Brewing method for improving ethyl acetate content and reducing fusel oil content of rice-flavor liquor

Abstract

The invention discloses a brewing method for improving the content of ethyl acetate and reducing the content of fusel oil in rice-flavor liquor. The method disclosed by the invention belongs to the technical field of baijiu brewing, and the method disclosed by the invention improves the content of ethyl acetate in the rice-flavor baijiu without increasing extra brewing time; according to the method, the outer layer of the rice is ground, the rice flour can be used for other purposes and is not wasted, fusel oil in the liquor body is reduced, and the produced rice-flavor liquor is cleaner and more refreshing in taste; the rice-flavor white spirit brewed by the method is prominent in flavor and chewy and refreshing in taste, and the product presents sweet and delicious fruity flavor similar to honey due to the rich ethyl acetate content.

Description

Technical Field

[0001] The invention belongs to the technical field of liquor brewing, and specifically refers to a brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content. Background Art

[0002] Traditional rice-flavored liquor is made from rice as raw material and Xiaoqu as saccharification and fermentation agent. It is made through solid saccharification, semi-solid fermentation, distillation, aging and blending. It has a complex aroma with ethyl lactate and β-phenylethanol as the main components.

[0003] The development of rice-flavor liquor has been divided into traditional rice-flavor liquor and new-era rice-flavor liquor. Traditional rice-flavor liquor uses small pots or pottery jars for fermentation, which has high labor intensity and low efficiency. The saccharification and fermentation equipment of new-era rice-flavor liquor are all stainless steel equipment. Stainless steel fermentation equipment improves the sanitation and cleanliness of production and reduces the impact of microorganisms in the environment and equipment. At the same time, new-era rice-flavor liquor gradually adopts pure microbial cultivation to make koji. The microorganisms of koji are relatively simple, resulting in low lactic acid ethyl ester and ethyl acetate content, low total acid and total ester content, and high fusel oil content in fermented rice wine, resulting in insufficient typicality of the aroma of the wine, weak taste, and easy to get drunk after drinking. Ethyl acetate is the flavor skeleton component of rice-flavor liquor. The reduction of ethyl acetate leads to the reduction of the quality of rice-flavor liquor. Fusel oil is one of the key flavor components of rice-flavor liquor, but too much fusel oil will lead to uncoordinated aroma of the wine, bitter taste, and easy to get drunk after drinking. Therefore, it is a very important technology to increase the content of ester substances in rice-flavor liquor and reduce the content of fusel oil.

[0004] Chinese invention patent CN106350371A discloses a method for increasing the content of ethyl lactate in mechanized liquor. The main technical solution is to cool the mash after cooking and gelatinization in the mechanized workshop, add koji, and inoculate the microorganisms in the traditional process site, and then put it into a stainless steel container and ferment it in the fermentation room. The disadvantage of this patent is that it is limited to the production process of solid liquor and does not involve the process of liquid fermentation liquor.

[0005] Chinese invention patent CN103937642A discloses a method of increasing the content of esters and acids produced in the process of liquor brewing by changing the relevant process parameters in the liquor production process. However, this method mainly increases acetic acid and ethyl acetate, and this method is mainly achieved by extending the fermentation period, which is 60 to 70 days. It is only suitable for the production of flavored liquor, not for mass production of base liquor.

[0006] Chinese invention patent CN201811433238.8 discloses a brewing method for increasing the ethyl lactate content of rice-flavor liquor and reducing the fusel oil content. This method mainly involves soaking rice to obtain lactic acid bacteria in the rice, which increases lactic acid and produces more ethyl lactate. However, this method does not increase the ethyl acetate content.

[0007] Japanese sake technology and Chinese rice-flavor liquor technology are of the same origin. Japanese sake uses rice grinding to reduce the protein and fat content in rice, which is called rice polishing. Rice grinding can reduce the production of fusel oil. The rice grinding ratio of Japanese sake ranges from 30-99%. After many experiments, the inventor found that grinding 70% of the outer layer of early rice can achieve the effect of removing fusel oil without affecting the content of ester flavor substances.

