Method for producing high-temperature Daqu for light and mild Maotai-flavor liquor

Abstract

The application discloses a production method of high-temperature Daqu for light and elegant Maotai-flavor liquor, and comprises the following steps: preparation of functional bacteria intensifier: preparation of Aspergillus kawachi seed, Saccharomyces cerevisiae seed and compound Bacillus seed; preparation of high-temperature Daqu: mixing of the functional bacteria intensifier and Daqu raw materials, compression molding, horizontal Daqu stacking, covering, heat preservation and Daqu management to prepare the high-temperature Daqu; storage of Daqu and prevention and treatment of Daqu insects: storage and physical prevention and treatment of Daqu insects of the prepared high-temperature Daqu; the functional bacteria intensifier is prepared by mixing the Aspergillus kawachi seed, the Saccharomyces cerevisiae seed and the compound Bacillus seed at a weight ratio of 3:3:4; and the weight ratio of the functional bacteria intensifier and Daqu raw materials is (3-5):100. The application integrates specific functional bacteria groups, and innovatively introduces technologies such as tray three-dimensional separation, dry and wet straw mixed use and precise segmented temperature control, and systematically solves the problems of poor air permeability, heat preservation and moisture removal contradiction and insufficient Daqu fragrance of traditional Maotai-flavor Daqu.

Description

Technical Field

[0001] This invention relates to the field of brewing technology, specifically to a method for producing high-temperature Daqu (a type of starter culture) for a light-aroma baijiu. Background Technology

[0002] Maotai-flavor baijiu is beloved by consumers for its prominent Maotai aroma, mellow body, and long-lasting aftertaste. Traditional Maotai-flavor daqu (fermentation starter) production involves a long cycle and high temperatures (up to 60-65℃), making it a typical high-temperature daqu, rich in heat-resistant microorganisms and enzymes. However, the traditional process has the following shortcomings: High density and poor air permeability of the crepe blocks can easily lead to water accumulation, core burning, or mold growth in the crepe core. The use of straw is limited, and it is difficult to balance the contradictions of heat preservation and moisture removal. The raw liquor produced often has a strong aroma of fermented grains but lacks "delicate" flavor due to insufficient abundance or imbalance of microorganisms that produce precursors of soy sauce aroma.

[0003] To meet the new consumer demand for light-aroma baijiu—that is, a light and elegant aroma, a pleasant complex aroma, a smooth taste, and a mellow, sweet, and refreshing finish—this invention aims to develop a high-temperature koji (fermentation starter) specifically for the production of light-aroma baijiu and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a method for producing high-temperature Daqu (fermented starter culture) for light-aroma baijiu. By selecting functional microorganisms to strengthen the inoculants, innovating the management and storage process of the starter culture room, the abundance of specific hydrolytic enzymes and flavor precursors in the high-temperature Daqu is increased, ensuring the stability of the starter culture production process and the quality of the finished starter culture, and ultimately achieving the "light-aroma" style characteristics of the brewed liquor.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for producing high-temperature Daqu for light-flavored soy sauce-flavored Baijiu, comprising the preparation of functional microbial enhancers, the preparation of high-temperature Daqu, the storage of Daqu and the control of Daqu pests; the functional microbial enhancers include Aspergillus oryzae seeds, brewing yeast seeds and compound Bacillus seeds.

[0006] The microbial strains used were Saccharomyces cerevisiae (CICC 1421), Bacillus licheniformis (CICC 10037), Bacillus subtilis (CICC 10071), and Bacillus coagulans (CICC 24625). Most of the microbial strains used in this invention were purchased from the China Industrial Microbial Culture Collection Center, while Aspergillus hanoiense was isolated and screened from Taishan Winery's space-grown Aspergillus hanoiense bran koji.

[0007] Hanoi white aspergillus is a master of acid-producing saccharification in the fungal world. This strain, through targeted screening and domestication, exhibits strong heat resistance and maintains its activity during the high-temperature stage of koji making. It also possesses strong abilities to produce saccharifying enzymes and acidic proteases, which can increase the content of reducing sugars and amino acids in the mash, providing precursors for the Maillard reaction.

[0008] Saccharomyces cerevisiae CICC 1421 is a highly resilient yeast strain for alcohol production. It is tolerant of acidity up to pH 3.0, alcohol content up to 14% vol, and has a maximum growth temperature exceeding 42℃. Even in fermentation pits, it maintains strong fermentation power, ensuring high alcohol yield and base liquor production.

