Process for improving quality of Luzhou-flavor liquor

Abstract

The invention provides a technology for improving the quality of Luzhou-flavor liquor, and belongs to the technical field of liquor brewing. Comprising the following steps of raw material preparation, raw material pretreatment, raw material bacterium cultivation, raw material fermentation, distillation for liquor production and the like, liquor liquid stored for one year is taken out, blended, sterilized and packaged, and the Luzhou-flavor liquor is obtained. The aroma in the wine is richer, and the wine has the mellow flavor of grains and also has some natural warm and moist tastes; secondly, a bacillus subtilis microbial agent is specially cultivated, the bacillus subtilis microbial agent is used for cultivating the raw materials, subsequent fermentation treatment is carried out, and the temperature is accurately controlled during fermentation, so that flavor substances in the wine are more sufficient, and the ester flavor is coordinated and not abrupt.

Description

Technical Field

[0001] This invention relates to the field of baijiu brewing technology, and in particular to a process for improving the quality of strong-aroma baijiu. Background Technology

[0002] Baijiu is a type of distilled spirit made from starchy or sugary raw materials using yeast and starter culture as saccharifying and fermenting agents. It is produced through cooking, saccharification, fermentation, distillation, aging, and blending. Baijiu is a unique Chinese distilled spirit and one of the world's seven major distilled spirits. It is colorless or slightly yellow and transparent, with a pure and fragrant aroma. It is smooth, sweet, and refreshing on the palate and has a relatively high alcohol content. After aging, it develops a complex aroma mainly composed of esters. In particular, strong-aroma baijiu has a strong and fragrant aroma that is very popular.

[0003] Currently, there are various types of strong-aroma baijiu on the market. With its unique sensory flavor and more comfortable after-drinking experience, strong-aroma baijiu is increasingly favored by consumers. The body of strong-aroma baijiu contains a richer variety of flavor substances and bioactive components. The brewing process of each type of strong-aroma baijiu is also very different, which results in inconsistent taste and quality of strong-aroma baijiu. Therefore, a process for improving the quality of strong-aroma baijiu is proposed. Summary of the Invention

[0004] The technical problem this invention aims to solve is that strong-aroma baijiu contains a richer variety of flavor substances and bioactive components, and the brewing processes of each type of strong-aroma baijiu are also very different, which results in inconsistent tastes and differences in the quality of strong-aroma baijiu. The question is how to improve the quality of strong-aroma baijiu.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a process for improving the quality of strong-aroma baijiu, comprising the following steps: Step 1: Prepare the ingredients: 100-150 parts barley, 50-80 parts peas, 200-240 parts wheat, 10-16 parts hawthorn, 1-3 parts astragalus, 10-15 parts jujubes, 4-6 parts bamboo leaves, 300-330 parts sorghum, 150-180 parts rice, 250-280 parts glutinous rice, and 50-58 parts corn. Step 2, Raw material pretreatment: The above raw materials are soaked, dried, pre-steamed and fully steamed in sequence, and then mixed to obtain mixed raw materials; Step 3: Raw material cultivation: The mixed raw materials are molded and pressed into koji blanks. Then, the prepared solid inoculant is added to the koji blanks for fermentation and cultivation. The maximum fermentation temperature is 60-75℃, and it is maintained for 6-8 days. Step 4: Raw material fermentation: Ferment the mixed raw materials after bacterial culture; Step 5: Distillation: Distill the mixed raw materials obtained from fermentation to obtain alcohol. The distillation temperature is 100-105℃, the steam pressure is 0.3-0.5MPa, and the temperature of the flowing alcohol is 35-45℃, which yields strong-aroma base liquor. Step Six: After settling the strong-aroma base liquor obtained in Step Five, adsorb it with maifan stone, filter the base liquor using a microporous filter membrane, and add a small amount of sandalwood and agarwood to the filtered base liquor. Ferment in the open air for 15-20 days, separate the liquor, clarify and filter it, and put the liquor into new oak barrels with a volume of 300-550L. Place them in a cool and dry room, maintain an indoor temperature of 15-25℃ and a humidity of 55-75%, and store for 4-8 months. After storing in new barrels for 4-8 months, store in old oak barrels for 1 year under the same environmental conditions. Take out the liquor after 1 year of storage, blend it, sterilize and package it to obtain strong-aroma baijiu.

[0006] Preferably, in step three, the mixed raw materials are molded and pressed into koji blanks, and then the obtained solid microbial agent is added to the koji blanks for fermentation and cultivation. The method for preparing the solid microbial agent includes: Strain activation: Bacillus subtilis was isolated from high-temperature Daqu (a type of starter culture), and the Bacillus subtilis was placed in glycerol tubes for preservation. A small number of cells were selected from the glycerol tubes and streaked on solid culture plates. The plates were incubated at 37°C for 18 hours. After single colonies grew, single colonies were picked and streaked again. This process was repeated three times to activate and purify the strain. Primary seed culture: A small number of single colonies were picked from the activated Bacillus subtilis plate and inoculated into the liquid culture medium at a volume of 15 ml / 150 ml. The culture was carried out at 37 °C and 200 r / min until the growth stabilized. Secondary seed culture: Inoculate 10% (V / V) of the primary seed culture into the liquid culture medium, with a liquid volume of 15ml / 250ml, and culture at 37℃ and 200r / min until the growth stabilizes.

