Method for improving fermentation stability and quality of mulberry wine

Abstract

The invention belongs to the technical field of fruit wine preparation, and provides a method for improving fermentation stability and quality of mulberry wine, and the method specifically comprises the following steps: selecting and pretreating raw materials; carrying out inoculation and culture by adopting filmed saccharomyces fibuligerus; fermentation conditions are controlled, yeast assimilable nitrogen, pectinase and glucosidase are added, intermittent stirring is carried out, and an anaerobic environment is changed along with increase of the alcohol concentration; after the fermentation is finished, carrying out multiple times of tank pouring, filtering, and adding a preservative and an antioxidant; finally, filtering by using diatomite, bottling, and sterilizing; according to the mulberry wine, the fermentation stability of the mulberry wine can be improved by using the filmed yeast; by adding yeast assimilable nitrogen, pectinase and glucosidase, the fermentation environment can be optimized, the growth and metabolism of yeast are promoted, and the instability in the fermentation process is reduced; and through ageing and cold stabilizing treatment, the wine body can be more mature and mellow, and the taste is richer.

Description

Technical Field

[0001] The invention belongs to the technical field of fruit wine preparation, in particular to a method for improving the fermentation stability and quality of mulberry wine. Background Art

[0002] Mulberry is the fruit of mulberry tree, also known as mulberry fruit. The special growth environment of mulberry makes mulberry fruit grow naturally without any pollution, so mulberry is also called "folk holy fruit". Mulberry contains rich active protein, vitamins, amino acids, carotene, minerals and other ingredients, has multiple functions, and is praised by the medical community as "the best health fruit of the 21st century". Eating mulberry regularly can significantly improve human immunity, delay aging, and beautify the skin.

[0003] Fruit wine has a long history of brewing. It is a wine made by fermenting the sugar in the fruit itself into alcohol by yeast, and it contains the flavor of fruit. Fruit wine is rich in vitamins and amino acids, vitamins B1, B2, vitamin C, and mineral elements such as iron, potassium, magnesium, and zinc that the human body needs. Its alcohol content is very low compared to liquor and wine. Compared with other alcoholic beverages such as liquor and beer, fruit wine contains a large amount of polyphenols, which can inhibit the accumulation of fat in the human body. In addition, fruit wine also has a good effect of caring for the heart and regulating emotions.

[0004] Mulberry wine is the best fruit wine. It contains 18 kinds of amino acids and multiple trace elements required by the human body, including almost all the nutrients in red wine. It has the effects of nourishing, nourishing the body and replenishing blood. After drinking, it can not only improve the condition of cold hands and feet, but also has the effects of replenishing blood, strengthening the body, benefiting the liver, nourishing the kidneys, and improving eyesight.

[0005] However, traditional winemaking methods mostly use natural fermentation or common yeasts, which often have limitations in alcohol tolerance and fermentation efficiency. Many conventional yeasts are easily inhibited at high alcohol concentrations, resulting in incomplete or stagnant fermentation, affecting the yield and quality of the wine. At the same time, some yeasts will produce excess membranes during the fermentation process, causing the wine to be turbid and unstable, which in turn affects the sensory characteristics of the wine; and the traditional brewing method has a relatively simple regulation of the fermentation environment, which fails to effectively meet the growth and metabolic needs of yeast, resulting in insufficient production of flavor substances during fermentation, which greatly reduces the taste and aroma of the final wine. In addition, the byproducts produced by yeast metabolism and changes in enzyme activity may also cause the flavor of the wine to deteriorate or become unstable; and in traditional methods, there is a lack of effective measures to resist oxidation and enhance the flavor of the wine, which causes the wine to be easily oxidized during storage and transportation, losing its original flavor and quality.

[0006] Therefore, those skilled in the art have proposed a method for improving the fermentation stability and quality of mulberry wine. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a method for improving the fermentation stability and quality of mulberry wine to solve the problems raised in the background technology.

