Low-temperature dried jasmine flower green and sweet green tea and preparation method thereof

Abstract

The invention relates to a preparation method of low-temperature dried jasmine flower green and sweet green tea, which comprises the following steps: S1, pretreatment of finished green tea: spraying water mist to the finished green tea for softening, putting the softened tea leaves into a steam box, introducing high-temperature steam for treatment, transferring into a drying oven, and drying at low temperature to obtain a tea base; s2, performing scenting and compound fermentation: performing scenting and aroma enhancing on the tea base for multiple times by using jasmine flowers, uniformly mixing jasmine flower residues with the aroma-enhanced tea base according to a proportion, and then performing steaming, compressing, compound fermentation for eurotium cristatum growing and drying to obtain the brick tea; s3, crushing: crushing the brick tea in crushing equipment to obtain the tea brick. The method has the advantages that jasmine flowers and finished green tea are used as raw materials, firstly, the finished green tea is pretreated, then a proper amount of jasmine flowers are used for scenting and aroma increasing, then matching and compound fermentation are conducted, a brand-new broken green tea product is obtained, tea soup is yellow green in color and slightly green, fragrance strikes the nose, the taste is mellow and sweet after taste, and the broken green tea is a good tea drink product; the quality guarantee period can reach more than 3 years, and the defect that the quality guarantee period of traditional broken green tea is short is overcome.

Description

Technical Field

[0001] The invention belongs to the field of tea making, and particularly relates to low-temperature dried jasmine green sweet tea and a preparation method thereof. Background Art

[0002] Traditional green broken tea, also known as green tea powder, is essentially still green tea. It is a tea product made from green tea as raw material and finely processed. The preparation steps of traditional green broken tea are as follows: picking - picking new shoots and leaves of tea trees in spring or autumn; withering - natural or mechanical withering to reduce the moisture in the tea leaves, making the tea leaves soft and convenient for subsequent rolling; rolling - manual or mechanical rolling to make the juice inside the tea leaves overflow, which is conducive to the fermentation and drying of the tea leaves; deblocking - using a deblocking machine to disperse the rolled tea blocks into loose tea leaves; screening - using a screening machine to grade and classify the tea leaves according to size and shape; frying - removing the grass taste in the tea leaves and improving the aroma of the tea leaves; drying - further reducing the moisture in the tea leaves to reach an appropriate moisture content; screening - the dried tea leaves are screened through a screening machine to screen out the broken tea leaves, which are the main raw materials for green broken tea; packaging - packaging the screened broken tea leaves. In addition, there is currently another process for making green broken tea using finished green tea as raw material for secondary processing: the finished green tea is dried again, then lightly crushed, and finally cut and ground on the equipment to obtain granular green broken tea.

[0003] The shelf life of green tea is usually short, generally about 1 year. The green broken tea produced by the above two methods cannot overcome the short shelf life of green tea, and the green broken tea produced by using fresh tea leaves or newly manufactured green tea as raw materials has a relatively acceptable shelf life. However, there are a large number of mid-to-high-end green tea products (high price and low sales) approaching their expiration dates on the market every year. If green broken tea can be prepared with these as raw materials and the shelf life of the green broken tea can be appropriately extended, the problem of mid-to-high-end green tea becoming waste due to expiration can be effectively solved and the losses of tea farmers can be appropriately compensated. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a low-temperature dried jasmine green sweet tea and a preparation method thereof, aiming to provide a new green broken tea product which is between green tea and Fu'er tea, has a good shelf life and a unique taste and a strong aroma.

[0005] The technical solution of the present invention to solve the above technical problem is as follows: a preparation method of low-temperature dried jasmine green sweet tea, comprising the following steps:

[0006] S1. Pretreatment of finished green tea: Spray water mist on the finished green tea at room temperature to soften it for 20-30min, then place the softened tea leaves in a steamer, pass steam at 100-105°C, treat for 45-75s, then transfer to an oven, dry the tea leaves at low temperature to obtain a water content of 15-20%;

[0007] S2 scenting composite fermentation: using jasmine tea obtained in S1 for multiple scenting aroma, scenting system after the completion of jasmine flower residue and aroma tea after mixing in proportion, and then steaming, pressing, composite fermentation flower, drying, tea brick;

[0008] S3. Crushing: crushing the tea bricks obtained in S2 in a crushing device to obtain.

