Process for preparing Derled group sour tea based on stainless steel tank fermentation

Abstract

The invention discloses a stainless steel tank fermentation-based process for making Dehead group sour tea, which comprises the following steps: step (1), picking fresh leaves; step (2), performing fixation with fire, wherein the fixation temperature is 120-130 DEG C; step (3), rolling and forming; step (4), activating strains, namely compounding lactobacillus plantarum and the traditional Tween group sour tea old bacteria liquid according to a ratio, and activating the lactobacillus plantarum and the traditional Tween group sour tea old bacteria liquid; (5) tank fermentation: mixing the rolled leaves with the activated bacterial liquid, putting the mixture into a 304 stainless steel fermentation tank, and pre-coating the inner wall of the 304 stainless steel fermentation tank with a food-grade argil coating; step (6), geothermal drying: drying in a Tengchong geothermal drying room to obtain finished tea; and (7) aging and storing. According to the invention, through precise temperature control enzyme deactivation and aroma enhancement, tea polyphenol is kept to be greater than or equal to 18%, metal sealing performance and soil energy conduction are realized, the acid production efficiency is improved by 40%, the total acid content reaches 4.5-5.2 g / kg, the fermentation period is shortened to 60-90 days, and the productivity is improved by 30%.

Description

Technical Field

[0001] The invention relates to the technical field of tea processing, and in particular to a production process of Deang acid tea based on stainless steel tank fermentation. Background Art

[0002] Deang acid is an ancient tea after the seven famous teas of green tea, black tea, white tea, yellow tea, oolong tea, dark tea and Pu'er tea. Its tea is made from ancient large-leaf tea trees, with unique flavor, sour and sweet aftertaste, golden and translucent soup color, without any additives and chemical raw materials, and is a pure natural treasure. The brewing method is consistent with the Pu'er tea method. When drinking, if you can drink it alternately with Pu'er tea, its taste will be even sweeter. Traditional Deang acid tea is fermented in bamboo tubes, which has the following shortcomings: 1. The bamboo tubes are too woody, resulting in bitterness hidden in the sour taste of the tea leaves (wood overcomes soil); 2. The temperature and humidity of underground burial are uncontrollable, and it is easy to breed miscellaneous bacteria (such as Penicillium); 3. The fermentation cycle is long (6-12 months) and the production efficiency is low. At the same time, the existing technology uses a constant temperature box for fermentation, but does not solve the problem of compatibility between metal containers and strains. Therefore, in order to avoid the shortcomings of the existing technology, it is necessary to improve the existing technology. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings and deficiencies in the prior art and provide a Deang sour tea production process based on stainless steel tank fermentation.

[0004] The present invention is achieved through the following technical solutions:

[0005] A production process of Deang sour tea based on stainless steel tank fermentation, comprising the following steps:

[0006] Step (1): picking fresh leaves;

[0007] Step (2): Fixing the leaves at a temperature of 120-130°C for 3-5 minutes until the leaves are soft and the grass smell disappears;

[0008] Step (3): rolling and shaping: after the withered leaves have cooled, they are gently rolled and shaped in a stainless steel rolling machine;

[0009] Step (4): activating the strains, mixing Lactobacillus plantarum and traditional Deang sour tea old strain liquid in proportion and activating them;

[0010] Step (5): tank fermentation, mixing the rolled leaves with the activated bacterial solution, loading into a 304 stainless steel fermentation tank, the inner wall of the 304 stainless steel fermentation tank being pre-coated with a food-grade clay coating, and then sealing and fermenting at a constant temperature of 28-32° C. for 60-90 days;

[0011] Step (6): geothermal drying: after the fermented leaves are taken out, they are dried in a geothermal drying room in Tengchong until the moisture content is ≤7%, thereby obtaining finished tea;

[0012] Step (7): Aging and storage: the finished tea is placed in a volcanic rock pottery jar for aging to obtain Deang sour tea.

[0013] Furthermore, in step (1), fresh leaves of Yunnan large-leaf tea trees are selected, and one bud and two leaves are picked after the dew has dried up in the early morning.

[0014] Furthermore, in the step (2), an electric heating drum tea-fixing machine is used for tea-fixing.

[0015] Furthermore, in the step (3), the dough is gently kneaded in a stainless steel kneading machine for 15 minutes, and the strip forming rate is ≥85%.

[0016] Furthermore, in the step (4), Lactobacillus plantarum and Deang traditional sour tea old bacteria liquid are compounded in a ratio of 1:2 and activated at 37° C. for 24 hours.

[0017] Furthermore, in the step (5), the rolled leaves are mixed with the activated bacterial solution at a mass ratio of 100:1.

[0018] Furthermore, in step (5), the volume of the 304 stainless steel fermentation tank is 200 L, and the thickness of the food-grade clay coating is 0.5 mm-1 mm.

