Rhodotorula mucilaginosa northern 29, application thereof and wine brewing method

Abstract

The invention relates to the technical field of beverage wine brewing, in particular to rhodotorula mucilaginosa northern 29, application thereof and a wine brewing method. The rhodotorula mucilaginosa North 29 is preserved in the China Center for Type Culture Collection in December 2013, and the preservation number is CCTCC NO: M2013660. Compared with traditional mixed fermentation of saccharomyces cerevisiae and non-saccharomyces cerevisiae, the process has the remarkable advantages in the aspects of fermentation thoroughness and aroma: in the aspect of fermentation, complete alcohol fermentation of the saccharomyces cerevisiae can be promoted; in the aspect of aroma, the content of C13-norisoprene compounds, terpenes and other compounds is remarkably increased, and the wine is endowed with richer fruit aroma and flower aroma. The method is suitable for the brewing process of various grapes and fruit wine, especially shows a remarkable aroma enhancement effect in raw materials with relatively low aroma precursor content, and has a good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of beverage brewing technology, and in particular to a type of red yeast rice (North 29), its application, and a method for brewing wine. Background Technology

[0002] In recent years, global warming has led to a significant increase in heat resources in agricultural production areas, which has noticeably impacted the growth and ripening of grapes. In most major grape-producing regions, the average temperature during the ripening period has increased by approximately 2-3°C compared to previous years, resulting in faster sugar accumulation and a decrease in organic acid content, creating a typical "high sugar, low acid" characteristic. This trend has been verified in continuous monitoring in Ningxia, Shandong, Xinjiang, and other regions. Climate warming has advanced the ripening period of grapes, causing a mismatch between physiological and flavor maturation. While sugar content is high, the accumulation of aroma precursors, especially terpenes and C, is insufficient. 13 - The limited formation of aroma compounds such as norisoprene is one of the main reasons for the current decline in the aroma quality of wine.

[0003] Under these raw material conditions, the metabolic activity and aroma synthesis capacity of yeast are easily affected during the winemaking process. On the one hand, a high sugar-acid ratio and ethanol accumulation can cause changes in cell membrane permeability, affecting substance transport and energy metabolism; on the other hand, reduced acidity weakens the release and retention of aroma compounds, resulting in a wine with a single aroma and insufficient complexity. With the intensification of global warming, "sugar-acid imbalance and insufficient aroma" has become a common technical problem in the wine industry.

[0004] To improve aroma characteristics, existing research mainly focuses on fermentation process control, such as temperature-controlled fermentation, cold maceration, optimized fermentation sequence, and the addition of active non-Saccharibrew yeasts or nutrient sources. These methods can promote the formation of fermentation aroma compounds (such as acetates and fatty acid ethyl esters) to some extent, but they are less effective for varietal aroma compounds (such as terpenes, C...). 13 The promoting effect of norisoprene is limited. Meanwhile, active co-fermentation systems suffer from intermicrobial competition and poor system stability; the use of nutrients and enzymes also increases costs and may alter the natural flavor balance of the wine. Therefore, current technologies still struggle to simultaneously achieve the dual goals of fermentation stability and varietal aroma enhancement. To address this issue, a new winemaking approach is urgently needed that can promote the comprehensive accumulation of aroma compounds and enhance the flavor profile and sensory quality of the wine without altering traditional processes. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a *Rhodotorula glutinis* North 29 yeast, its application, and a method for winemaking. Cell fragments of *Rhodotorula glutinis* North 29 are rich in carotenoids, polysaccharides, proteins, and flavor-related enzymes. In the fermentation system, these fragments can improve yeast fermentation performance, promote the accumulation of varietal aroma compounds and carotenoids, and enhance the overall flavor harmony of the wine through mechanisms such as adsorbing medium-chain fatty acids, alleviating ethanol stress, and promoting the conversion of aromatic precursors. Compared with traditional methods of adding live bacteria, this method offers advantages such as high stability, ease of operation, strong compatibility, and significant aroma enhancement, providing a new technical approach for high-quality winemaking in modern times.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a Rhodotorula mucilaginosa North 29 yeast, which was deposited at the China Center for Type Culture Collection in December 2013 with accession number CCTCCNO: M2013660.

[0008] The present invention also provides the application of the above-described red yeast rice 29 in increasing the carotenoid content in wine.

[0009] The present invention also provides the application of the aforementioned Red Yeast North 29 in improving the aroma content of wine.