[0009] On the basis of the above technical solutions, the present invention can also have the following further specific options.

[0010] Specifically, the water content of the finished green tea after the softening by spraying water mist in S1 is 40-50%.

[0011] Specifically, the finished green tea in S1 is medium to high-grade green tea and is close to its expiration date.

[0012] Specifically, the low-temperature drying temperature in the oven in S1 is 30-45° C., and the continuous drying time is 4-12 hours.

[0013] Specifically, each time the scenting is performed in S2, the tea leaves prepared in S1 are mixed with freeze-dried jasmine flowers in a weight ratio of 9-12:1, and then placed in a sealed wooden scenting box for scenting at room temperature for 18-24 hours. After each scenting is completed, the box is opened and sieved, and the sieved tea leaves are scented again with another portion of newly taken freeze-dried jasmine flowers. The sieved freeze-dried jasmine flowers are jasmine flower residues, which are stored for later use.

[0014] Specifically, each portion of tea leaves in S2 is scented at least three times to obtain aroma.

[0015] Specifically, the tea leaves after multiple scenting in S2 are mixed with jasmine flower residues in a weight ratio of 10-12:1.

[0016] Specifically, in S2, the steaming temperature is controlled at 100-102°C for 20-30s, the pressing pressure is 70-80 tons, the temperature during composite fermentation and flowering is controlled at 20-25°C for 7-10 days, the drying temperature is controlled at 35-45°C, and the moisture content of the tea brick after drying is controlled at 9-13%.

[0017] Specifically, the dimensions of the broken tea material obtained after the tea bricks are crushed in S3 are less than 3 mm in all directions.

[0018] In addition, the present invention also provides a low-temperature dried jasmine green sweet tea, which is prepared by the above method.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The invention uses jasmine flowers and finished green tea as raw materials, firstly performs mist humidification and softening on the finished green tea, performs short-term high-temperature steam treatment and dries it into tea leaves, then uses appropriate amounts of jasmine flowers and the tea leaves to mix and scent for multiple times to enhance the aroma, then proportions and mixes the jasmine flower residues with the tea leaves after the aroma enhancement, steams, presses, performs compound fermentation to flower, dries, and finally grinds them to obtain a new green broken tea product (green sweet tea), the tea soup of which is yellow-green and slightly green, has a fragrant aroma, and has a mellow and sweet taste, and is an excellent tea drink.

[0021] Since the preparation process includes steps such as high-temperature steaming of the finished green tea, scenting and steaming of jasmine flowers, pressing and compound fermentation, it can not only effectively kill harmful microorganisms carried by the finished green tea due to long-term storage, but also utilize the antibacterial effect of jasmine flowers themselves and the tea-modifying effect of compound fermentation. The resulting new green broken tea has certain characteristics (color) of traditional green broken tea, and also has the taste of black tea and Pu'er tea and the advantages of a longer shelf life. The shelf life of the resulting tea is more than 3 years.

[0022] In particular, the present invention can utilize mid-to-high-grade finished green tea that is close to its expiration date, effectively extending its expiration date. The higher the quality of the finished green tea, the higher the quality of the resulting jasmine green sweet tea, and can effectively reduce the loss caused by the finished green tea easily becoming waste due to expiration. DETAILED DESCRIPTION

[0023] The principles and features of the present invention are described below in conjunction with specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0024] To avoid redundant description, the methods used in the following embodiments are all conventional techniques in the art unless otherwise specified. The finished green teas used are all commercially available products, especially mid-to-high-end finished green teas. The jasmine flowers used to scent the green tea are not fresh flowers that are easily perishable but freeze-dried flowers that are easier to preserve. The freeze-dried jasmine flowers are obtained by rapidly freeze-drying fresh jasmine flowers (buds) at about -40°C in a freeze-drying device, and the water content is less than 5%. The specific freeze-drying operation of fresh flowers is mastered by those skilled in the art and will not be elaborated in detail here.

