阅读说明：本技术 一种采用重压复揉法的冷泡红茶及其加工工艺 (Cold-brewed black tea adopting repeated pressing and kneading method and processing technology thereof ) 是由 申东� 蒲荡 卫倩如 于 2021-09-13 设计创作，主要内容包括：本发明属于红茶加工工艺技术领域,公开了一种采用重压复揉法的冷泡红茶及其加工工艺。其包括：萎凋、重力揉捻、解块、发酵、毛火、摊凉、复揉、解块、曲形、并锅、干燥、摊凉、提香、成品。该工艺的发酵工序主要是在萎凋槽上进行,打破常规发酵法,发酵叶在发酵时有充足的氧气供应,能够控制叶温保持在30℃以下,能够使发酵有一个良好的发酵环境,避免茶叶发酵时产生的劣变。该加工工艺能够使发酵在温度较低环境中进行,有效地阻止或延缓不良真菌生长,在发酵过程中避免了茶叶发酵过急或过重以及酸馊现象,成品茶品质更加稳定。(The invention belongs to the technical field of black tea processing technology, and discloses cold-brewed black tea adopting a repeated pressing and re-kneading method and a processing technology thereof. It includes: withering, gravity rolling, deblocking, fermenting, gross fire, spreading for cooling, re-kneading, deblocking, curving, merging, drying, spreading for cooling, extracting fragrance, and obtaining a finished product. The fermentation process of the process is mainly carried out on a withering trough, the conventional fermentation method is broken through, sufficient oxygen is supplied to the fermented leaves during fermentation, the temperature of the fermented leaves can be controlled to be below 30 ℃, a good fermentation environment can be provided for fermentation, and deterioration generated during tea fermentation is avoided. The processing technology can make fermentation carried out in a lower temperature environment, effectively prevent or delay the growth of harmful fungi, avoid the phenomena of over-urgent or over-heavy fermentation of tea leaves and rancidness in the fermentation process, and make the quality of the finished tea more stable.)

1. A cold-making black tea processing technology adopting a repeated pressing and re-kneading method is characterized by comprising the following steps:

(1) withering: picking fresh leaves with one bud and one leaf to two buds, and spreading the fresh leaves in a withering trough for withering treatment;

(2) and (3) gravity rolling: putting the withered tea leaves into a rolling machine for rolling treatment; wherein, a rolling method is adopted, and the pressure is not increased;

(3) deblocking: the rolled tea leaves after the rolling treatment enter a deblocking machine for deblocking, and the tea leaves are kept loose and are not agglomerated;

(4) fermentation: placing the deblocked tea leaves into a withering trough for natural fermentation treatment at normal temperature;

(5) gross fire: performing gross fire treatment on the fermented tea leaves by using a de-enzyming machine, wherein the treatment temperature is kept between 240 and 260 ℃, and the moisture content of the gross fire leaves is not lower than 45 percent;

(6) spreading for cooling: flatly spreading the tea leaves subjected to the gross fire on a platform, and carrying out blast cooling;

(7) re-kneading: loading the spread and cooled tea leaves into a rolling machine for re-rolling treatment, starting to have no pressure for 5-10min, rotating at 40-50 r/min, then rolling for 15-30min for the second time without pressing, and after re-pressing, having no pressure again, wherein the whole time is 60 min; the cell damage rate is not lower than 83%;

(8) deblocking, namely loading the re-kneaded tea leaves into a deblocking machine for deblocking treatment;

(9) curve form: loading the deblocked tea leaves into a curling machine for curving;

(10) and (3) cooking: the curved leaves in one pan of the curved edge bending machine are merged into another pan for pan shaping treatment; keeping the temperature at 110-120 ℃, adopting small arc for frying arc, frying at medium speed for 50-70 min, frying in a pan until the arc is curled, and ensuring that the water content is not lower than 9%;

(11) and (3) drying: spreading the cooled leaves in a dryer for drying;

(12) spreading for cooling: spreading the dried tea leaves into a spreading and cooling platform for spreading and cooling, wherein the spreading and cooling thickness is 2-3 cm, and carrying out blast cooling;

(13) and (3) fragrance extraction: and (3) carrying out aroma-improving treatment on the spread and cooled tea leaves, wherein the aroma-improving temperature is set to be 80-110 ℃, and the time is 1-2 hours.

2. A process for processing cold-brew black tea using double pressing and re-rolling as claimed in claim 1, wherein in said step (1), the fresh leaves are spread to a thickness of 10-15cm and cooled with cold air for 20-40min, and then withered with hot air, and the mixture is turned over every 3h for 12-20 h, until the water content is not less than 60%.