[0010] Preferably, the aroma substances include terpenoids and C. 13 -One or more of the following: norisoprene, higher alcohols and benzene derivatives;

[0011] The terpenoid compounds include one or more of linalool, α-terpineol, citronellol, and nerol;

[0012] The C 13 -Norepinephrines include one or more of the following: edullan, isofluryn, β-damascone, trans-β-ionone, ginsenoynol and irisone;

[0013] The higher alcohols include one or more of isobutanol, isooctanol, 2,3-butanediol and 1-nonanol;

[0014] The benzene derivatives include phenethyl acetate and / or benzyl alcohol.

[0015] The present invention also provides a dry powder for winemaking, the preparation method of which includes the following steps:

[0016] 1) Ferment and culture the Rhodotorula glutinis North 29 described in the above technical solution, and collect the cells by centrifugation;

[0017] 2) The bacterial cells described in step 1) are disrupted and then freeze-dried to obtain dry powder.

[0018] Preferably, the fermentation conditions in step 1) include: culturing at 28°C and 160 rpm in a dark shaker for 180 h; and the inoculum size of the red yeast North 29 is 1×10⁻⁶. 6 CFU / mL; the fermentation medium used for the fermentation culture includes: sucrose as the carbon source, beef extract as the nitrogen source, a carbon-to-nitrogen ratio of 1.0, a sucrose concentration of 70 g / L, an ethanol concentration of 4% vol, and a pH of 3.5; the centrifugation conditions include: centrifugation at 4°C and 8000 rpm / min for 15 min;

[0019] Step 2) The freeze-drying conditions include: freeze-drying at -60℃ and 15kPa for 72h.

[0020] The present invention also provides a method for making wine, comprising the following steps:

[0021] 1) After destemming and crushing the grapes, mix them with sulfur dioxide and cold-soak them to obtain the soaking material;

[0022] 2) The impregnating material described in step 1) is mixed with pectinase, brewer's yeast, and the dry powder described in the above technical solution, and then fermented.

[0023] 3) When the specific gravity drops to 1.05, the pomace is separated to obtain a clear liquid. The clear liquid is then fermented. When the residual sugar is below 2 g / L, it is mixed with sulfur dioxide to obtain wine.

[0024] Preferably, the amount of sulfur dioxide added in step 1) is 60 mg / L;

[0025] The conditions for cold impregnation include: a temperature of 4°C and a time of 48–72 hours.

[0026] Preferably, the impregnating material in step 2) is heated to 20°C before being mixed with pectinase, brewer's yeast, and dry powder;

[0027] The mass ratio of the impregnating material to pectinase is 100:0.5;

[0028] The amount of brewing yeast added is 1×10 6 CFU / mL;

[0029] The amount of the dry powder added is 240 mg / L;

[0030] The fermentation conditions include a temperature of 18–20°C.

[0031] Preferably, the amount of sulfur dioxide added in step 3) is 60 mg / L.

[0032] The beneficial effects of this invention are:

[0033] 1) This invention provides a winemaking method using Rhodotorula glutinis North 29 dry powder. This method can significantly improve the fermentation performance of yeast in conventional grape must fermentation systems, reduce the risk of fermentation stagnation, and increase ethanol conversion efficiency.

[0034] 2) The process of this invention promotes the conversion of carotenoids into aromatic compounds, significantly increasing C 13 - The content of isoprene, terpenes and fruit esters is increased, and the characteristics of floral, sweet fruit and tropical fruit aromas are more prominent.

[0035] 3) The non-active dry powder used in this invention has high stability and good process compatibility. It does not require activation culture, is easy to operate and highly repeatable, and avoids the instability problem of antagonism between active co-fermentation bacteria.

[0036] 4) The process of this invention is applicable to a variety of wine raw materials and fermentation systems of different scales, and can stably obtain high-quality wines, and has good prospects for industrial promotion. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0038] Figure 1 This is a flowchart illustrating the technical process of the present invention.

[0039] Figure 2 The colony morphology and cell morphology of Rhodotorula glutinis North 29 were analyzed.

[0040] Figure 3 It is in the form of non-active dry powder of Rhodotorula glutinis North 29;

[0041] Figure 4 This is a comparison diagram of the fermentation kinetics of the process of this invention and the traditional process;

[0042] Figure 5 This is an aroma sensory analysis of the process of this invention and the traditional process.