[0008] A method for improving the fermentation stability and quality of mulberry wine, comprising the following steps:

[0009] S1. Select fresh mulberries with moderate maturity and no pests and diseases as raw materials, and pre-treat the mulberries, including removing stems and crushing;

[0010] S2, streak the capsule-coated yeast onto a solid medium containing yeast extract, peptone and glucose (YPD), and then pick a single colony and inoculate it into a liquid medium containing YPD;

[0011] S3, centrifuge the obtained bacterial solution at 4°C and 3000r / min for 10min, discard the supernatant, resuspend the bacterial cells and centrifuge again to obtain the precipitate;

[0012] S4, pouring the processed fruit juice into a fermentation container, inoculating activated capsule-covered yeast, and adding yeast assimilable nitrogen YAN, pectinase and glucosidase;

[0013] S5. During fermentation, the temperature is maintained at 20-30°C, and oxygen supply is increased by intermittent stirring in the early stage of fermentation. As the alcohol concentration increases, the environment is switched to an anaerobic environment. When the alcohol content is no longer changed, the fermentation is terminated.

[0014] S6. After the alcohol fermentation is completed, the mulberry wine is poured into the tank for the first time to separate the wine and the sludge, so that the wine in the fermentation tank is full, and a one-way valve is used to seal it. The residual sugar fermentation is carried out at 20° C. for 10-30 days, and then activated bentonite is added in an amount of 0.4-1 g / L. After stirring evenly, it is allowed to stand for 2-7 days to clarify the wine;

[0015] S7. After the residual sugar fermentation is completed, the second tank is poured to separate the wine and the sediment, and 0.05-0.1g / L potassium pyrosulfite and 0.1-0.3g / L grape seed extract are added and stirred evenly; the mulberry wine is sealed in a stainless steel tank and aged for 2-3 months;

[0016] S8, after aging for 2-3 months, the third canning is performed, 0.2 g / L lysozyme is added, and the mulberry wine is sealed in the can and cold stabilized for 4-6 months, and unstable substances are precipitated and removed by low-temperature freezing;

[0017] S9. Use diatomaceous earth to filter, and then add 0.05-0.1g / L potassium metabisulfite after filtration. When bottling, the filtered mulberry wine should be aseptically filled. The bottled mulberry wine should be aged in a cool and ventilated place for at least 6 months.

[0018] Preferably, the mulberries are first soaked in light salt water for 5-10 minutes and then cleaned; the mulberries are screened before crushing, and the screened mulberries are blanched in 60°C hot water for 30 seconds; the mulberries are dried after blanching, and after crushing, the pomace is removed by juicing and filtering.

[0019] Preferably, the capsule-coated yeast is streaked onto a YPD solid culture medium and cultured at 26° C. for 20 h, a single colony is picked and inoculated into a YPD liquid culture medium and cultured at 26° C. and 150 r / min for 20 h.

[0020] Preferably, the yeast assimilable nitrogen YAN is added in an amount of 240 mg / L, the pectinase is added in an amount of 0.03 g / L, and the glucosidase is added in an amount of 0.1-0.3 g / L.

[0021] Preferably, when the processed fruit juice is poured into a fermentation container, the liquid volume of the fermentation container is 175 mL / 250 mL, the inoculation amount of the capsule-coated yeast is 2%, and the fermentation is carried out at 28° C. for 12 days.

[0022] Preferably, when the tank is emptied for the first time, the fermented liquid is taken out, coarsely filtered with 7 layers of gauze, and then sterilized in a constant temperature water bath at 65-85° C. for 30 minutes.

[0023] Preferably, the bottling is performed by pasteurization at a constant temperature of 60-70°C for 20-30 minutes; or by ultra-high temperature instantaneous sterilization at 131.5°C for 2-4 seconds.

[0024] Preferably, after the pretreatment of the mulberry juice is completed, 60 mg / L potassium metabisulfite is added to adjust the sugar content to 18° Bx, and citric acid is used to adjust the pH to 3.5-4.5.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention helps to improve the fermentation stability of mulberry wine by using capsule-coated yeast; and optimizes the fermentation environment, promotes yeast growth and metabolism, and reduces instability during the fermentation process by adding yeast assimilable nitrogen, pectinase and glucosidase.

[0027] 2. The present invention can not only enhance the antioxidant capacity of the wine, but also improve the taste and flavor of the wine by adding grape seed extract during the fermentation process; and through aging and cold stabilization treatment, the wine can be made more mature, mellow and have a richer taste.