[0025] Example 1

[0026] A method for preparing low-temperature dried jasmine green sweet tea comprises the following steps:

[0027] S1. Pretreatment of finished green tea: Spray water mist on the finished green tea at room temperature for 20 minutes to soften it. After softening, the finished green tea leaves are relatively stretched and soft, with a moisture content of 40-42%. Then, the softened tea leaves are placed in a steamer and steamed at 100°C for 75 seconds. Then, they are quickly transferred to an oven and dried at 30°C to obtain tea leaves with a moisture content of 15%.

[0028] S2. scenting composite fermentation: using freeze-dried jasmine flowers to scent the tea obtained in S1 for multiple times, each time scenting, the tea obtained in S1 and freeze-dried jasmine flowers are mixed in a weight ratio of 9:1 and placed in a sealed wooden scenting box, and scented for 18 hours at room temperature. After each scenting, the box is opened and sieved, and the sieved tea is scented again with another portion of newly taken freeze-dried jasmine flowers, and the sieved freeze-dried jasmine flowers are jasmine flower residues, which are stored for later use; Each portion of tea leaves is subjected to three repeated scenting processes to obtain aroma; the jasmine flower residue after scenting is mixed with the tea leaves after aroma extraction in a weight ratio of 1:12, and then steamed, pressed, compound fermented and dried, the steaming temperature is controlled at 100°C, the time is 30s, the pressing pressure is 70 tons, the temperature during compound fermentation and flowering is controlled at 20°C, the fermentation and flowering time is 7 days, the drying temperature is controlled at 35°C, and the moisture content of the tea brick after drying is controlled at 11-13%, thereby obtaining a tea brick;

[0029] S3. Crushing: The tea bricks obtained in S2 are crushed in a crushing device, and the sizes of the crushed tea materials obtained after crushing are less than 3 mm in all directions.

[0030] Example 2

[0031] A method for preparing low-temperature dried jasmine green sweet tea comprises the following steps:

[0032] S1. Pretreatment of finished green tea: Spray water mist on the finished green tea at room temperature for 23 minutes to soften it. After softening, the finished green tea leaves are relatively stretched and soft, with a moisture content of 42-45%. Then, the softened tea leaves are placed in a steamer and steamed at 101°C for 60 seconds. Then, they are quickly transferred to an oven and dried at 35°C to obtain tea leaves with a moisture content of 20%.

[0033] S2. scenting and compound fermentation: the tea obtained in S1 is scented multiple times with freeze-dried jasmine flowers. Each time the tea is scented, the tea obtained in S1 is mixed with freeze-dried jasmine flowers in a weight ratio of 10:1 and then placed in a sealed wooden scenting box for scenting at room temperature for 18 hours. After each scenting, the box is opened and sieved. The sieved tea is scented again with another portion of newly taken freeze-dried jasmine flowers. The sieved freeze-dried jasmine flowers are jasmine flower residues, which are stored for later use. Each portion of tea leaves is scented three times; the jasmine flower residue after scenting is mixed with the tea leaves after scenting in a weight ratio of 1:12, and then steamed, pressed, compound fermented and dried, the steaming temperature is controlled at 100°C, the time is 28s, the pressing pressure is 75 tons, the temperature during compound fermentation and flowering is controlled at 22°C, the fermentation and flowering time is 7 days, the drying temperature is controlled at 38°C, and the moisture content of the tea brick after drying is controlled to be 11-13%, so as to obtain tea bricks;

[0034] S3. Crushing: The tea bricks obtained in S2 are crushed in a crushing device, and the sizes of the crushed tea materials obtained after crushing are less than 3 mm in all directions.

