Fermented sparkling wine and preparation method thereof

Abstract

The invention relates to the technical field of wine production and processing, and in particular to a fermented sparkling wine and a preparation method thereof. The preparation method comprises the following steps: 1) primary fermentation: mixing glutinous rice, water, distiller's yeast and a No. 1 yeast agent, culturing at 22-32° C. for 20-30 hours, then lowering the culturing temperature to 18-20° C. until the alcohol content in the primary fermentation system reaches 12-18% by volume, ending the fermentation, discarding the solid after solid-liquid separation, and using the liquid as a base wine; 2) blending the base wine: blending the base wine with a sugar solution to achieve an alcohol content of 4.0-5.0% by volume, 130-150 g / L of reducing sugar, and 1-3 g / L of total acid in the base wine; and 3) secondary fermentation: mixing the No. 2 yeast agent with the blended base wine, and performing secondary fermentation at 12-20° C. After the fermentation is completed, collecting the supernatant to obtain the fermented sparkling wine. The fermented sparkling wine of the present invention does not use any additional additives, and thus the flavor is more harmonious and the bubbles are more fully and delicately associated to the greatest extent possible, and the bubble holding time can reach 10 to 15 minutes.

Description

Technical Field

[0001] The present invention relates to the technical field of wine production and processing, in particular to a fermented sparkling wine and a preparation method thereof. Background Art

[0002] Sparkling wine, also commonly known as sparkling wine or sparkling wine, contains carbon dioxide to create bubbles. Carbon dioxide can form naturally in the wine container through fermentation, or it can be artificially introduced. Sparkling wine has a lighter taste and generally has a hint of sweetness, making it more appealing to younger consumers. Sparkling rice wine, brewed from high-quality glutinous rice, is richer in vitamins, glucose, amino acids, and other nutrients than more common sake brewed from refined rice. Combined with the refreshing effect of carbon dioxide, it can refresh and relieve fatigue, stimulate the appetite, relieve summer heat, invigorate the blood, and nourish yin and kidney health. Currently, rice wine is the most common rice beverage on the market, with a relatively limited variety and flavors. Sparkling wine, on the other hand, is primarily fruit-flavored blends and sparkling sake. Fermented sparkling rice wine not only enriches the variety of rice wine beverages but also improves the taste and quality of sparkling wine.

[0003] Sparkling wines currently on the market can be divided into blended and fermented varieties. Blended sparkling wines are made by directly blending finished wines and adding carbon dioxide through artificial aeration. These blended sparkling wines often have an unbalanced, monotonous, and rough aroma and flavor, with low levels of flavor association, weak foam retention, and a less refined foam. They also have relatively low nutritional value and contain various additives. As people's pursuit of taste and health increases, these products are struggling to maintain their market position. Fermented sparkling wines, on the other hand, are fermented by mixing various raw materials. Nutrients are enriched and combined over a long period of time, resulting in a harmonious taste and flavor. The carbon dioxide generated by the fermentation process is fully integrated into the wine, resulting in a fine, long-lasting foam and ultimately excellent quality. Most existing fermented sparkling wines require adjusting the sugar content of the fermentation broth with juice, white sugar, or sucrose. This results in an unbalanced taste and a lack of freshness. Flavor and mouthfeel are key indicators of sparkling wine quality. At the technical level, the fermentation cycle of existing fermented sparkling wines is relatively long. Therefore, how to improve the taste and flavor of existing fermented sparkling wines while simplifying the fermentation conditions and shortening the production cycle is a current challenge. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a fermented sparkling wine and a preparation method thereof, so as to solve the problems in the prior art.

