reduced. Most of the aromatic substances have been absorbed by tea, and the flower shape is "goose skin wrinkle"-like contraction, while the tea blank is moist and soft. At this time, it is necessary to quickly screen out the flower residue to prevent the fermentation of flower residue from damaging the quality of tea. If the screened tea leaves need to continue to be contiguous, they should be diluted in a ventilated place in time. Pick flowers in time, quickly and cleanly. The sifted tea heads must be quickly picked out and separated manually, and even the wet blanks should be immediately spread and cooled and quickly baked. Stacking is not allowed. Layers of tea must be separated manually. When more than five kinds of scents of jasmine flower residue or jacquard flower residue bloom, the color is bright and white, and there are still scents to be embossed or dried in time. The embossing time is generally between 10 am and 1 1 am. After flowering, the flower residue is cooled as much as possible and used for embossing in time. After the flower residue is mixed with the tea blank, the pile height is 40-60 cm, and the flowers are allowed to stand for 3-4 hours, not more than 5 hours.
Sixth, baking.
Baking operation has a great influence on the quality of jasmine tea, and baking should be based on ensuring the maximum aroma in tea. Combined with the increase of drying moisture required for each tea leaf, the moisture content of continuous cropping (1-2), second cropping (3-4) and third cropping (5-6) is generally controlled at 5% and 6.5 respectively. If the temperature reaches 39-40 degrees, in order to improve the freshness of tea in the last two scents, it is not necessary to use the continuous scenting method. Six-fragrance tea needs to be divided into seven or eight flavors if it needs to be divided into five or six flavors. High-grade tea can also be roasted, with a moisture content of 8-8.5%, spread and cooled, evenly packed and packaged. The layered tea-connected wooden frame can be dried in a hand dryer to avoid tea damage. The baking temperature of jasmine tea should not be too high. If it is too high, the fragrance will be lost. Generally, the temperature is controlled between 80- 120 degrees. Because of the high water content of tea, the machine temperature can be higher, and it will gradually decrease with the increase of tea. The machine temperature of baking is also slightly higher than that of baking. In order to judge whether the aroma quality and moisture content meet the requirements of different baking time, tea samples must be taken from the machine mouth frequently during the drying process to check the aroma quality and moisture content to judge the baking degree. This is also an important measure in the baking process.
Tea inclusion treatment before jacquard weaving.
Special (high-grade) jasmine tea requires high appearance, and cannot contain any non-tea inclusions, stems, chips, powder, buds, flower chips and so on. Non-tea inclusions and fragments, powder, flower stems, flower buds, flower pieces, etc. Tea leaves produced in the process of multiple scenting must be removed before jacquard weaving. It can be operated by mechanical and manual picking. It is required that the appearance of tea leaves should be uniform and clean, and there should be no tea leaves outside this batch to ensure the appearance and quality characteristics of special (advanced) jasmine tea.
Eight, jacquard.
In the process of scenting jasmine, after scenting once, part of the flower fragrance absorbed by tea leaves escapes with the evaporation of water, and part of it remains in the tea leaves, so that the finished product has both tea fragrance and flower fragrance. However, the roasted tea leaves are not fragrant enough. In order to make up for this shortcoming, a small amount of high-quality jasmine flowers were mixed with tea for 6-8 hours for the last time, and the flowers were evenly stacked without baking. The water content of tea used in jacquard machine is usually in the range of 6.5-7%. Therefore, the increase of moisture content after jacquard weaving must be controlled at 1- 1.5% to ensure that the moisture content of the finished product meets the technical standards.
Nine, uniform stacking and packaging
Uniform stacking and packaging is the last process of jasmine tea scenting. Before uniform stacking and packaging, small samples should be assembled first, and after moisture, powder and other tests and quality appraisal meet the product specifications and standards, uniform stacking and packaging can be carried out in proportion. At the same time, a large number of finished products samples were taken for physical and chemical inspection and quality identification. The empty boxes before packing should be checked one by one to ensure that there is no dust, sundries and peculiar smell in the boxes.