Special distiller's yeast for tea wine and preparation method thereof

Abstract

The present application belongs to the technical field of wine starter preparation, and particularly relates to a tea wine special wine starter and a preparation method thereof. The preparation method comprises the following steps: S1. raw material preparation: taking 4-8 parts of barley, 85-95 parts of wheat and 2-5 parts of tea leaves, uniformly mixing, crushing, and adjusting the moisture content to 50-70%, to obtain starter preparation materials; S2. starter blank preparation: preparing the starter preparation materials into starter blanks; S3. starter blank culture: culturing the starter blanks under the condition of 18-25 DEG C, until the temperature of the starter blanks is constant; S4. secondary fermentation: carrying out secondary fermentation on the starter blanks by increasing the temperature to 40-50 DEG C, until the moisture content of the starter blanks is reduced to 12-15%, to obtain the tea wine special wine starter. The tea wine brewed by using the tea wine special wine starter as a saccharifying fermentation agent has a mellow flavor, and the tea aroma and wine aroma are combined to form a unique tea wine quality.

Description

Technical Field

[0001] This invention belongs to the field of yeast preparation technology, specifically relating to a yeast for tea and wine and its preparation method. Background Technology

[0002] Traditionally, tea wine refers to a category of alcoholic beverages made primarily from tea leaves, produced through direct extraction, blending, or biological fermentation, possessing the aroma of tea and the mellowness of wine. It combines the characteristics of both tea and wine, and is a low-alcohol, low-sugar beverage that integrates nutrition and health benefits. The development of tea wine has progressed from the initial steeping method to the blending method using distillation, and then to the natural fermentation and distillation method, with increasing refinement and specificity.

[0003] However, existing patent databases for fermented tea wines mostly use traditional yeast as the fermenting agent, such as patent applications CN115074197A and CN113583784A. Invention patent CN113322143B uses pure black tea containing *Aspergillus cristatus* as raw material and enhanced yeast strains to ferment sorghum mash, producing tea-aroma compounds during fermentation. However, in this patent, the fermentation period is 60 days. In patent application 2023116708090, the applicant seeks protection for a low-alcohol tea wine with a complex tea and wine aroma. This tea wine also uses traditional daqu (a type of yeast starter) as the fermenting agent, with a fermentation period of 60-90 days.

[0004] Overall, the fermentation cycle of fermented tea wines is currently too long, which is not conducive to cost control. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a special yeast starter for tea wine preparation, thereby shortening the fermentation cycle of tea wine preparation. The tea wine referred to in this invention is a type of baijiu (Chinese white liquor) with a unique flavor, made from five grains (sorghum, rice, glutinous rice, wheat, and corn) and tea leaves as the main raw materials, produced through biological fermentation. It possesses the fragrance of tea and the mellowness of liquor, combining the characteristics of both tea and liquor.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A method for preparing a special yeast starter for tea and wine includes the following steps:

[0008] S1. Raw material preparation: By weight, take 4-8 parts of barley, 85-95 parts of wheat and 2-5 parts of tea, mix them evenly and then crush them, and adjust the moisture content to 50-70% to obtain the raw materials for making koji.

[0009] S2. Forming the blank: The raw materials for making koji are made into koji blanks;

[0010] S3. Curing of the shaped blank: The shaped blank is placed at 18-25℃ and cultured until the temperature of the shaped blank is constant;

[0011] S4. Secondary fermentation: The temperature is raised to 40-50℃ to carry out secondary fermentation of the koji blank until the moisture content of the koji blank drops to 12-15%, thus obtaining the tea wine koji.

[0012] In some embodiments, in S1, the tea leaves include at least two of green tea, oolong tea, black tea, white tea, dark tea, or yellow tea.

[0013] In some embodiments, in S1, the fineness of the raw material for making koji is 50-80 mesh.

[0014] In some embodiments, in S2, the size of the blank is 20-30cm × 15-20cm × 10-15cm.

[0015] In some implementations, in S2, the method for making the blank is mechanical pressing or manual treading.

[0016] The present invention also provides a special yeast for tea and wine prepared by the above preparation method.

[0017] The present invention also provides the application of the above-mentioned tea and wine-specific yeast in the brewing of tea and wine.

[0018] In some embodiments, the application includes preparing a tea-and-wine aroma composite tea wine using the tea-and-wine-specific yeast as a fermentation agent. The preparation method of the tea-and-wine aroma composite tea wine includes the following steps:

[0019] High-quality grain raw materials are selected and then subjected to washing, soaking, steaming and saccharification steps to obtain grain residue;

[0020] Add the tea-wine-specific yeast to the grain lees, seal and ferment for 40-50 days to obtain the lees;

[0021] Under aseptic conditions, add the mixed tea leaves to the fermented mash and stir well, then continue fermentation for 3-7 days under the same conditions;

[0022] After fermentation, the alcohol is distilled.