[0005] To achieve the above-mentioned and other related objectives, the present invention provides a method for preparing fermented sparkling wine, comprising the following steps:

[0006] 1) Primary fermentation: glutinous rice, water, distiller's yeast, and No. 1 yeast inoculum are mixed and incubated at 22-32° C. for 20-30 hours. The incubation temperature is then lowered to 18-20° C. until the alcohol content in the primary fermentation system reaches 12-18% vol. The fermentation is terminated, and the solid is discarded after solid-liquid separation, and the liquid is used as the base wine;

[0007] 2) Blending base wine: Blending base wine with the sugar solution to make the alcohol content in the base wine 4.0-5.0% vol, the reducing sugar content 130-150 g / L, and the total acid content 1-3 g / L;

[0008] 3) Secondary fermentation: Mix the No. 2 yeast agent with the prepared base wine and carry out secondary fermentation at 12-20°C. After the fermentation is completed, the supernatant is taken as the fermented sparkling wine.

[0009] As described above, the fermented sparkling wine and its preparation method of the present invention have the following beneficial effects: they do not contain any additives, have simple process conditions, and have a short production cycle (primary fermentation time is 10 to 15 days, and secondary fermentation time is 5 to 7 days). The developed product improves the flavor, bubble volume, and bubble retention of the sparkling wine, and has a harmonious aroma, rich nutrition, clarity, full body, refreshing taste, mellow and harmonious taste, and fine foam. They are the key to meeting consumers' growing demand for product quality and promoting the healthy, stable, sustainable, and rapid development of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Shown is a schematic diagram of the process for preparing yeast agent No. 1 and yeast agent No. 2 of the present invention.

[0011] Figure 2 Shown is a schematic diagram of the process for preparing the sugar solution of the present invention.

[0012] Figure 3 Shown is a schematic diagram of the primary fermentation process of the present invention.

[0013] Figure 4 Shown is a schematic diagram of the process of secondary fermentation in a bottle according to the present invention.

[0014] Figure 5 Shown is a schematic diagram of the process of secondary fermentation in a tank according to the present invention. DETAILED DESCRIPTION

[0015] The present invention provides a method for preparing fermented sparkling wine, comprising the following steps:

[0016] 1) Primary fermentation: glutinous rice, water, distiller's yeast, and No. 1 yeast inoculum are mixed and incubated at 22-32° C. for 20-30 hours. The incubation temperature is then lowered to 18-20° C. until the alcohol content in the primary fermentation system reaches 12-18% vol. The fermentation is terminated, and the solid is discarded after solid-liquid separation, and the liquid is used as the base wine;

[0017] 2) Blending base wine: Blending base wine with the sugar solution to make the alcohol content in the base wine 4.0-5.0% vol, the reducing sugar content 130-150 g / L, and the total acid content 1-3 g / L;

[0018] 3) Secondary fermentation: Mix the No. 2 yeast agent with the prepared base wine and carry out secondary fermentation at 12-20°C. After the fermentation is completed, the supernatant is taken as the fermented sparkling wine.

[0019] In certain embodiments of the present invention, the glutinous rice is cooked glutinous rice. In the present invention, the cooked glutinous rice is prepared by the following method: soaking the rice for 2 to 3 hours and then steaming the rice for 0.5 to 1 hour to obtain the cooked glutinous rice.

[0020] In certain embodiments of the present invention, the koji is rice koji, which is purchased from Kosei Sangyo Co., Ltd.

[0021] In certain embodiments of the present invention, Yeast No. 1 refers to a yeast obtained by the following method: culturing a strain purchased from CGMCC, numbered 2.1392, with the Latin name Saccharomyces cerevisia, at 22-32° C. until the alcohol content in the yeast fermentation environment reaches 15% vol or higher and the total acidity in the environment remains within 7 g / L. The strain isolated from the system at this time is Yeast No. 1.

[0022] The No. 1 yeast inoculant can be a liquid inoculant or a solid inoculant. In one embodiment, the No. 1 yeast inoculant is a liquid inoculant. The number of No. 1 yeast cells in the No. 1 liquid inoculant is ≥ 100 million cells / ml. The number of No. 1 yeast cells in the No. 1 solid inoculant is ≥ 100 million cells / g.

