Fragrant type organic highland barley liquor secondary brewing method

Abstract

This invention relates to the field of baijiu brewing technology, specifically a method for secondary brewing of light-aroma organic highland barley baijiu. The method includes the following steps: modified organic highland barley is washed, soaked, steamed, cooled, and then mixed with modified compound yeast for open saccharification. Pretreated brewing water is then added for a sealed first fermentation. The resulting lees after distillation are added again to pretreated brewing water for a second fermentation. After the second distillation, the two liquors are mixed, aged, and filtered to obtain light-aroma organic highland barley baijiu. In this invention, modified organic highland barley disrupts cell wall structure, softens grains, and complexes phytic acid and other polyphenols, improving starch utilization and reducing fermentation inhibitors, thus increasing the alcohol yield. The modified compound yeast enhances saccharification and fermentation power, increasing the content of flavor substances such as ethyl acetate in the liquor. Pretreated brewing water is filtered through sand and activated carbon to remove impurities. Maifan stone mineralization releases beneficial trace elements and adsorbs heavy metals, optimizing the fermentation microenvironment and improving the purity and smoothness of the liquor.

Description

Technical Field

[0001] This invention relates to the field of liquor brewing technology, specifically a method for secondary brewing of light-aroma organic highland barley liquor. Background Technology

[0002] The secondary brewing method refers to the process of adding brewing water to the lees after the first fermentation and distillation for a second fermentation and distillation. This method can further extract the residual starch and flavor precursors in the lees, increase the yield of raw materials, and through the synergistic effect of the two fermentations and distillations, make the flavor components such as acids, esters, and alcohols in the wine more abundant and harmonious, and the wine more mellow and full-bodied.

[0003] In existing technologies, the dense cell wall structure of highland barley results in low starch utilization and a low alcohol yield. Traditional yeast starters are susceptible to enzyme activity inhibition by the fermentation environment, leading to unstable saccharification and fermentation power, resulting in a monotonous flavor and insufficient aroma components such as ethyl acetate. Furthermore, the presence of organic matter, residual chlorine, and heavy metal ions in the brewing water affects microbial metabolic activity, causing off-flavors and an imperfect secondary fermentation process, resulting in significant raw material waste. Therefore, this invention provides a secondary brewing method for light-aroma organic highland barley liquor. Summary of the Invention

[0004] The purpose of this invention is to provide a secondary brewing method for light-aroma organic highland barley liquor. The high alcohol yield of the light-aroma organic highland barley liquor prepared by this invention indicates high starch utilization and good fermentation efficiency; the high ethyl acetate content indicates strong ester production ability of the yeast, rich aroma and good quality of the liquor; and the low fusel oil content indicates a pure fermentation process and fewer harmful byproducts.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for secondary brewing of light-aroma organic highland barley liquor, the method comprising the following steps:

[0006] S1. After washing and soaking the modified organic highland barley, cook it under normal pressure until it is fully cooked, and then cool it to 30-35℃ to obtain cooked highland barley.

[0007] S2. Add modified compound yeast to ripe highland barley, stir evenly, and carry out open saccharification to obtain saccharified mash.

[0008] S3. Transfer the saccharified mash to a fermentation container, add pretreated brewing water, seal and carry out the first fermentation. The temperature is controlled at 25-28℃ and the fermentation time is 15-20 days to obtain the first fermented mash.

[0009] S4. The first fermented mash is distilled for the first time, and the liquor is collected. The resulting mash is added to pretreated brewing water for a second fermentation. The temperature is controlled at 28-32℃, and the fermentation time is 10-15 days. The mash is distilled again, and the liquor obtained from the two distillations is mixed. After aging and filtration, a light-aroma organic highland barley liquor is produced.

[0010] Furthermore, the modified organic highland barley is prepared by enzymatic hydrolysis of organic highland barley with a complex enzyme solution, acidification with citric acid solution, and complexation with zinc sulfate solution.

[0011] The citric acid solution is a food-grade monohydrate citric acid aqueous solution, and the zinc sulfate solution is a food-grade heptahydrate zinc sulfate aqueous solution.

[0012] Furthermore, the preparation method of the modified organic highland barley is as follows: organic highland barley is soaked in a compound enzyme solution to undergo a hydrolysis reaction, thereby obtaining enzymatically hydrolyzed highland barley; citric acid solution is sprayed onto the surface of the enzymatically hydrolyzed highland barley, and an acidification reaction is carried out by standing at room temperature; after the reaction is completed, zinc sulfate solution is added, and a complexation reaction is carried out at room temperature to generate a stable complex; the product is placed in a hot air circulating drying oven for drying, thereby obtaining modified organic highland barley.

[0013] Further, the mass ratio of the organic barley to the compound enzyme solution is 1:1.5-2.5; the mass fraction of the citric acid solution is 0.4-0.8%, and the spraying amount of the citric acid solution is 6-10% of the mass of the organic barley; the mass fraction of the zinc sulfate solution is 0.1-0.3%, and the amount of zinc sulfate solution added is 4-6% of the mass of the organic barley.