[0007] Preferably, the method for preparing the solid microbial agent further includes: Preparation of solid inoculum: Take wheat husk and wheat flour, and put them into stainless steel basins. Mix wheat flour and wheat husk at a mass ratio of 1:1 in each stainless steel basin. Add 300 ml of secondary seed liquid (inoculation amount of 10%) and 750 ml of water to each 3 kg of raw material, so that the final moisture content is 37.1%. Cover the stainless steel basin with gauze and place it in a high-temperature incubator for solid culture. On the first day, incubate at 37℃ for 24 h in the incubator. On the second day, adjust the culture temperature to 44℃ and continue for 1 day. On the third day of fermentation, adjust the culture temperature to 52℃ and maintain high-temperature aroma for 2 days. Repeat this process twice to prepare solid inoculum. Observe the fermentation during the fermentation process, and add water, stir, and measure the temperature every day according to the humidity. Solid microbial agent enhancement: The prepared microbial agent is naturally dried and then ground into powder to obtain an enhanced solid microbial agent.

[0008] Preferably, the initial steaming and final steaming processes in step two include: Preliminary steaming and cooking: Mix sorghum, rice, glutinous rice, and corn evenly and put them into a steamer for steaming. The steam pressure is 0.5-0.8 MPa and the steaming time is 45-50 minutes. After steaming and cooking, the raw material after preliminary steaming and cooking is obtained. Steaming treatment: The raw materials after the initial steaming treatment are mixed with the steamed rice husks and then distilled in a still. The distillation temperature is 100-105℃, the steam pressure is 0.3-0.7MPa, and the steaming time is 50-70min to obtain the raw materials after steaming treatment.

[0009] Preferably, the raw material preparation includes preliminary screening of the selected raw materials based on the differences in grain characteristics to obtain high-quality raw materials that meet quality standards; for the selection of sorghum, japonica sorghum is selected, with plump grains, thin and uniform skin, impurities ≤1%, moisture ≤14.5%, and bulk density ≥720g / L; the crushing degree is 70%-80% with 4-8 segments and a 1.2mm sieve aperture passing rate of 20%-30%, which is used as the raw material for sorghum; for the selection of wheat / barley / peas, wheat bulk density ≥770g / L and impurities ≤1.0%, and pea purity rate ≥95%; the crushing degree is based on the sorghum screening standard; corn is crushed into 2-4 segments, and rice / glutinous rice is selected with plump whole grains.

[0010] Preferably, in step two, the above-mentioned raw materials are soaked in different ways according to their different characteristics. Sorghum, rice, and glutinous rice are soaked at high temperature (87-90℃) for 18-24 hours to promote starch expansion; wheat is soaked at medium temperature (40-45℃) for 16-20 hours to protect the protein from denaturation; and corn is soaked at high temperature (87-90℃) for a long time (40-48 hours) to break down the dense starch structure.

[0011] Preferably, in step four, the method for fermenting the mixed raw materials after bacterial culture includes: (a) Preparations before fermentation: Disinfection of earthenware vats: Traditional earthenware vats are used. They are rinsed with boiling water three times in advance, dried, and then coated with a layer of sterile cooked lard on the vat wall. Adding fermented mash: Add the mature fermented mash to the mash at a ratio of "cultivation raw material: mash = 1:3-3.5". The microbial community contained in the mash can assist fermentation and adjust the acidity to 0.1-0.3, providing a suitable acid-base environment for fermentation. (II) Fermentation in the vat: Mix the cultured raw materials evenly with the prepared mash, and put them into the ground vat. The filling height is 10cm from the vat opening. After spreading the surface evenly, cover it with a 2cm thick layer of sterile rice husks, then seal the vat opening with plastic film, tie it tightly, and cover it with a burlap sack for insulation. Inlet temperature control: In cold season, when the temperature is below 10℃, the inlet temperature should be 22-24℃; in hot season, when the temperature is above 25℃, the inlet temperature should be 18-20℃. (III) Segmented control of the fermentation process The pre-fermentation period is 1-5 days, during which the starch is converted into sugar and then into alcohol. The temperature is raised naturally, and on the 3rd day, the material temperature rises to 28-30℃. The temperature is maintained by adjusting the thickness of the burlap sack. The lid is opened for ventilation for 3 minutes every day, and the alcohol content is tested at the same time. On the 5th day, it should be ≥8% vol. If the alcohol content is too low, 0.1% saccharifying enzyme activator needs to be added. The main fermentation period is 6-12 days, during which a large amount of light and fragrant core flavor substances are generated. Maintain the material temperature at 26-28℃, avoiding exceeding 30℃. Test the acidity every 2 days, maintaining it between 0.8-1.2. If the acidity is >1.5, add 0.2% calcium carbonate to adjust and inhibit acid-producing bacteria. At the same time, test the ethyl acetate content, which should be ≥0.8g / L on the 12th day. The post-fermentation period lasts 13-30 days, during which flavor compounds transform into each other; the temperature naturally drops to 20-22℃ for slow fermentation; the alcohol content stabilizes at 12%-14% vol, the acidity is 0.1.4-1.8, and the raw materials have no raw grain smell or sour smell, but emit a pure and fresh aroma, indicating that fermentation is complete.

[0012] Preferably, in step five, before distilling the fermented mixed raw materials, the process further includes pre-treatment of the fermented raw materials. After fermentation, the mud pit lid is opened, and the fermented mash (mixed raw materials + fermentation products) is removed. The state of the mash is checked; it should be brownish-red in color, loose in texture, free of sour / rotten odor, and contain an appropriate amount of pit mud fragments. If the mash is clumped together, it should be broken up with sterile tools. The moisture content of the mash should be controlled at 58%-60%, and the acidity at 1.4-1.8. If the moisture content is too high, it should be spread out and cooled for 10 minutes; if it is too low, it should be sprayed with 35°C warm water to adjust. Before distillation, a traditional ceramic still or a 304 stainless steel still is selected, rinsed three times with boiling water, dried, and then a 5cm layer is laid at the bottom of the still. Thick, sterile rice husks; the connection between the steamer lid and the steamer bucket is sealed with sterile gauze to prevent steam leakage; a thermometer (accuracy ±0.5℃) is installed at the steamer lid vent and connected to a condenser, with the condensate temperature controlled at 15-20℃.