[0043] Biological Preservation Instructions

[0044] Rhodotorula mucilaginosa, or Rhodotorula mucilaginosa North 29, was deposited on December 13, 2013, at the China Center for Type Culture Collection (CCTCC) with accession number CCTCC NO: M2013660, located at Wuhan University, Wuhan, China. Detailed Implementation

[0045] This invention provides a strain of Rhodotorula mucilaginosa, North 29, which was deposited in the China Center for Type Culture Collection (CCTCC) in December 2013 with accession number CCTCC NO: M2013660. In this invention, the Rhodotorula mucilaginosa North 29 strain was selected from soil samples from the vineyard of Great Wall Winery Co., Ltd. in the Shacheng wine region of Hebei Province. The colonies are orange-red, round, with neat edges and a smooth, glossy surface; the cells are oval or short rod-shaped, existing singly, in pairs, or in clusters. This strain exhibits strong environmental adaptability, is rich in polysaccharides, proteins, and carotenoids, and retains certain glycosidase and esterase activities after cell disruption, which can promote the formation of aroma compounds.

[0046] The present invention also provides the application of the above-described red yeast rice 29 in increasing the carotenoid content in wine.

[0047] This invention also provides the application of the aforementioned Red Yeast 29 in increasing the aroma content of wine. In this invention, the aroma substances preferably include terpenoids and C... 13 - One or more of norisoprene, higher alcohols, and benzene derivatives. In this invention, the terpene compounds include one or more of linalool, α-terpineol, citronellol, and nerol; the C 13 -The norisoprene class includes one or more of edulane, isofluryn, β-damascone, trans-β-ionone, ginsenoside alcohol, and irisone; the higher alcohols include one or more of isobutanol, isooctyl alcohol, 2,3-butanediol, and 1-nonanol; the benzene derivatives include phenethyl acetate and / or benzyl alcohol.

[0048] The present invention also provides a dry powder for winemaking, the preparation method of which includes the following steps:

[0049] 1) Ferment and culture the Rhodotorula glutinis North 29 described in the above technical solution, and collect the cells by centrifugation;

[0050] 2) The bacterial cells described in step 1) are disrupted and then freeze-dried to obtain dry powder.

[0051] In this invention, the preferred fermentation conditions include: culturing at 28°C and 160 rpm in a dark shaker for 180 h; and the inoculum size of the red yeast North 29 is 1 × 10⁻⁶. 6CFU / mL; the fermentation medium used for the fermentation culture includes: sucrose as the carbon source, beef extract as the nitrogen source, a C / N ratio of 1.0, a sucrose concentration of 70 g / L, an ethanol concentration of 4% vol, and a pH of 3.5; the centrifugation conditions include centrifugation at 4°C and 8000 rpm / min for 15 min. In this invention, the freeze-drying conditions preferably include freeze-drying at –60°C and 15 kPa for 72 h.

[0052] The present invention also provides a method for making wine, comprising the following steps:

[0053] 1) After destemming and crushing the grapes, mix them with sulfur dioxide and cold-soak them to obtain the soaking material;

[0054] 2) The impregnating material described in step 1) is mixed with pectinase, brewer's yeast, and the dry powder described in the above technical solution, and then fermented.

[0055] 3) When the specific gravity drops to 1.05, the pomace is separated to obtain a clear liquid. The clear liquid is then fermented. When the residual sugar is below 2 g / L, it is mixed with sulfur dioxide to obtain wine.

[0056] This invention involves destemming and crushing grapes, mixing them with sulfur dioxide, and then cold-macerating the mixture to obtain a macerating agent. This invention does not specify a particular grape variety; conventional varieties can be used. In this invention, the preferred amount of sulfur dioxide added is 60 mg / L. In this invention, the preferred cold-maceration conditions include a temperature of 4°C and a time of 48–72 hours.

[0057] In this invention, the impregnating material is mixed with pectinase, brewer's yeast, and the dry powder described in claim 5, and then fermented. In this invention, the impregnating material is preferably heated to 20°C before being mixed with the pectinase, brewer's yeast, and dry powder. In this invention, the mass ratio of the impregnating material to the pectinase is preferably 100:0.5. In this invention, the amount of brewer's yeast added is preferably 1×10⁻⁶. 6 The CFU / mL concentration of the brewing yeast is not specifically limited in this invention; conventional sources are acceptable. In this invention, the preferred amount of the dry powder added is 240 mg / L. In this invention, the preferred fermentation conditions include a temperature of 18–20°C. In this invention, the pectinase is sourced from: manufacturer: LALLEMAND, origin: France, model: LALLZYME EX.