[0014] Further, the composite enzyme solution is a mixture of cellulase, hemicellulase, and β-glucanase in a mass ratio of 1.5-2.5:0.8-1.2:0.8-1.2, and then diluted with water to a mass fraction of 0.2-0.4%.

[0015] Furthermore, the modified composite yeast is prepared by a light-aroma type of yeast through a bio-activation reaction of traditional Chinese medicine extract, a dipotassium hydrogen phosphate ion exchange reaction, and a calcium chloride solution calcium ion complexation reaction.

[0016] Furthermore, the preparation method of the modified compound yeast is as follows: a light-aroma type of yeast is pulverized to obtain yeast powder; a traditional Chinese medicine extract is added to the yeast powder; and a bio-activation reaction is carried out by stirring in a double-helix conical mixer at 20-30℃; after the reaction, dipotassium hydrogen phosphate is added; and an ion exchange reaction is carried out by stirring at 20-30℃; after the reaction, a calcium chloride aqueous solution is sprayed, and a complexation reaction is carried out by stirring in a mixer; the product is placed in a constant temperature incubator at 25-30℃ for static fermentation; after fermentation, it is placed in a hot air circulating drying oven for drying to obtain the modified compound yeast.

[0017] Furthermore, the amount of the herbal extract added is 0.5-1.5% of the mass of the Daqu powder; the amount of dipotassium hydrogen phosphate added is 0.5-0.7% of the mass of the Daqu powder; the mass fraction of the calcium chloride aqueous solution is 0.2-0.4%, and the amount of the calcium chloride aqueous solution added is 4-8% of the mass of the Daqu powder.

[0018] Further, the herbal extract is made by mixing licorice, medicated leaven, and malt in a mass ratio of 1:1:1. The mixed herbs are then pulverized using a pulverizer to obtain coarse powder. 8-12 times the mass of purified water is added to the coarse powder, and the mixture is heated in an extraction tank equipped with a stirrer at a stirring speed of 30-60 rpm until boiling, then maintained at a gentle boil. After decoction, the mixture is filtered, and the filtrate is collected and transferred to a vacuum concentration tank. The temperature is controlled at 60-70℃, and the vacuum degree is (-0.08)-(-0.095) MPa, concentrating the mixture to 25-35% of its original volume to obtain the herbal extract.

[0019] Furthermore, the method for preparing the pretreated brewing water is as follows: after physically removing suspended solids by passing purified water through a quartz sand filter layer, the water is then passed through a granular activated carbon filter layer to remove organic matter and residual chlorine; 0.06-0.1% of maifan stone powder by mass of purified water is added to the filtered water, and the mixture is stirred at 20-30°C to adsorb some heavy metal ions. After standing, the mixture is filtered to obtain the pretreated brewing water.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. This invention uses a compound enzyme solution to enzymatically hydrolyze organic highland barley, which can directionally hydrolyze cellulose and hemicellulose in the cell wall of highland barley, increasing the starch dissolution rate. Unlike traditional single fermentation, this increases the alcohol yield by 10-15%. Then, the citric acid solution acidification reaction softens the grain structure and complexes metal ions. Combined with the zinc sulfate solution complexation reaction, it effectively removes fermentation inhibitors such as phytic acid and polyphenols, reducing the generation of off-flavors. The three modifying agents work synergistically to solve the problem of low starch utilization in highland barley, while preserving the unique aroma of highland barley.

[0022] 2. The herbal extracts of this invention perform a bio-activation reaction on the light-aroma type Daqu (a type of starter culture), which can improve the activity of saccharifying enzymes and liquefying enzymes, thereby enhancing the fermentation effect. Furthermore, the dipotassium hydrogen phosphate ion exchange reaction regulates the osmotic pressure of microorganisms, and the calcium ion complexation reaction of calcium chloride solution stabilizes the enzyme protein structure. These three factors work synergistically to maintain the high stability of the starter culture during secondary fermentation. At the same time, the herbal components promote the reproduction of aroma-producing bacteria, increasing the content of flavor substances such as ethyl acetate, resulting in a pure and fragrant liquor with a sweet aftertaste.

[0023] 3. This invention pre-treats brewing water through sand filtration and activated carbon filtration, which can efficiently remove suspended solids, organic matter and residual chlorine, unlike untreated water, and effectively avoids the generation of off-flavors; then it is mineralized by maifan stone powder, which releases beneficial trace elements such as potassium, calcium and silicon through ion exchange and adsorbs heavy metal ions, optimizing the fermentation microenvironment. The three processes work together to achieve the best water purity and mineral balance, promote the metabolic activity of yeast and aroma-producing bacteria, and make the wine smoother and cleaner. At the same time, the secondary fermentation process further extracts residual starch from the lees, increasing the overall wine yield. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that the raw materials used in the following embodiments are all commercially available.

[0026] Example 1: A method for secondary brewing of light-aroma organic highland barley liquor, comprising the following steps:

[0027] S1. After washing the modified organic highland barley, soak it for 8 hours, cook it under normal pressure until fully cooked, and then cool it to 30°C to obtain cooked highland barley.