[0008] The ethyl acetate in liquor is mainly produced by the esterification enzyme produced by yeast acting on acetic acid and ethanol. Compared with single-strain fermentation, mixed fermentation of yeasts of different genera can enhance some beneficial flavor compounds, so using brewer's yeast and non-brewer's yeast as fermentation starting strains can enhance some beneficial flavor compounds and ethyl acetate. Therefore, according to the study by Tang Jie et al. in 2012, the difference in flavor substances under mixed inoculation and sequential inoculation was compared with single-strain as the control. It was found that sequential inoculation of Pichia anomala and Saccharomyces cerevisiae can produce more ethyl acetate. Based on this background technology, combined with the existing steps of saccharification before fermentation of rice-flavor liquor, the inventors chose to inoculate the koji in batches and types. The first time was mainly saccharification, and Rhizopus oryzae and Pichia anomala were first inoculated for saccharification and preliminary fermentation. The second inoculation was Saccharomyces cerevisiae (purchased from Angel Yeast). Summary of the invention

[0009] The purpose of the present invention is to provide a brewing method for increasing the ethyl acetate content of rice-flavored liquor and reducing the fusel oil content. The present invention grinds off 70% of the outer layer of rice. The protein and fat contained in the rice are mainly present in the outer layer. Physical wear and tear removes the protein and fat, which is equivalent to reducing the raw materials for producing fusel oil, thereby achieving the purpose of reducing fusel oil. The present invention inoculates the mixed distiller's yeast A mixed with existing Rhizopus oryzae and Pichia anomala as the first step of inoculation of small koji, and then adds the mixed distiller's yeast B mainly composed of saccharomyces cerevisiae after saccharification. Different yeasts can be inoculated in batches to produce more ethyl acetate, so that the fermented grains can produce more ethyl acetate, which can enhance the flavor of the liquor and improve the quality of the original liquor.

[0010] In order to achieve the above object, the technical scheme adopted by the present invention is as follows: a brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content, the brewing method comprising the following steps:

[0011] (1) Rice selection: Select early rice harvested that year that is fresh, mold-free, and free of odor and produced in the Sunshui River Basin in Loudi City, Hunan Province;

[0012] (2) Rice grinding: Use a rice polishing machine (purchased from Japan's Satake SATAAKE VTA7C vertical sand roller rice mill) to grind away 30%-70% of the outer layer of the white rice to obtain the rice core, and collect the rice flour;

[0013] (3) Cleaning: Use drinking water to rinse off the excess rice flour on the surface of the rice core;

[0014] (4) Soaking the rice core: Add room temperature drinking water to cover the rice core;

[0015] (5) Steaming rice: Put the soaked rice core into the steamer and flatten it, then steam it for 20 minutes;

[0016] (6) Mixing koji A - saccharification: Break up the steamed rice core and cool it to 30 degrees Celsius. Sprinkle 0.3-0.8% of the weight of the rice with mixed koji A (made from Rhizopus oryzae, Pichia anomala, rice flour and rice husk in a ratio of 5:1) and mix well;

[0017] (7) Saccharification: Pour the rice and wine with the koji into the vat, dig a trumpet-shaped hole in the middle, cover the vat, and keep it warm or cool down according to the season, so that the rice and wine can saccharify and ferment at a suitable constant temperature. The saccharification process takes about 40 hours.

[0018] (8) Mixing koji and fermentation: Add 2 times the volume of rice and mix 0.3-0.6% of the weight of rice with mixed koji B. Maintain the temperature at 30-35 degrees and ferment for 7-14 days;

[0019] (9) Distillation: Pour the fermented mash into a distillation pot and remove the head and tail to obtain the base wine.

[0020] Furthermore, the rice flour obtained in step (2) can be used to make distiller's yeast.

[0021] Furthermore, the soaking time of the rice core in step (4) is: 2-3 hours in summer and 5-8 hours in winter.

[0022] Furthermore, the distiller's yeast A in step (6) is a mixed yeast made from Rhizopus oryzae and Pichia anomala (both purchased from Angel Yeast Co., Ltd.).