[0028] 3. The present invention embodies the innovative development of the brewing industry by combining traditional brewing technology with modern biotechnology and can promote the development of the entire industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flow chart of a method for improving the fermentation stability and quality of mulberry wine;

[0030] Figure 2 A line graph showing the effect of the yeast inoculation amount on the alcohol content and sensory score of mulberry wine of the present invention;

[0031] Figure 3 A line graph showing the effect of the material-liquid ratio on the alcohol content and sensory score of the mulberry wine of the present invention;

[0032] Figure 4 It is a line graph showing the effect of the fermentation temperature on the alcohol content and sensory score of mulberry wine of the present invention. DETAILED DESCRIPTION

[0033] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0034] As attached Figure 1 As shown:

[0035] Embodiment 1: The present invention provides a method for improving the fermentation stability and quality of mulberry wine, which specifically comprises the following steps:

[0036] S1. Select fresh mulberries with moderate maturity and no pests and diseases as raw materials, and pre-treat the mulberries, including cleaning, stem removal, and crushing; soak the mulberries in light salt water for 5-10 minutes before cleaning; screen the mulberries before crushing, and blanch them in 60℃ hot water for 30 seconds to kill surface microorganisms and reduce contamination by bacteria; dry the mulberries after blanching to prevent unnecessary fungi from being produced or causing turbidity in the subsequent fermentation process; and after crushing, remove the pomace by squeezing and filtering, and crushing facilitates better release of juice and promotes the role of yeast in the fermentation process. After the pretreatment of the mulberry juice is completed, add 60mg / L potassium metabisulfite, adjust the sugar content to 18°Bx, and adjust the pH to 3.5-4.5 with citric acid. Potassium metabisulfite, as an antioxidant and antibacterial agent, can effectively protect the wine from oxidation and reduce contamination by bacteria.

[0037] S2, streak the capsule-covered yeast onto the yeast extract powder peptone glucose YPD solid medium, then pick a single colony and inoculate it into the YPD liquid medium; streak the capsule-covered yeast onto the YPD solid medium, culture it at 26℃ for 20h, pick a single colony and inoculate it into the YPD liquid medium, and culture it at 26℃ and 150r / min for 20h. The capsule-covered yeast can produce more lipids and alcohols, giving the mulberry wine a richer aroma and taste.

[0038] S3, centrifuge the obtained bacterial solution at 4°C and 3000r / min for 10min, discard the supernatant, resuspend the bacterial cells and centrifuge again to obtain the precipitate;

[0039] S3. Pour the processed fruit juice into a fermentation container with a liquid volume of 175mL / 250mL, inoculate activated capsule-covered yeast, the capsule-covered yeast inoculation amount is 2%, and ferment for 12 days at 26°C; and add yeast assimilable nitrogen YAN, pectinase and glucosidase; the addition amount of yeast assimilable nitrogen YAN is 240mg / L, the addition amount of pectinase is 0.03g / L, and the addition amount of glucosidase is 0.1-0.3g / L. Yeast assimilable nitrogen YAN is used to improve the activity and fermentation efficiency of yeast, improve the flavor and quality of mulberry wine, pectinase is used to decompose pectin in mulberries, improve the clarity and aroma of wine, and glucosidase is used to decompose glucosides in mulberries to improve the aroma and flavor of wine.

[0040] S4. Keep the temperature at 26℃ during fermentation, and increase the oxygen supply through intermittent stirring in the early stage of fermentation to promote yeast reproduction. As the alcohol concentration increases, turn to an anaerobic environment to prevent aerobic microbial contamination and ensure smooth alcohol fermentation. When the alcohol content is no longer changing, stop the fermentation.

[0041] S5. After the alcohol fermentation is completed, the mulberry wine is poured into the tank for the first time to separate the wine and the sludge, so that the wine in the fermentation tank is full, the wine in the fermentation tank is full, the oxygen contact is reduced, and oxidation is prevented; and a one-way valve is used for sealing to release the generated carbon dioxide, and the residual sugar fermentation is carried out at 20°C for 10-30 days; then activated bentonite is added in an amount of 0.4-1g / L, stirred evenly and allowed to stand for 2-7 days to clarify the wine; by adding activated bentonite after the residual sugar fermentation, the suspended matter and sediment in the wine can be effectively removed to ensure the clarity and stability of the mulberry wine, and when pouring the tank for the first time, the fermented liquid at the end of fermentation is taken out, coarsely filtered with 7 layers of gauze, and then sterilized in a constant temperature water bath at 65-85°C for 30 minutes.