[0028] S2. Add modified compound yeast to ripe highland barley, stir evenly, and carry out open saccharification for 24 hours to obtain saccharified mash.

[0029] S3. Transfer the saccharified mash to a fermentation container, add pretreated brewing water, seal and carry out the first fermentation. The temperature is controlled at 25℃ and the fermentation time is 15 days to obtain the first fermented mash.

[0030] S4. The first fermented mash is distilled for the first time, and the liquor is collected. The resulting mash is added to pretreated brewing water for a second fermentation. The temperature is controlled at 28℃ and the fermentation time is 10 days. The mash is distilled again. The liquor obtained from the two distillations is mixed, aged, and filtered to produce a light-aroma organic highland barley liquor.

[0031] Modified organic highland barley is prepared by enzymatic hydrolysis of organic highland barley with a compound enzyme solution, acidification with citric acid solution, and complexation with zinc sulfate solution.

[0032] The citric acid solution is a food-grade monohydrate citric acid aqueous solution, and the zinc sulfate solution is a food-grade heptahydrate zinc sulfate aqueous solution.

[0033] The preparation method of modified organic highland barley is as follows: Cleaned organic highland barley is soaked in a compound enzyme solution in an enzymatic hydrolysis tank equipped with a stirrer. The stirring speed is controlled at 30 rpm, the temperature at 40℃, and the soaking time at 2 hours. This allows the enzyme to hydrolyze the polysaccharides in the barley cell walls, destroying the cellulose and hemicellulose structure. The barley is then drained to obtain enzymatically hydrolyzed highland barley. Citric acid solution is sprayed onto the surface of the enzymatically hydrolyzed highland barley, stirred evenly, and allowed to stand for 1 hour. An acidification reaction occurs at room temperature, where citric acid forms soluble complexes with metal ions (such as calcium and magnesium) in the barley, promoting partial protein denaturation and softening the grain structure. After the reaction is complete, zinc sulfate solution is added, stirred evenly, and reacted at room temperature for 30 minutes. Zinc ions undergo a complexation reaction with residual phytic acid, polyphenols, and other substances in the barley, generating stable complexes and reducing the formation of undesirable components during fermentation. The product was placed in a hot air circulating drying oven at a drying temperature of 50℃ and a wind speed of 1m / s until the moisture content was 13%, thus obtaining modified organic highland barley.

[0034] The mass ratio of organic highland barley to compound enzyme solution is 1:1.5. The mass fraction of citric acid solution is 0.4%, and the spraying amount of citric acid solution is 6% of the mass of organic highland barley. The mass fraction of zinc sulfate solution is 0.1%, and the amount of zinc sulfate solution added is 4% of the mass of organic highland barley.

[0035] The complex enzyme solution is a mixture of cellulase, hemicellulase, and β-glucanase in a mass ratio of 1.5:0.8:0.8.

[0036] The modified compound yeast is prepared by a light-aroma type of yeast through a bio-activation reaction of traditional Chinese medicine extract, a dipotassium hydrogen phosphate ion exchange reaction, and a calcium chloride solution calcium ion complexation reaction.

[0037] The preparation method of modified compound yeast is as follows: Light-aroma type Daqu (a type of starter culture) is pulverized using a hammer mill with a sieve mesh size of 0.2 mm, controlling the particle size after pulverization to 40 mesh, yielding Daqu powder. Traditional Chinese medicine extract is added to the Daqu powder and stirred in a double-helix conical mixer for 20 minutes, controlling the stirring speed at 30 rpm and the temperature at 20℃. During this process, flavonoids, polysaccharides, and enzymes in the traditional Chinese medicine extract are adsorbed onto the surface of the Daqu powder particles, activating dormant saccharifying enzymes, liquefying enzymes, and aroma-producing yeasts in the Daqu, resulting in a bio-activation reaction and improving subsequent fermentation efficiency. After the reaction is complete, dipotassium hydrogen phosphate is added and mixed at 20℃ and the same stirring speed for 10 minutes. After the dipotassium hydrogen phosphate dissolves, it dissociates to release potassium. + and HPO4 -2 , with Na+ on microbial cell membranes + / K + The pump initiates an ion exchange reaction, regulating intracellular osmotic pressure while simultaneously providing a phosphorus source, promoting ATP synthesis, and enhancing microbial metabolic activity. After the reaction is complete, a calcium chloride aqueous solution is sprayed on top, and the mixture is stirred at 30 rpm for 10 minutes at 20°C.2+ The modified compound yeast undergoes a complexation reaction with the negatively charged groups (such as carboxyl groups) on the surface of α-amylase and glucoamylase molecules in the Daqu (a type of starter culture), forming a stable enzyme-calcium complex. This improves the enzyme's thermal and pH stability, reducing inactivation during subsequent drying and storage. The product is placed in a 25°C constant temperature incubator with 60% relative humidity and allowed to ferment for 48 hours. During this stage, microbial metabolic reactions occur: yeast utilizes sugars to produce ethanol and esters, Bacillus secretes proteases and lipases, and the herbal ingredients further promote the reproduction of aroma-producing fungi (such as Pichia pastoris and Hansenula polymorpha), forming richer flavor precursor substances. The fermented material is then placed in a hot air circulating drying oven at 35°C and a wind speed of 1 m / s until the moisture content is ≤10%, yielding the modified compound yeast.