[0009] Bacillus licheniformis CICC 10037 and Bacillus subtilis CICC 10071 are classic thermophilic enzyme-producing bacteria that secrete highly active proteases. These proteases deeply hydrolyze large protein molecules in the raw materials into free amino acids, increasing the variety and quantity of amino acids. This provides sufficient precursors for biosynthesis, thermal degradation, and non-enzymatic chemical reactions. Simultaneously, they produce esterases and a small amount of amylase, promoting ester synthesis and enhancing the smoothness of the wine. Bacillus coagulans CICC 24625 combines the characteristics of both lactic acid bacteria and Bacillus, being heat- and acid-resistant. In addition to producing proteases, it can also metabolize lactic acid and various esterases, making it a key strain that imparts a mellow, sweet, and smooth texture to the wine. The three Bacillus strains work synergistically to improve the quality of the base wine from three aspects: increasing precursors, promoting esterification, and enhancing flavor, resulting in an elegant, smooth, and complexly flavorful wine.

[0010] Preferably, the isolation and screening steps for Aspergillus hanoiensis are as follows: I. Strain Source and Rejuvenation Our company has been using the space-grown Hanoi white koji bran koji, but it is prone to degeneration due to long-term propagation, so we first carry out rejuvenation and screening.

[0011] 1. Separation and purification Spread the mixture onto plates using wheat bran extract (100g / L wheat bran decoction, 2% agar, natural pH, with 0.03% sodium deoxycholate added to limit colony spread) after serial dilution, and incubate at 35°C for 3-4 days.

[0012] Select typical single colonies with abundant spores and robust hyphae, transfer them to Czapek's slant, and incubate at 35°C for 5 days to obtain pure cultures.

[0013] 2. Targeted Screening High enzyme activity and heat resistance strains were screened under conditions close to the high temperature fermentation environment of Daqu (a type of starter culture).

[0014] Initial screening of acidic proteases: Inoculate on casein agar plates, adjust pH to 4.5, incubate at 35℃ for 48 h, measure the diameter of the clear zone, and select strains with large clear zones.

[0015] Preliminary screening of saccharifying enzymes: Inoculate on soluble starch medium plates at pH 4.5, and after incubation, develop color with dilute iodine solution, selecting strains with large transparent zones.

[0016] Initial screening for heat resistance: The above-screened strains were transferred to bran slant and cultured at 45℃ and 50℃ for 48h respectively. Strains that could grow normally and produce spores were selected.

[0017] 3. Second sieving of bran in Erlenmeyer flasks Three to five dominant strains obtained from the initial screening were cultured in Erlenmeyer flasks using wheat bran as a starter culture: 100g of wheat bran was mixed with 80-85ml of water, moistened for 30 minutes, and then sterilized at 121℃ for 30 minutes. The mixture was then inoculated with slant spore suspension and cultured at 35℃ until the mycelium was fully distributed. The flasks were then inverted and cultured for a total of 5 days. After the starter culture was produced, it was dried at 35℃, and the following parameters were measured: saccharification power, acidic protease activity, and spore number. Heat resistance and viability were then tested: the starter powder was placed under dry heat at 55℃ for 2 hours, and the spore germination rate was measured again. Strains with a survival rate >80% were selected.

[0018] Ultimately, the strain with the highest saccharification power and enzyme activity, as well as the strongest heat resistance, was selected as the application strain.

[0019] II. Adaptive Domestication To ensure the selected strains can still survive and produce enzymes at temperatures of 60-65℃ in high-temperature Daqu (a type of starter culture), they were acclimatized. Using bran-based culture medium, four temperature gradients were established: 40℃, 44℃, 48℃, and 52℃. First, a generation was cultured at 40℃. The earliest spore-producing cells were selected and inoculated onto the 44℃ medium, and this process was repeated step-by-step. The strain that could still grow slowly at 52℃ without spore death was the most adaptable and could be used to prepare a fortifying agent for high-temperature Daqu (a type of starter culture).

[0020] Preferably, the preparation steps of the functional microbial enhancer are as follows: (1) Preparation of Hanoi Aspergillus seeds: Hanoi Aspergillus strains that have been isolated, screened and domesticated were selected.

