Manufacturing method of white tea withered in stages

Abstract

The invention relates to the technical field of tea processing, in particular to a segmented withering white tea making method which comprises the following steps: withering tea leaves in a refrigeration house for 28 hours until the water content is 35-45%; transferring the tea leaves withered in the refrigeration house into a withering trough, controlling the temperature of the withering trough to be 29 + / -3 DEG C and the air humidity to be 80 + / -3%, and continuously withering until the water content of the tea leaves is 12%; drying the tea leaves withered in the withering trough with hot air at 70 DEG C for 1 hour; according to the invention, through a segmented withering mode of combining temperature control of the refrigeration house and the withering trough, the stable temperature and humidity environment of the refrigeration house is utilized to avoid the process defects of red leaf color, red soup color, fermentation gas in aroma and the like caused by the influence of climate fluctuation such as high temperature, high humidity, cloudy and rainy days and the like in traditional withering; meanwhile, the production period is shortened, and the white tea production efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of tea processing technology, and in particular to a method for producing white tea through segmented withering. Background Technology

[0002] Leishan County is located in the high-altitude tea-producing area (800-1200m) of Qiandongnan Prefecture, Guizhou Province. It is often cloudy and foggy with significant temperature differences between day and night, and the air humidity is greater than 85% during the rainy season. The local white tea processing relies on natural withering and compound withering, but the climate fluctuations result in the utilization rate of summer and autumn tea being less than 40%.

[0003] Traditional withering processes often involve a complex process, such as a short 2-hour daytime sun withering (at temperatures of 28-32℃) followed by indoor withering, totaling 60±3 hours. This process is not only time-consuming but also prone to problems such as reddish leaf color, reddish liquor color, and a fermented aroma under unfavorable climatic conditions like high temperature and humidity or rainy days, affecting the quality of white tea. Furthermore, traditional processes are significantly constrained by climate, resulting in low production efficiency and making it difficult to meet the demands for high-value utilization of summer and autumn teas.

[0004] Therefore, there is a need for a withering method that can overcome climate constraints, shorten the production cycle, and ensure the quality of white tea. Summary of the Invention

[0005] The purpose of this invention is to provide a segmented withering method for white tea production, which solves the problems of traditional white tea production being greatly affected by climate, having a long production cycle, and unstable quality.

[0006] To achieve the above objectives, the present invention provides a method for producing white tea using segmented withering, comprising the following steps:

[0007] The tea leaves are placed in a cold storage for 28 hours to wither until the moisture content reaches 35-45%.

[0008] The tea leaves that have been withered in the cold storage are transferred to the withering trough. The temperature of the withering trough is controlled at 29±3℃ and the air humidity is 80±3%. The withering continues until the moisture content of the tea leaves is 12%.

[0009] The tea leaves that have been withered in the withering trough are dried with hot air at 70℃ for 1 hour.

[0010] Among them, in the section "withering the tea leaves in a cold storage for 28 hours until the moisture content reaches 35-45%":

[0011] The tea leaves are Fuding Da Bai tea, consisting of one bud and two leaves, with an initial moisture content of 68-72%.

[0012] Among them, in the section "withering the tea leaves in a cold storage for 28 hours until the moisture content reaches 35-45%":

[0013] The criterion for determining the end point of cold storage withering is that the edges of the tea leaves harden and there is no reddening.

[0014] Among them, in the section "withering the tea leaves in a cold storage for 28 hours until the moisture content reaches 35-45%",

[0015] Maintain ventilation during the withering stage in cold storage.

[0016] Among them, in the section "drying the tea leaves after withering in the withering trough with hot air at 70℃ for 1 hour":

[0017] After the tea leaves are dried, the moisture content of the tea leaves is ≤8.5%.

[0018] The present invention discloses a segmented withering method for white tea production. By using a cold storage to reduce the ambient temperature and humidity, it can avoid the process defects of white tea caused by adverse factors such as high temperature and high humidity or rainy weather, such as reddish leaf color, reddish liquor color, and fermented aroma. At the same time, it can reduce the total withering time of tea leaves and improve the production efficiency of white tea. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0020] Figure 1 This is a flowchart of the segmented withering method for making white tea according to the present invention. Detailed Implementation

[0021] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0022] This invention provides a method for producing white tea using segmented withering, comprising the following steps:

[0023] S101: Place the tea leaves in a cold storage for 28 hours to wither until the moisture content is 35-45%.

[0024] Specifically, the tea leaves mentioned are Fuding Da Bai tea, consisting of one bud and two leaves, with an initial moisture content of 68-72%.

[0025] Specifically, the criterion for determining the end point of cold storage withering is that the edges of the tea leaves harden and there is no reddening.

[0026] Specifically, ventilation should be maintained during the withering stage of cold storage.

[0027] Specifically, the cold storage temperature is 6-10℃ and the humidity is 70-80%.

[0028] Specifically, the total withering time for the cold storage withering stage and the withering trough withering stage is 48 hours.

[0029] In this embodiment, the cold storage temperature is controlled for the first 28 hours (temperature and humidity are set according to group). Ventilation is required during this stage. The principle behind this is that the core of the chemical reaction principle of white tea lies in mild, slow enzymatic oxidation and hydrolysis. Traditional double withering processes suffer from unstable temperature and humidity. For example, if the temperature rises to 35-45℃ for a short period during the sun withering stage, enzyme activity will surge, leading to over-oxidation. This causes theaflavins to be excessively converted into thearubigins and theabrownins, resulting in a less clear tea liquor that tastes strong and astringent, losing the delicate characteristics of white tea. Furthermore, the aroma changes from a fresh floral scent to a ripe fruit aroma, even exhibiting a fermented flavor, somewhat resembling black tea. After 28 hours, once the moisture content of the tea leaves drops to 35-45%, they are transferred to withering troughs for further withering.