[0013] Preferably, in step five, the mixed raw materials obtained from fermentation are distilled to produce alcohol. During the distillation process, the temperature of the still lid needs to be monitored in real time. If the temperature suddenly rises above 105°C, there is insufficient moisture in the mash, and 35°C warm water needs to be sprayed to adjust it. If the temperature remains low below 90°C, there is air leakage in the equipment, and it needs to be sealed in time.

[0014] Preferably, the steamed rice husks are steamed at a temperature of 100-105℃, a steam pressure of 0.7-0.9MPa, and a steaming time of 35-45min.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: This invention enriches the raw materials by combining various grains with ingredients such as hawthorn and astragalus, resulting in a more complex aroma in the liquor, with a mellow grain flavor and a naturally smooth taste. Secondly, it utilizes a specially cultivated Bacillus subtilis inoculant to cultivate bacteria in the raw materials for subsequent fermentation. Precise temperature control during fermentation ensures a richer aroma and a harmonious, non-overpowering ester fragrance. Temperature control and fractional distillation remove harmful impurities such as methanol and fusel oils, resulting in a purer liquor. The use of maifanite adsorption, microporous filtration, and sandalwood and agarwood for aroma enhancement further purifies the liquor, adding a mellow, complex aroma. The use of both new and old oak barrels for staged aging results in a smoother, more mellow taste, significantly improving the flavor of strong-aroma baijiu and thus enhancing its overall quality. Attached Figure Description

[0016] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0017] Figure 1 A schematic diagram of the process structure for improving the quality of strong-aroma baijiu; As shown in the figure, specific structures and devices are marked in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0018] The circuit autonomous inspection type box-type substation and its inspection method provided by the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0019] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when describing a specific feature, structure, or characteristic in conjunction with embodiments, the implementation of such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described, should be within the knowledge of those skilled in the art.

[0020] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0021] It is understood that the meanings of “on”, “above”, and “above” in this invention should be interpreted in the broadest manner, such that “on” means not only “directly on” something, but also includes the meaning of being “on” something with an intervening feature or layer, and that “above” or “above” means not only “on” something, but also includes the meaning of being “on” something without an intervening feature or layer.

[0022] Furthermore, spatially related terms such as “below,” “under,” “lower,” “above,” and “upper” are used herein for convenience to describe the relationship of one element or feature to one or more other elements or features, as illustrated in the accompanying drawings. Spatially related terms are intended to cover different orientations in the use or operation of the device other than those depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially related descriptive terms used herein can be interpreted similarly.

[0023] Example 1:

[0024] This specific implementation method is a process for improving the quality of strong-aroma baijiu, such as... Figure 1 As shown, it includes the following steps: Step 1: Prepare the ingredients: 100-150 parts barley, 50-80 parts peas, 200-240 parts wheat, 10-16 parts hawthorn, 1-3 parts astragalus, 10-15 parts jujubes, 4-6 parts bamboo leaves, 300-330 parts sorghum, 150-180 parts rice, 250-280 parts glutinous rice, and 50-58 parts corn. Step 2, Raw material pretreatment: The above raw materials are soaked, dried, pre-steamed and fully steamed in sequence, and then mixed to obtain mixed raw materials; Step 3: Raw material cultivation: The mixed raw materials are molded and pressed into koji blanks. Then, the prepared solid inoculant is added to the koji blanks for fermentation and cultivation. The maximum fermentation temperature is 60-75℃, and it is maintained for 6-8 days. Step 4: Raw material fermentation: Ferment the mixed raw materials after bacterial culture; Step 5: Distillation: Distill the mixed raw materials obtained from fermentation to obtain alcohol. The distillation temperature is 100-105℃, the steam pressure is 0.3-0.5MPa, and the temperature of the flowing alcohol is 35-45℃, which yields strong-aroma base liquor. Step Six: After settling the strong-aroma base liquor obtained in Step Five, adsorb it with maifan stone, filter the base liquor using a microporous filter membrane, and add a small amount of sandalwood and agarwood to the filtered base liquor. Ferment in the open air for 15-20 days, separate the liquor, clarify and filter it, and put the liquor into new oak barrels with a volume of 300-550L. Place them in a cool and dry room, maintain an indoor temperature of 15-25℃ and a humidity of 55-75%, and store for 4-8 months. After storing in new barrels for 4-8 months, store in old oak barrels for 1 year under the same environmental conditions. Take out the liquor after 1 year of storage, blend it, sterilize and package it to obtain strong-aroma baijiu.

[0025] This invention enriches the raw materials by combining various grains with ingredients such as hawthorn and astragalus, resulting in a more complex aroma in the liquor, with a mellow grain flavor and a naturally smooth taste. Secondly, it utilizes a specially cultivated Bacillus subtilis inoculant to cultivate bacteria in the raw materials for subsequent fermentation. Precise temperature control during fermentation ensures a richer aroma and a harmonious, non-overpowering ester fragrance. Temperature control and fractional distillation remove harmful impurities such as methanol and fusel oils, resulting in a purer liquor. The use of maifanite adsorption, microporous filtration, and sandalwood and agarwood for aroma enhancement further purifies the liquor, adding a mellow, complex aroma. The use of both new and old oak barrels for staged aging results in a smoother, more mellow taste, significantly improving the flavor of strong-aroma baijiu and thus enhancing its overall quality.