[0023] Furthermore, the preparation of the distiller's yeast A comprises the following steps:

[0024] (1) selecting 100 kg of rice flour obtained in step (2), passing through a 40-mesh sieve, sterilizing the rice flour and spreading it to cool, lowering the temperature to about 28 to 35 degrees, adding 0.2 kg of Rhizopus oryzae and 20 kg of water to mix, and then placing it on a plate and placing it in a culture room, the culture method can be according to the conventional preparation method in the field, and finally drying to make pure Rhizopus oryzae rice koji;

[0025] (2) selecting 20 kg of rice husks obtained in step (2), sterilizing and cooling to about 30 degrees, pouring 0.02 kg of pure anomalous Pichia pastoris into the raw material, adding 10 kg of water and stirring evenly, culturing according to conventional methods in the art, and finally drying to obtain pure anomalous Pichia pastoris;

[0026] (3) 100 kg of Rhizopus oryzae rice koji and 20 kg of Pichia pastoris koji were mixed to obtain a mixed koji.

[0027] Furthermore, the mixed koji B in step (8) is prepared by mixing brewer's yeast koji and traditional Chinese medicine powder, and the brewer's yeast is purchased from Angel Yeast Co., Ltd.

[0028] Furthermore, the preparation of the mixed koji B comprises the following steps: selecting 20 kg of rice husks obtained in step (2), sterilizing and cooling to about 30 degrees, pouring 0.02 kg of pure brewer's yeast into the raw materials, adding 10 kg of water and stirring evenly, culturing according to conventional methods in the art, and drying to obtain pure brewer's yeast. Finally, 1 kg of traditional Chinese medicine powder (prepared by drying and crushing Polygonum hydropiper, Licorice, and Polygonatum odoratum in a ratio of 1:1:1) is added to the mixture to prepare the mixed koji B.

[0029] The beneficial effects achieved by the present invention using the above structure are as follows: (1) the method of the present invention increases the ethyl acetate content in the rice-flavored liquor without increasing the additional brewing time; (2) the method of the present invention grinds the outer layer of rice into powder, the rice powder can be used for other purposes without being wasted, and the fusel oil in the liquor body is reduced, so that the rice-flavored liquor produced has a cleaner and more refreshing taste; (3) the rice-flavored liquor brewed by the method of the present invention has a prominent aroma and a strong and refreshing taste. Due to the rich ethyl acetate content, the product presents a sweet fruity aroma similar to honey. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Comparison of brown rice before and after grinding.

[0031] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0034] The experimental methods in the following examples are conventional methods unless otherwise specified; the test materials and test strains used in the following examples are purchased from commercial channels unless otherwise specified.

[0035] Example 1

[0036] Brewing method for increasing ethyl acetate content and reducing fusel oil content in rice-flavor liquor

[0037] The brewing method comprises the following steps:

[0038] (1) Rice selection: Select early rice harvested that year that is fresh, mold-free, and free of odor and produced in the Sunshui River Basin in Loudi City, Hunan Province;

[0039] (2) Rice grinding: Use a rice polishing machine (purchased from Japan Satake SATAAKE VTA7C vertical sand roller rice mill) to grind 30%-70% of the outer layer of the white rice to obtain the rice core, and collect the rice flour; Figure 1 The middle left picture shows before rice grinding. Figure 1 The middle right picture shows the rice after grinding.

[0040] (3) Cleaning: Use drinking water to rinse off the excess rice flour on the surface of the rice core;

[0041] (4) Soaking the rice core: Add room temperature drinking water to cover the rice core;

[0042] (5) Steaming rice: Put the soaked rice core into the steamer and flatten it, then steam it for 20 minutes;

[0043] (6) Mixing koji A - saccharification: Break up the steamed rice core and cool it to 30 degrees Celsius. Sprinkle 0.3-0.8% of the weight of the rice with mixed koji A (made from Rhizopus oryzae, Pichia anomala, rice flour and rice husk in a ratio of 5:1) and mix well;

[0044] (7) Saccharification: Pour the rice and wine with the koji into the vat, dig a trumpet-shaped hole in the middle, cover the vat, and keep it warm or cool down according to the season, so that the rice and wine can saccharify and ferment at a suitable constant temperature. The saccharification process takes about 40 hours.