[0021] Primary seed: Bran extract glucose medium was used. 100 mL of the medium was placed in a 500 mL Erlenmeyer flask, sterilized at 121℃ for 30 min, cooled, and then inoculated. The culture was carried out at 35℃ and 180 rpm for 24 h with shaking. Secondary seed: 60L of fermentation liquid was prepared in a 100L fermentation tank, the culture medium was the same as above, the inoculum size was 5%, the temperature was 35℃, the speed was 200rpm, the aeration ratio was 1:0.6, and the culture time was 18h. Third-grade seeds: Inoculate the second-grade seed liquid at a mass ratio of 5% into sterilized and pulverized wheat culture medium, and incubate in a culture room at 37-40℃ for 36-48 hours to obtain the seed solution.

[0022] (2) Preparation of brewing yeast seed: brewing yeast with preservation number CICC 1421 was selected.

[0023] Primary seed: Malt extract medium was used. 150 mL of the medium was placed in a 500 mL Erlenmeyer flask and sterilized at 121℃ for 30 min. After inoculation, the culture was carried out at 30℃ and 160 rpm for 18 h. Secondary seed: 60L of fermentation liquid in a 100L fermentation tank, inoculation amount 3%, 30℃, 180rpm, aeration ratio 1:0.5, culture for 16h; Third-grade seeds are obtained by inoculating sterilized and pulverized wheat culture medium and stacking them at 30-32℃ for 24-36 hours.

[0024] (3) Preparation of compound Bacillus seed: The compound strain includes Bacillus licheniformis (CICC 10037), Bacillus subtilis (CICC 10071) and Bacillus coagulans (CICC 24625).

[0025] Primary seed: Using peptone beef extract medium, pH 7.0, the three types of bacteria were cultured separately in Erlenmeyer flasks at 37℃ and 200 rpm for 24 h; Secondary seeds: Mix the three primary seeds in equal volume ratio, inoculate into a 100L fermenter, with a total inoculation amount of 5%, and incubate at 37℃ and 220rpm for 24h. Third-grade seeds: Inoculate sterilized and pulverized wheat culture medium with the compound bacterial solution at a mass ratio of 5%, and pile it up and culture at 37-40℃ for 36-48 hours to obtain the seeds.

[0026] (4) Preparation of functional microbial enhancer: Mix Aspergillus oryzae seeds, Saccharomyces cerevisiae seeds, and Bacillus complex seeds evenly in a weight ratio of 3:3:4. The weight ratio of the functional microbial enhancer to the raw materials for koji making is (3-5):100.

[0027] Preferably, the preparation process of high-temperature Daqu (a type of Chinese liquor) includes the following steps: (1) Raw material processing and mixing: The main raw material is high-quality wheat, with a soft to hard wheat ratio of 6:4. The fine powder should pass through a 20-mesh sieve, accounting for 42%-47%. The functional bacteria enhancer is added to the master koji mixer in proportion, and mixed evenly with the master koji and the crushed wheat. Water is added and stirred. The amount of master koji is 5% of the amount of wheat, and the material-to-water ratio is 100:(37-40), so that the moisture content of the koji is controlled at 37%-40%. This ensures that the mixed raw material is free of lumps and dry powder, and can be formed into a ball by hand without sticking.

[0028] (2) Compression molding and horizontal stacking: The mixed materials are mechanically pressed into koji blocks. Before laying the koji blocks horizontally, a clean plastic tray is laid flat on the floor of the koji room, followed by a layer of straw. The koji blocks are then stacked sideways in a three-by-three pattern, with the upper and lower layers also staggered in a three-by-three pattern. The top and last rows of koji blocks are stacked in a straight line. The koji blocks are stacked to a height of 5 layers, with trays placed in the middle of the stack to separate them horizontally and vertically. The bottom of the trays contacts the trays on the ground, forming a three-dimensional ventilation barrier to enhance air permeability and ensure stability while facilitating oxygen entry and microbial growth and reproduction.

[0029] (3) Innovation in the covering material for bacon: After the koji piles are separated, they are covered for insulation and moisture retention. The covering material uses an alternating mix of dry straw and fresh wet straw: the bottom layer where the koji are placed is covered with fresh wet straw (50-60% moisture content) that has been sterilized by high-temperature steaming, providing the humidity required for mold growth; wet straw with a moisture content of 30%-40% is used between the koji; the outer layer and the area between the koji piles and the trays are covered with clean dry straw to form an insulation layer and absorb moisture evaporated during desiccation.

[0030] (4) Precise segmented temperature-controlled culture tube management: This invention employs a typical high-temperature koji cultivation process, the core of which is "slow initial growth, rapid middle growth, and slow final decline," as detailed below: The entire culture process is strictly divided into three key stages, which are managed meticulously through a combination of intelligent temperature control system and human experience.