[0030] S102: Transfer the tea leaves that have undergone cold storage withering to the withering trough, control the temperature of the withering trough at 29±3℃ and the air humidity at 80±3%, and continue withering until the moisture content of the tea leaves is 12%.

[0031] In this embodiment, after the tea leaves are transferred to the withering trough, the white tea has already begun to develop a "fresh, sweet, and mellow" flavor base due to the previous stage of temperature-controlled withering in cold storage. Therefore, transferring it to the withering trough at this stage can increase the withering speed. The temperature of the withering trough is controlled at a constant 29±3℃ and the humidity is controlled at 80±3% to continue withering until the moisture content reaches 12%. Then, it is transferred to a dryer for drying, and the withering time is recorded.

[0032] S103: Dry the tea leaves that have been withered in the withering trough with hot air at 70℃ for 1 hour.

[0033] Specifically, after the tea leaves are dried, the moisture content of the tea leaves should be ≤8.5%.

[0034] In this embodiment, the drying stage uses 70℃ hot air drying for 1 hour, which can not only efficiently remove the remaining moisture in the tea leaves and control the moisture content to ≤8.5%, but also retain the flavor substances and nutrients formed in the early withering stage of white tea to the greatest extent.

[0035] Example:

[0036] Raw materials: Fuding Dabai (one bud and two leaves, moisture content 68-72%), set up in 8 groups according to temperature (1-5℃, 6-10℃, 11-18℃, 19-25℃) and air humidity (70-80%, 81-90%), and the temperature is controlled for 28 hours in the cold storage stage, and then transferred to the withering tank to complete the subsequent processes.

[0037]

[0038]

[0039] Comparative example:

[0040] Group T1 (combined withering): 2 hours of short-term daytime sun withering (temperature 28-32℃) followed by indoor withering, total time 60±3 hours. Drying stage: 70℃ hot air drying for 1 hour until moisture content ≤8.5%.

[0041]

[0042] in conclusion:

[0043] Based on the table above, the optimal group is G3; sensory advantages: vibrant green leaf color (superior to the grayish-green of traditional processing), and significantly lower grassy smell intensity than traditional processing; production advantages: total time 48 hours (60 hours for compound withering). Other group defects:

[0044] Low temperature group (G1-G2): Slow metabolism leads to dark leaf color and severe residual green odor;

[0045] Medium temperature and high humidity group (G4, G6): water stains / wet pile smell problems are prominent;

[0046] High-temperature group (G7-G8): loss of freshness (G7 is sweet but lacks freshness), high risk of mold growth (G8).

[0047] Compared with the traditional withering cycle:

[0048] Traditional process (t1): 60h (moisture content 72% → 10%);

[0049] The process of this invention: 48h (28h in cold storage → 20h in withering tank), reducing the time consumption by 20%;

[0050] Sensory evaluation data:

[0051] index New process group (G3) Traditional Craftsmanship Group (T1) Appearance rating 24 / 25 (Round and emerald green) 22 / 25 (Loose gray-green) Aroma purity 23 / 25 (Fresh Fragrance with a Slight Greenish hue) 20 / 25 (Strong grassy flavor) taste 28 / 30 Fresh, sweet, and slightly astringent) 20 / 30 (Standardized by youthful inexperience) soup color 8 / 10 Light apricot yellow bright 7 / 10 Orange-yellow Bright Leaf uniformity 9 / 10 (Soft, yellowish-green, even and glossy) 7 / 10 (Mixed flavors, lacks elasticity)

[0052] The segmented withering method for white tea production of this invention has a standardized processing cycle of 48 hours, which is 20% shorter than the traditional process (60 hours), and breaks the climate constraint of "no three consecutive sunny days".

[0053] Product form upgrade: Round and emerald green 24 / 25;

[0054] Flavor universality: New process teas have improved "aging potential"; traditional process teas have a strong astringent taste in the early stages, resulting in poor market palatability.

[0055] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A method for producing white tea using segmented withering, characterized in that, Includes the following steps: The tea leaves are placed in a cold storage for 28 hours to wither until the moisture content reaches 35-45%. The tea leaves that have been withered in the cold storage are transferred to the withering trough. The temperature of the withering trough is controlled at 29±3℃ and the air humidity is 80±3%. The withering continues until the moisture content of the tea leaves is 12%. The tea leaves that have been withered in the withering trough are dried with hot air at 70℃ for 1 hour.

2. The method for producing white tea by segmented withering as described in claim 1, characterized in that, In the section "withering the tea leaves in a cold storage for 28 hours until the moisture content reaches 35-45%": The tea leaves are Fuding Da Bai tea, consisting of one bud and two leaves, with an initial moisture content of 68-72%.

3. The method for producing white tea by segmented withering as described in claim 1, characterized in that, In the section "withering the tea leaves in a cold storage for 28 hours until the moisture content reaches 35-45%": The criterion for determining the end point of cold storage withering is that the edges of the tea leaves harden and there is no reddening.

4. The method for producing white tea by segmented withering as described in claim 1, characterized in that, In the process of "withering the tea leaves in a cold storage for 28 hours until the moisture content reaches 35-45%", Maintain ventilation during the withering stage in cold storage.

5. The method for producing white tea by segmented withering as described in claim 1, characterized in that, In the section "drying the tea leaves that have been withered in the withering trough with hot air at 70℃ for 1 hour": After the tea leaves are dried, the moisture content of the tea leaves is ≤8.5%.

Images