A method for preparing rice wine by fermentation

Abstract

This invention discloses a method for preparing rice wine through fermentation, belonging to the field of fermentation technology. The method includes: cooking, saccharification, fermentation, and treatment. In the fermentation process, Angel yeast is added to the saccharification liquid, followed by a fermentation regulator and water. Fermentation is then carried out at 28-30℃ for 35-36 hours, with sterile air continuously introduced and the mixture stirred periodically. Afterward, sterile air is stopped, and the mixture is fermented in a sealed environment at 28-30℃ for 50-55 hours, followed by another sealed fermentation at 14-16℃ for 75-80 hours to obtain the fermented liquid. This invention can reduce the content of miscellaneous bacteria and harmful microorganisms in the mash, shorten the fermentation time, and simultaneously improve the yield and taste of the rice wine.

Description

Technical Field

[0001] This invention relates to the field of fermentation technology, and specifically to a method for preparing rice wine through fermentation. Background Technology

[0002] Yellow wine is a traditional Chinese fermented wine made primarily from rice, millet, sorghum, corn, wheat, and water. The process involves steaming, adding yeast, saccharification, fermentation, pressing, filtering, heating, storage, and blending. The most important process is fermentation, and the strains of microorganisms and fermentation conditions used during fermentation have a significant impact on the quality of yellow wine.

[0003] The fermentation of rice wine is a three-stage fermentation process that occurs simultaneously and collaboratively with saccharification and decomposition, yeast fermentation, and bacterial fermentation. The "three-stage fermentation theory of rice wine" states that the raw materials for rice wine use yeast as a saccharifying agent, and yeast or dry yeast and bacteria in the yeast starter and wheat starter as fermenting agents. After soaking and steaming rice, different types of molds, yeasts, and bacteria participate, and the types and quantities of yeasts and bacteria change dynamically with the change of alcohol content. Therefore, Shaoxing wine is a type of brewed wine produced through a three-pronged fermentation process: simultaneous saccharification and decomposition, alcohol production through fermentation by multiple varieties and high-density yeasts, and acid production through fermentation by multiple varieties and high-density bacteria. In the early stages of fermentation, saccharification and decomposition by enzymes in the starter culture (qu) are the primary processes, while bacterial saccharification and decomposition or direct utilization of starch and dextrin in the mash are secondary processes. In the later stages of fermentation, bacterial saccharification and decomposition or direct utilization of starch and dextrin in the mash are the primary processes, while the activity of enzymes in the starter culture decreases sharply due to the increase in alcohol content, and saccharification and decomposition by the starter culture becomes secondary. The sugars, amino acids, nucleic acids, vitamins, and other nutrients produced by bacterial saccharification and decomposition promote yeast fermentation. At the same time, bacterial fermentation produces acids that lower the pH and lactobacillus, which, together with the alcohol produced by yeast fermentation, inhibit the growth and reproduction of harmful bacteria, ensuring the normal progress of fermentation.

[0004] Currently, the following problems still exist in the fermentation of rice wine: First, rice wine is fermented in an open manner, and the yeast, water, and tools used contain a large number of miscellaneous bacteria, as well as harmful microorganisms in the air, which can lead to the spoilage of the mash; Second, active dry yeast is usually used as a saccharification and fermentation agent in the fermentation of rice wine, but the yield of alcohol is low.

[0005] To address the aforementioned issues, the most common method currently is to lower the fermentation temperature to reduce the content of miscellaneous bacteria and harmful microorganisms in the mash, thereby preventing spoilage. Additionally, yeast and saccharifying enzymes are added during fermentation to increase the fermentation speed and further improve the alcohol yield.

[0006] However, lowering the fermentation temperature will prolong the fermentation time, which will reduce the efficiency of rice wine production. Adding yeast and saccharifying enzymes together during fermentation can accelerate the conversion of starch into sugar, producing sugar in a very short time. However, there is a problem that the sugar is not fully fermented, resulting in a bitter taste in the rice wine, which affects its flavor. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the present invention provides a method for fermenting and preparing rice wine, which can reduce the content of miscellaneous bacteria and harmful microorganisms in the mash, shorten the fermentation time, and at the same time improve the yield and taste of rice wine.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing rice wine by fermentation includes: cooking, saccharification, fermentation, and treatment;

[0010] The steaming process involves washing the dried glutinous rice, soaking it in water at 20-35℃, then placing it in a sterilizer and steaming it at 121℃ to obtain steamed glutinous rice.