3. A process for processing cold brew black tea as claimed in claim 1, wherein in step (2), the withered tea leaves are processed in a rolling machine at a speed of 10-15r/min and a pressure of 30-35 r/min for 18-30 min; the cell is circulated for 4-8 times to make the cell disruption rate not less than 75%.

4. A process for processing cold brew black tea as claimed in claim 1, wherein in step (4), the fermentation process is carried out in a withering tank under ventilation for a period of 4-6 hours.

5. A process for manufacturing cold brew black tea with a repetitive press and rub method as claimed in claim 1, wherein said step (9) is carried out by setting the temperature between 110 ℃ and 140 ℃; the arc is large arc, and the water content of the leaf of wampee is not less than 30%.

6. The process for processing cold-brewed black tea by adopting a repeated pressing and kneading method as claimed in claim 1, wherein in the step (11), the combined pot leaves are thinly spread on a spreading and cooling platform for spreading and cooling, wherein the spreading and cooling thickness is 2-3 cm, air blast cooling is performed rapidly, and the spreading and cooling time is 20-35 min.

7. A process for preparing cold-brew black tea according to claim 1, wherein in step (12), the pan-combined cooled leaves are spread on a leaf spreading sieve of a drier and dried, and the drying temperature is set at 60-80 ℃ for 1-3 hours.

8. A process according to claim 1, wherein the dried leaves are transferred to an aroma raising treatment, the aroma raising temperature is set at 80-110 ℃ for 1-2 h, and the leaves are cooled.

9. A cold-brew black tea produced by a double press and mull process wherein a black tea product is produced by a cold-brew black tea process as claimed in any one of claims 1 to 8.

Technical Field

The invention belongs to the technical field of black tea processing technology, and particularly relates to cold-brewed black tea adopting a repeated pressing and re-kneading method and a processing technology thereof.

Background

At present, no patent report of cold-making black tea exists, and the main problems of the existing production and processing method of the black tea are as follows:

the rolling time is short, the rolling method is basically carried out according to textbooks and production experiences of tea evaluation, the cell breakage rate of the finished tea in the rolling mode is about 30-40%, due to the fact that the cell breakage rate is too low, the ingredients cannot be soaked in the tea soup by cold water at normal temperature, and the processed black tea can only be brewed by boiling water. The existing black tea products are only brewed by boiling water, and are not suitable for mass consumption in hot summer and autumn. 3. The existing black tea fermentation adopts methods such as heating, accumulation and the like, and the fermented leaves are often fermented in a severe environment, the temperature of the leaves is more than 35 ℃, and the oxygen introducing state is poor, so that the deterioration phenomenon often occurs, and the taste is seriously influenced.

In order to ensure that leaf cells are damaged to the maximum extent during rolling, the invention adopts a heavy-pressure rolling and re-rolling mode to ensure that the cell damage rate is up to more than 80 percent, and the tea can be drunk only after being brewed with normal-temperature water for 4-5 min. The fermentation process of the invention is mainly carried out on the withering trough, the conventional fermentation method is broken through, the fermented leaves have sufficient oxygen supply during fermentation, the temperature of the leaves can be controlled to be kept below 30 ℃, the fermentation has a good fermentation environment, the deterioration of the tea during fermentation is avoided, and the quality of the finished tea is more stable.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide cold-brewed black tea adopting a repeated pressing and kneading method and a processing technology thereof.

The technical scheme adopted by the invention is as follows: a cold-making black tea processing technology adopting a repeated pressing and re-kneading method comprises the following steps:

(1) withering: picking standard fresh leaves with one bud and one leaf to two buds, and spreading the fresh leaves in a withering trough for withering treatment;

(2) and (3) gravity rolling: putting the withered tea leaves into a rolling machine for rolling treatment; wherein, a heavy pressure rolling method is adopted, and no pressure and low speed are started;

(3) deblocking: the rolled tea leaves after the rolling treatment enter a deblocking machine for deblocking, and the tea leaves are kept loose and are not agglomerated;

(4) fermentation: placing the deblocked tea leaves into a withering trough for natural fermentation treatment at normal temperature;

(5) gross fire: and (3) carrying out the gross fire treatment on the fermented tea leaves after the fermentation by using a fixation machine. Wherein the treatment temperature is kept between 240 ℃ and 260 ℃, and the moisture content of the gross fire leaves is not lower than 45%;