[0045] (8) Mixing koji and fermentation: Add 2 times the volume of rice and mix 0.3-0.6% of the weight of rice with mixed koji B. Maintain the temperature at 30-35 degrees and ferment for 7-14 days;

[0046] (9) Distillation: Pour the fermented mash into a distillation pot and remove the head and tail to obtain the base wine.

[0047] The rice flour obtained in step (2) can be used to make distiller's yeast.

[0048] Wherein, the soaking time of the rice core in step (4) is: 2-3 hours in summer and 5-8 hours in winter.

[0049] Example 2

[0050] Preparation of koji A

[0051] The preparation of the distiller's yeast A comprises the following steps:

[0052] (1) selecting 100 kg of rice flour obtained in step (2), passing through a 40-mesh sieve, sterilizing the rice flour and spreading it to cool, lowering the temperature to about 28 to 35 degrees, adding 0.2 kg of Rhizopus oryzae and 20 kg of water to mix, and then placing it on a plate and placing it in a culture room, the culture method can be according to the conventional preparation method in the field, and finally drying to make pure Rhizopus oryzae rice koji;

[0053] (2) selecting 20 kg of rice husks obtained in step (2), sterilizing and cooling to about 30 degrees, pouring 0.02 kg of pure anomalous Pichia pastoris into the raw material, adding 10 kg of water and stirring evenly, culturing according to conventional methods in the art, and finally drying to obtain pure anomalous Pichia pastoris;

[0054] (3) 100 kg of Rhizopus oryzae rice koji and 20 kg of Pichia pastoris koji were mixed to obtain a mixed koji.

[0055] Example 3

[0056] Preparation of koji B

[0057] The preparation of the mixed koji B comprises the following steps: selecting 20 kg of rice husks obtained in step (2), sterilizing and cooling to about 30 degrees, pouring 0.02 kg of pure brewer's yeast into the raw materials, adding 10 kg of water and stirring evenly, culturing according to a conventional method in the art, and drying to obtain pure brewer's yeast. Finally, 1 kg of traditional Chinese medicine powder (prepared by drying and crushing Polygonum hydropiper, Licorice, and Polygonatum odoratum in a ratio of 1:1:1) is added to prepare the mixed koji B.

[0058] Experimental Example 1

[0059] Study on the effect of different rice grinding ratios on fusel oil in finished rice-flavor liquor

[0060] The experiment was divided into 6 groups, with rice grinding rates of 30%, 40%, 50%, 60%, 70%, and 80%, respectively. They were numbered in sequence from group 1 to group 6. After brewing, the appropriate rice grinding rate was determined by testing the fusel oil content and comparing the taste.

[0061] (1) Rice selection: Select early rice harvested that year that is fresh, mold-free, and free of odor and produced in the Sunshui River Basin in Loudi City, Hunan Province.

[0062] (2) Rice grinding: Use a rice polishing machine (purchased from Japan's Satake SATAAKE VTA7C vertical sand roller rice mill) to grind away 30-80% of the outer layer of the white rice to obtain the rice core, and collect rice flour (rice flour can be used to make wine koji).

[0063] (3) Cleaning: Use drinking water to rinse off the excess rice flour on the surface of the rice core.

[0064] (4) Soak the rice core: Add enough room temperature drinking water to cover the rice core. Soak for 2-3 hours in summer and 5-8 hours in winter.

[0065] (5) Steaming rice: Place the soaked rice core into a steamer and flatten it. Steam for 20 minutes.

[0066] (6) Mixing koji A - saccharification: Break up the steamed rice core and cool it to 30 degrees Celsius. Sprinkle 0.8% of the weight of the rice with mixed koji A (made from Rhizopus oryzae, Pichia anomala, rice flour and rice husk in a ratio of 5:1) and mix well.

[0067] (7) Saccharification: Pour the rice and wine with the yeast into a jar, dig a trumpet-shaped hole in the middle, cover the jar, and keep it warm or cool down according to the season, so that the rice and wine can be saccharified and fermented at a suitable constant temperature. The saccharification process takes about 40 hours.