[0026] Raw material preparation: During production, select 100-150 parts barley, 50-80 parts peas, 200-240 parts wheat, 10-16 parts hawthorn, 1-3 parts astragalus, 10-15 parts jujube, 4-6 parts bamboo leaves, 300-330 parts sorghum, 150-180 parts rice, 250-280 parts glutinous rice, and 50-58 parts corn as raw materials. Preliminary screening is conducted based on the differences in grain characteristics to ensure the acquisition of high-quality raw materials that meet quality standards. For sorghum: select japonica sorghum, requiring plump grains, thin and uniform skin, impurity content ≤1%, moisture content ≤14.5%, and bulk density ≥720g / L. After grinding, 70%-80% of the grains should be 4-8 cloves, and the passing rate through a 1.2mm sieve should be controlled at 20%-30%. Avoid grinding too finely, which could cause the mash to stick together, or too coarsely, which could affect starch gelatinization. Wheat / Barley / Peas: Wheat bulk density ≥770g / L, impurity content ≤1.0%, pea purity ≥95%; fineness of grinding refers to the sorghum screening standard, i.e., 70%-80% of the grains are 4-8 cloves, and 20%-30% pass through a 1.2mm sieve, ensuring the growth and metabolism of microorganisms during subsequent koji-making. Corn: Grind it into 2-4 cloves. Because corn starch has a dense structure, this fineness of grinding can increase the contact area between starch and enzymes, improving conversion efficiency. Rice / Glutinous Rice: Select plump, undamaged, and mold-free whole grains of rice to avoid flavor loss due to grinding, while ensuring air permeability during fermentation. Hawthorn, Astragalus, Jujube, Lophatherum gracile: Select high-quality raw materials that are free from mold, insect infestation, and normal color. Remove the pits from the hawthorn, slice the astragalus, remove the pits from the jujube, and wash and dry the lophatherum gracile for later use.

[0027] 2. Raw material pretreatment Soaking Treatment: Different soaking methods are used according to the characteristics of the raw materials to ensure that the raw materials fully absorb water, laying the foundation for subsequent starch gelatinization: Sorghum, Rice, and Glutinous Rice: Soak at 87-90℃ for 18-24 hours. High temperature promotes the expansion of starch granules and breaks the hydrogen bonds between starch molecules, facilitating subsequent cooking and gelatinization. Wheat: Soak at 40-45℃ for 16-20 hours. Medium temperature avoids protein denaturation in wheat and ensures the nutrients needed by microorganisms during the koji-making process. Corn: Soak at 87-90℃ for a long time for 40-48 hours. Due to the dense structure of corn starch and its high dietary fiber content, extended soaking time ensures that water fully penetrates to the grain core and breaks down the dense starch structure. Barley and Peas: Similar to the soaking method for wheat, soak at 40-45℃ for 16-20 hours. Hawthorn, Astragalus, Jujube, and Lophatherum gracile: Soak in 35-40℃ warm water for 3-4 hours to soften them fully and facilitate the dissolution of active ingredients.

[0028] Drying process: After soaking, remove all ingredients and lay them flat on a clean, well-ventilated drying area to air dry naturally. During the drying process, turn them over regularly to ensure that the surface moisture evaporates evenly. Dry until there is no free water on the surface of the ingredients and they are no longer sticky to the touch. At this point, the moisture content of the ingredients should be controlled at 30%-35%. Avoid excessive moisture, which may lead to mold, or insufficient moisture, which may affect the subsequent steaming and cooking results.

[0029] Preliminary steaming: Grind sorghum, rice, glutinous rice, and corn into powder, mix thoroughly, and place in a traditional ceramic steamer or a 304 stainless steel steamer for preliminary steaming. Control the steam pressure at 0.5-0.8 MPa and the steaming time at 45-50 minutes. The high temperature and pressure initially gelatinize the starch in the raw materials, breaking down the starch granule structure and killing any bacteria on the surface. During steaming, observe the raw materials every 10 minutes to ensure they are cooked but not sticky, and have no uncooked center. After preliminary steaming, remove the raw materials and let them cool to 35-40℃.

[0030] Steaming Treatment: First, steam the rice husks at a temperature of 100-105℃ and a steam pressure of 0.7-0.9 MPa for 35-45 minutes to remove impurities and harmful substances. Then, mix the steamed rice husks (10%-15% of the total raw material mass) into the pre-steamed raw material, stir well, and steam again. Control the distillation temperature at 100-105℃, the distillation steam pressure at 0.3-0.7 MPa, and the cooking time at 50-70 minutes to fully gelatinize the starch in the raw material. Simultaneously, utilize the permeability of the rice husks to provide a favorable microenvironment for subsequent fermentation. After steaming, remove the raw material and let it cool to 25-30℃.

[0031] Mixing Process: Thoroughly mix the steamed sorghum, rice, glutinous rice, and corn with the soaked and dried barley, peas, wheat, hawthorn, astragalus, jujubes, and bamboo leaves to obtain a mixed raw material. During mixing, ensure even distribution of all ingredients to avoid localized high concentrations that could negatively impact fermentation. The moisture content of the mixed raw material should be controlled at 45%-50%. In this embodiment, in step three, the mixed raw materials are molded and pressed into koji blanks, and then the obtained solid microbial agent is added to the koji blanks for fermentation and cultivation. The method for preparing the solid microbial agent includes: Strain activation: Bacillus subtilis was isolated from high-temperature Daqu (a type of starter culture), and the Bacillus subtilis was placed in glycerol tubes for preservation. A small number of cells were selected from the glycerol tubes and streaked on solid culture plates. The plates were incubated at 37°C for 18 hours. After single colonies grew, single colonies were picked and streaked again. This process was repeated three times to activate and purify the strain. Primary seed culture: A small number of single colonies were picked from the activated Bacillus subtilis plate and inoculated into the liquid culture medium at a volume of 15 ml / 150 ml. The culture was carried out at 37 °C and 200 r / min until the growth stabilized. Secondary seed culture: Inoculate 10% (V / V) of the primary seed culture into the liquid culture medium, with a liquid volume of 15ml / 250ml, and culture at 37℃ and 200r / min until the growth stabilizes.