(6) spreading for cooling: flatly spreading the tea leaves subjected to the gross fire on a platform, and carrying out blast cooling;

(7) re-kneading: loading the spread and cooled tea leaves into a rolling machine for re-rolling treatment, starting to have no pressure for 5-10min, rotating at 40-50 r/min, then pressing and kneading for 15-30min for the second time, and after re-pressing, having no pressure again, wherein the whole time is 60 min; the cell damage rate is not lower than 83%;

(8) deblocking, namely loading the re-kneaded tea leaves into a deblocking machine for deblocking treatment;

(9) curve form: loading the deblocked tea leaves into a curling machine for curving;

(10) and (3) cooking: the curved leaves in one pan of the curved edge bending machine are merged into another pan for pan shaping treatment; keeping the temperature at 110-120 ℃, adopting small arc for frying arc, frying at medium speed for 50-70 min, frying in a pan until the arc is curled, and ensuring that the water content is not lower than 9%;

(11) and (3) drying: spreading the cooled leaves in a dryer for drying;

(12) spreading for cooling: spreading the dried tea leaves into a spreading and cooling platform for spreading and cooling, wherein the spreading and cooling thickness is 2-3 cm, and carrying out blast cooling;

(13) and (3) fragrance extraction: and (3) carrying out aroma-improving treatment on the spread and cooled tea leaves, wherein the aroma-improving temperature is set to be 80-110 ℃, and the time is 1-2 hours.

Preferably, in the step (1), the fresh leaves are spread to a thickness of 10-15cm, blown with cold air for 20-40min, and then subjected to hot air withering, and are turned and stirred once every 3h, the withering time is 12-20 h, and the withering is carried out until the water content is not lower than 60%.

Preferably, in the step (2), the withered tea leaves are put into a rolling machine for treatment, the pressure is not increased for 8-12min at the beginning, the rotating speed is 10-15r/min, and then the speed is 30-35 r/min and the pressure is increased for 18-30 min; the cell is circulated for 4-8 times to make the cell disruption rate not less than 75%.

Preferably, in the step (4), the fermentation process is performed in a withering trough with ventilation, and the fermentation time is kept between 4 and 6 hours.

Preferably, in the step (9), the temperature is set to be 110 ℃ to 140 ℃; the arc frying adopts a large arc, the speed is high, and the moisture content of the fermented wampee leaves is not lower than 30%.

Preferably, in the step (11), the combined pot leaves are thinly spread on a spreading cooling platform for spreading cooling, wherein the spreading cooling thickness is 2-3 cm, and the air blast quick cooling is performed for 20-35 min.

Preferably, in the step (12), the pot-combined cooled leaves are scattered into a leaf spreading sieve of a dryer for drying treatment, and the drying temperature is set to be 60-80 ℃ for 1-3 h.

Preferably, the dried leaves are transferred to the aroma raising treatment, the aroma raising temperature is set to be 80-110 ℃, the time is 1-2 h, and the leaves are cooled.

Preferably, the black tea product is obtained by a process for cold brew black tea using a re-press re-rolling process as claimed in any one of claims 1 to 8, a process for cold brew black tea using a re-press re-rolling process.

The invention has the beneficial effects that:

compared with the prior art, the processing technology creatively invents're-pressing and re-kneading', and utilizes a physical method and a mechanical principle to damage leaf cells to the maximum extent, so that the traditional processing method is broken through. In the fermentation process, according to the influence of the fermentation medium on the fermentation process, the withering trough fermentation method is adopted, so that the adverse environment of the fermentation process is avoided, the fermentation is carried out in the environment with lower temperature, ventilation, sufficient oxygen and the like, the tea fermentation speed is slowed down, and the growth of some adverse fungi is effectively prevented or delayed, so that the phenomena of over-urgency or over-heaviness and rancidity of the tea fermentation are avoided in the fermentation process.

Therefore, the invention can provide a novel processing mode for ensuring the quality of the cold-brewed black tea.

Drawings

Figure 1 is a flow chart of the industrial processing process of the cold-brewed black tea.

Detailed Description

The present invention is further illustrated below with reference to specific examples. It will be appreciated by those skilled in the art that the following examples, which are set forth to illustrate the present invention, are intended to be part of the present invention, but not to be construed as limiting the scope of the present invention. The reagents used are all conventional products which are commercially available.

Example 1:

industrial production process of cold-brewed black tea

The process flow is as follows:

withering → gravity rolling → deblocking → fermentation → gross fire → spreading cool → repeat kneading → deblocking → curving → merging pan → drying → spreading cool → aroma → finished product.