[0068] (8) Fermentation with koji: Add 2 times the volume of rice and 0.3% of the weight of rice in mixed koji B. Maintain the temperature at 30-35 degrees and ferment for 7-14 days.

[0069] (9) Distillation: Pour the fermented mash into a distillation pot. After distillation, remove the head and tail to obtain the original wine, which is then stored in a pottery jar for aging.

[0070] Table 1: Comparison of physical and chemical indicators and taste of base wines of the examples and control samples

[0071]

[0072] Note: The control sample is rice-flavor liquor produced by traditional rice-flavor liquor process.

[0073] Results: Compared with the control sample, the fusel oil content of group 1 was significantly reduced, indicating that rice grinding is indeed effective in reducing fusel oil. At 70% rice grinding ratio, the fusel oil content was reduced to about 50% of the control sample, and continuing to grind rice to 80% did not significantly improve the wine quality.

[0074] Experimental Example 2

[0075] Study on the appropriate ratio of Rhizopus oryzae and Pichia anomala

[0076] The wines were divided into five groups according to the ratios of 1:1, 2:1, 3:1, 4:1 and 5:1, respectively, and raw wines were brewed according to the method of the present invention, and the total ester (calculated as ethyl acetate) was tested.

[0077] Table 2 Comparison of base wine ethyl acetate indicators obtained by implementation case and traditional method

[0078] Total ester (calculated as ethyl acetate) g / L Group 1 The content of Rhizopus oryzae is too low and the saccharification is not thorough, resulting in brewing failure Group 2 The content of Rhizopus oryzae is too low and the saccharification is not thorough, resulting in brewing failure Group 3 0.85 Group 4 0.68 Group 5 1.36 Control group (traditional method) 1.03

[0079] Result analysis: The ethyl acetate content of the base wine obtained in group 5 was the highest, higher than that of the control group using the traditional method.

[0080] Experimental Example 3

[0081] The physicochemical indexes of the rice-flavor liquor brewed by the method of the present invention and the traditional rice-flavor liquor were compared.

[0082] (1) Rice selection: Select early rice harvested that year that is fresh, mold-free, and free of odor and produced in the Sunshui River Basin in Loudi City, Hunan Province.

[0083] (2) Rice grinding: Use a rice polishing machine (purchased from Japan's Satake SATAAKE VTA7C vertical sand roller rice mill) to grind off 70% of the outer layer of the white rice to obtain the rice core, and collect rice flour (rice flour can be used to make wine koji).

[0084] (3) Cleaning: Use drinking water to rinse off the excess rice flour on the surface of the rice core.

[0085] (4) Soak the rice core: Add enough room temperature drinking water to cover the rice core. Soak for 2-3 hours in summer and 5-8 hours in winter.

[0086] (5) Steaming rice: Place the soaked rice core into a steamer and flatten it. Steam for 20 minutes.

[0087] (6) Mixing koji A - saccharification: Break up the steamed rice core and cool it to 30 degrees Celsius. Sprinkle 0.8% of the weight of the rice with mixed koji A (made from Rhizopus oryzae, Pichia anomala, rice flour and rice husk in a ratio of 5:1) and mix well.

[0088] (7) Saccharification: Pour the rice and wine with the yeast into a jar, dig a trumpet-shaped hole in the middle, cover the jar, and keep it warm or cool down according to the season, so that the rice and wine can be saccharified and fermented at a suitable constant temperature. The saccharification process takes about 40 hours.

[0089] (8) Fermentation with koji: Add 2 times the volume of rice and 0.3% of the weight of rice in mixed koji B. Maintain the temperature at 30-35 degrees and ferment for 7-14 days.

[0090] (9) Distillation: Pour the fermented mash into a distillation pot and remove the head and tail to obtain the base wine.

[0091] Table 3. Comparison of physical and chemical indicators and taste between implementation cases and control samples

[0092]

[0093] Results analysis: The yield of the method of the present invention is basically the same as that of the traditional rice-flavor liquor, but the ethyl acetate, ethyl lactate and total acid of the method are higher than those of the traditional rice-flavor liquor process. And the content of fusel oil and methanol are lower than that of the traditional method. In terms of taste, the method has an elegant fragrance and a refreshing drinking taste, which is significantly better than the traditional method.