[0023] In certain embodiments of the present invention, the method for obtaining the No. 1 yeast liquid inoculum is as follows: after shaking culture of No. 1 yeast in yeast culture medium for 20 to 30 hours, standing at 0 to 5° C. to precipitate, and discarding the supernatant to obtain the No. 1 yeast liquid inoculum.

[0024] In the present invention, the yeast culture medium comprises 0.5-1.5 parts by weight of glutinous rice, 0.5-1.5 parts by weight of malt, 0.05-0.15 parts by weight of koji, and 2-4 parts by weight of water. The koji is rice koji purchased from Kosei Sangyo Co., Ltd.

[0025] In certain embodiments of the present invention, the weight ratio of the glutinous rice, water, distiller's yeast and No. 1 yeast agent is: 1: (1-1.5): (0.1-0.15): (0.1-0.15).

[0026] In certain embodiments of the present invention, the glutinous rice, water, wine yeast and No. 1 yeast agent are mixed and stirred for 20 to 30 minutes. The ventilation rate is 0.05 to 0.07 m 3 / min.

[0027] In certain embodiments of the present invention, the primary fermentation is carried out in a stainless steel tank.

[0028] In certain embodiments of the present invention, the primary fermentation is performed using a rice feeding method. Specifically, the rice feeding step comprises: first, mixing 60-80% by weight of glutinous rice with water, distiller's yeast, and yeast agent No. 1, and then incubating at 22-32°C for 20-30 hours. The remaining glutinous rice is then fed with rice on the third to fifth day after the addition of the ingredients.

[0029] In certain embodiments of the present invention, at the end of one fermentation, the total acid in the system is 4-8 g / L, the amino acid nitrogen is 0.1-0.3 g / L, the alcohol content is 14-16% vol, and the total sugar is ≤10 g / L.

[0030] In certain embodiments of the present invention, the method for preparing the sugar solution comprises the following steps:

[0031] 2-1) Mix cooked glutinous rice, water, and distiller's yeast, and saccharify at 60-70°C for 16-20 hours;

[0032] 2-2) Cooling to below 35°C and then performing filter press;

[0033] 2-3) The liquid obtained by filter pressing is decolorized and impurities removed to obtain a sugar solution.

[0034] In certain embodiments of the present invention, in step 2-1), the weight ratio of glutinous rice, water, and koji is (0.8-1.2) parts by weight: (1.2-1.6) parts by weight: (0.12-0.17) parts by weight.

[0035] In certain embodiments of the present invention, activated carbon is used for decolorization in step 2-3). The decolorization time is more than 4 hours. In certain embodiments of the present invention, diatomaceous earth is used for impurity removal.

[0036] The physical and chemical indicators of the sugar solution are total sugar 250-350g / L, total acid 0.5-1.5g / L, and amino acid nitrogen 0.1-0.2g / L.

[0037] The sugar content of the base wine is adjusted using the decolorized and impurity-removed sugar solution, which achieves the purpose of adjusting the total sugar content and avoids the use of additives. The taste of the sugar solution is more coordinated with the base wine of the first fermentation, reducing the impact on the flavor of the base wine.

[0038] In certain embodiments of the present invention, Yeast No. 2 refers to yeast obtained by the following method: a strain purchased from CGMCC, numbered 2.1392, with the Latin name Saccharomyces cerevisia, is cultured at 12-20° C. until the alcohol content in the yeast fermentation environment reaches 8% vol or higher and the total acidity in the environment is maintained within 5 g / L. The strain isolated from the system at this time is Yeast No. 2.

[0039] The No. 2 yeast inoculant can be a liquid or solid inoculant. In one embodiment, the No. 2 yeast inoculant is a liquid inoculant. The number of No. 1 yeast in the No. 2 liquid inoculant is ≥ 100 million cells / ml. The number of No. 2 yeast in the No. 2 solid inoculant is ≥ 100 million cells / g.