As shown in fig. 1.

The method comprises the following steps: picking standard fresh leaves with one bud and one leaf to two buds, and spreading the fresh leaves in a withering trough for withering treatment. Spreading the leaves with the thickness of 15cm, starting an air blower to blow cold air for 30min, then starting a heating device to wither the leaves by hot air (not opened in summer), turning and stirring once every 3h, wherein actions during turning and stirring are light, mechanical damage is avoided, the withering time is 12 h-20 h, and the leaves are withered until the water content is 62% +/-2.

Step two: and (5) putting the withered leaves into a rolling machine for rolling treatment. The rolling method adopts a heavy-load rolling method, a 55-type or 65-type speed-adjustable rolling machine is selected, the non-pressure is started for 10min, the rotating speed is 10-15r/min, and then the speed is changed into 30-35 r/min and the heavy load is 20 min; the pressure is not increased for 5min and the pressure is increased for 25min for the second time; third pressureless for 5min and heavily pressing for 25 min; fourth pressureless for 5min and heavily pressing for 25 min; fifth pressureless for 5min and heavy pressure for 25 min; sixth pressureless for 5min, and heavy pressing for 20 min; the pressure is not increased for 5min, the whole rolling time is 3h, and the cell breakage rate needs to reach more than 75%.

Step three: and the rolled leaves after rolling enter a deblocking machine for deblocking, and the tea leaves are kept loose and not agglomerated.

Step four: and (4) placing the deblocked tea leaves into a withering tank for natural fermentation treatment at normal temperature. The thickness of the spread leaves is 20cm, the wet cloth covers the spread leaves, and as the withering trough has good ventilation performance, oxygen at the bottom can rapidly penetrate through leaf layers, the leaves are rapidly and uniformly fermented, the phenomenon of rancidity caused by heating in the leaves is not easy to occur, and the whole fermentation time is 4-6 hours.

Step five: the fermented leaves are treated by a roller continuous enzyme deactivating machine. The temperature is set to be 240-260 ℃, and the moisture content of the gross fire leaves is about 45%.

Step six: spreading the raw leaves on a spreading cooling platform for cooling, wherein the spreading cooling thickness is 2-3 cm, and blasting for quick cooling for 30 min.

Step seven: putting the cool leaves spread by the gross fire into a rolling machine for re-rolling treatment, wherein the type of the fresh leaves of the rolling machine is 40-65, the leaf feeding amount is 15-80 kg, the pressure is not increased for 5min at the beginning, the rotating speed is 30-35 r/min, and then the leaves are pressed and kneaded for 20min by weight; kneading for the second time for 5min, pressing again for 20min, and no pressure for 5min, with the whole process time of 60 min; the cell damage rate is more than 83 percent.

Step eight: loading the re-kneaded tea leaves into a deblocking machine for deblocking treatment;

and step 9: and (5) kneading the leaves again, and putting the leaves into a curly hair machine for curling treatment. The type 45-60 of the Quhao machine is selected, 3-5 kg of re-kneaded leaves are put into each pot, the temperature is set at 110-140 ℃, the arc frying adopts large arc, the speed is fast, the time is 30-50 min, and the moisture content of the Quhao leaves is about 30%.

Step ten: and (4) merging the curved leaves in one pan in the curling machine into another pan for pan shaping treatment. Setting the temperature at 110-120 deg.c, frying in small arc at medium speed for 50-700 min, and frying in pot until the water content is 9-15%.

Step eleven: and spreading the combined pot leaves on a spreading cooling platform for spreading for cooling, wherein the spreading cooling thickness is 2-3 cm, and blasting for quick cooling for 30 min.

Step twelve: and scattering the merged cooling leaves into a leaf spreading sieve of a box type dryer, and then putting the merged cooling leaves into the dryer for drying treatment, wherein the drying temperature is set to be 60-80 ℃, and the time is 1-3 hours.

Step thirteen: and (3) converting the dried leaves into aroma raising treatment, setting the aroma raising temperature to be 80-110 ℃, and cooling for 1-2 hours to obtain the cold-brewing black tea.

For the above-mentioned 55-type speed-adjustable rolling machine, it is within the protection scope of the present invention for the device to be able to perform corresponding speed-adjusting and rolling actions, and not limited to this device.

Example 2:

industrial production process of cold-brewed black tea

The process flow is as follows: withering → gravity rolling → deblocking → fermentation → gross fire → spreading cool → repeat kneading → deblocking → curving → merging pan → drying → spreading cool → aroma → finished product. As shown in fig. 1.