[0058] To further illustrate the present invention, the following detailed description is provided in conjunction with embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0059] Example 1

[0060] A method for brewing wine using dried Red Yeast Rice North 29 powder, the process steps of which are as follows:

[0061] 1) Dry powder: The Rhodotorula glutinis North 29 dry powder used is derived from the preserved strain (CCTCC NO: M2013660). This strain was prepared into inactive dry powder through conventional liquid culture, cell disruption, and freeze-drying. The resulting dry powder is orange-red and can be directly used in wine fermentation systems;

[0062] Dry powder preparation:

[0063] Strain activation and expansion culture: Take 1 mL of Rhodotorula glutinis North 29 glycerol preservation solution and inoculate it into 10 mL of YPD medium (inoculation concentration 10%). Incubate at 28℃ for 24 h to activate. Then, transfer 10% of the inoculation into 100 mL of YPD medium and expand culture at 28℃ and 160 rpm / min in a dark shaker for 40-48 h.

[0064] Red yeast rice North 29 was used at 1×10 6 The inoculum was inoculated at a concentration of CFU / mL into fermentation medium (sucrose as carbon source, beef extract as nitrogen source, C / N ratio 1.0, sucrose concentration 70 g / L, ethanol concentration 4% vol, pH 3.5), and cultured for approximately 180 h in a dark shaker at 28 °C and 160 rpm / min. After culture, the culture was centrifuged at 4 °C and 8000 rpm / min for 15 min, the supernatant was discarded, and the cells were washed twice with 0.9% NaCl solution. The precipitate was collected, the cells were lysed, and then freeze-dried at -60 °C and 15 kPa for 72 h to obtain Rhodotorula glutinis North 29 powder.

[0065] 2) Raw material processing: Select mature wine grapes (Hutai No. 8, harvested in Xi'an, Shaanxi Province in 2023), destem and crush them, add 60 mg / L SO2, stir well, and cold-mash at 4℃ for 48 hours, then raise the temperature to 20℃. Add 0.5% pectinase by weight and mix well.

[0066] 3) Yeast activation: Weigh 0.02g of Saccharomyces cerevisiae SC-19 dry powder (strain derived from the preserved strain CCTCC NO: M2023128), inoculate it into 10mLYPD medium, and culture at 28℃ with shaking for 24h. Then, transfer it to 100mLYPD medium at a 5% inoculation rate and culture at 28℃ and 160r / min for 48h to obtain Saccharomyces cerevisiae fermentation broth.

[0067] 4) Fermentation Start: Ferment according to the natural sugar content of the raw materials, with an initial pH of 3.5. Add brewer's yeast fermentation broth (inoculum size 1×10⁻⁶) to the fermentation system. 6 Add 240 mg / L of dried red yeast rice powder (CFU / mL) and mix well.

[0068] 5) Fermentation control: Ferment at 18-20℃, monitoring temperature and specific gravity every 8 hours. When the specific gravity drops to 1.050, separate the skin and pulp, and continue the clear juice fermentation until the residual sugar is <2g / L.

[0069] 6) Storage: After fermentation, add 60 mg / L SO2, seal the container, and store it in a cold storage at 4℃.

[0070] The basic physicochemical indicators of the wine samples in this invention are based on GB / T15038-2006 General Analytical Methods for Wine and Fruit Wine.

[0071] The method for detecting aroma compounds in this invention refers to (Li, Y.-Q., Hu, K., Xu, Y.-H., Mei, W.-C., & Tao, Y.-S. (2020). Biomass suppression of hanseniaspora uvarum by killersaccharomyces cerevisiae highly increased fruity esters in mixed culturefermentation. LWT, 132, 109839. https: / / doi.org / 10.1016 / j.lwt.2020.109839), and the content of aroma compounds is detected using SPME-GC-MS. The aroma characteristics of the wine samples were analyzed using sensory evaluation methods, referring to (Kong, C., Li, A., Jin, G.-J., Zhu, X., & Tao, Y. (2019). Evolution of volatile compounds treated with selected non-saccharomyces extracellular extract during pinot noir winemaking in monsoon climate. Food Research International, 119, 177-186. https: / / doi.org / 10.1016 / j.foodres.2019.01.036).