[0035] Example 3

[0036] A method for preparing low-temperature dried jasmine green sweet tea comprises the following steps:

[0037] S1. Pretreatment of finished green tea: Spray water mist on the finished green tea at room temperature for 26 minutes to soften it. After softening, the finished green tea leaves are relatively stretched and soft, with a moisture content of 44-46%. Then, the softened tea leaves are placed in a steamer and steamed at 104°C for 52 seconds. Then, they are quickly transferred to an oven and dried at 45°C to obtain tea leaves with a moisture content of 20%.

[0038] S2. scenting and compound fermentation: the tea obtained in S1 is scented multiple times with freeze-dried jasmine flowers. Each time the tea is scented, the tea obtained in S1 is mixed with freeze-dried jasmine flowers in a weight ratio of 11:1 and then placed in a sealed wooden scenting box for scenting at room temperature for 20 hours. After each scenting, the box is opened and sieved. The sieved tea is scented again with another portion of newly taken freeze-dried jasmine flowers. The sieved freeze-dried jasmine flowers are jasmine flower residues, which are stored for later use. Each portion of tea leaves is scented four times repeatedly to obtain aroma; the jasmine flower residue after scenting is mixed with the tea leaves after aroma in a weight ratio of 1:11, and then steamed, pressed, compound fermented and dried, the steaming temperature is controlled at 101°C, the time is 22s, the pressing pressure is 75 tons, the temperature during compound fermentation and flowering is controlled at 25°C, the fermentation and flowering time is 8 days, the drying temperature is controlled at 40°C, and the moisture content of the tea brick after drying is controlled to be 9-11% to obtain a tea brick;

[0039] S3. Crushing: The tea bricks obtained in S2 are crushed in a crushing device, and the sizes of the crushed tea materials obtained after crushing are less than 3 mm in all directions.

[0040] Example 4

[0041] A method for preparing low-temperature dried jasmine green sweet tea comprises the following steps:

[0042] S1. Pretreatment of finished green tea: Spray water mist on the finished green tea at room temperature for 30 minutes to soften it. After softening, the finished green tea leaves are relatively stretched and soft, with a moisture content of 46-50%. Then, the softened tea leaves are placed in a steamer and steamed at 105°C for 45 seconds. Then, they are quickly transferred to an oven and dried at 40°C to obtain tea leaves with a moisture content of 15%.

[0043] S2. scenting and compound fermentation: the tea obtained in S1 is scented multiple times with freeze-dried jasmine flowers. Each time the scenting is performed, the tea obtained in S1 is mixed with freeze-dried jasmine flowers in a weight ratio of 12:1 and then placed in a sealed wooden scenting box for scenting at room temperature for 24 hours. After each scenting, the box is opened and sieved. The sieved tea is scented again with another portion of newly taken freeze-dried jasmine flowers. The sieved freeze-dried jasmine flowers are jasmine flower residues, which are stored for later use. Each portion of tea leaves is scented four times repeatedly to obtain aroma; the jasmine flower residue after scenting is mixed with the tea leaves after aroma in a weight ratio of 1:10, and then steamed, pressed, compound fermented and dried, the steaming temperature is controlled at 102°C, the time is 20s, the pressing pressure is 80 tons, the temperature during compound fermentation and flowering is controlled at 20°C, the fermentation and flowering time is 10 days, the drying temperature is controlled at 45°C, and the moisture content of the tea brick after drying is controlled to be 9-11% to obtain a tea brick;

[0044] S3. Crushing: The tea bricks obtained in S2 are crushed in a crushing device, and the sizes of the crushed tea materials obtained after crushing are less than 3 mm in all directions.

[0045] Comparative Example 1

[0046] A method for preparing low-temperature dried jasmine green sweet tea comprises the following steps:

[0047] Compared with Example 1, this comparative example has the following differences: the steam treatment time in step S1 is 90s, and the moisture content of the tea leaves obtained by low-temperature drying is 10%.

[0048] Comparative Example 2

[0049] A method for preparing low-temperature dried jasmine green sweet tea comprises the following steps:

[0050] Compared with Example 1, this comparative example has the following differences: the steam treatment time in step S1 is 30 seconds, and the moisture content of the tea leaves obtained by low-temperature drying is 28%.