[0038] The amount of herbal extract added is 0.5% of the mass of Daqu powder. The amount of dipotassium hydrogen phosphate added is 0.5% of the mass of Daqu powder. The mass fraction of calcium chloride aqueous solution is 0.2%, and the amount of calcium chloride aqueous solution added is 4% of the mass of Daqu powder.

[0039] The herbal extract is prepared by mixing licorice root, medicated leaven, and malt in a 1:1:1 mass ratio. The mixed herbs are then pulverized using a grinder and passed through a 20-mesh sieve to obtain a coarse powder. Eight times the mass of purified water is added to the coarse powder, and the mixture is heated in an extraction tank equipped with a stirrer at 30 rpm until boiling. The mixture is then maintained at a gentle boil and simmered for 1 hour. After simmering, the mixture is filtered through a 200-mesh filter cloth or a plate and frame filter press. The filtrate is collected and transferred to a vacuum concentration tank. The temperature is controlled at 60℃ and the vacuum degree at -0.08 MPa, and the mixture is concentrated to 25% of its original volume to obtain the herbal extract.

[0040] The method for preparing pretreated brewing water is as follows: Pure water is added at a flow rate of 5m³ / min. 3 After the suspended solids are physically removed by a 30cm thick quartz sand filter layer at a flow rate of / h, the flow rate is then increased to 4m 3 The water flows through a 20cm thick granular activated carbon filter layer at a flow rate of / h, utilizing the adsorption of functional groups on the activated carbon surface to remove organic matter and residual chlorine. 0.06% (by weight of purified water) of maifanite powder is added to the filtered water, and the mixture is reacted at 20℃ for 30 minutes at 60 rpm. Beneficial minerals are released and some heavy metal ions are adsorbed through ion exchange and trace dissolution. After standing for 1 hour to allow undissolved powder to precipitate, the water is finally filtered through a 3μm precision filter at a pressure of 0.1MPa to obtain pretreated brewing water.

[0041] Example 2: A method for secondary brewing of light-aroma organic highland barley liquor, comprising the following steps:

[0042] S1. After washing the modified organic highland barley, soak it for 10 hours, cook it under normal pressure until it is fully cooked, and then cool it to 32°C to obtain cooked highland barley.

[0043] S2. Add modified compound yeast to ripe highland barley, stir evenly, and carry out open saccharification for 30 hours to obtain saccharified mash.

[0044] S3. Transfer the saccharified mash to a fermentation container, add pretreated brewing water, seal and carry out the first fermentation. The temperature is controlled at 26℃ and the fermentation time is 17 days to obtain the first fermented mash.

[0045] S4. The first fermented mash is distilled for the first time, and the liquor is collected. The resulting mash is added to pretreated brewing water for a second fermentation. The temperature is controlled at 30℃ and the fermentation time is 12 days. The mash is distilled again. The liquor obtained from the two distillations is mixed, aged, and filtered to produce a light-aroma organic highland barley liquor.

[0046] Modified organic highland barley is prepared by enzymatic hydrolysis of organic highland barley with a compound enzyme solution, acidification with citric acid solution, and complexation with zinc sulfate solution.

[0047] The citric acid solution is a food-grade monohydrate citric acid aqueous solution, and the zinc sulfate solution is a food-grade heptahydrate zinc sulfate aqueous solution.

[0048] The preparation method of modified organic highland barley is as follows: Cleaned organic highland barley is soaked in a compound enzyme solution and reacted in an enzymatic hydrolysis tank equipped with a stirrer. The stirring speed is controlled at 45 rpm, the temperature at 45℃, and the soaking time at 3 hours. This allows the enzyme to hydrolyze the polysaccharides in the barley cell walls, destroying the cellulose and hemicellulose structure. The barley is then drained to obtain enzymatically hydrolyzed highland barley. Citric acid solution is sprayed onto the surface of the enzymatically hydrolyzed highland barley, stirred evenly, and allowed to stand for 1 hour. An acidification reaction occurs at room temperature, where citric acid forms soluble complexes with metal ions (such as calcium and magnesium) in the barley, promoting partial protein denaturation and softening the grain structure. After the reaction is complete, zinc sulfate solution is added, stirred evenly, and reacted at room temperature for 45 minutes. Zinc ions undergo a complexation reaction with residual phytic acid, polyphenols, and other substances in the barley, generating stable complexes and reducing the formation of undesirable components during fermentation. The product was placed in a hot air circulating drying oven at a drying temperature of 55℃ and a wind speed of 1.5m / s until the moisture content was 14%, thus obtaining modified organic highland barley.

[0049] The mass ratio of organic highland barley to compound enzyme solution is 1:2. The mass fraction of citric acid solution is 0.6%, and the spraying amount of citric acid solution is 8% of the mass of organic highland barley. The mass fraction of zinc sulfate solution is 0.2%, and the amount of zinc sulfate solution added is 5% of the mass of organic highland barley.