[0042] S6. After the residual sugar fermentation is completed, the second decanting is carried out to separate the wine and the sediment, and 0.05-0.1g / L potassium metabisulfite and 0.1-0.3g / L grape seed extract are added and stirred evenly; the addition of potassium metabisulfite and grape seed extract can effectively improve the antioxidant capacity of mulberry wine, extend the shelf life, and enhance the flavor and stability of the wine. Then the mulberry wine is sealed in a stainless steel tank for aging for 2-3 months.

[0043] S7. After aging for 2-3 months, the wine is emptied for the third time to remove the sediment and add 0.2g / L lysozyme to inhibit microbial activity and prevent the increase of volatile acid content. The wine is then sealed in a can and cold stabilized for 4-6 months. The unstable substances are precipitated and removed through low-temperature freezing to improve the stability and clarity of the wine.

[0044] S8. Use diatomaceous earth to filter and remove suspended matter and microorganisms. After filtering, add 0.05-0.1g / L potassium metabisulfite. When bottling, the filtered mulberry wine is aseptically filled. The bottled mulberry wine is aged in a cool and ventilated place for at least 6 months to make the wine more mellow. When bottling, pasteurization is also used at a constant temperature of 60-70℃ for 20-30 minutes, or ultra-high temperature instant sterilization is used at 131.5℃ for 2-4 seconds for sterilization.

[0045] From the above, we can see that the use of non-traditional brewing yeast capsule-coated yeast, which has strong alcohol tolerance and low film production, helps to improve the fermentation stability of mulberry wine. At the same time, the addition of yeast assimilable nitrogen YAN, pectinase and glucosidase can optimize the fermentation environment, promote yeast growth and metabolism, and reduce instability during the fermentation process; adding grape seed extract during the fermentation process can not only enhance the antioxidant capacity of the wine, but also improve the taste and flavor of the wine. In addition, through aging and cold stabilization treatment, the wine can be made more mature, rounder, and richer in taste; pasteurization or ultra-high temperature instantaneous sterilization before bottling can effectively kill microorganisms in the wine and extend the shelf life of mulberry wine. At the same time, adding an appropriate amount of potassium pyrosulfite as a preservative can also inhibit the growth of microorganisms and maintain the stability of the wine.

[0046] As attached Figure 2 To Attachment Figure 4 As shown:

[0047] Example 2: The single factor rotation method was used for the fermentation process of mulberry wine, and the effects of yeast inoculation amount (1%, 2%, 3%, 4%, 5%), mulberry to water ratio (100:0, 85:15, 70:30, 55:45, 40:60 (g:mL)) and fermentation temperature (22°C, 24°C, 26°C, 28°C, 30°C) on the alcohol content and sensory quality of mulberry wine were investigated in turn. The sensory evaluation was conducted by a review panel composed of 10 personnel who had undergone sensory training. The mulberry wine was evaluated from the aspects of color, aroma, taste and typicality, with a full score of 100 points. The sensory evaluation standards for mulberry wine are shown in the following table:

[0048]

[0049] Depend on Figure 2 It can be seen that when the yeast inoculation amount is 1% to 2%, the sensory score and alcohol content of mulberry wine gradually increase; when the yeast inoculation amount is 2%, the sensory score and alcohol content of mulberry wine are the highest, 83 points and 7.9% vol respectively; when the yeast inoculation amount is greater than 2%, the sensory score and alcohol content of mulberry wine gradually decrease. The reason may be that when the yeast inoculation amount is low, the fermentation speed is slow and the pre-fermentation time is long, resulting in a low alcohol content, affecting the flavor and taste; when the inoculation amount is high, too much yeast leads to too fast fermentation speed and too high center temperature, and the wine production rate decreases accordingly. At the same time, the cell wall adsorption of yeast will lead to a decrease in anthocyanin content, unstable wine color, and after the fermentation is completed, the wine has a strong yeast smell, affecting the taste and nutrients; therefore, the yeast inoculation amount is determined to be 2%.