[0032] In this embodiment, the method for preparing the solid microbial agent further includes: Preparation of solid inoculum: Take wheat husk and wheat flour, and put them into stainless steel basins. Mix wheat flour and wheat husk at a mass ratio of 1:1 in each stainless steel basin. Add 300 ml of secondary seed liquid (inoculation amount of 10%) and 750 ml of water to each 3 kg of raw material, so that the final moisture content is 37.1%. Cover the stainless steel basin with gauze and place it in a high-temperature incubator for solid culture. On the first day, culture at 37 ℃ for 24 h in the incubator. On the second day, adjust the culture temperature to 44 ℃ and continue for 1 day. On the third day of fermentation, adjust the culture temperature to 52 ℃ and maintain high-temperature aroma for 2 days. Repeat this process twice to prepare the solid inoculum. Observe the fermentation during the fermentation process, and add water, stir, and measure the temperature every day according to the humidity. Solid microbial agent enhancement: The prepared microbial agent is naturally dried and then ground into powder to obtain an enhanced solid microbial agent.

[0033] The mixed raw materials are loaded into a custom mold and pressed into cube-shaped koji blanks with a thickness of 3-5cm and a side length of 15-20cm. The pressing pressure is controlled at 0.3-0.5MPa to ensure that the koji blanks are compact but not hardened, and have good air permeability. A solid inoculant is evenly sprinkled onto the surface of the koji blank at 0.5%-1% of the weight of the mixed raw materials, and simultaneously spread evenly with a sterile brush to ensure full contact between the inoculant and the koji blank. The inoculated koji blanks are placed in a cultivation chamber, initially controlled at a temperature of 25-30℃ and a humidity of 85%-90%. During the cultivation process, the koji blanks will heat up due to the heat generated by microbial metabolism. When the temperature of the koji blanks reaches 60-75℃, this temperature is maintained for 6-8 days, with ventilation twice a day for 30 minutes each time. Moisture is added according to the humidity of the koji blanks to ensure a stable cultivation process. After cultivation, a uniform mycelial layer forms on the surface of the koji blanks, emitting a rich aroma, indicating that the mixed raw materials have been successfully cultivated.

[0034] In this embodiment, the initial steaming and final steaming processes in step two include: Preliminary steaming and cooking: Mix sorghum, rice, glutinous rice, and corn evenly and put them into a steamer for steaming. The steam pressure is 0.5-0.8 MPa and the steaming time is 45-50 minutes. After steaming and cooking, the raw material after preliminary steaming and cooking is obtained. Steaming treatment: The raw material after the initial steaming treatment is mixed with the steamed rice husks and then distilled in a still. The distillation temperature is 100-105℃, the steam pressure is 0.3-0.7MPa, and the steaming time is 50-70min to obtain the raw material after steaming treatment.

[0035] In this embodiment, the raw material preparation includes preliminary screening of the selected raw materials based on the differences in grain characteristics to obtain high-quality raw materials that meet the quality standards. For sorghum selection, japonica sorghum is selected, with plump grains, thin and uniform skin, impurities ≤1%, moisture ≤14.5%, and bulk density ≥720g / L. The raw materials with a crushing degree of 4-8 pieces accounting for 70%-80% and a 1.2mm sieve aperture passing rate of 20%-30% are used as sorghum raw materials. For wheat / barley / peas selection, wheat bulk density ≥770g / L and impurities ≤1.0% are selected, and pea purity rate ≥95% is selected. The crushing degree is based on the sorghum screening standard. Corn is crushed into 2-4 pieces, and rice / glutinous rice is selected with plump whole grains.

[0036] In this embodiment, the method of soaking the above-mentioned raw materials in step two is as follows: different soaking methods are used according to the differences in the characteristics of the raw materials. Sorghum, rice, and glutinous rice are soaked at high temperature (87-90℃) for 18-24 hours to promote starch expansion; wheat is soaked at medium temperature (40-45℃) for 16-20 hours to protect the protein from denaturation; and corn is soaked at high temperature (87-90℃) for a long time (40-48 hours) to break down the dense starch structure.

[0037] Example 2:

[0038] Based on Example 1, in this example, the fermentation method for the cultured mixed raw materials in step four includes: (a) Preparations before fermentation: Disinfection of earthenware vats: Traditional earthenware vats are used. They are rinsed with boiling water three times in advance, dried, and then coated with a layer of sterile cooked lard on the vat wall. Adding fermented mash: Add the mature fermented mash to the mash at a ratio of "cultivation raw material: mash = 1:3-3.5". The microbial community contained in the mash can assist fermentation and adjust the acidity to 0.1-0.3, providing a suitable acid-base environment for fermentation. (II) Fermentation in the vat: Mix the cultured raw materials evenly with the prepared mash, and put them into the ground vat. The filling height is 10cm from the vat opening. After spreading the surface evenly, cover it with a 2cm thick layer of sterile rice husks, then seal the vat opening with plastic film, tie it tightly, and cover it with a burlap sack for insulation. Inlet temperature control: In cold season, when the temperature is below 10℃, the inlet temperature should be 22-24℃; in hot season, when the temperature is above 25℃, the inlet temperature should be 18-20℃. (III) Segmented control of the fermentation process The pre-fermentation period is 1-5 days, during which the starch is converted into sugar and then into alcohol. The temperature is raised naturally, and on the 3rd day, the material temperature rises to 28-30℃. The temperature is maintained by adjusting the thickness of the burlap sack. The lid is opened for ventilation for 3 minutes every day, and the alcohol content is tested at the same time. On the 5th day, it should be ≥8% vol. If the alcohol content is too low, 0.1% saccharifying enzyme activator needs to be added. The main fermentation period is 6-12 days, during which a large amount of light and fragrant core flavor substances are generated. Maintain the material temperature at 26-28℃, avoiding exceeding 30℃. Test the acidity every 2 days, maintaining it between 0.8-1.2. If the acidity is >1.5, add 0.2% calcium carbonate to adjust and inhibit acid-producing bacteria. At the same time, test the ethyl acetate content, which should be ≥0.8g / L on the 12th day. The post-fermentation period lasts 13-30 days, during which flavor compounds transform into each other; the temperature naturally drops to 20-22℃ for slow fermentation; the alcohol content stabilizes at 12%-14% vol, the acidity is 0.1.4-1.8, and the raw materials have no raw grain smell or sour smell, but emit a pure and fresh aroma, indicating that fermentation is complete.