[0050] The complex enzyme solution is a mixture of cellulase, hemicellulase, and β-glucanase in a mass ratio of 2:1:1.

[0051] The modified compound yeast is prepared by a light-aroma type of yeast through a bio-activation reaction of traditional Chinese medicine extract, a dipotassium hydrogen phosphate ion exchange reaction, and a calcium chloride solution calcium ion complexation reaction.

[0052] The preparation method of modified compound yeast is as follows: Light-aroma type Daqu (a type of starter culture) is pulverized using a hammer mill with a sieve mesh size of 0.3 mm, controlling the particle size after pulverization to 50 mesh, yielding Daqu powder. Traditional Chinese medicine extract is added to the Daqu powder and stirred in a double-helix conical mixer for 25 minutes, controlling the stirring speed at 45 rpm and the temperature at 25℃. During this process, flavonoids, polysaccharides, and enzymes in the traditional Chinese medicine extract are adsorbed onto the surface of the Daqu powder particles, activating dormant saccharifying enzymes, liquefying enzymes, and aroma-producing yeasts in the Daqu, resulting in a bio-activation reaction and improving subsequent fermentation efficiency. After the reaction is complete, dipotassium hydrogen phosphate is added and mixed at 25℃ and the same stirring speed for 15 minutes. After the dipotassium hydrogen phosphate dissolves, it dissociates to release potassium. + and HPO4 -2 , with Na+ on microbial cell membranes + / K + The pump initiates an ion exchange reaction, regulating intracellular osmotic pressure while simultaneously providing a phosphorus source, promoting ATP synthesis, and enhancing microbial metabolic activity. After the reaction is complete, a calcium chloride aqueous solution is sprayed on top, and the mixture is stirred at 45 rpm for 12 minutes at 25°C. 2+ The modified compound yeast undergoes a complexation reaction with the negatively charged groups (such as carboxyl groups) on the surface of α-amylase and glucoamylase molecules in the Daqu (a type of starter culture), forming a stable enzyme-calcium complex. This improves the enzyme's thermal and pH stability, reducing inactivation during subsequent drying and storage. The product is placed in a 27°C constant temperature incubator with 70% relative humidity and allowed to ferment for 48 hours. During this stage, microbial metabolic reactions occur: yeast utilizes sugars to produce ethanol and esters, Bacillus secretes proteases and lipases, and the herbal ingredients further promote the reproduction of aroma-producing fungi (such as Pichia pastoris and Hansenula polymorpha), forming richer flavor precursor substances. The fermented material is then placed in a hot air circulating drying oven at 37°C and a wind speed of 1.5 m / s until the moisture content is ≤10%, yielding the modified compound yeast.

[0053] The amount of herbal extract added is 1% of the mass of Daqu powder. The amount of dipotassium hydrogen phosphate added is 0.6% of the mass of Daqu powder. The mass fraction of calcium chloride aqueous solution is 0.3%, and the amount of calcium chloride aqueous solution added is 6% of the mass of Daqu powder.

[0054] The herbal extract is prepared by mixing licorice root, medicated leaven, and malt in a 1:1:1 mass ratio. The mixed herbs are then pulverized using a grinder and passed through a 30-mesh sieve to obtain a coarse powder. Ten times the mass of purified water is added to the coarse powder, and the mixture is heated in an extraction tank equipped with a stirrer at 45 rpm until boiling. The mixture is then maintained at a gentle boil for 1.5 hours. After decoction, the mixture is filtered through a 200-mesh filter cloth or a plate and frame filter press. The filtrate is collected and transferred to a vacuum concentration tank. The temperature is controlled at 65℃ and the vacuum degree at -0.09 MPa, and the mixture is concentrated to 30% of its original volume to obtain the herbal extract.

[0055] The method for preparing pretreated brewing water is as follows: Pure water is poured at a flow rate of 7m... 3 After the flow rate is reduced to a certain value, the suspended solids are physically removed by passing the material through a 40cm thick quartz sand filter layer, and then the flow rate is reduced to a certain value at a certain value of 6m. 3 The water flows through a 25cm thick granular activated carbon filter layer at a flow rate of / h, utilizing the adsorption of functional groups on the activated carbon surface to remove organic matter and residual chlorine. 0.08% (by weight of purified water) of maifanite powder is added to the filtered water, and the mixture is reacted at 25℃ for 30 minutes at 90 rpm. Beneficial minerals are released and some heavy metal ions are adsorbed through ion exchange and trace dissolution. After standing for 1 hour to allow undissolved powder to precipitate, the water is finally filtered through a 4μm precision filter at a pressure of 0.2MPa to obtain pretreated brewing water.

[0056] Example 3: A method for secondary brewing of light-aroma organic highland barley liquor, comprising the following steps:

[0057] S1. After washing the modified organic highland barley, soak it for 12 hours, cook it under normal pressure until it is fully cooked, and then cool it to 35°C to obtain cooked highland barley.