[0031] The first stage, from the accumulation of the koji blocks to the first turning of the koji blocks, is the stage in which the koji blocks heat up and change color.

[0032] Temperature control targets: 2-3 days after laying the curd, control the core temperature to slowly rise from room temperature to 40-45℃, and maintain the surface temperature between 35-38℃, ensuring uniform growth of white spots (such as *Enteromorpha*, *Rhizopus*, etc.) on the surface of the curd block, without any fluffy black mold. 4-6 days after laying the curd, ensure the curd block temperature reaches approximately 60℃.

[0033] Control measures: During this stage, the "close doors and windows, turn on the circulating air" mode is adopted. When the core temperature rises too quickly (exceeding 2℃ / h), the dehumidification vent is opened intermittently for micro-ventilation, and the dry straw covering the top layer of the koji blocks is replaced with moist and breathable straw to increase the heat capacity to buffer the temperature rise and ensure "slow heating and even coating".

[0034] The second stage, from the first to the second turning of the koji, is the aroma-developing stage of the koji blocks. This stage is the core stage for the formation of precursor substances and flavor compounds in high-temperature koji.

[0035] At the end of the first stage (approximately 8-10 days), when the core temperature reaches 62-65℃, the first turning of the koji is carried out. During turning, the positions of the upper and lower layers, and the inner and outer rows of koji blocks should be reversed to achieve a more even temperature distribution throughout the koji blocks. The stacking during turning is the same as when the koji blocks are placed in the room. During the turning process, damp straw should be replaced with dry straw to facilitate the drainage of moisture from the koji blocks.

[0036] The top-fire, constant-temperature aroma-developing stage: After turning the koji, the temperature of the koji blocks will drop, mainly due to the effect of turning. The temperature will then continue to rise, reaching another peak 3-5 days after the first turning. The core of this stage is to precisely control the temperature within the elegant aroma golden range of 60℃-62℃ and maintain it for 7-8 days. This temperature efficiently drives protein pyrolysis and the continuous and stable Maillard reaction between amino acids and reducing sugars, generating a delicate and rich soy sauce aroma and caramel aroma. It also effectively avoids intense caramelization and charring caused by excessively high temperatures, fundamentally reducing the excessive formation of bitter substances such as pyrazines and aldehydes. The temperature control methods during this stage are: when the temperature approaches the upper limit of 62℃, the system automatically activates micro-ventilation to remove moisture and uncovers the outer layer of insulating straw curtains; when the temperature drops to the lower limit of 60℃, an additional insulating layer is immediately added and the ambient humidity is appropriately increased to keep the top-fire curve stable.

[0037] The third stage: from the second turning of the koji to the dismantling of the koji, is the drying stage of the koji blocks.

[0038] Temperature control objective: To cause the temperature of the starter culture to slowly and evenly drop from 60-62℃ to 40-45℃, while simultaneously draining excess moisture from the starter culture core to prevent "water retention" which would result in a dark cross-section and bland taste in the finished product.

[0039] Control measures: A second turning of the koji is performed, the operation of which is the same as the first turning, but the straw adhering to the koji blocks must be removed, all separating trays must be removed, and the koji pile must be increased to 6 layers, making them more compact. The temperature of the koji blocks will initially decrease and then rise, similar to after the first turning, but the rise will be significantly smaller. This is mainly because a large amount of moisture is lost from the koji blocks, reducing their heat and moisture retention effect and inhibiting microbial metabolism, thus preventing the temperature from rising back to the previous level. During this stage, the residual heat inside the koji blocks is fully utilized, and the dehumidification system is activated to control the relative humidity between 60% and 70%, allowing the koji temperature to drop steadily by 2-3℃ daily. This gradually forms an ideal loose mycelial structure with a yellowish-brown surface and a grayish-white or yellow cross-section. The cultivation time is 40-45 days. Once the sensory and physicochemical indicators are satisfactory, the koji can be removed from the fermentation chamber and stored. A koji aroma also forms during this stage, but it is not as pronounced as in the second stage.