[0023] In some embodiments, the amount of the tea-wine-specific yeast added is 15-25% of the mass of the grain residue.

[0024] In some embodiments, the mixed tea is obtained by uniformly mixing yellow tea, black tea, red tea and white tea in a mass ratio of 10-20:1-10:2-12:2-10.

[0025] It should be noted that although the population and quantity of microorganisms attached to the surface of grains vary with seasons and temperatures, the applicant's preliminary research found that even when the raw materials for making the koji are wheat, barley, and tea under different seasons or temperature conditions, the final quality of the tea-wine koji prepared using the method of this invention, such as the types and quantities of microorganisms, fermentation capacity, and total acid and total ester content, remains at the same level. In other words, the initial state of the raw materials does not affect the quality of the final koji. Therefore, the tea-wine koji of this invention does not require the addition of any external microbial agents to control the types of microorganisms during preparation.

[0026] The applicant speculates that this is because certain saccharifying or fermenting bacteria naturally present in grains have a competitive advantage over other microorganisms during the cultivation of the starter culture. Simultaneously, the tea leaves added to the raw materials contain a large amount of phenolic substances, which have an antagonistic effect on some miscellaneous bacteria. Therefore, as the cultivation time continues, these dominant strains gradually proliferate and reach equilibrium, while other microorganisms gradually die off. Although the initial numbers of these dominant microorganisms may differ under different seasons or climates, the final competitive outcome is the same under the cultivation conditions of this invention. Therefore, the starter culture exhibits the same physicochemical properties.

[0027] This invention involves two main stages in the cultivation of the koji (fermentation starter). In the first stage, the temperature is relatively low, and the microorganisms primarily engage in aerobic respiration, consuming the oxygen in the koji. Once the oxygen is depleted, the temperature of the koji no longer changes significantly. At this point, the second stage begins, where the temperature of the koji is increased, and the microorganisms undergo secondary fermentation. This stage primarily involves anaerobic fermentation. As the temperature gradually increases, the moisture content of the koji gradually decreases over time until it reaches a certain limit, at which point fermentation is terminated, yielding the starter culture.

[0028] It should be noted that the proportions of barley, wheat, and tea leaves used in this invention need to be strictly limited. Because tea leaves have a lower density than barley or wheat, excessive tea leaves will make it difficult to prepare the koji (fermentation starter), specifically making it difficult to compress and compact the starter. Insufficient tea leaves will result in insufficient porosity and low oxygen content in the starter, affecting its cultivation and fermentation.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention provides a special yeast starter for tea and wine. Using this yeast starter as a saccharification and fermentation agent to brew tea and wine represents a major transformation and innovation in yeast starter technology. It is a breakthrough achievement for yeast starters used in brewing, especially in enabling the production of tea and wine and forming a unique tea-flavored baijiu quality. It has significant innovative and application value.

[0031] 2. Using the tea-wine-specific yeast of this invention as a saccharification and fermentation agent to brew tea wine can effectively shorten the fermentation cycle. Compared with tea wine fermented with traditional Daqu, the aroma activity values ​​such as ethyl isovalerate and ethyl hexanoate are higher, while the activity values ​​of dimethyl trisulfide with fishy odor are lower. The flavor is more mellow, and the tea and wine aromas are more integrated and revealed, forming a unique tea wine quality. Detailed Implementation

[0032] The technical solution of the present invention will be further described in detail below with reference to Embodiment 1, but the scope of protection of the present invention is not limited to the following description.

[0033] Example 1

[0034] Prepare a special yeast for tea and wine by following these steps:

[0035] S1. Raw material preparation: By weight, take 6 parts barley, 90 parts wheat and 5 parts mixed tea (of which, the mixed tea consists of 1 part green tea, 2 parts black tea, 1 part white tea and 1 part dark tea), mix all raw materials evenly and grind them to a fineness of 60 mesh, then add water to adjust the moisture content to 60% to obtain the raw materials for making koji.

[0036] S2. Forming the blank: The raw materials for making koji are put into a koji-making basket and formed into koji blanks with a size of 20cm (length) × 15cm (width) × 10cm (height) by manually stepping on the koji.

[0037] S3. Curing of the skewer: The skewer is placed at 20°C and the temperature is monitored at all times. The curing is stopped when the temperature of the skewer no longer changes.

[0038] S4. Secondary fermentation: The ambient temperature of the koji cake is raised to 45℃ for secondary fermentation. During the secondary fermentation, the moisture content of the koji cake continuously decreases until it drops to 14%. At this point, the fermentation is terminated, and the tea wine koji is obtained.