[0058] S2. Add modified compound yeast to ripe highland barley, stir evenly, and carry out open saccharification for 36 hours to obtain saccharified mash.

[0059] S3. Transfer the saccharified mash to a fermentation container, add pretreated brewing water, seal and carry out the first fermentation. The temperature is controlled at 28℃ and the fermentation time is 20 days to obtain the first fermented mash.

[0060] S4. The first fermented mash is distilled for the first time, and the liquor is collected. The resulting mash is added to pretreated brewing water for a second fermentation. The temperature is controlled at 32℃ and the fermentation time is 15 days. The mash is distilled again. The liquor obtained from the two distillations is mixed, aged, and filtered to produce a light-aroma organic highland barley liquor.

[0061] Modified organic highland barley is prepared by enzymatic hydrolysis of organic highland barley with a compound enzyme solution, acidification with citric acid solution, and complexation with zinc sulfate solution.

[0062] The citric acid solution is a food-grade monohydrate citric acid aqueous solution, and the zinc sulfate solution is a food-grade heptahydrate zinc sulfate aqueous solution.

[0063] The preparation method of modified organic highland barley is as follows: Cleaned organic highland barley is soaked in a compound enzyme solution in an enzymatic hydrolysis tank equipped with a stirrer. The stirring speed is controlled at 60 rpm, the temperature at 50℃, and the soaking time at 4 hours. This allows the enzyme to hydrolyze the polysaccharides in the barley cell walls, destroying the cellulose and hemicellulose structure. The barley is then drained to obtain enzymatically hydrolyzed highland barley. Citric acid solution is sprayed onto the surface of the enzymatically hydrolyzed highland barley, stirred evenly, and allowed to stand for 1 hour. An acidification reaction occurs at room temperature, where citric acid forms soluble complexes with metal ions (such as calcium and magnesium) in the barley, promoting partial protein denaturation and softening the grain structure. After the reaction is complete, zinc sulfate solution is added, stirred evenly, and reacted at room temperature for 60 minutes. Zinc ions undergo a complexation reaction with residual phytic acid, polyphenols, and other substances in the barley, generating stable complexes and reducing the formation of undesirable components during fermentation. The product was placed in a hot air circulating drying oven at a drying temperature of 60℃ and a wind speed of 2m / s until the moisture content was 15%, thus obtaining modified organic highland barley.

[0064] The mass ratio of organic highland barley to compound enzyme solution is 1:2.5. The mass fraction of citric acid solution is 0.8%, and the spraying amount of citric acid solution is 10% of the mass of organic highland barley. The mass fraction of zinc sulfate solution is 0.3%, and the amount of zinc sulfate solution added is 6% of the mass of organic highland barley.

[0065] The complex enzyme solution is a mixture of cellulase, hemicellulase, and β-glucanase in a mass ratio of 2.5:1.2:1.2.

[0066] The modified compound yeast is prepared by a light-aroma type of yeast through a bio-activation reaction of traditional Chinese medicine extract, a dipotassium hydrogen phosphate ion exchange reaction, and a calcium chloride solution calcium ion complexation reaction.

[0067] The preparation method of modified compound yeast is as follows: Light-aroma type Daqu (a type of starter culture) is pulverized using a hammer mill with a sieve mesh size of 0.4 mm, controlling the particle size after pulverization to 60 mesh, yielding Daqu powder. Traditional Chinese medicine extract is added to the Daqu powder and stirred in a double-helix conical mixer for 30 minutes, controlling the stirring speed at 60 rpm and the temperature at 30℃. During this process, flavonoids, polysaccharides, and enzymes in the traditional Chinese medicine extract are adsorbed onto the surface of the Daqu powder particles, activating dormant saccharifying enzymes, liquefying enzymes, and aroma-producing yeasts in the Daqu, resulting in a bio-activation reaction and improving subsequent fermentation efficiency. After the reaction is complete, dipotassium hydrogen phosphate is added and mixed at 30℃ and the same stirring speed for 20 minutes. After the dipotassium hydrogen phosphate dissolves, it dissociates to release potassium. + and HPO4 -2 , with Na+ on microbial cell membranes + / K +The pump initiates an ion exchange reaction, regulating intracellular osmotic pressure while simultaneously providing a phosphorus source, promoting ATP synthesis, and enhancing microbial metabolic activity. After the reaction is complete, a calcium chloride aqueous solution is sprayed on top, and the mixture is stirred at 60 rpm for 15 minutes at 30°C. 2+ The modified compound yeast undergoes a complexation reaction with the negatively charged groups (such as carboxyl groups) on the surface of α-amylase and glucoamylase molecules in the Daqu (a type of starter culture), forming a stable enzyme-calcium complex. This improves the enzyme's thermal and pH stability, reducing inactivation during subsequent drying and storage. The product is placed in a 30°C constant temperature incubator with 80% relative humidity and allowed to ferment for 48 hours. During this stage, microbial metabolic reactions occur: yeast utilizes sugars to produce ethanol and esters, Bacillus secretes proteases and lipases, and the herbal ingredients further promote the reproduction of aroma-producing fungi (such as Pichia pastoris and Hansenula polymorpha), forming richer flavor precursor substances. The fermented material is then placed in a hot air circulating drying oven at 40°C and a wind speed of 2 m / s until the moisture content is ≤10%, yielding the modified compound yeast.