[0039] In this embodiment, step five, before distilling the fermented mixed raw materials, includes pre-treatment of the fermented raw materials. After fermentation, the mud pit lid is opened, and the fermented mash (mixed raw materials + fermentation products) is taken out. The state of the mash is checked; it should be brownish-red in color, loose in texture, free of sour / rotten smell, and contain an appropriate amount of pit mud fragments. If the mash is clumped together, it should be broken up with sterile tools. The moisture content of the mash should be controlled at 58%-60%, and the acidity at 1.4-1.8. If the moisture content is too high, it should be spread out and cooled for 10 minutes; if it is too low, it should be sprayed with 35°C warm water to adjust. Before distillation, a traditional ceramic still or a 304 stainless steel still is selected, rinsed with boiling water three times in advance, dried, and then a 5cm layer is laid at the bottom of the still. Thick, sterile rice husks; the connection between the steamer lid and the steamer bucket is sealed with sterile gauze to prevent steam leakage; a thermometer (accuracy ±0.5℃) is installed at the steamer lid vent and connected to a condenser, with the condensate temperature controlled at 15-20℃.

[0040] In this embodiment, in step five, the fermented mixed raw materials are distilled to produce alcohol. During the distillation process, the temperature of the still lid needs to be monitored in real time. If the temperature suddenly rises above 105°C, there is insufficient moisture in the mash, and 35°C warm water needs to be sprayed to adjust it. If the temperature remains low below 90°C, there is air leakage in the equipment, and it needs to be sealed in time.

[0041] Distillation operation: (1) Loading the still: The "layered loading" method is adopted. Each time, 10-15cm thick mash is loaded, spread out with a wooden rake and pressed lightly to avoid the mash being too tight and affecting the steam penetration or too loose and causing the mash to collapse. Repeat the operation until the mash is filled to 80% of the still capacity. The loading time is controlled at 30-40 minutes to ensure that the mash is evenly distributed and conducive to the full dissolution of flavor substances. (2) Heating and Distillation: Ignite the bottom stove or start the steam boiler, and first heat up rapidly with high heat (high heat tailing stage, 0-15 minutes) to raise the temperature of the mash in the still from room temperature to 90-95℃, awakening the high-boiling-point flavor substances in the mash; when the condenser outlet starts dripping alcohol, switch to medium heat (medium heat distillation stage, 15-90 minutes), maintain the still lid temperature at 95-100℃, and control the flow rate at 3-4 kg / min; when the alcohol content drops below 55% vol, switch to low heat (low heat distillation tailing stage, 90-120 minutes), maintain the still lid temperature at 100-105℃, and recover the residual flavor substances. During the distillation process, the still lid temperature needs to be monitored in real time. If the temperature suddenly rises (>105℃), it may be that the mash is not moist enough, and 35℃ warm water should be sprayed immediately to adjust it; if the temperature remains low (<90℃), it may be that the equipment is leaking air, and it needs to be sealed in time. (3) Segmented distillation: Distilling is strictly carried out in segments according to the "heads - body - tails" method. First distillate: The liquid distilled in the first 5-8 minutes, with an alcohol content of ≥75% vol. This part has a strong spiciness and pungent aroma, and contains low-boiling-point impurities such as methanol and acetaldehyde. 3-5 kg ​​of this liquid should be discarded per 100 kg of mash to avoid affecting the quality of the liquor.

[0042] The main body of the spirit (initial base spirit): The spirit distilled in 8-85 minutes has an alcohol content of 65%-55% vol, a rich cellar aroma, a smooth and sweet taste, and contains core flavor substances such as ethyl hexanoate and ethyl acetate. It is divided into 65%-60% vol (superior base spirit) and 60%-55% vol (first-grade base spirit) according to alcohol content, and is separately sealed in sterilized ceramic jars.

[0043] Tail: The liquid distilled at 85-120 minutes has an alcohol content of <55% vol, a strong bitter taste, a bland aroma, and contains high-boiling-point impurities such as fusel oil and ethyl lactate. It is collected separately and used for the next round of redistillation to recover residual flavor substances.

[0044] (4) Distillation endpoint judgment: When the drip rate at the condenser outlet is ≤5 drops / minute and the alcohol content drops below 45% vol, stop distillation.

[0045] In this embodiment, the steamed rice husks are steamed at a temperature of 100-105℃, a steam pressure of 0.7-0.9MPa, and a steaming time of 35-45min.

[0046] Refined raw material processing: Through differentiated screening, soaking, and cooking processes, the characteristics of different raw materials are fully adapted to improve starch gelatinization efficiency and the amount of flavor precursors generated. At the same time, ingredients such as hawthorn and astragalus are added to enrich the nutritional components and flavor layers of the wine.

[0047] Targeted microbial cultivation: Solid microbial agents are prepared using purified Bacillus subtilis. The activity of the microbial agents is enhanced through precise temperature control and cultivation, which promotes aroma metabolism in a targeted manner, resulting in a significant increase in the content of core flavor substances (such as ethyl hexanoate) in baijiu and a richer cellar aroma.