[0050] Depend on Figure 3 It can be seen that when the material-liquid ratio is 40:60, 55:45, and 70:30 (g:mL), the alcohol content and sensory score of mulberry wine gradually increase; when the material-liquid ratio is 70:30 (g:mL), the alcohol content and sensory score of mulberry wine are the highest, 8.3% vol and 86 points respectively; when the material-liquid ratio is 70:30, 85:15, and 100:0 (g:mL), the alcohol content and sensory score of mulberry wine gradually decrease. The size of the material-liquid ratio will affect the coordination of the aroma and taste of the wine. When the material-liquid ratio is too low, the mulberry original juice is less, resulting in a weaker fruity aroma of the wine and poor typicality of the mulberry wine; when the material-liquid ratio is too high, the mulberry original juice is more, the wine is relatively viscous, the acidity is more prominent, and the sensory score is lower; therefore, the optimal material-liquid ratio is determined to be 70:30 (g:mL).

[0051] Depend on Figure 4It can be seen that as the fermentation temperature increases within the range of 22-24°C, the sensory score gradually increases; when the fermentation temperature is 24°C, the sensory score reaches a maximum of 87 points; when the fermentation temperature is greater than 24°C, the sensory score gradually decreases. As the fermentation temperature increases within the range of 22-26°C, the alcohol content gradually increases; when the fermentation temperature is 26°C, the alcohol content reaches a maximum of 8.57% vol; when the fermentation temperature is greater than 26°C, the alcohol content gradually decreases. When the fermentation temperature is too low, it is not only easy to be contaminated by bacteria, but also the yeast activity is low, the growth and reproduction rate is slow, resulting in insufficient fermentation, so the mulberry wine has a low alcohol content and a poor flavor; when the temperature is high, while inhibiting the metabolic capacity of microorganisms, it will also degrade anthocyanins in the fruit wine, resulting in low alcohol content, unstable color, and destroyed taste and ingredients. Therefore, the optimal fermentation temperature is determined to be 26°C.

[0052] From the above, we can see that the fermentation conditions suitable for the button capsule coated yeast were obtained through single factor experiments: yeast inoculation amount 2%, material-liquid ratio 70:30 (g:mL), and fermentation temperature 26°C.

[0053] Example 3: Determination of volatile flavor substances in the mulberry wine, the specific method is as follows:

[0054] Pretreatment: The extraction head was activated at the injection port of the gas chromatography-mass spectrometry (GC-MS) instrument for 25 minutes, 2.5 mL of mulberry wine was extracted from the middle of the sample bottle with a precision syringe and injected into a sealed headspace bottle with a magnetic stirrer, and then 3 g of NaCl was added. The temperature of the wine sample was controlled by adjusting the water bath with a constant temperature magnetic stirrer, and the activated extraction head was inserted into the headspace bottle for headspace extraction for 5 minutes. After the extraction time was reached, the extraction head was pulled out and inserted into the injection port of the gas chromatograph for desorption;

[0055] Gas chromatography conditions: carrier gas was high-purity helium (He), flow rate 1.00 mL / min; injection mode was splitless manual injection; injection port temperature was 250 °C; initial temperature was 40 °C and maintained for 3 min, then the temperature was raised to 230 °C at 5 °C / min and maintained for 10 min;

[0056] Mass spectrometry conditions: electron ionization (El) source; electron energy 70 eV; transfer line temperature 250 °C; ion source temperature 230 °C; quadrupole temperature 150 °C; scanning range 20-550 amu;

[0057] Qualitative and quantitative methods: Based on the parent ion information in the full scan image, the National Institute of Standards and Technology (NIST) MS Search2.3 database was used for substance identification. The detected components were qualitatively analyzed, and the relative content of each volatile flavor component was calculated by the peak area normalization method.

[0058] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, improvements, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0059] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0060] It should be understood that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but for those of ordinary skill having the benefit of this disclosure, without undue experimentation, the development effort will be a routine task of design, fabrication, and production.