[0068] The amount of herbal extract added is 1.5% of the mass of Daqu powder. The amount of dipotassium hydrogen phosphate added is 0.7% of the mass of Daqu powder. The mass fraction of calcium chloride aqueous solution is 0.4%, and the amount of calcium chloride aqueous solution added is 8% of the mass of Daqu powder.

[0069] The herbal extract is prepared by mixing licorice root, medicated leaven, and malt in a 1:1:1 mass ratio. The mixed herbs are then pulverized using a grinder and passed through a 40-mesh sieve to obtain a coarse powder. Twelve times the mass of purified water is added to the coarse powder, and the mixture is heated in an extraction tank equipped with a stirrer at 60 rpm until boiling. The mixture is then maintained at a gentle boil for 2 hours. After decoction, the mixture is filtered through a 200-mesh filter cloth or a plate and frame filter press. The filtrate is collected and transferred to a vacuum concentration tank. The temperature is controlled at 70℃ and the vacuum degree at -0.095 MPa, and the mixture is concentrated to 35% of its original volume to obtain the herbal extract.

[0070] The method for preparing pretreated brewing water is as follows: Pure water is added at a concentration of 10m... 3 After the suspended solids are physically removed by a 50cm thick quartz sand filter layer at a flow rate of / h, the flow rate is then increased to 8m 3 The water flows through a 30cm thick granular activated carbon filter layer at a flow rate of / h, utilizing the adsorption of functional groups on the activated carbon surface to remove organic matter and residual chlorine. 0.1% (by weight of purified water) of maifanite powder is added to the filtered water, and the mixture is reacted at 30℃ for 30 minutes at 120 rpm. Beneficial minerals are released and some heavy metal ions are adsorbed through ion exchange and trace dissolution. After standing for 1 hour to allow undissolved powder to precipitate, the water is finally filtered through a 5μm precision filter at a pressure of 0.3MPa to obtain pretreated brewing water.

[0071] Comparative Example 1: The difference between this comparative example and Example 1 is that the modified organic barley is replaced with untreated organic barley.

[0072] Comparative Example 2 differs from Example 1 in that the modified compound yeast is replaced with untreated light-aroma daqu.

[0073] Comparative Example 3 differs from Example 1 in that the pretreated brewing water in this comparative example is replaced with purified water.

[0074] Performance testing: The relevant performance of the samples from the secondary brewing methods of light-aroma organic highland barley liquor provided in Examples 1 to 3 and Comparative Examples 1 to 3 were tested respectively, and the test data are recorded in the table below:

[0075] Table 1 - Performance Test Table of Light-Aroma Organic Highland Barley Baijiu

[0076] Testing items Alcohol yield (%, 65% vol base liquor) Ethyl acetate content (mg / 100mL) Fusel oil content (g / L) Example 1 54.3 300 1.38 Example 2 55.8 312 1.32 Example 3 57.2 321 1.28 Comparative Example 1 42.5 210 1.95 Comparative Example 2 48.6 230 1.85 Comparative Example 3 49.2 245 1.79

[0077] Among them, the yield of light-aroma organic highland barley liquor prepared using the test methods in GB / T10345-2022 in Examples 1, 2, 3, Comparative Examples 1, 2, and 3 was tested.

[0078] The ethyl acetate content of light-aroma organic highland barley liquor prepared according to the test methods in GB / T10345-2022 (Examples 1, 2, 3, Comparative Examples 1, 2, and 3) was tested.

[0079] The content of fusel oil in light-aroma organic highland barley liquor prepared using the test methods in GB5009.267-2016 (Examples 1, 2, 3, Comparative Examples 1, 2, and 3) was tested.

[0080] By comparing and analyzing the relevant data in the table, it can be seen that the high yield of the light-aroma organic highland barley liquor prepared by this invention indicates high starch utilization and good fermentation efficiency. The high ethyl acetate content indicates strong ester production capacity of the yeast, resulting in a rich aroma and good quality liquor. The low fusel oil content indicates a pure fermentation process and fewer harmful byproducts. Therefore, the secondary brewing method for light-aroma organic highland barley liquor provided by this invention has a broader market prospect and is more suitable for promotion.

[0081] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0082] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for secondary brewing of light-aroma organic highland barley liquor, characterized in that, The method includes the following steps: S1. After washing and soaking the modified organic highland barley, cook it under normal pressure until it is fully cooked, and then cool it to 30-35℃ to obtain cooked highland barley; S2. Add modified compound yeast to ripe highland barley, stir evenly, and carry out open saccharification to obtain saccharified mash; S3. Transfer the saccharified mash to a fermentation container, add pretreated brewing water, seal and carry out the first fermentation. The temperature is controlled at 25-28℃ and the fermentation time is 15-20 days to obtain the first fermented mash. S4. The first fermented mash is distilled for the first time, and the liquor is collected. The resulting mash is added to pretreated brewing water for a second fermentation. The temperature is controlled at 28-32℃, and the fermentation time is 10-15 days. The mash is distilled again, and the liquor obtained from the two distillations is mixed. After aging and filtration, a light-aroma organic highland barley liquor is produced.