[0019] Furthermore, in step (6), the drying temperature in the Tengchong geothermal drying room is 50°C-60°C.

[0020] Furthermore, in step (7), the finished tea is aged for more than 2 years in a storage room with a humidity of ≤40%.

[0021] Furthermore, in the step (7), the storage room is set in the southwest direction.

[0022] Compared with the prior art, the present invention uses fire to kill green, precise temperature control to inactivate enzymes and enhance aroma, retaining tea polyphenols ≥ 18%; the stainless steel tank body includes 304 food grade material + clay coating, which has both metal sealing and earthy energy conduction; the composite bacteria, the traditional old bacteria liquid and plant lactobacillus are compounded, the acid production efficiency is increased by 40%; geothermal drying, using the geothermal resources of Tengchong volcano, reduces energy consumption and gives the tea leaves fire and earth properties, so that the total acid content of De'ang sour tea reaches 4.5-5.2g / kg, which is much more than the 3.8-4.5g / kg of the traditional process, the flavor is mellower, the fermentation cycle is shortened to 60-90 days, the production capacity is increased by 30%, the stainless steel tank body replaces the bamboo tube, the residual wood gas is reduced by 92%, and the implicit bitterness is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the attached drawings required for the description of the embodiments or the prior art. Obviously, the attached drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other attached drawings can also be obtained based on these drawings.

[0024] Figure 1 This is a flowchart of the De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank body of the present invention. Detailed implementation manners

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the attached drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] As Figure 1 shown, a De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank body of the present invention includes the following steps.

[0027] Step (1): Fresh leaf picking;

[0028] Step (2): Fixing with appropriate heat. The fixing temperature is 120 - 130 °C, and the fixing time is 3 - 5 minutes until the leaf texture becomes soft and the grassy smell dissipates.

[0029] Step (3): Rolling into shape. After the fixed leaves are cooled, they are gently rolled into shape in a stainless steel rolling machine.

[0030] Step (4): Strain activation. Lactobacillus plantarum and the traditional old strain liquid of De'ang ethnic group's sour tea are compounded and activated in proportion.

[0031] Step (5): Tank body fermentation. The rolled leaves are mixed with the activated strain liquid and loaded into a 304 stainless steel fermentation tank. The inner wall of the 304 stainless steel fermentation tank is pre-coated with a food-grade kaolin coating, and after sealing, it is fermented at a constant temperature of 28 - 32 °C for 60 - 90 days.

[0032] Step (6): Drying with geothermal energy. After the fermented leaves are taken out, they are dried in the Tengchong geothermal drying room until the moisture content ≤ 7% to obtain the finished tea.

[0033] Step (7): Aging and storage. The finished tea is aged in a volcanic rock pottery pot to obtain the De'ang ethnic group's sour tea.

[0034] The present invention uses stir-frying to deactivate enzymes and precisely controls the temperature to remove enzymes and enhance fragrance, retaining ≥18% of tea polyphenols; the stainless-steel tank body consists of 304 food-grade material + clay coating, combining metal tightness and earth energy conduction; a composite strain, a traditional old bacterial liquid and Lactobacillus plantarum are compounded, and the acid production efficiency is increased by 40%; geothermal drying is used, taking advantage of the geothermal resources of Tengchong volcano, reducing energy consumption and endowing the tea with the attributes of fire and earth, making the total acid content of De'ang ethnic group's sour tea reach 4.5 - 5.2 g / kg, much higher than 3.8 - 4.5 g / kg of the traditional process, with a more mellow flavor, the fermentation cycle is shortened to 60 - 90 days, the production capacity is increased by 30%, the stainless-steel tank body replaces the bamboo tube, and the residual amount of wood gas is reduced by 92%, avoiding implicit bitterness.

[0035] In step (1), fresh leaves of Yunnan large-leaf tea trees are selected and one bud with two leaves are picked after the morning dew has dried.

[0036] In step (2), an electric drum stir-frying machine is used for stir-frying.

[0037] In step (2), the preferred stir-frying temperature is 125°C, and after stir-frying, the activity of polyphenol oxidase in the tea is reduced to less than 15% of the initial value.

[0038] In step (3), gentle rolling is carried out in a stainless-steel rolling machine for 15 minutes, and the strip-forming rate is ≥85%.

[0039] In step (4), Lactobacillus plantarum and the traditional sour tea old bacterial liquid of the De'ang ethnic group are compounded in a ratio of 1:2 and activated at 37°C for 24 hours.

[0040] In step (5), the rolled leaves are mixed with the activated bacterial liquid in a mass ratio of 100:1.

[0041] In step (5), the volume of the 304 stainless-steel fermentation tank is 200 L, and the thickness of the food-grade clay coating is 0.5 mm - 1 mm.