[0072] The basic physicochemical index data of the wine samples of this invention are shown in Table 1:

[0073] Table 1. Basic physicochemical properties and carotenoid content of the tested wine samples

[0074]

[0075] Note: - indicates not detected; CK is traditional brewing; Mix is ​​processed with added red yeast rice powder (North 29).

[0076] As shown in Table 1, all physicochemical indicators meet the requirements of GB / T 15037-2006 "Wine" standard. Compared with the traditional process, the ethanol content of the wine sample obtained by the process of this invention is significantly increased, from 12.64% vol to 15.82% vol, indicating that the dry powder of *Rhodotorula glutinis* can promote more complete fermentation of brewing yeast and a higher ethanol conversion rate. The titratable acid content decreased slightly (from 6.05 g / L to 5.89 g / L), which is beneficial to maintaining the balance of acidity and taste of the wine. The volatile acidity decreased from 0.36 g / L to 0.29 g / L, indicating that the process can effectively inhibit the formation of undesirable acids and improve the purity of the wine. The lactic acid content did not change much, indicating that the process did not cause additional lactic acid accumulation; while the residual sugar content decreased significantly from 62.24 g / L to 0.42 g / L, fully demonstrating complete fermentation and high sugar utilization. The glycerol content increased slightly (from 14.73 g / L to 14.76 g / L), giving the wine a smoother and more mellow taste. The pH value remained stable (around 4.0), within the ideal range for fruit wine fermentation.

[0077] like Figure 4 As shown, the fermentation process of this invention proceeds more rapidly. Traditional processes still leave approximately 62.24 g / L of sugar residue after 14 days, while the process of this invention achieves complete fermentation by day 10, with residual sugar close to the detection limit. Under high sugar conditions (approximately 290 g / L), traditional brewing yeast is easily inhibited by osmotic pressure and ethanol accumulation, leading to delayed or halted fermentation. This invention, by adding inactive Resveratrol yeast powder, effectively alleviates high sugar stress, improves yeast metabolic activity and sugar utilization, thereby significantly shortening the fermentation cycle and increasing ethanol conversion efficiency.

[0078] Table 2. Content of aroma compounds in fruit wines obtained through different fermentation processes (μg / L)

[0079] compound CK Mix Terpenes 611±18 686±3 <![CDATA[C 13 -Norepinephrine]]> 33±1 71±8 higher alcohols 23712±748 31433±161 Acetates 16004±149 13916±423 Ethanol esters 1261±165 862±108 Other esters 10347±18 9397±82 fatty acid 3427±38 1973±34 benzene derivatives 32531±293 37119±26 Total 90850±1242 98117±1685

[0080] As shown in Table 2, the contents of various aroma compounds all meet the requirements of GB / T15037-2006 "Wine" standard. Compared with the traditional process, the total amount of aroma substances in the wine sample obtained by the process of this invention is increased from 90850 μg / L to 98117 μg / L, and the overall aroma composition is richer.

[0081] The process of this invention significantly promotes the production of terpenoids and C. 13The accumulation of norisoprene compounds increased from 611 μg / L and 33 μg / L to 686 μg / L and 71 μg / L, respectively. These two classes of substances have low odor thresholds and play a decisive role in the formation of floral, sweet fruit, and violet aromas. Simultaneously, the main alcohols and esters in the fermentation system were maintained at appropriate levels, resulting in a harmonious aroma and a more balanced flavor profile.

[0082] like Figure 5 As shown, wines produced using the process of this invention outperform those produced using traditional methods in overall sensory performance. Radar chart results indicate that the wines produced using this invention score higher in floral, sweet fruit, and tropical fruit aromas, exhibiting a richer, more harmonious aroma and more complex flavor profile. This invention's process, through the addition of Red Yeast Rice North 29 dry powder, effectively promotes the release and transformation of aromatic precursors, shifting the aroma characteristics of the fruit wine from a single fruity type to a complex blend of floral and fruity aromas, resulting in a smoother and more rounded palate. The wines produced using this process demonstrate excellent aroma concentration, balance, and persistence, indicating that this invention has significant technical advantages in enhancing the flavor and quality of wine.