[0048] Segmented fermentation: Through precise control of the three stages of fermentation (pre-, mid-, and post-fermentation), the fermentation temperature, acidity, and alcohol content are effectively controlled, inhibiting the growth of unwanted bacteria, reducing the generation of off-flavors, and making the wine taste purer and smoother.

[0049] Precise distillation: The combination of segmented temperature-controlled distillation and graded spirit extraction maximizes the extraction of flavor compounds while efficiently removing harmful impurities such as methanol and fusel oils, thus improving drinking safety.

[0050] Post-processing optimization: Maifan stone adsorption, microporous filtration, flavor enhancement, and staged storage in new and old oak barrels further improve the purity of the liquor, harmonize the aroma components, and enhance the aged aroma, so that the final product has the characteristics of a high-quality strong-aroma baijiu with "rich cellar aroma, smooth and sweet taste, harmonious aroma, and long aftertaste", with a good drinking experience, high safety, and strong market competitiveness.

[0051] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0052] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A process for improving the quality of strong-aroma baijiu, characterized in that, Includes the following steps: Step 1: Prepare the ingredients: 100-150 parts barley, 50-80 parts peas, 200-240 parts wheat, 10-16 parts hawthorn, 1-3 parts astragalus, 10-15 parts jujubes, 4-6 parts bamboo leaves, 300-330 parts sorghum, 150-180 parts rice, 250-280 parts glutinous rice, and 50-58 parts corn. Step 2, Raw material pretreatment: The above raw materials are soaked, dried, pre-steamed and fully steamed in sequence, and then mixed to obtain mixed raw materials; Step 3: Raw material cultivation: The mixed raw materials are molded and pressed into koji blanks. Then, the prepared solid inoculant is added to the koji blanks for fermentation and cultivation. The maximum fermentation temperature is 60-75℃, and it is maintained for 6-8 days. Step 4: Raw material fermentation: Ferment the mixed raw materials after bacterial culture; Step 5: Distillation: Distill the mixed raw materials obtained from fermentation to obtain alcohol. The distillation temperature is 100-105℃, the steam pressure is 0.3-0.5MPa, and the temperature of the flowing alcohol is 35-45℃, which yields strong-aroma base liquor. Step Six: After settling the strong-aroma base liquor obtained in Step Five, adsorb it with maifan stone, filter the base liquor using a microporous filter membrane, and add a small amount of sandalwood and agarwood to the filtered base liquor. Ferment in the open air for 15-20 days, separate the liquor, clarify and filter it, and put the liquor into new oak barrels with a volume of 300-550L. Place them in a cool and dry room, maintain an indoor temperature of 15-25℃ and a humidity of 55-75%, and store for 4-8 months. After storing in new barrels for 4-8 months, store in old oak barrels for 1 year under the same environmental conditions. Take out the liquor after 1 year of storage, blend it, sterilize and package it to obtain strong-aroma baijiu.

2. The process for improving the quality of strong-aroma baijiu according to claim 1, characterized in that, In step three, the mixed raw materials are molded and pressed into koji blanks, and then the obtained solid microbial agent is added to the koji blanks for fermentation and cultivation. The method for preparing the solid microbial agent includes: Strain activation: Bacillus subtilis was isolated from high-temperature Daqu (a type of starter culture), and the Bacillus subtilis was placed in glycerol tubes for preservation. A small number of cells were selected from the glycerol tubes and streaked on solid culture plates. The plates were incubated at 37°C for 18 hours. After single colonies grew, single colonies were picked and streaked again. This process was repeated three times to activate and purify the strain. Primary seed culture: A small number of single colonies were picked from the activated Bacillus subtilis plate and inoculated into the liquid culture medium at a volume of 15 ml / 150 ml. The culture was carried out at 37 °C and 200 r / min until the growth stabilized. Secondary seed culture: Inoculate 10% (V / V) of the primary seed culture into the liquid culture medium, with a liquid volume of 15ml / 250ml, and culture at 37℃ and 200r / min until the growth stabilizes.

3. The process for improving the quality of strong-aroma baijiu according to claim 2, characterized in that, The method for preparing the solid microbial agent further includes: Preparation of solid microbial agent: Take wheat husk and wheat flour, and put them into stainless steel basins. Mix wheat flour and wheat husk in each stainless steel basin at a mass ratio of 1:

1. Add 300 ml of secondary seed liquid and 750 ml of water to each 3 kg of raw material, so that the final moisture content is 37.1%. Cover the stainless steel basin with gauze and put it into a high-temperature incubator for solid culture. On the first day, culture at 37 ℃ for 24 h. On the second day, adjust the culture temperature to 44 ℃ and continue for 1 day. On the third day of fermentation, adjust the culture temperature to 52 ℃ and maintain high-temperature aroma for 2 days. Repeat this process twice to prepare solid microbial agent. Observe the fermentation during the fermentation process, and add water, stir, and measure the temperature every day according to the humidity. Solid microbial agent enhancement: The prepared microbial agent is naturally dried and then ground into powder to obtain an enhanced solid microbial agent.

4. The process for improving the quality of strong-aroma baijiu according to claim 1, characterized in that, The initial steaming and final steaming processes in step two include: Preliminary steaming and cooking: Mix sorghum, rice, glutinous rice, and corn evenly and put them into a steamer for steaming. The steam pressure is 0.5-0.8MPa and the steaming time is 45-50 minutes. After steaming and cooking, the raw material after preliminary steaming and cooking is obtained. Steaming treatment: The raw material after the initial steaming treatment is mixed with the steamed rice husks and then distilled in a still. The distillation temperature is 100-105℃, the steam pressure is 0.3-0.7MPa, and the steaming time is 50-70min to obtain the raw material after steaming treatment.