[0011] During the steaming or boiling process, the soaking time is 14-15 hours;

[0012] The steaming time is 50-60 minutes;

[0013] The saccharification process involves cooling the steamed glutinous rice to 35-37°C, crushing Angel rice wine yeast into powder and sprinkling it evenly, then sprinkling the saccharifying enzyme mixture evenly, stirring it evenly, making a well, and saccharifying at 32-35°C. During this process, sterile air is continuously introduced and the mixture is stirred regularly. The saccharification liquid is obtained after the saccharification is completed.

[0014] In the saccharification process, the amount of Angel rice wine starter added accounts for 0.25-0.26% of the mass fraction of the dry glutinous rice;

[0015] The amount of the saccharifying enzyme mixture added is 1.5-1.6% of the mass fraction of the dry glutinous rice;

[0016] The saccharification time is 38-40 hours;

[0017] The ventilation rate of the sterile air is 0.04-0.05 vvm;

[0018] The method of periodic stirring is to stir once every 5 hours, and each stirring time is 20-30 minutes;

[0019] The method for preparing the saccharifying enzyme mixture is as follows: after mixing the saccharifying enzyme, α-amylase, mannan oligosaccharide and pregelatinized starch evenly, the mixture is frozen and then stored at low temperature.

[0020] In the preparation of the saccharifying enzyme mixture, the mass ratio of saccharifying enzyme, α-amylase, mannan oligosaccharide, and pregelatinized starch is 1-1.2:1:4-4.5:6-7.

[0021] The freezing process is carried out at a temperature of -25°C to -20°C for 20-25 hours.

[0022] The temperature for low-temperature preservation is 2-4℃;

[0023] The enzyme activity of the saccharifying enzyme is 50,000 U / g;

[0024] The enzyme activity of the α-amylase is 10000 U / g;

[0025] The fermentation process involves adding Angel yeast to the saccharified liquid, followed by a fermentation promoter and water. The mixture is then fermented at 28-30°C for 35-36 hours, with sterile air continuously introduced and the mixture stirred periodically. After the sterile air is introduced, the mixture is fermented in a sealed environment at 28-30°C for 50-55 hours, followed by another sealed fermentation at 14-16°C for 75-80 hours to obtain the fermentation liquid.

[0026] In the fermentation process, the amount of Angel yeast added accounts for 0.06-0.07% of the mass fraction of the dry glutinous rice;

[0027] The amount of fermentation accelerator added is 0.3-0.32% of the mass of dry glutinous rice;

[0028] The amount of water added should be 1.7-2 times the weight of the dry glutinous rice;

[0029] The ventilation rate of the sterile air is 0.04-0.05 vvm;

[0030] The periodic stirring is carried out once every 5 hours, and each stirring time is 20-30 minutes.

[0031] The fermentation promoter is prepared by mixing L-lysine, L-threonine, L-leucine, and L-arginine in a mass ratio of 2-2.5:4-4.5:12-13:9-10.

[0032] The process involves pressing and filtering the fermentation broth, sterilizing it at 85-95℃ for 15-20 minutes, cooling it, and storing it in a sealed container.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] (1) The fermentation method for preparing rice wine of the present invention can reduce the content of miscellaneous bacteria and harmful microorganisms in the mash, thereby reducing the total acid content in the rice wine. The total acid content in the prepared rice wine is 4.3-4.5 g / L.

[0035] (2) The fermentation method for preparing rice wine of the present invention can shorten the fermentation time. During the fermentation, the present invention ferments at 28-30℃ for 35-36 hours under the condition of continuous introduction of sterile air, and then ferments at 28-30℃ for 50-55 hours under the condition of sealing, and ferments at 14-16℃ for 75-80 hours, with a total fermentation time of 160-171 hours.

[0036] (3) The fermentation method for preparing rice wine of the present invention can improve the yield of wine and the alcohol content of the prepared rice wine is 14.6-14.9% vol;

[0037] (4) The fermentation method for preparing rice wine of the present invention can improve the taste of rice wine. The prepared rice wine is evaluated by rice wine drinkers and the appearance is 23-24 points (25 points), the aroma is 22-23 points (25 points), the taste is 23-24 points (25 points), and the style is 21-22 points (25 points). Detailed Implementation

[0038] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.

[0039] Example 1

[0040] A method for preparing rice wine through fermentation, specifically as follows:

[0041] 1. Steaming: After washing the dried glutinous rice, soak it in water at 20℃ for 14 hours, then put it in a sterilizer and steam it at 121℃ for 50 minutes to obtain the steamed glutinous rice.