[0083] Therefore, this invention relates to a method for winemaking based on the dry powder of Rhodotorula glutinis North 29. This method significantly improves the fermentation activity and sugar utilization of the wine yeast by adding inactive Rhodotorula glutinis dry powder at the initial stage of fermentation, resulting in a faster and more stable fermentation process and a significant reduction in residual sugar content. Compared with traditional processes, the wine obtained by this invention has a higher ethanol content and significantly improved flavor harmony and aroma complexity.

[0084] The process of this invention can promote the reaction of terpenes and C in fruit wine. 13 The formation of key aromatic compounds such as norisoprene compounds, along with the accumulation of carotenoids, gives the wine a richer floral and fruity aroma and a smoother, more rounded taste. Furthermore, this process achieves complete fermentation and flavor enhancement without altering the traditional fermentation process, demonstrating excellent industrial adaptability and potential for widespread application.

[0085] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A Rhodotorula mucilaginosa North 29, characterized in that, The Rhodotorula mucilaginosa Bei 29 is preserved in China Center for Type Culture Collection in December 2013, and the preservation number is CCTCC NO: M2013660.

2. The Rhodotorula mucilaginosa Bei 29 of claim 1 is applied to increase the content of carotenoids in grape wine.

3. The Rhodotorula mucilaginosa Bei 29 of claim 1 is applied to increase the content of aroma substances in grape wine.

4. Use according to claim 3, characterized in that, The aroma substances include one or several of terpenes, C 13 - one or several of pinenes, limonenes, myrcenes, caryophyllenes, ocimenes, pinene oxides, pinene alcohols, pinene aldehydes, pinene ketones, pinene esters, pinene ethers, pinene glycosides, pinene glycosides, pinene glycosides, pinene glycosides, pinene The terpenes include one or more of linalool, alpha-terpineol, citronellol and nerol; The C 13 - norisoprenoids include one or several of idurans, iso-eugenol, beta-damascenone, trans-beta-ionone, panasinsinol and iridin; The higher alcohols include one or more of isobutyl alcohol, isooctanol, 2,3-butanediol and 1-nonanol; The benzene derivatives include phenethyl acetate and / or benzyl alcohol.

5. A dry powder for brewing wine, characterized in that, The preparation method of the dry powder comprises the following steps: 1) The Rhodotorula mucilaginosa Bei 29 of claim 1 is subjected to fermentation culture, and the bacterial bodies are collected by centrifugation; 2) The bacterial bodies of step 1) are subjected to cell disruption and then freeze-drying to obtain a dry powder.

6. The dry powder of claim 5, wherein, Step 1) the fermentation culture conditions include: culturing for 180 h in a 28℃, 160 rpm dark incubator; the inoculation amount of the red yeast North 29 is 1 x 10 6 CFU / mL; the fermentation medium used in the fermentation culture includes: sucrose as the carbon source, beef extract as the nitrogen source, a carbon-nitrogen ratio of 1.0, a sucrose concentration of 70 g / L, an ethanol concentration of 4% vol, and a pH of 3.5; the centrifugation conditions include: centrifugation at 4℃, 8000 rpm / min for 15 min; The freeze-drying conditions of step 2) include freeze-drying at -60℃ and 15kPa for 72h.

7. A method of making wine, characterized by, The method comprises the following steps: 1) The grapes are crushed and mixed with sulfur dioxide and subjected to cold immersion to obtain an immersion material; 2) The immersion material of step 1) is mixed with pectinase, Saccharomyces cerevisiae and the dry powder of claim 5 and then subjected to fermentation; 3) When the specific gravity decreases to 1.05, the clear liquid is obtained by separating the skin residues, and the clear liquid is continuously fermented, mixed with sulfur dioxide when the residual sugar is lower than 2g / L to obtain grape wine.

8. The method of claim 7, wherein, The addition amount of sulfur dioxide of step 1) is 60mg / L; The cold immersion conditions include a temperature of 4℃ and a time of 48-72h.

9. The method of claim 7, wherein, The immersion material of step 2) is mixed with pectinase, Saccharomyces cerevisiae and dry powder after being heated to 20℃; The mass ratio of the immersion material to pectinase is 100:0.5; The addition amount of the S. cerevisiae is 1 x 10 6 CFU / mL; The addition amount of the dry powder is 240mg / L; The fermentation conditions include a temperature of 18-20℃.

10. The method of claim 6, wherein, The addition amount of sulfur dioxide of step 3) is 60mg / L.

Images