[0039] Example 2

[0040] Prepare a special yeast for tea and wine by following these steps:

[0041] S1. Raw material preparation: By weight, take 8 parts barley, 85 parts wheat and 3 parts mixed tea (of which, the mixed tea consists of 1 part green tea, 1 part black tea and 1 part oolong tea), mix all raw materials evenly and grind them to a fineness of 60 mesh, then add water to adjust the moisture content to 60% to obtain the raw materials for making koji.

[0042] S2. Blank making: The raw materials for making koji are made into koji blanks with a size of 25cm (length) × 20cm (width) × 10cm (height) by mechanical koji making;

[0043] S3. Curing of the skewer: The skewer is placed at 22°C and the temperature is monitored at all times until the temperature of the skewer does not change.

[0044] S4. Secondary fermentation: The ambient temperature of the koji cake is raised to 50℃ for secondary fermentation until the moisture content of the koji cake gradually decreases to 14%, at which point the fermentation is terminated, and the tea wine koji is obtained.

[0045] Comparative Example 1

[0046] The preparation of a yeast starter differs from that of Example 1 in that the proportions of the raw materials in S1 are different. Specifically, the raw materials of Comparative Example 1 are 6 parts barley, 75 parts wheat, and 20 parts mixed tea (of which the mixed tea consists of 5 parts green tea, 5 parts black tea, 5 parts white tea, and 5 parts dark tea).

[0047] Comparative Example 2

[0048] The preparation of a yeast starter differs from that of Example 1 in that the proportions of the raw materials in S1 are different. Specifically, the raw materials of Comparative Example 2 are 10 parts barley, 90 parts wheat, and 1 part mixed tea (wherein, the mixed tea consists of 0.25 parts green tea, 0.25 parts black tea, 0.25 parts white tea, and 0.25 parts dark tea).

[0049] Comparative Example 3

[0050] The preparation of a yeast starter differs from that in Example 1 in that, after S3, the yeast starter is air-dried at room temperature until the moisture content is 14%.

[0051] Comparative Example 4

[0052] The preparation of a yeast starter differs from that in Example 1 in that, after S2, the yeast starter is placed at 40°C for cultivation until its moisture content reaches 14%.

[0053] Quality evaluation of yeast:

[0054] The yeast and mold counts of the yeast prepared in the above examples were determined according to GB / T 4789.15-2016, the total acid content was determined according to GB12456-2021, the total ester content was determined according to GB / T 10345-2022, the pH value was determined according to NY / T 525-2021, the theanine content was determined according to GB / T 23193-2017, and the tea polyphenol content was determined according to GB / T 8313-2018. The results are shown in Table 1 below.

[0055] Table 1

[0056]

[0057]

[0058] Comparing Example 1 with Comparative Examples 1 and 2, the raw material ratio mainly affects the ratio of yeast to mold in the starter culture, which directly influences the saccharification and fermentation of the starter culture and is one of the key factors affecting the final quality of the liquor. Comparing Example 1 with Comparative Examples 3 and 4, it was found that the single-fermentation process, regardless of temperature, leads to the death of yeast in the starter culture and also results in an excessively low total ester content, both of which severely degrade the quality of the starter culture.

[0059] Example 3

[0060] A low-alcohol tea-infused wine with a complex tea and wine aroma is prepared through the following steps:

[0061] S5. Select plump, mold-free, and impurity-free corn, wheat, and sorghum with suitable moisture content and mix them evenly in a weight ratio of 1:1:1 as grain raw materials. Then, according to the general methods in the art, the grain raw materials are sequentially subjected to washing, soaking, steaming, and saccharification steps to obtain grain residue.

[0062] S6. Add 20% by mass of the tea wine-specific yeast prepared in Example 1 to the grain lees, and seal and ferment at about 27°C for 40 days to obtain the lees.

[0063] S7. Under aseptic conditions, add 40% by weight of mixed tea leaves of the grain raw materials to the fermented mash and mix well, then continue fermentation at around 27°C for 5 days;

[0064] S8. After fermentation, the wine is distilled using a three-stage distillation method. The wine obtained from the distillation is the tea wine product.

[0065] The mixed tea is obtained by mixing dried Ya'an Tibetan tea, Sichuan black tea, Gongmei tea and rock tea in a mass ratio of 10:3:3:3. The mixed tea has been sterilized before being added.

[0066] Comparative Example 5

[0067] The preparation of a tea wine differs from Example 3 in that, in S6, the yeast from Example 1 is replaced with commercially available Daqu (Shengyuan Biotechnology), while the other steps are the same.

[0068] Comparative Example 6

[0069] To prepare a tea wine, based on Comparative Example 5, the fermentation time in S7 was extended to 30 days.