Step two: and (3) gravity rolling: and (5) putting the withered leaves into a rolling machine for rolling treatment. The rolling method adopts a heavy-load rolling method, a 55-type or 65-type speed-adjustable rolling machine is selected, the non-pressure is started for 10min, the rotating speed is 10-15r/min, and then the speed is changed into 30-35 r/min and the heavy load is 20 min; the pressure is not increased for 5min and the pressure is increased for 25min for the second time; third pressureless for 5min and heavily pressing for 25 min; fourth pressureless for 5min and heavily pressing for 25 min; fifth pressureless for 5min and heavy pressure for 25 min; sixth pressureless for 5min, and heavy pressing for 20 min; the pressure is not increased for 5min, the whole rolling time is 3h, and the cell breakage rate needs to reach more than 75%.

Step eight: re-kneading: putting the cool leaves spread by the gross fire into a rolling machine for re-rolling treatment, wherein the fresh leaves of the rolling machine are 40-65 type, the spread leaf amount is 15-80 kg, the pressure is not increased for 5min at the beginning, the rotating speed is 30-35 r/min, and then the leaves are heavily pressed and kneaded for 20 min; kneading for the second time for 5min, pressing again for 20min, and no pressure for 5min, with the whole process time of 60 min; the cell damage rate is more than 83 percent.

1. Cell breakage rate determination:

and (3) soaking the twisted leaves, the curved leaves and the pot leaves for 5 minutes by using a 10% potassium permanganate solution, then rinsing the leaves by using clear water, and calculating the cell damage rate according to the proportion of a clean dyeing part.

Test results

Item	Rolling (%)	Gross fire (%)	Double kneading (%)	Curve (%)	Pan combination (%)
						Test examples	77	78	87	88	88
Control group (traditional rolling method)	31	32	----	----	----

According to tests, the cell damage rate of the leaf cells in the examples is far higher than that of the comparative example from the beginning of rolling, the cell damage rate reaches 75% after the first rolling, the cell damage rate reaches 88% after the pan-combining modeling, and the cell damage rate of the comparative example is only 32% at most.

2. And (3) normal-temperature water soaking test:

experimental example: the finished black tea strips prepared in examples 1 and 2 were put into black tea bags made of nonwoven fabric, and the bags were placed in drinking water at normal temperature, left to stand after the bags were completely soaked, and the state and taste of the tea soup were observed after 5, 15, and 20 minutes, respectively.

Control group: a cold-brewing tea bag is prepared by a traditional rolling method.

The experimental results are as follows:

as can be seen from the above, the cold-brewed tea prepared in examples 1 and 2 has a short soaking time, a high soaking and leaching rate, and a good taste. The color and taste of the tea soup of the control group can not meet the requirements after the tea soup is soaked for 20 minutes.

The black tea prepared by the method can be brewed by conventional hot water and can also be brewed by cold water at normal temperature. The product can be enjoyed only by filling the bottled mineral water tea at normal temperature for 5-15 minutes. Simple, convenient, fast, efficient and time-saving.

The invention provides a cold-making black tea processing technology adopting a repeated pressing and repeated kneading method, the existing black tea fermentation adopts heating, stacking and other methods, the fermented leaves are often fermented in a severe environment, the leaf temperature is more than 35 ℃, the oxygen introducing state is poor, so the deterioration phenomenon is often caused, and the taste is seriously influenced. The fermentation process of the invention is mainly carried out on the withering trough, the conventional fermentation method is broken through, the sufficient oxygen supply is provided during the fermentation of the fermented leaves, the temperature of the fermented leaves can be controlled to be below 30 ℃, the fermentation has a good fermentation environment, and the deterioration generated during the tea fermentation is avoided.

The gradual pressing and long-time rolling method adopted by the invention ensures the leaching rate of the tea leaves and is suitable for cold soaking.

The processing technology can guarantee the quality of the cold-brewed black tea, and provides a novel processing mode.

The present invention is not limited to the above alternative embodiments, and any other products in various forms can be obtained by the present invention, and the present invention is within the protection scope of the present invention. The above embodiments should not be construed as limiting the scope of the present invention, and it will be understood by those skilled in the art that modifications may be made to the technical solutions described in the above embodiments, or equivalent substitutions may be made to some or all of the technical features thereof, without departing from the scope of the present invention, and at the same time, such modifications or substitutions may not make the essence of the corresponding technical solutions depart from the scope of the embodiments of the present invention.