[0040] In certain embodiments of the present invention, the method for obtaining the No. 2 yeast liquid inoculum is as follows: after shaking culture of No. 2 yeast in yeast culture medium for 20 to 30 hours, standing at 0 to 5° C. to precipitate, and discarding the supernatant to obtain the No. 2 yeast liquid inoculum.

[0041] In certain embodiments of the present invention, the blended base wine is sterilized at 70-90° C. and cooled to below 25° C. before being mixed with the No. 2 yeast agent.

[0042] In certain embodiments of the present invention, the inoculation amount of yeast agent No. 2 is 0.2-0.5%.

[0043] In certain embodiments of the present invention, the secondary fermentation temperature is 12-20°C.

[0044] Secondary fermentation can be done in a tank or in a bottle under pressure.

[0045] The fermentation method of pressure fermentation in the tank is: after mixing the No. 2 yeast agent with the prepared base wine, the fermentation is terminated when the pressure in the tank reaches 0.2-0.3MPa. After the fermentation is completed, the supernatant is taken out for pressure filling and sterilization to obtain the fermented sparkling wine.

[0046] Fermentation is terminated when the pressure reaches 0.2-0.3 MPa. At this point, gas production is moderate, presenting no safety issues. The foam can last for 10-15 minutes, and the foam is moderately strong and continuous during drinking. Excessive pressure not only poses a safety hazard when opening the bottle, but also causes gas to escape quickly after pouring into the glass, resulting in poor foam retention and a less elegant and harmonious taste.

[0047] In one embodiment, the sterilization method is heating at 70-90° C. for 20-30 minutes.

[0048] In-bottle pressure fermentation takes place directly within pressure-resistant bottles. Compared to closed tank fermentation, pressure bottles eliminate the need for high-pressure fermentation and filtration equipment, as well as pressure-resistant, low-temperature bottling equipment. This eliminates the need for significant equipment investment, further reducing process costs and making it an ideal choice for small-batch production of this sparkling wine.

[0049] The bottle pressure fermentation method comprises mixing a No. 2 yeast culture with the prepared base wine, fermenting for 4-6 days, terminating the fermentation, and sterilizing to obtain a fermented sparkling wine. Preferably, the fermentation temperature is lowered to 12-17°C after incubation at 18-20°C for 20-25 hours.

[0050] The fermented sparkling wine has an alcohol content of 5-6% vol, a reducing sugar content of 110-130 g / L, and a total acid content of 3-4 g / L.

[0051] In one embodiment, the method for preparing the fermented sparkling wine further comprises cooling the fermented sparkling wine sterilized in the secondary fermentation and then freezing and clarifying it at 0-5° C. This step allows the yeast mud to precipitate and increases the solubility of carbon dioxide in the wine.

[0052] The present invention also provides fermented sparkling wine obtained by the preparation method.

[0053] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0054] Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific specific embodiments described below; it should also be understood that the terms used in the examples of the present invention are for describing specific specific embodiments rather than for limiting the scope of protection of the present invention; in the present specification and claims, unless otherwise expressly stated herein, the singular forms "a", "an" and "the" include plural forms.

[0055] When numerical ranges are given in the examples, it should be understood that, unless otherwise specified herein, both endpoints of each numerical range and any value between the two endpoints may be used. Unless otherwise defined, all technical and scientific terms used in this invention have the same meanings as those commonly understood by those skilled in the art. In addition to the specific methods, equipment, and materials used in the examples, any methods, equipment, and materials in the prior art that are similar or equivalent to those described in the examples of this invention may also be used to implement the present invention, based on the prior art knowledge of those skilled in the art and the description of this invention. The detection methods of the present invention for total sugar, total acid, amino acid nitrogen, and alcohol content refer to: GB / T 13662-2018.