[0070] Comparative Example 7

[0071] A tea-infused liquor was prepared, differing from Example 3 in that the mixed tea leaves were added before fermentation began. Specifically, 40% by weight of mixed tea leaves from the grain raw materials were added to the grain lees and stirred evenly. Then, the tea-infused liquor-specific yeast was added, and the mixture was directly sealed and fermented at approximately 27°C for 45 days, followed by distillation to obtain the liquor.

[0072] The tea wine products brewed in the above examples were subjected to sensory evaluation by professionals, and the evaluation results are shown in Table 2 below.

[0073] Table 2

[0074]

[0075]

[0076] The components of the tea wine were analyzed using two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC TOF MS) and liquid chromatography-mass spectrometry (LC-MS). Table 3 shows the relative flavor activity (ROAV) values ​​and aroma descriptions of the volatile components in the tea wine.

[0077] Table 3

[0078]

[0079] As shown in Table 2, the tea wine of Example 3 has a more unique flavor than wines brewed with conventional Daqu (a type of starter culture). Comparative Example 5 was brewed for the same time as Example 3, but its tea aroma was weaker, indicating a certain disadvantage. Comparative Example 6 had excellent aroma and taste, but its fermentation time was too long, making cost control difficult. Comparative Example 7 had a slightly different brewing process than Example 3, and also suffered from a weak tea aroma. According to Table 3, in Example 3, the aroma activity values ​​of substances producing rich aromas, such as ethyl isovalerate and ethyl hexanoate, were higher than those of Comparative Examples 5 and 6, while the aroma activity values ​​of fishy-smelling substances, such as dimethyl trisulfide, were lower. The tea wine provided by this invention has a more mellow flavor, with a more integrated and pronounced tea and wine aroma, forming a unique tea wine quality superior to Comparative Examples 5-7.

[0080] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for preparing a special yeast starter for tea and wine, characterized in that, Includes the following steps: S1. Raw material preparation: By weight, take 4-8 parts of barley, 85-95 parts of wheat and 2-5 parts of tea, mix them evenly and then crush them, and adjust the moisture content to 50-70% to obtain the raw materials for making koji. S2. Forming the blank: The raw materials for making koji are made into koji blanks; S3. Curing of the koji blank: The koji blank is placed at 20℃ or 22℃ and cultured until the temperature of the koji blank is constant; S4. Secondary fermentation: The temperature is raised to 45-50℃ to carry out secondary fermentation of the koji blank until the moisture content of the koji blank drops to 12-15%, thereby obtaining a koji blank containing theanine and tea polyphenols for tea wine. The koji blanks obtained after the second fermentation do not need to be stored; In S3, the constant temperature of the koji blank is used as the criterion for judging the completion of aerobic respiration and the depletion of oxygen, while in S4, anaerobic fermentation is carried out.

2. The method for preparing a special yeast for tea and wine according to claim 1, characterized in that, In S1, the tea includes at least two of the following: green tea, oolong tea, black tea, white tea, dark tea, or yellow tea.

3. The method for preparing a special yeast for tea and wine according to claim 1, characterized in that, In S1, the fineness of the raw materials for making koji is 50-80 mesh.

4. The method for preparing a special yeast for tea and wine according to claim 1, characterized in that, In S2, the size of the blank is 20-30cm × 15-20cm × 10-15cm.

5. The method for preparing a special yeast for tea and wine according to claim 1, characterized in that, In S2, the method for making the blank is mechanical pressing or manual treading.

6. A special yeast for tea and wine prepared according to any one of claims 1-5.

7. The application of the tea-wine-specific yeast as described in claim 6 in the brewing of tea wine.

8. The application of the tea-and-wine-specific yeast according to claim 7 in the brewing of tea-and-wine includes using the tea-and-wine-specific yeast as a fermenting agent to prepare a tea-and-wine-fragrant composite tea-and-wine, the preparation method of the tea-and-wine-fragrant composite tea-and-wine-fragrant ... High-quality grain raw materials are selected and then subjected to washing, soaking, steaming and saccharification steps to obtain grain residue; Add the tea-wine-specific yeast to the grain lees, seal and ferment for 40-50 days to obtain the lees; Under aseptic conditions, add the mixed tea leaves to the fermented mash and stir well, then continue fermentation for 3-7 days under the same conditions; After fermentation, the alcohol is distilled.

9. The application of the tea-wine-specific yeast according to claim 8 in the brewing of tea wine, characterized in that, The amount of the tea-wine-specific yeast added is 15-25% of the mass of the grain residue.

10. The application of the tea-wine-specific yeast according to claim 8 in the brewing of tea wine, characterized in that, The mixed tea is obtained by mixing yellow tea, black tea, red tea and white tea in a mass ratio of 10-20:1-10:2-12:2-10.

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