[0094] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0095] The present invention and its embodiments are described above, and such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.

Claims

1. A brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content, characterized in that: The brewing method comprises the following steps: (1) Rice selection: Choose early rice that is fresh, mold-free, and has no odor. (2) Rice grinding: Use a rice polishing machine to grind away 30%-70% of the outer layer of white rice to obtain the rice core, and collect rice flour; (3) Cleaning: Use drinking water to rinse off excess rice flour on the surface of the rice core; (4) Soaking the rice core: Add room temperature drinking water to cover the rice core; (5) Steaming rice: Put the soaked rice core into the steamer and flatten it, then steam it for 20 minutes; (6) Mixed koji A - saccharification: Break up the steamed rice core and cool it to 30 degrees Celsius. Sprinkle 0.3-0.8% of the weight of the rice with mixed koji A and stir evenly. The mixed koji A is made of rice koji made from Rhizopus oryzae, Pichia anomala, rice flour and rice husk in a ratio of 5:1; (7) Saccharification: Pour the rice and wine with the koji into the vat, dig a trumpet-shaped hole in the middle, cover the vat, and keep it warm or cool down according to the season, so that the rice and wine can saccharify and ferment at a constant temperature. The saccharification process takes about 40 hours. (8) Mixing and fermenting: Add water twice the volume of rice and mix 0.3-0.6% of mixed koji B by weight of rice, maintain the temperature at 30-35 degrees, and ferment for 7-14 days; (9) Distillation: Pour the fermented mash into a distillation pot and remove the head and tail to obtain the base wine.

2. The brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content according to claim 1, characterized in that: The rice flour obtained in step (2) can be used to make distiller's yeast.

3. The brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content according to claim 2, characterized in that: The soaking time of the rice core in step (4) is: 2-3 hours in summer and 5-8 hours in winter.

4. The brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content according to claim 3, characterized in that: The distiller's yeast A in step (6) is a mixed yeast made from Rhizopus oryzae and Pichia anomala.

5. The brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content according to claim 4, characterized in that: The preparation of the distiller's yeast A comprises the following steps: (1) selecting 100 kg of rice flour obtained in step (2), passing through a 40-mesh sieve, sterilizing the rice flour and spreading it to cool, lowering the temperature to about 28 to 35 degrees, adding 0.2 kg of Rhizopus oryzae and 20 kg of water to mix, and then placing it on a plate and placing it in a culture room, the culture method can be according to the conventional preparation method in the field, and finally drying to make pure Rhizopus oryzae rice koji; (2) selecting 20 kg of rice husks obtained in step (2), sterilizing and cooling to about 30 degrees, pouring 0.02 kg of pure anomalous Pichia pastoris into the raw material, adding 10 kg of water and stirring evenly, culturing according to conventional methods in the art, and finally drying to obtain pure anomalous Pichia pastoris; (3) 100 kg of Rhizopus oryzae rice koji and 20 kg of Pichia pastoris koji were mixed to obtain a mixed koji.

6. The brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content according to claim 5, characterized in that: The mixed koji B in step (8) is prepared by mixing brewer's yeast koji and traditional Chinese medicine powder.

7. The brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content according to claim 6, characterized in that: The preparation of the mixed koji B comprises the following steps: selecting 20 kg of rice husks obtained in step (2), sterilizing and cooling to about 30 degrees, pouring 0.02 kg of pure brewer's yeast into the raw materials, adding 10 kg of water and stirring evenly, culturing according to conventional methods in the art, and drying to obtain pure brewer's yeast. Finally, 1 kg of traditional Chinese medicine powder is added to mix and prepare the mixed koji B.

8. The brewing method for increasing the ethyl acetate content of rice-flavor liquor and reducing the fusel oil content according to claim 7, characterized in that: The traditional Chinese medicine powder is prepared by drying and crushing Polygonum hydropiper, Licorice and Polygonatum sibiricum according to a ratio of 1:1:1.

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