[0056] The preparation method of the fermented sparkling rice wine of the present invention comprises the following steps: first, using glutinous rice as a raw material and using No. 1 yeast to carry out primary fermentation to a target alcohol content; second, using glutinous rice as a raw material to prepare a sugar solution required for sugar adjustment; performing solid-liquid separation on each of the solutions; and uniformly mixing the solutions to achieve a target index before secondary fermentation; then, introducing No. 2 yeast as a fermentation strain, carrying out liquid fermentation in a closed tank, and performing pressure filling after reaching a target pressure; and sterilizing the fermented sparkling wine with harmonious flavor, clear body, fine foam and strong foam retention. The fermentation conditions are simple and time-saving, the process is stable, and the final index is controllable, thereby avoiding the problems of thin taste and unharmonious body caused by various additives. The wine can also maintain a long shelf life after sterilization.

[0057] Example 1 process flow

[0058] 1. Yeast Culture

[0059] (1) Yeast No. 1 is used as the strain for the primary fermentation, and yeast No. 2 is used as the strain for the secondary fermentation. Both yeast No. 1 and yeast No. 2 have been screened. The method for obtaining yeast No. 1 is as follows: the strain purchased from CGMCC, numbered 2.1392, with the Latin name Saccharomyces cerevisia, is acclimated and cultured at 22-32°C until the alcohol content in the yeast fermentation environment reaches 17% vol or more and the total acidity in the environment is maintained within 7 g / L. At this time, the strain in the separation system is yeast No. 1. The method for obtaining yeast No. 2 is as follows: the strain purchased from CGMCC, numbered 2.1392, with the Latin name Saccharomyces cerevisia, is acclimated and cultured at 12-20°C until the alcohol content in the yeast fermentation environment reaches 8% vol or more and the total acidity in the environment is maintained within 5 g / L. At this time, the strain in the separation system is yeast No. 2. The two yeasts were respectively subjected to fermentation control experiments with the 2.1392 strain. Through the glutinous rice wine fermentation control experiment, it was found that at a temperature of 25°C and the same fermentation time, yeast No. 1 had relatively strong fermentation activity, higher alcohol production and better flavor evaluation, and was therefore used as the yeast for the primary fermentation stage. Through the glutinous rice wine fermentation control experiment, it was found that at a temperature of 15°C and the same fermentation time, yeast No. 2 had relatively higher pressure generation rate and final pressure during the pressurized fermentation process, that is, it had a stronger ability to convert sugars into gas, and was therefore used as the yeast for the secondary fermentation stage.

[0060] (2) Preparation of yeast culture medium:

[0061] Raw materials Weight ratio Sticky rice 1 part by weight Malt (physical crushing) 1 part by weight yeast 0.1 parts by weight water 3 parts by weight

[0062] Soak rice for 2 hours, steam for 0.5-1 hour until cooked through, and cook according to the recipe above. The koji is rice koji purchased from Kosei Sangyo Co., Ltd. After mixing, bring the mixture to approximately 45°C and place in an incubator for saccharification at 65°C for 20 hours. After cooling naturally to below 35°C, filter press to obtain a yeast culture. The physicochemical properties of the filtered yeast culture are: total sugar 112 g / L, total acid 1.87 g / L, amino acid nitrogen 0.6 g / L, pH 5.2, and sugar content 14.21.

[0063] (3) The yeast culture medium was diluted and sterilized at a dilution ratio of yeast culture medium: water = 3:1, and used for inoculation of yeast No. 1 and yeast No. 2. The physical and chemical indicators of the yeast culture medium after dilution were total sugar 82 g / L, total acid 1.41 g / L, amino acid nitrogen 0.47 g / L, pH 5.18, and sugar content 10.51.

[0064] (4) After inoculating yeast No. 1 and yeast No. 2 in the yeast culture medium, place it in a 25°C incubator for shaking culture for 24 hours and set aside.

[0065] 2. Base wine brewing (primary fermentation)

[0066] Using regular glutinous rice to brew rice wine as the base wine, the steps are as follows:

[0067] (1) During the primary fermentation, yeast No. 1 was selected, and the target fermentation endpoint was controlled to an alcohol content of 15% vol.