[0042] 2. Saccharification: Cool the steamed glutinous rice to 35℃, crush Angel rice wine yeast into powder and sprinkle it evenly. The amount of Angel rice wine yeast added accounts for 0.25% of the mass of dry glutinous rice. Then sprinkle the saccharifying enzyme mixture evenly. The amount of saccharifying enzyme mixture added accounts for 1.5% of the mass of dry glutinous rice. Stir evenly, make a well, and saccharify at 32℃ for 38 hours. During this period, sterile air is continuously introduced at a rate of 0.04 vvm. Stir once every 5 hours for 20 minutes each time. The saccharified liquid is obtained after saccharification.

[0043] The preparation method of the saccharifying enzyme mixture is as follows: saccharifying enzyme, α-amylase, mannan oligosaccharide and pregelatinized starch are mixed evenly in a mass ratio of 1:1:4:6, frozen at -25℃ for 20h, and then stored at 2℃.

[0044] The enzyme activity of the saccharifying enzyme is 50,000 U / g;

[0045] The enzyme activity of the α-amylase is 10000 U / g;

[0046] 3. Fermentation: Add Angel yeast to the saccharification liquid at a concentration of 0.06% of the dry glutinous rice mass. Then add a fermentation accelerator at a concentration of 0.3% of the dry glutinous rice mass. Add water at a concentration of 1.7 times the mass of the dry glutinous rice. Ferment at 28°C for 35 hours. During fermentation, sterile air is continuously introduced at a rate of 0.04 vvm. Stir the mixture every 5 hours for 20 minutes each time. Then stop introducing sterile air and ferment in a sealed container at 28°C for 50 hours. Finally, ferment in a sealed container at 14°C for 75 hours to obtain the fermentation liquid.

[0047] The fermentation promoter is prepared by mixing L-lysine, L-threonine, L-leucine, and L-arginine in a mass ratio of 2:4:12:9.

[0048] 4. Processing: After pressing and filtering the fermentation broth, sterilize it at 85℃ for 15 minutes, cool it, and store it in a sealed container.

[0049] Example 2

[0050] A method for preparing rice wine through fermentation, specifically as follows:

[0051] 1. Steaming: After washing the dried glutinous rice, soak it in water at 30℃ for 14.5 hours, then put it in a sterilizer and steam it at 121℃ for 55 minutes to obtain the steamed glutinous rice.

[0052] 2. Saccharification: Cool the steamed glutinous rice to 36℃, crush Angel rice wine yeast into powder and sprinkle it evenly. The amount of Angel rice wine yeast added accounts for 0.25% of the mass of dry glutinous rice. Then sprinkle the saccharifying enzyme mixture evenly. The amount of saccharifying enzyme mixture added accounts for 1.5% of the mass of dry glutinous rice. Stir evenly, make a well, and saccharify at 34℃ for 39 hours. During this period, sterile air is continuously introduced at a rate of 0.04 vvm. Stir once every 5 hours for 25 minutes each time. The saccharified liquid is obtained after saccharification.

[0053] The preparation method of the saccharifying enzyme mixture is as follows: saccharifying enzyme, α-amylase, mannan oligosaccharide, and pregelatinized starch are mixed evenly in a mass ratio of 1.1:1:4.2:6.5, frozen at -23℃ for 22 hours, and then stored at 3℃.

[0054] The enzyme activity of the saccharifying enzyme is 50,000 U / g;

[0055] The enzyme activity of the α-amylase is 10000 U / g;

[0056] 3. Fermentation: Add Angel yeast to the saccharification liquid at a concentration of 0.06% of the dry glutinous rice mass. Then add a fermentation accelerator at a concentration of 0.31% of the dry glutinous rice mass. Add water at a concentration of 1.8 times the mass of the dry glutinous rice. Ferment at 29°C for 35.5 hours. During fermentation, sterile air is continuously introduced at a rate of 0.04 vvm. Stir the mixture every 5 hours for 25 minutes each time. Then stop introducing sterile air and ferment in a sealed container at 29°C for 52 hours. Finally, ferment in a sealed container at 15°C for 78 hours to obtain the fermentation liquid.

[0057] The fermentation promoter is prepared by mixing L-lysine, L-threonine, L-leucine, and L-arginine in a mass ratio of 2.2:4.2:12.5:9.5.

[0058] 4. Processing: After pressing and filtering the fermentation broth, sterilize it at 90℃ for 18 minutes, cool it, and store it in a sealed container.

[0059] Example 3

[0060] A method for preparing rice wine through fermentation, specifically as follows:

[0061] 1. Steaming: After washing the dried glutinous rice, soak it in water at 35℃ for 15 hours, then put it in a sterilizer and steam it at 121℃ for 60 minutes to obtain the steamed glutinous rice.