5. The process for improving the quality of strong-aroma baijiu according to claim 1, characterized in that, The raw material preparation includes preliminary screening of the selected raw materials based on the differences in grain characteristics to obtain high-quality raw materials that meet quality standards. For sorghum selection, japonica sorghum is selected, with plump grains, thin and uniform skin, impurities ≤1%, moisture ≤14.5%, and bulk density ≥720g / L. The raw materials with a crushing degree of 4-8 pieces accounting for 70%-80% and a 1.2mm sieve aperture passing rate of 20%-30% are used as sorghum raw materials. For wheat / barley / peas selection, wheat bulk density ≥770g / L and impurities ≤1.0% are selected, and pea purity rate ≥95% is selected. The crushing degree is based on the sorghum screening standard. Corn is crushed into 2-4 pieces, and rice / glutinous rice is selected with plump whole grains.

6. The process for improving the quality of strong-aroma baijiu according to claim 1, characterized in that, In step two, the above-mentioned raw materials are soaked in different ways according to their different characteristics. Sorghum, rice, and glutinous rice are soaked at high temperature (87-90℃) for 18-24 hours to promote starch expansion. Wheat is soaked at medium temperature (40-45℃) for 16-20 hours to protect the protein from denaturation. Corn is soaked at high temperature (87-90℃) for a long time (40-48 hours) to break down the dense starch structure.

7. The process for improving the quality of strong-aroma baijiu according to claim 1, characterized in that, In step four, the fermentation method for the mixed raw materials after bacterial culture includes: Preparation before fermentation: Disinfection of earthenware vats: Traditional earthenware vats are used. They are rinsed with boiling water three times in advance, dried, and then coated with a layer of sterile cooked lard on the vat wall. Adding pre-fermented mash: Add the pre-fermented mash to the mature fermented mash at a ratio of 1:3-3.5 (raw material: pre-fermented mash). The microbial community contained in the pre-fermented mash can assist fermentation and adjust the acidity to 0.1-0.3, providing a suitable acid-base environment for fermentation. Fermentation process in the vat: Mix the cultured raw materials evenly with the prepared mash, and put them into the earthen vat. The filling height is 10cm from the vat opening. After spreading the surface evenly, cover it with a 2cm thick layer of sterile rice husks, then seal the vat opening with plastic film, tie it tightly, and cover it with a burlap sack for insulation. Inlet temperature control: In cold season, when the temperature is below 10℃, the inlet temperature should be 22-24℃; in hot season, when the temperature is above 25℃, the inlet temperature should be 18-20℃. Segmented control of the fermentation process: The pre-fermentation period is 1-5 days, during which the starch is converted into sugar and then into alcohol. The temperature rises naturally, and on the 3rd day, the material temperature rises to 28-30℃. The temperature is maintained by adjusting the thickness of the burlap bag. The lid is opened for ventilation for 3 minutes every day, and the alcohol content is tested at the same time. On the 5th day, it should be ≥8% vol. If the alcohol content is too low, 0.1% saccharifying enzyme activator needs to be added. The main fermentation period is 6-12 days, during which a large amount of light and fragrant core flavor substances are generated. Maintain the material temperature at 26-28℃, avoiding exceeding 30℃. Test the acidity every 2 days, maintaining it between 0.8-1.

2. If the acidity is >1.5, add 0.2% calcium carbonate to adjust and inhibit acid-producing bacteria. At the same time, test the ethyl acetate content, which should be ≥0.8g / L on the 12th day. The post-fermentation period lasts 13-30 days, during which flavor compounds transform into each other; the temperature naturally drops to 20-22℃ for slow fermentation; the alcohol content stabilizes at 12%-14% vol, the acidity is 0.1.4-1.8, and the raw materials have no raw grain smell or sour smell, but emit a pure and fresh aroma, indicating that fermentation is complete.

8. The process for improving the quality of strong-aroma baijiu according to claim 1, characterized in that, In step five, before distilling the fermented mixed raw materials, pretreatment of the fermented raw materials is also included. After fermentation, the mud pit lid is opened, and the fermented mash is taken out. The state of the mash is checked. The state of the mash should meet the following requirements: brownish-red color, loose texture, no sour / rotten smell, and contain an appropriate amount of pit mud debris. If the mash is sticky and clumped together, it should be broken up with sterile tools. The moisture content of the mash is controlled at 58%-60%, and the acidity is 1.4-1.

8. If the moisture content is too high, spread it out to cool for 10 minutes; if it is too low, spray it with 35℃ warm water to adjust. Before distillation, prepare the operation by using a traditional ceramic pottery pot or a 304 stainless steel pot, rinse it with boiling water 3 times in advance, and after drying, spread a 5cm thick layer of sterile rice husks at the bottom of the pot. Seal the connection between the pot lid and the pot with sterile gauze to prevent steam leakage. Install a thermometer (accuracy ±0.5℃) at the vent of the pot lid, connect it to the condenser, and control the condensate temperature at 15-20℃.

9. The process for improving the quality of strong-aroma baijiu according to claim 8, characterized in that, In step five, the fermented mixed raw materials are distilled to produce alcohol. During the distillation process, the temperature of the still lid needs to be monitored in real time. If the temperature suddenly rises above 105°C, the mash is not moist enough and 35°C warm water needs to be sprayed to adjust it. If the temperature remains low below 90°C, the equipment is leaking and needs to be sealed in time.

10. The process for improving the quality of strong-aroma baijiu according to claim 4, characterized in that, The steamed rice husks are steamed at a temperature of 100-105℃, a steam pressure of 0.7-0.9MPa, and a steaming time of 35-45min.

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