[0068] (2) The No. 1 yeast solution obtained by the above culture was allowed to settle at 4°C, and the supernatant was discarded to ensure that the number of yeast in the final yeast culture solution was ≥ 100 million / ml. This is to obtain the No. 1 yeast liquid inoculum for use.

[0069] (3) Primary fermentation ingredients

[0070]

[0071]

[0072] (5) Fermentation process:

[0073] First, 70% by weight of glutinous rice is soaked for 2 hours, steamed for 0.5 to 1 hour until cooked, and then cooked according to the recipe, with ventilation and stirring for 20 minutes. After incubation at 25°C for 24 hours, the indicators are tested, including alcohol content, reducing sugar, total acid, amino acid nitrogen, pH value, and yeast count. The remaining 30% of glutinous rice is soaked and steamed, and then fed with rice on the third and fifth days of feeding. Thereafter, the culture is switched to 20°C according to the fermentation situation, and the indicators are tracked daily. The final fermentation time is 10 days, and the target alcohol content is 15.0%vol. After solid-liquid separation, rice wine is brewed as the base wine.

[0074] 3. Sugar Solution Preparation

[0075] (1) Sugar solution preparation ingredients

[0076] Raw materials Proportion Sticky rice 1 part by weight water 1.4 parts by weight yeast 0.15 parts by weight

[0077] (2) Soak the rice for 2 hours, steam it for 0.5-1 hour until it is cooked through, and then cook it according to the recipe. The mixing temperature of the rice is about 60℃, and it is placed in a constant temperature incubator at 65℃ for saccharification for 16 hours. After it cools naturally to below 35℃, it is filtered.

[0078] (3) The sugar solution is decolorized using activated carbon for ≥4 hours, and then filtered with diatomaceous earth to remove impurities to reduce the impact on the base wine.

[0079] (4) The physical and chemical indicators of the sugar solution are total sugar 280g / L, total acid 0.46g / L, amino acid nitrogen 0.14g / L, pH 4.7, and sugar content 32.

[0080] 4. Indicator Allocation

[0081] (1) The base wine of the first fermentation was blended with sugar solution to achieve the target alcohol content and sugar content. The initial blending targets before the second fermentation were: alcohol content 4.5% vol, reducing sugar 140 g / L, and total acid 2 g / L.

[0082] (2) After the primary fermented rice wine is filtered and clarified, it is mixed with the decontaminated and decolorized sugar solution. After the mixture is completed, it is sterilized at 80°C and inoculated after cooling.

[0083] 5. Tank fermentation (secondary fermentation)

[0084] (1) During the secondary fermentation, yeast No. 2 is selected. The No. 2 yeast solution obtained by culture is allowed to settle at 0-5°C, and the supernatant is discarded to obtain a No. 2 yeast liquid inoculum, wherein the number of yeasts is ≥ 100 million / ml, which is set aside.

[0085] (2) The blended base wine is sterilized at 80°C, and when cooled to below 25°C, it is transferred to a pressure-resistant stainless steel fermentation tank and inoculated with No. 2 yeast at an inoculation rate of 0.3%.

[0086] (3) After culturing at 20°C for 24 hours, the fermentation temperature was changed to 15°C and the fermentation time was 5 days. During this period, the gas pressure in the tank was observed by a pressure gauge. The fermentation was terminated when the pressure reached 0.3 MPa.

[0087] (4) After fermentation, the supernatant is taken, filled under pressure, and sterilized at 80°C to obtain the finished product. After natural cooling, it is transferred to a freezer at about 4°C for clarification, which can also increase the solubility of carbon dioxide in the wine.

[0088] Pour 10 bottles of finished wine into tulip glasses and observe the bubble holding time. The bubble holding time of each parallel sample can reach 13 minutes. During the actual drinking process, the taste is moderate and the bubbles are fine and continuous.