[0062] 2. Saccharification: Cool the steamed glutinous rice to 37℃, crush Angel rice wine yeast into powder and sprinkle it evenly. The amount of Angel rice wine yeast added accounts for 0.26% of the dry glutinous rice mass. Then sprinkle the saccharifying enzyme mixture evenly. The amount of saccharifying enzyme mixture added accounts for 1.6% of the dry glutinous rice mass. Stir evenly, make a well, and saccharify at 35℃ for 40 hours. During this period, sterile air is continuously introduced at a rate of 0.05 vvm. Stir once every 5 hours for 30 minutes each time. The saccharification liquid is obtained after the saccharification is completed.

[0063] The preparation method of the saccharifying enzyme mixture is as follows: saccharifying enzyme, α-amylase, mannan oligosaccharide, and pregelatinized starch are mixed evenly in a mass ratio of 1.2:1:4.5:7, frozen at -20℃ for 25 hours, and then stored at 4℃.

[0064] The enzyme activity of the saccharifying enzyme is 50,000 U / g;

[0065] The enzyme activity of the α-amylase is 10000 U / g;

[0066] 3. Fermentation: Add Angel yeast to the saccharification liquid at a concentration of 0.07% of the dry glutinous rice mass. Then add a fermentation accelerator at a concentration of 0.32% of the dry glutinous rice mass. Add water at a concentration twice the mass of the dry glutinous rice. Ferment at 30°C for 36 hours. During fermentation, sterile air is continuously introduced at a rate of 0.05 vvm. Stir the mixture every 5 hours for 30 minutes each time. Then stop introducing sterile air and ferment in a sealed container at 30°C for 55 hours. Finally, ferment in a sealed container at 16°C for 80 hours to obtain the fermentation liquid.

[0067] The fermentation promoter is prepared by mixing L-lysine, L-threonine, L-leucine, and L-arginine in a mass ratio of 2.5:4.5:13:10.

[0068] 4. Processing: After pressing and filtering the fermentation broth, sterilize it at 95℃ for 20 minutes, cool it, and store it in a sealed container.

[0069] Comparative Example 1

[0070] Based on Example 1, this comparative example omits the addition of mannan oligosaccharide and pregelatinized starch in the preparation of the saccharifying enzyme mixture in the second saccharification step.

[0071] The remaining operations are the same as in Example 1.

[0072] Comparative Example 2

[0073] This comparative example is based on Example 1, except that the fermentation promoter is omitted in the third fermentation step;

[0074] The remaining operations are the same as in Example 1.

[0075] Experimental Example 1

[0076] The total acid content and alcohol content of rice wine were tested according to GB / T 13662-2018 standard, and the test results are as follows:

[0077]

[0078] Experimental Example 2

[0079] According to the GB / T 13662-2018 standard, 100 rice wine drinkers were selected to conduct a sensory evaluation of the rice wine. The rice wine of Example 1 was evaluated based on appearance, aroma, taste, and style, and the average value was taken. The evaluation results are as follows:

[0080]

[0081] Evaluation criteria:

[0082] Appearance (25 points):

[0083] Golden yellow transparent liquid, clear and bright with a glossy appearance; 17-25 points.

[0084] Golden yellow transparent liquid, clear and slightly glossy, 9-16 points;

[0085] Pale yellow transparent liquid, clear and free of impurities (0-8 points);

[0086] Aroma (25 points):

[0087] It has the unique rich and mellow aroma of Shaoxing wine, with no off-odors (17-25 points).

[0088] It has a rich and mellow aroma unique to Shaoxing wine, with no off-odors (9-16 points).

[0089] It has the unique mellow aroma of Shaoxing wine and no off-odors (0-8 points).

[0090] Taste (25 points):

[0091] Rich and odorless, 17-25 points;

[0092] Rich and smooth, with no off-odor (9-16 points);

[0093] Smooth and mellow, with no off-odor (0-8 points);

[0094] Style (25 points):

[0095] Body harmony: 17-25 points;

[0096] The wine is well-balanced, 9-16 points.

[0097] The wine is fairly well-balanced, scoring 0-8 points.

[0098] The results of Experiment 1-2 show that omitting the addition of mannan oligosaccharide and pregelatinized starch in the preparation of the saccharifying enzyme mixture in the second step of saccharification leads to an increase in the total acid content, a decrease in the alcohol content, and a decrease in the sensory evaluation score of the prepared rice wine; omitting the addition of the fermentation promoter in the third step of fermentation leads to a decrease in the total acid content and alcohol content, and a decrease in the sensory evaluation score of the prepared rice wine.