[0042] In step (6), the drying temperature in the Tengchong geothermal drying room is 50°C - 60°C.

[0043] In step (7), the finished tea is aged in a storage room with a humidity ≤40% for more than 2 years.

[0044] In step (7), the storage room is set at the position of the southwest Kun position.

[0045] Example 1

[0046] (1) 10 kg of fresh leaves of Mengku large-leaf tea are picked and stir-fried electrically (125°C × 4 min);

[0047] (2) After rolling, the composite bacterial liquid is inoculated (old bacterial liquid: Lactobacillus plantarum = 2:1) and loaded into a 200 L stainless-steel tank;

[0048] (3) After fermentation at 30°C for 75 days, the lactic acid content reached 4.8 g / kg;

[0049] (4) Geothermal drying (55°C × 8h), the moisture content of the finished product is 6.5%;

[0050] (5) Aged in a clay pot for 24 months, the tea soup is bright red with a lasting sour aroma.

[0051] By innovatively improving the traditional sour tea withering, fermentation and storage processes, combined with modern microbial technology, the problems of excessive woodiness and uneven fermentation in traditional processes have been solved. The core process includes high-temperature withering, stainless steel tank sealed fermentation, geothermal assisted drying and other steps, which significantly improve the quality stability and health attributes of sour tea, while adapting to specific five-element energy requirements. The present invention is suitable for the inheritance of intangible cultural heritage, the development of healthy foods and the upgrading of regional characteristic industries.

[0052] Patent Advantage Statement

[0053] 1. Cultural inheritance: The core intangible cultural heritage of De'ang nationality's sour tea "anaerobic fermentation" is completely preserved.

[0054] 2. Scientific innovation: It is the first time that stainless steel tank + clay coating is used in tea fermentation.

[0055] 3. Commercial value: Solve the defect of excessive woodiness in traditional sour tea and expand the health and wellness consumer market.

[0056] 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 production process of De'ang ethnic group's sour tea based on fermentation in a stainless steel tank, characterized in that: It includes the following steps: Step (1): Fresh leaf picking; Step (2): Fixing with a certain temperature, the fixing temperature is 120 - 130 °C, and the fixing time is 3 - 5 minutes until the leaf texture becomes soft and the grassy smell dissipates; Step (3): Rolling into shape. After the fixed leaves are cooled, gently roll them into shape in a stainless - steel rolling machine; Step (4): Strain activation. Re - compound and activate Lactobacillus plantarum and the traditional old strain liquid of De'ang ethnic group's sour tea in proportion; Step (5): Tank fermentation. Mix the rolled leaves with the activated strain liquid, put them into a 304 stainless - steel fermentation tank. The inner wall of the 304 stainless - steel fermentation tank is pre - coated with a food - grade clay coating, and after sealing, ferment at a constant temperature of 28 - 32 °C for 60 - 90 days; Step (6): Geothermal drying. After taking out the fermented leaves, dry them in the Tengchong geothermal drying room until the moisture content ≤ 7% to obtain the finished tea; Step (7): Aging storage. Place the finished tea in a volcanic rock pottery pot for aging to obtain the De'ang ethnic group's sour tea.

2. The De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank as claimed in claim 1, wherein: In the said step (1), select fresh leaves of Yunnan big - leaf tea trees and pick one bud with two leaves after the morning dew dries.

3. The De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank according to claim 1, characterized in that: In the said step (2), use an electric drum - type fixing machine for fixing.

4. The De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank as claimed in claim 1, characterized in that: In the said step (3), gently roll in a stainless - steel rolling machine for 15 minutes, and the strip - forming rate ≥ 85%.

5. The De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank as claimed in claim 1, wherein: In the said step (4), re - compound Lactobacillus plantarum and the traditional old strain liquid of De'ang ethnic group's sour tea in a ratio of 1:2 and activate at 37 °C for 24 hours.

6. The De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank as claimed in claim 1, characterized in that: In the said step (5), mix the rolled leaves with the activated strain liquid in a mass ratio of 100:

1.

7. The De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank as claimed in claim 1, characterized in that: In the said step (5), the volume of the 304 stainless - steel fermentation tank is 200 L, and the thickness of the food - grade clay coating is 0.5 mm - 1 mm.

8. The De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank as claimed in claim 1, characterized in that: In the said step (6), the drying temperature in the Tengchong geothermal drying room is 50 °C - 60 °C.

9. The De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank as claimed in claim 1, characterized in that: In the said step (7), the finished tea is aged in a storage room with humidity ≤ 40% for more than 2 years.

10. The De'ang ethnic group's sour tea production process based on fermentation in a stainless steel tank according to claim 9, characterized in that: In the said step (7), the storage room is set at the position of Kun in the southwest direction.

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