Preparation technology of Laiwu old dried tea

Abstract

The invention discloses a preparation technology of Laiwu old dried tea, and relates to the technical field of tea processing. Comprising the following steps of fresh leaf picking, withering, fixation, first-time heaping for yellowing, rolling, second-time heaping for yellowing, first-time baking, third-time heaping for yellowing, fourth-time heaping for yellowing, second-time baking, tea steaming, drying and electrostatic color sorting and impurity removal. The preparation technology of the Laiwu old dried tea is optimized on the basis of material selection and technology of traditional Laiwu old dried tea, and the tea leaves are complete in appearance, fresh and fresh in fragrance, good in surface fragrance and high in concentration and durability of the fragrance; the tea is high in content of tea polysaccharide, caffeine and amino acid, mellow in taste, low in water content and resistant to brewing.

Description

Technical Field

[0001] The invention relates to the technical field of tea processing, in particular to a preparation process of Laiwu aged dried tea. Background Art

[0002] Laiwu old dried tea is a yellow tea and is a common daily tea in Laiwu, Shandong. It is native to Huoshan and Lu'an in Anhui Province and was introduced to Laiwu in the Ming Dynasty, more than 400 years ago.

[0003] The raw materials of Laiwu Old Dry Baked Tea have always been one bud, three leaves or even four or five leaves of Anhui micro-leaf terrace tea. In recent years, due to excessive picking and repeated planting of the land, the nutrition is seriously malnourished and the water extract is getting less and less, which directly leads to the current Laiwu Old Dry Baked Tea basically becoming a "clear soup" after three brewings, and the taste is very light. In order to maximize profits, some tea farmers began to fertilize and spray pesticides, and the pesticide residues exceeded the standard, seriously affecting food safety.

[0004] At present, the traditional technology of dry-roasting tea is seriously missing. Some tea merchants who are eager for quick success and instant benefits use ordinary rock tea technology to make Laiwu old dry-roasted tea, which completely changes the special properties of yellow tea as one of the six major types of tea. Summary of the invention

[0005] In order to solve the above-mentioned problems in the prior art, the present invention provides a preparation process of Laiwu old dried tea, which is optimized on the basis of material selection and process of traditional Laiwu old dried tea. The tea leaves have a complete appearance, fresh aroma, good surface fragrance, and strong aroma concentration and persistence.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a preparation process of Laiwu old dried tea, comprising the following steps: S1; Fresh leaf picking: Fresh leaves are best picked around March 20; Picking requirements: one bud, two or three leaves and tender stems; The picking location is Laiwu District, Jinan City, Shandong Province, and its geographical coordinates are 117°19'-117°58' east longitude and 36°02'-36°33' north latitude.

[0007] The area is located in the hinterland of the mountainous area in central Shandong Province. It has a warm temperate semi-humid monsoon climate. The area has high humidity, an annual average relative humidity of 63%, and is surrounded by clouds and mist. The frost-free period is 204 days, which is in line with the characteristics of tea trees that like to sprout and is suitable for tea planting. The area is located in Lianhua Mountain, with an average altitude of 500 meters. The main peak Lianhuajian is 994 meters above sea level. The high altitude has an annual average temperature of 14.2-16.7℃, which is about 5℃ lower than the plain all year round. The temperature difference between day and night is large, and less organic matter is consumed at night, which slows down the growth rate of tea leaves, making the tea growth period longer and the picking period shorter, which greatly retains the nutrition of tea leaves and is conducive to the accumulation of tea polyphenols, caffeine and other substances in the "Laiwu Laoganhong" leaves. The temperature in the territory is low, there are many clouds and fogs all year round, and the vegetation coverage rate is high, which forms a shading condition, which is conducive to the change of direct sunlight into diffuse light. Plants absorb red-orange light and infrared light with longer wavelengths, allowing blue-orange light and ultraviolet light with shorter wavelengths to pass through. Weak light promotes the synthesis of chlorophyll B in tea leaves, increases the accumulation of substances in leaves, and promotes the formation of aromatic substances, so that it can still emit a strong aroma after brewing; at the same time, weak light also reduces the bitter components of thea in tea leaves and increases the content of theanine, making "Laiwu Laoganhong" large branches and leaves, mellow taste, and resistant to brewing. The average annual precipitation in the area is 698.1mm, and most of it is concentrated in March-September when tea trees grow, which provides sufficient water for the growth of tea trees, making the fresh tea leaves of "Laiwu Laoganhong" thick and tender. There are many rivers and ditches in the territory, 98% of which belong to the Dawen River system and 2% to the Zibo River system. The total water storage capacity is 3.5 billion cubic meters and the annual average relative humidity is 63%. The humid environment is conducive to the evaporation of surface water into the air, and the water condenses to form fog droplets, forming a high-humidity and foggy tea garden environment.