[0089] 7. Bottle fermentation (secondary fermentation)

[0090] (1) During the secondary fermentation, yeast No. 2 is selected. The No. 2 yeast solution obtained by culture is allowed to settle at 0-5°C, and the supernatant is discarded to obtain a No. 2 yeast liquid inoculum, wherein the number of yeasts is ≥ 100 million / ml, which is set aside.

[0091] (2) The blended base wine is sterilized at 80°C and inoculated when cooled to below 25°C with an inoculation amount of 0.3%.

[0092] (3) Pressure-resistant bottles are used as containers for fermentation, which is suitable for high-end small-batch production. After culturing at 20°C for 24 hours, the fermentation temperature is changed to 15°C, and the fermentation time is 5 days. During this period, samples are taken to track and test physical and chemical indicators.

[0093] (4) After fermentation is complete, sterilize at 80°C to obtain the finished product. After natural cooling, transfer to a freezer at around 4°C for clarification, which can also precipitate the yeast mud and increase the solubility of carbon dioxide in the wine.

[0094] The sparkling rice wine prepared by the present invention consists solely of rice, water, rice koji, and two yeasts. The two yeasts, when used under different fermentation conditions, are more suitable for the environments of the two fermentation stages, respectively providing a higher alcohol content and greater gas production. This results in a richer flavor for the final product while keeping the overall fermentation cycle and energy consumption low. The primary fermentation stage lasts 10 to 15 days, and the secondary fermentation stage lasts 5 to 7 days. The preparation process is simple and time-saving, and the raw materials are all natural grains, effectively controlling costs. Natural fermentation controls the alcohol content, while using decolorized and decontaminated glutinous rice saccharification liquid to adjust the sugar content, avoiding the use of additional additives. This maximizes the harmonious flavor and the finer, more fully integrated, bubble-forming process, achieving a sustained bubble time of 10 to 15 minutes.

[0095] The above examples are intended to illustrate the embodiments disclosed herein and are not to be construed as limiting the present invention. In addition, the various modifications listed herein and variations of the methods in the invention will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. Although the present invention has been specifically described in conjunction with various specific preferred embodiments of the present invention, it should be understood that the present invention should not be limited to these specific embodiments. In fact, various modifications apparent to those skilled in the art as described above to obtain the invention should be included within the scope of the present invention.

Claims

1. A method for preparing fermented sparkling wine, characterized in that: The preparation method comprises the following steps: 1) Primary fermentation: Mix glutinous rice, water, koji, and No. 1 yeast inoculant, incubate at 22-32°C for 20-30 hours, then lower the incubation temperature to 18-20°C until the alcohol content in the primary fermentation system reaches 12-18% vol. Fermentation is terminated. After solid-liquid separation, discard the solids and use the liquid as the base wine. 2) Blending base wine: Use sugar solution to blend base wine to make the alcohol content of base wine 4.0-5.0%vol, reducing sugar content 130-150g / L, and total acid content 1-3g / L; 3) Secondary fermentation: Mix the No. 2 yeast culture with the blended base wine and perform secondary fermentation at 12-20°C. After fermentation, the supernatant is collected to obtain the fermented sparkling wine. The secondary fermentation can be performed under pressure in a tank or bottle. Yeast No. 1 refers to yeast obtained by the following method: strain No. 2.1392, Saccharomyces cerevisia, purchased from CGMCC, is cultured at 22-32°C until the alcohol content in the yeast fermentation environment reaches 15% vol or higher and the total acidity in the environment is maintained within 7 g / L. The strain isolated from the system at this time is Yeast No. 1; The No. 1 yeast inoculum is a liquid inoculum or a solid inoculum; the number of No. 1 yeast in the No. 1 yeast liquid inoculum is ≥ 100 million per ml; the No. 1 yeast liquid inoculum is obtained by culturing No. 1 yeast in a yeast culture medium for 20 to 30 hours, allowing the No. 1 yeast to settle at 0 to 5° C., and discarding the supernatant to obtain the No. 1 yeast liquid inoculum; Yeast No. 2 refers to yeast obtained by the following method: strain No. 2.1392, Saccharomyces cerevisia, purchased from CGMCC, is cultured at 12-20°C until the alcohol content in the fermentation environment reaches 8% vol or higher and the total acidity in the environment is maintained within 5 g / L. The strain isolated from the system at this time is Yeast No. 2; The No. 2 yeast inoculum is a liquid inoculum or a solid inoculum; the No. 2 yeast liquid inoculum contains ≥ 100 million No. 2 yeast per ml; the No. 2 yeast liquid inoculum is obtained by culturing No. 2 yeast in a yeast culture medium for 20 to 30 hours, allowing the No. 2 yeast to settle at 0 to 5° C., and discarding the supernatant to obtain the No. 2 yeast liquid inoculum.