[0099] In Examples 1-3 and Comparative Example 2, the saccharifying enzyme mixture added in the second step of saccharification was a mixture of saccharifying enzyme, α-amylase, manno-oligosaccharide, and pregelatinized starch, followed by freezing. During freezing, the manno-oligosaccharide and pregelatinized starch immobilized the saccharifying enzyme and α-amylase. Simultaneously, the activities of the saccharifying enzyme and α-amylase decreased during freezing. After the addition of the saccharifying enzyme mixture, the activities of the saccharifying enzyme and α-amylase gradually recovered and were gradually released from the surface of the manno-oligosaccharide and pregelatinized starch, thus controlling their activity. The manno-oligosaccharide and pregelatinized starch also promoted saccharification, achieving full fermentation of the sugar, thereby avoiding excessively high total acidity caused by excessively high initial activity of the saccharifying enzyme and α-amylase, which would affect alcohol production. Furthermore, manno-oligosaccharide, as a novel antigenic active substance extracted from the cell walls of yeast culture, can reduce the content of miscellaneous bacteria and harmful microorganisms in the mash.

[0100] The amino acid composition added in the third fermentation step is a combination of basic amino acids, which can promote fermentation, shorten fermentation time, and reduce the total acid content in rice wine.

[0101] Unless otherwise stated, all percentages used in this invention are mass percentages.

[0102] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing rice wine through fermentation, characterized in that, include: Steaming, saccharification, fermentation, processing; The saccharification process involves cooling the steamed glutinous rice to 35-37°C, crushing Angel rice wine yeast into powder and sprinkling it evenly, then sprinkling the saccharifying enzyme mixture evenly, stirring it evenly, making a well, and saccharifying at 32-35°C. During this process, sterile air is continuously introduced and the mixture is stirred regularly. The saccharification liquid is obtained after the saccharification is completed. The method for preparing the saccharifying enzyme mixture is as follows: saccharifying enzyme, α-amylase, mannan oligosaccharide, and pregelatinized starch are mixed evenly in a mass ratio of 1-1.2:1:4-4.5:6-7, then frozen at -25℃ to -20℃ for 20-25 hours, and then stored at 2-4℃. The fermentation process involves adding Angel yeast to the saccharified liquid, followed by a fermentation promoter and water. The mixture is then fermented at 28-30°C for 35-36 hours, with sterile air continuously introduced and the mixture stirred periodically. After the sterile air is introduced, the mixture is fermented in a sealed environment at 28-30°C for 50-55 hours, followed by another sealed fermentation at 14-16°C for 75-80 hours to obtain the fermentation liquid. In the fermentation process, the fermentation promoter is prepared by mixing L-lysine, L-threonine, L-leucine, and L-arginine in a mass ratio of 2-2.5:4-4.5:12-13:9-10. The process involves pressing and filtering the fermentation broth, sterilizing it at 85-95℃ for 15-20 minutes, cooling it, and storing it in a sealed container.

2. The method for preparing rice wine by fermentation according to claim 1, characterized in that, The steaming process involves washing the dried glutinous rice, soaking it in water at 20-35℃, then placing it in a sterilizer and steaming it at 121℃ to obtain steamed glutinous rice. During the steaming or boiling process, the soaking time is 14-15 hours; The cooking time is 50-60 minutes.

3. The method for preparing rice wine by fermentation according to claim 1, characterized in that, In the saccharification process, the amount of Angel rice wine starter added accounts for 0.25-0.26% of the mass fraction of the dry glutinous rice; The amount of the saccharifying enzyme mixture added is 1.5-1.6% of the mass fraction of the dry glutinous rice; The saccharification time is 38-40 hours; The ventilation rate of the sterile air is 0.04-0.05 vvm; The method of periodic stirring is to stir once every 5 hours, and each stirring time is 20-30 minutes.

4. The method for preparing rice wine by fermentation according to claim 1, characterized in that, In the preparation of the amylase mixture, the enzyme activity of the amylase is 50,000 U / g; The enzyme activity of the α-amylase is 10000 U / g.

5. The method for preparing rice wine by fermentation according to claim 1, characterized in that, In the fermentation process, the amount of Angel yeast added accounts for 0.06-0.07% of the mass fraction of the dry glutinous rice; The amount of fermentation accelerator added is 0.3-0.32% of the mass of dry glutinous rice; The amount of water added should be 1.7-2 times the weight of the dry glutinous rice; The ventilation rate of the sterile air is 0.04-0.05 vvm; The periodic stirring is carried out once every 5 hours, and each stirring time is 20-30 minutes.

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