[0008] S2: Withering: After picking, the fresh leaves are evenly spread on the greening rack and placed in a cool and dry place with good air circulation for natural withering. The withering time is 3-4 hours. The fresh leaves with a moisture content of 55-65% are obtained. When testing, the two ends of the fresh leaves can be folded in half. If they are not broken, they meet the requirements. S3: Killing the tea leaves: The temperature of the iron pan is controlled at 260-300℃, pour in the tea leaves and stir-fry quickly. There should be no mushy spots and the stems and leaves should not turn red. The killing standard is to kill them thoroughly and thoroughly. S4: First yellowing: After stir-frying, seal and store for the first yellowing, and the temperature will drop to room temperature until the leaves, buds and tender stems turn completely yellow; S5: Rolling: Pour the yellow tea leaves into the rolling machine at once. Do not add or reduce them in the middle. Roll lightly for 13-17 minutes and then pressurize at a uniform speed. Continue rolling for 15-25 minutes after pressurization. After the tea leaves are squeezed out of juice, reduce the pressure again. Roll lightly to collect all the juice into the tea. Stop rolling when you smell the rich grain aroma. S6: Second yellowing: After the tea leaves are rolled and sealed, they are yellowed for the second time. When left naturally, the temperature of the tea leaves rises to 33-37℃. S7: First baking: The tea leaves are shaken and baked for the first time at a temperature of 50-60°C for 7-9 hours; S8: The third time of yellowing: After baking, the tea leaves are sealed and yellowed for the third time. After the water vapor is completely absorbed by the tea leaves and softened, they are dried in the sun. When the moisture content of the tea leaves reaches 6-10%, they are collected in containers. S9: The fourth yellowing: The fourth yellowing is carried out after packing, and the yellowing time is at least 15 days, with the strong corn aroma after unpacking as the standard; S10: Second baking: Take out the tea leaves and bake them over charcoal fire for the second time until the bottom of the tea leaves are hard and the leaves are covered with frost.

[0009] S11: Steaming tea: the roasted tea leaves are heated by steam, the steam temperature is 140-160°C, and the heating temperature is 8-12 minutes; S12: Drying: After the tea leaves are completely softened, they are poured into bamboo baskets and sent to a drying room for drying. The temperature in the drying room is 60-80°C, the humidity is 6-10%, and the drying time is 70-74 hours. They are then packed and stored; S13: Electrostatic color sorting and impurity removal: At least 20 days after packing and storage, electrostatic color sorting and impurity removal are carried out, and the finished product is obtained after packaging.

[0010] The beneficial effects of the invention are as follows: the preparation process of the Laiwu old dried tea is optimized on the basis of the material selection and process of the traditional Laiwu old dried tea, the tea leaves have a complete appearance, a fresh aroma, a good surface aroma, and a strong concentration and persistence of the aroma; the tea polysaccharides, caffeine and amino acid contents are high, the tea leaves have a mellow taste, a low water content, and are resistant to brewing. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0012] This embodiment provides a preparation process of Laiwu old dried tea, comprising the following steps: S1; Fresh leaf picking: Fresh leaves are picked around March 20; Picking requirements: one bud, two or three leaves and tender stems; The picking location is Laiwu District, Jinan City, Shandong Province, and its geographical coordinates are 117°19'-117°58' east longitude and 36°02'-36°33' north latitude; S2: Withering: After picking, the fresh leaves are evenly spread on a greening rack and placed in a cool and dry place with good air circulation for natural withering. The withering time is 3 hours; the fresh leaves with a water content of 60% are obtained; S3: Killing the green tea: The temperature of the iron pan is controlled at 280℃, pour in the tea leaves and stir-fry quickly. There should be no mushy spots and the stems and leaves should not turn red. The killing standard is to kill thoroughly and thoroughly. S4: First yellowing: After stir-frying, seal and store for the first yellowing, and the temperature will drop to room temperature until the leaves, buds and tender stems turn completely yellow; S5: Rolling: Pour the yellow tea leaves into the rolling machine at once. Do not add or reduce them in the middle. Roll lightly for 15 minutes and then slowly increase the pressure. Continue rolling for 20 minutes after the tea leaves are rolled out of juice, then reduce the pressure. Roll lightly to collect all the juice into the tea. Stop rolling when you smell the rich grain aroma. S6: Second yellowing: After the tea leaves are rolled and sealed, they are yellowed for the second time. When left naturally, the temperature of the tea leaves rises to 35°C. S7: First baking: The tea leaves are shaken and baked for the first time at a baking temperature of 55°C for 8 hours; S8: The third time of yellowing: After baking, the tea leaves are sealed and yellowed for the third time. After the water vapor is completely absorbed by the tea leaves and softened, they are dried in the sun. When the moisture content of the tea leaves reaches 8%, they are put into containers. S9: The fourth yellowing: The fourth yellowing is carried out after packing, and the yellowing time is at least 15 days, with the strong corn aroma after unpacking as the standard; S10: Second baking: Take out the tea leaves and bake them over charcoal fire for the second time until the bottom of the tea leaves are hard and the leaves are covered with frost.