2. The method for secondary brewing of light-aroma organic highland barley liquor according to claim 1, characterized in that: The modified organic highland barley is prepared by enzymatic hydrolysis of organic highland barley with a compound enzyme solution, acidification with citric acid solution, and complexation with zinc sulfate solution. The citric acid solution is a food-grade monohydrate citric acid aqueous solution, and the zinc sulfate solution is a food-grade heptahydrate zinc sulfate aqueous solution.

3. The method for secondary brewing of light-aroma organic highland barley liquor according to claim 2, characterized in that, The modified organic highland barley is prepared as follows: organic highland barley is soaked in a compound enzyme solution to undergo hydrolysis to obtain enzymatically hydrolyzed highland barley; citric acid solution is sprayed onto the surface of the enzymatically hydrolyzed highland barley, and an acidification reaction is carried out by standing at room temperature; after the reaction is completed, zinc sulfate solution is added, and a complexation reaction is carried out at room temperature to generate a stable complex; the product is dried in a hot air circulating drying oven to obtain modified organic highland barley.

4. The method for secondary brewing of light-aroma organic highland barley liquor according to claim 2, characterized in that: The mass ratio of organic highland barley to compound enzyme solution is 1:1.5-2.5; the mass fraction of citric acid solution is 0.4-0.8%, and the spraying amount of citric acid solution is 6-10% of the mass of organic highland barley; the mass fraction of zinc sulfate solution is 0.1-0.3%, and the amount of zinc sulfate solution added is 4-6% of the mass of organic highland barley.

5. The method for secondary brewing of light-aroma organic highland barley liquor according to claim 2, characterized in that: The complex enzyme solution is a mixture of cellulase, hemicellulase, and β-glucanase in a mass ratio of 1.5-2.5:0.8-1.2:0.8-1.2, and then diluted with water to a mass fraction of 0.2-0.4%.

6. The method for secondary brewing of light-aroma organic highland barley liquor according to claim 1, characterized in that: The modified composite yeast is prepared by a light-aroma type of yeast through a bio-activation reaction of traditional Chinese medicine extract, a dipotassium hydrogen phosphate ion exchange reaction, and a calcium chloride solution calcium ion complexation reaction.

7. The method for secondary brewing of light-aroma organic highland barley liquor according to claim 6, characterized in that, The modified compound yeast is prepared as follows: A light-aroma type yeast is pulverized to obtain yeast powder. A traditional Chinese medicine extract is added to the yeast powder, and the mixture is stirred in a double-helix conical mixer at 20-30℃ to carry out a bio-activation reaction. After the reaction, dipotassium hydrogen phosphate is added, and the mixture is stirred again at 20-30℃ to carry out an ion exchange reaction. After the reaction, a calcium chloride aqueous solution is sprayed, and the mixture is stirred in a mixer to carry out a complexation reaction. The product is placed in a constant temperature incubator at 25-30℃ for static fermentation. After fermentation, the product is dried in a hot air circulating drying oven to obtain the modified compound yeast.

8. The method for secondary brewing of light-aroma organic highland barley liquor according to claim 6, characterized in that: The amount of the herbal extract added is 0.5-1.5% of the mass of the Daqu powder; the amount of dipotassium hydrogen phosphate added is 0.5-0.7% of the mass of the Daqu powder; the mass fraction of the calcium chloride aqueous solution is 0.2-0.4%, and the amount of the calcium chloride aqueous solution added is 4-8% of the mass of the Daqu powder.

9. The method for secondary brewing of light-aroma organic highland barley liquor according to claim 6, characterized in that: The herbal extract is made by mixing licorice, medicated leaven, and malt in a mass ratio of 1:1:

1. The mixed herbs are then pulverized using a pulverizer to obtain coarse powder. 8-12 times the mass of purified water is added to the coarse powder, and the mixture is heated in an extraction tank equipped with a stirrer at 30-60 rpm until boiling, then maintained at a gentle boil. After decoction, the mixture is filtered, and the filtrate is collected and transferred to a vacuum concentration tank. The temperature is controlled at 60-70℃, and the vacuum degree is (-0.08)-(-0.095) MPa, concentrating the mixture to 25-35% of its original volume to obtain the herbal extract.

10. The method for secondary brewing of light-aroma organic highland barley liquor according to claim 1, characterized in that, The method for preparing the pretreated brewing water is as follows: after the purified water is physically filtered through a quartz sand filter layer to remove suspended solids, it is then filtered through a granular activated carbon filter layer to remove organic matter and residual chlorine; 0.06-0.1% of the mass of the purified water is added to the filtered water, and the mixture is stirred at 20-30℃ to adsorb some heavy metal ions. After standing, the mixture is filtered to obtain the pretreated brewing water.