[0051] The jasmine green sweet tea prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were used as samples to brew tea soup, and the color, aroma and taste were compared. It was found that the tea products corresponding to Examples 1 to 4 all had the characteristics of yellow-green color and slightly green, rich aroma, mellow taste and sweet aftertaste, while the aroma of Comparative Examples 1 and 2 was obviously inferior to the others, and the taste was slightly bitter without obvious sweet aftertaste. This shows that when pretreating the finished green tea, the steaming time and the degree of drying have a significant effect on the subsequent scenting and composite fermentation with jasmine. If the water content of the tea base is too low, it will not be able to induce the jasmine aroma to emit and penetrate when it is mixed with jasmine freeze-dried flowers that are also freeze-dried and have a lower water content. If the water content of the tea base is too high, although the jasmine can be induced to emit, the effect of the tea base absorbing the aroma becomes worse. In addition, the shelf life of the teas prepared in Examples 1 to 4 was tested, and it was found that the shelf life of the obtained teas could easily reach more than 3 years, which is significantly better than traditional green tea and broken green tea.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing low-temperature dried jasmine green sweet tea, characterized in that: The steps include: S1. Pretreatment of finished green tea: Spray water mist on the finished green tea at room temperature to soften it for 20-30min, then place the softened tea leaves in a steamer, pass steam at 100-105°C, treat for 45-75s, then transfer to an oven, dry the tea leaves at low temperature to obtain a water content of 15-20%; S2 scenting composite fermentation: using jasmine tea obtained in S1 for multiple scenting aroma, scenting system after the completion of jasmine flower residue and aroma tea after mixing in proportion, and then steaming, pressing, composite fermentation flower, drying, tea brick; S3. Crushing: crushing the tea bricks obtained in S2 in a crushing device to obtain.

2. The method for preparing low-temperature dried jasmine green sweet tea according to claim 1, characterized in that: The moisture content of the finished green tea after the softening by spraying water mist in S1 is 40-50%.

3. The method for preparing low-temperature dried jasmine green sweet tea according to claim 1, characterized in that: The finished green tea in S1 is mid- to high-grade green tea and is close to its expiration date.

4. The method for preparing low-temperature dried jasmine green sweet tea according to claim 1, characterized in that: The low temperature drying temperature in the oven in S1 is 30-45°C, and the continuous drying time is 4-12h.

5. The method for preparing low-temperature dried jasmine green sweet tea according to claim 1, characterized in that: Each time the scenting is performed in S2, the tea leaves prepared in S1 are mixed with freeze-dried jasmine flowers in a weight ratio of 9-12:1 and then placed in a sealed wooden scenting box for scenting at room temperature for 18-24 hours. After each scenting is completed, the box is opened and sieved, and the sieved tea leaves are scented again with another portion of newly taken freeze-dried jasmine flowers. The sieved freeze-dried jasmine flowers are jasmine flower residues, which are stored for later use.

6. The method for preparing low-temperature dried jasmine green sweet tea according to claim 5, characterized in that: Each batch of tea leaves in S2 is scented at least three times to enhance the aroma.

7. The method for preparing low-temperature dried jasmine green sweet tea according to claim 1, characterized in that: The tea leaves after multiple scenting in S2 are mixed with jasmine flower residues in a weight ratio of 10-12:

1.

8. The method for preparing low-temperature dried jasmine green sweet tea according to claim 1, characterized in that: In S2, the steaming temperature is controlled at 100-102°C for 20-30s, the pressing pressure is 70-80 tons, the temperature during compound fermentation and flowering is controlled at 20-25°C for 7-10 days, the drying temperature is controlled at 35-45°C, and the moisture content of the tea brick after drying is controlled at 9-13%.

9. The method for preparing low temperature dried jasmine green sweet tea according to any one of claims 1 to 8, characterized in that: The dimensions of the broken tea material obtained after the tea bricks are crushed in S3 are less than 3 mm in all directions.

10. A low temperature dried jasmine green sweet tea, characterized in that: It is prepared by the method according to any one of claims 1 to 9.