2. The preparation method according to claim 1, characterized in that The glutinous rice is cooked glutinous rice; the preparation method of the cooked glutinous rice is as follows: soaking the rice for 2 to 3 hours, and steaming the rice for 0.5 to 1 hour to obtain the cooked glutinous rice; And / or, the distiller's yeast is rice koji.

3. The preparation method according to claim 1, characterized in that The weight ratio of the glutinous rice, water, distiller's yeast and No. 1 yeast agent is: 1: (1-1.5): (0.1-0.15): (0.1-0.15); the primary fermentation adopts the rice feeding method; and / or, At the end of the first fermentation, the total acid in the system is 4~8g / L, the amino acid nitrogen is 0.1~0.3g / L, the alcohol content is 14~16%vol, and the total sugar is ≤10g / L.

4. The preparation method according to claim 1, characterized in that The method for preparing the sugar solution in step 2) comprises the following steps: 2-1) Mix cooked glutinous rice, water, and koji, and saccharify at 60-70°C for 16-20 hours; 2-2) Cool to below 35℃ and filter press; 2-3) The liquid obtained by filtration is decolorized and impurities removed to obtain sugar solution.

5. The preparation method according to claim 4, characterized in that Also includes one or more of the following features: 2A. In step 2-1), the weight ratio of glutinous rice, water, and koji is (0.8-1.2):(1.2-1.6):(0.12-0.17); 2B. Decolorization using activated carbon in steps 2-3); 2C. The decolorization time in steps 2-3) is more than 4 hours; 2D. Steps 2-3) using diatomaceous earth to remove impurities; 2E. The physical and chemical indicators of the sugar solution are total sugar 250-350g / L, total acid 0.5-1.5g / L, and amino acid nitrogen 0.1-0.2g / L.

6. The preparation method according to claim 1, characterized in that Step 3) also includes one or more of the following features: 3A. Sterilize the blended base wine at 70-90°C and cool to below 25°C before mixing with Yeast Inoculant No.

2. The inoculum level for Yeast Inoculant No. 2 is 0.2-0.5%. 3B. Secondary fermentation temperature: 12-20°C; 3C. The fermentation method for the in-tank pressure fermentation is as follows: after mixing the No. 2 yeast culture with the prepared base wine, the fermentation is terminated when the pressure in the tank reaches 0.2-0.3 MPa. After the fermentation is completed, the supernatant is pressure-filled and sterilized to obtain the fermented sparkling wine. The method for the in-bottle pressure fermentation is as follows: after mixing the No. 2 yeast culture with the prepared base wine, the fermentation is terminated after 4-6 days. After the fermentation is completed and sterilized, the fermented sparkling wine is obtained.

7. The preparation method according to claim 1, characterized in that The method for preparing the fermented sparkling wine further comprises cooling the fermented sparkling wine sterilized in the secondary fermentation and then transferring it to 0-5° C. refrigeration for clarification.

8. Fermented sparkling wine obtained by the preparation method according to any one of claims 1 to 7.

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