[0013] S11: Steaming tea: the roasted tea leaves are heated by steam, the steam temperature is 150° C., and the heating temperature is 10 minutes; S12: Drying: After the tea leaves are completely softened, they are poured into bamboo baskets and sent to a drying room for drying. The temperature in the drying room is 70°C, the humidity is 8%, and the drying time is 72 hours. They are then packed and stored; S13: Electrostatic color sorting and impurity removal: Electrostatic color sorting and impurity removal are performed, and the finished product is obtained after packaging.

[0014] Of course, the above description is not limited to the above examples. Technical features not described in the present invention can be achieved by or by using existing technologies, which will not be repeated here. The above embodiments are only used to illustrate the technical scheme of the present invention and are not limitations of the present invention. The present invention is described in detail with reference to the preferred implementation methods. Ordinary technicians in this field should understand that changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention do not depart from the purpose of the present invention, and should also fall within the scope of protection of the claims of the present invention. The invention discloses a preparation process of Laiwu old dried tea, which is directed to the technical field of tea processing; the process comprises the following steps: fresh leaf picking, withering, killing green, first yellowing, rolling, second yellowing, first baking, third yellowing, fourth yellowing, second baking, steaming tea, drying, and electrostatic color sorting and impurity removal; the process adopts material-rich original ecological organic tea gardens and Yunnan stone ancient trees as raw materials, and is optimized on the basis of material selection and process of traditional Laiwu old dried tea, so that the tea leaves have a complete appearance, fresh aroma, good surface aroma, and strong aroma concentration and persistence.

Claims

1. A preparation process of Laiwu old dry tea, characterized in that: The steps include: S1; Fresh leaf picking: The picking location is Laiwu District, Jinan City, Shandong Province, with a geographical coordinate of 117°19'-117°58' east longitude and 36°02'-36°33' north latitude; the picking standard is one bud, two or three leaves and tender stems; S2: Withering: After picking, the fresh leaves are evenly spread on a greening rack and placed in a cool and dry place with good air circulation for natural withering. The withering time is 3-4 hours; the fresh leaves with a moisture content of 55-65% are obtained; S3: Fixing the tea leaves: Control the temperature of the iron pan at 260-300℃, pour in the tea leaves and stir-fry quickly; S4: First yellowing: After stir-frying, seal and store for the first yellowing, and the temperature will drop to room temperature until the leaves, buds and tender stems turn completely yellow; S5: Rolling: Pour the tea leaves into the rolling machine at once after they turn yellow. Do not add or reduce the tea leaves during the process. Roll the tea leaves gently for 13-17 minutes and then pressurize them. Continue rolling the tea leaves for 15-25 minutes. After the tea leaves have juice, decompress them and roll them gently to get all the juice back into the tea leaves. S6: Second yellowing: After the tea leaves are rolled and sealed, they are yellowed for the second time. When left naturally, the temperature of the tea leaves rises to 33-37℃. S7: First roasting: The tea leaves are shaken and roasted for the first time; S8: The third time of yellowing: After baking, the tea leaves are sealed and yellowed for the third time. After the water vapor is completely absorbed by the tea leaves and softened, they are dried in the sun. When the moisture content of the tea leaves reaches 6-10%, they are collected in containers. S9: The fourth yellowing: The fourth yellowing is carried out after packing, and the yellowing time is at least 15 days, with the strong corn aroma after unpacking as the standard; S10: Second baking: Take out the tea leaves and bake them for the second time over charcoal fire until the bottom of the tea leaves are hard and the leaves are covered with frost; S11: Steaming tea: the roasted tea leaves are heated by steam; S12: Drying: After the tea leaves become completely soft, they are poured into bamboo baskets and sent to the drying room for drying, and then packed into boxes for storage; S13: Electrostatic color sorting and impurity removal: At least 20 days after packing and storage, electrostatic color sorting and impurity removal are carried out, and the finished product is obtained after packaging.

2. The preparation process of Laiwu old dried tea according to claim 1, characterized in that: The temperature of the first baking in S7 is 50-60° C. and the baking time is 7-9 hours.

3. The preparation process of Laiwu old dried tea according to claim 1, characterized in that: The steam temperature in S11 is 140-160°C and the heating temperature is 8-12 minutes.

4. The preparation process of Laiwu old dried tea according to claim 1, characterized in that: The temperature of the drying chamber in S12 is 60-80°C, the humidity is 6-10%, and the drying time is 70-74 hours.