[0061] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for improving the fermentation stability and quality of mulberry wine, characterized in that: The specific steps include: S1. Select fresh mulberries with moderate maturity and no pests and diseases as raw materials, and pre-treat the mulberries, including removing stems and crushing; S2, streak the capsule-coated yeast onto a solid medium containing yeast extract, peptone and glucose (YPD), and then pick a single colony and inoculate it into a liquid medium containing YPD; S3, centrifuge the obtained bacterial solution at 4°C and 3000r / min for 10min, discard the supernatant, resuspend the bacterial cells and centrifuge again to obtain the precipitate; S4, pouring the processed fruit juice into a fermentation container, inoculating activated capsule-covered yeast, and adding yeast assimilable nitrogen YAN, pectinase and glucosidase; S5. During fermentation, the temperature is maintained at 20-30°C, and oxygen supply is increased by intermittent stirring in the early stage of fermentation. As the alcohol concentration increases, the environment is switched to an anaerobic environment. When the alcohol content is no longer changed, the fermentation is terminated. S6. After the alcohol fermentation is completed, the mulberry wine is poured into the tank for the first time to separate the wine and the sludge, so that the wine in the fermentation tank is full, and a one-way valve is used to seal it. The residual sugar fermentation is carried out at 20° C. for 10-30 days, and then activated bentonite is added in an amount of 0.4-1 g / L. After stirring evenly, it is allowed to stand for 2-7 days to clarify the wine; S7. After the residual sugar fermentation is completed, the second tank is poured to separate the wine and the sediment, and 0.05-0.1g / L potassium pyrosulfite and 0.1-0.3g / L grape seed extract are added and stirred evenly; the mulberry wine is sealed in a stainless steel tank and aged for 2-3 months; S8, after aging for 2-3 months, the third canning is performed, 0.2 g / L lysozyme is added, and the mulberry wine is sealed in the can and cold stabilized for 4-6 months, and unstable substances are precipitated and removed by low-temperature freezing; S9. Use diatomaceous earth to filter, and then add 0.05-0.1g / L potassium metabisulfite after filtration. When bottling, the filtered mulberry wine should be aseptically filled. The bottled mulberry wine should be aged in a cool and ventilated place for at least 6 months.

2. A method for improving the fermentation stability and quality of mulberry wine as claimed in claim 1, characterized in that: The mulberries are first soaked in light salt water for 5-10 minutes and then cleaned; the mulberries are screened before crushing, and the screened mulberries are blanched in 60°C hot water for 30 seconds; the mulberries are dried after blanching, and after crushing, the pomace is removed by juicing and filtering.

3. A method for improving the fermentation stability and quality of mulberry wine as claimed in claim 1, characterized in that: The capsule-coated yeast was streaked onto a YPD solid culture medium and cultured at 26° C. for 20 h. A single colony was picked and inoculated into a YPD liquid culture medium and cultured at 26° C. and 150 r / min for 20 h.

4. A method for improving the fermentation stability and quality of mulberry wine as claimed in claim 1, characterized in that: The yeast assimilable nitrogen YAN added in an amount of 240 mg / L, the pectinase added in an amount of 0.03 g / L, and the glucosidase added in an amount of 0.1-0.3 g / L.

5. A method for improving the fermentation stability and quality of mulberry wine as claimed in claim 1, characterized in that: When the processed fruit juice is poured into the fermentation container, the liquid volume of the fermentation container is 175mL / 250mL, the inoculation amount of the capsule-coated yeast is 2%, and the fermentation is carried out at 28°C for 12 days.

6. A method for improving the fermentation stability and quality of mulberry wine as claimed in claim 1, characterized in that: When the tank is emptied for the first time, the fermented liquid is taken out, coarsely filtered with 7 layers of gauze, and then sterilized in a constant temperature water bath at 65-85° C. for 30 minutes.

7. A method for improving the fermentation stability and quality of mulberry wine as claimed in claim 1, characterized in that: The bottling process is pasteurized at a constant temperature of 60-70° C. for 20-30 minutes; or ultra-high temperature instantaneous sterilization is used at 131.5° C. for 2-4 seconds for sterilization.

8. A method for improving the fermentation stability and quality of mulberry wine as claimed in claim 1, characterized in that: After the pretreatment of the mulberry juice is completed, 60 mg / L potassium metabisulfite is added to adjust the sugar content to 18° Bx, and citric acid is used to adjust the pH to 3.5-4.5.

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