[0040] In a preferred embodiment, the storage method of the Daqu (a type of starter culture) is as follows: After the finished high-temperature koji (fermented starter culture) passes inspection, it should be stored in a warehouse for at least 6 months. The storage environment should be kept dry, ventilated, protected from light, and free of odors. The storage temperature should be 15-25℃, and the relative humidity should be controlled between 50%-60%. The storage adopts the "layered height-limited loose stacking" method: the koji blocks are first stacked in a "well" shape, with the stack height not exceeding 7 layers and the distance between new and old stacks 50cm. After stacking, a layer of dry straw is covered on top of the stack. The straw's slow moisture absorption characteristics are used to regulate the excess moisture in the koji blocks in the early stage. After the straw has absorbed moisture (about 15 days), it is removed. This can effectively reduce the risk of mold growth in the koji blocks and promote the transformation of the aroma from dry and hot to light and mellow.

[0041] In a preferred embodiment, the method for controlling Aspergillus is as follows: A "sound and light ecological trapping system" is set up in the koji storage area: a specific wavelength of ultraviolet light is combined with 300-500Hz low-frequency sound waves to simulate the wing-beating signals of natural enemies, interfering with the mating and feeding behavior of koji insects, supplemented by pheromone-trapping traps. This purely physical control method is non-toxic and residue-free, avoiding the adverse effects of chemical pesticides on the flavor of koji. It has a wide coverage area, good insecticidal effect, and reduces the loss of koji at high temperatures.

[0042] Compared with existing technologies, the beneficial effects of this invention are as follows: By integrating specific functional microbial communities and innovatively introducing technologies such as three-dimensional tray partitioning, mixed use of dry and wet straw, and precise segmented temperature control, the invention systematically solves the pain points of traditional soy sauce-flavored koji, such as poor air permeability, contradictions between heat preservation and moisture removal, and insufficient koji aroma. The resulting koji has a reasonable enzyme system and a delicate soy sauce aroma, and can stably produce high-quality base liquor with a delicate, mellow, and sweet taste after brewing, exhibiting significant practical and economic value. Attached Figure Description

[0043] Figure 1 A chart comparing the core physicochemical properties of the high-temperature koji of this invention with those of ordinary high-temperature koji. Figure 2 This is a graph showing the yield and quality of grain-based liquor in this invention; Figure 3 This is a chart showing the sensory evaluation results of the grain liquor in the application pool and the control pool of this invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Example 1: Preparation of Functional Bacterial Enhancer Preparation of Hanoi Aspergillus seed culture: Hanoi Aspergillus strains that had been isolated, screened, and domesticated were selected. Primary seed culture was prepared using wheat bran extract glucose medium, with 100 mL of the medium in a 500 mL Erlenmeyer flask, sterilized at 121℃ for 30 min, cooled, and then inoculated. The culture was then incubated at 35℃ and 180 rpm with shaking for 24 h. Secondary seed culture was prepared using 60 L of the medium in a 100 L fermenter, with the same medium as above, an inoculation rate of 5%, incubated at 35℃ and 200 rpm with an aeration ratio of 1:0.6 for 18 h. Tertiary seed culture was prepared by inoculating the secondary seed culture at a mass ratio of 5% into sterilized, pulverized wheat medium, and then incubating in a culture chamber at 37-40℃ for 36-48 h.

[0046] Preparation of Saccharomyces cerevisiae seed culture: Saccharomyces cerevisiae with preservation number CICC 1421 was selected. Primary seed culture was prepared using malt extract medium, with 150 mL of liquid in a 500 mL Erlenmeyer flask, sterilized at 121℃ for 30 min, and then cultured at 30℃ and 160 rpm for 18 h after inoculation. Secondary seed culture was prepared using 60 L of liquid in a 100 L fermenter, with an inoculation amount of 3%, cultured at 30℃ and 180 rpm with an aeration ratio of 1:0.5 for 16 h. Tertiary seed culture was inoculated into sterilized and pulverized wheat culture medium and cultured in stock at 30-32℃ for 24-36 h.

[0047] Preparation of compound Bacillus seed culture: This compound culture includes Bacillus licheniformis (CICC 10037), Bacillus subtilis (CICC 10071), and Bacillus coagulans (CICC 24625). The primary seed culture was prepared using peptone beef extract medium, pH 7.0, with each of the three strains cultured separately in Erlenmeyer flasks at 37°C and 200 rpm for 24 h. The secondary seed culture was prepared by mixing the three primary seed cultures in equal volume ratios and inoculating them into a 100L fermenter at a total inoculum of 5%, cultured at 37°C and 220 rpm for 24 h. The tertiary seed culture was prepared by inoculating the compound bacterial culture solution at a mass ratio of 5% into sterilized, pulverized wheat culture medium, and cultured in a pile at 37-40°C for 36-48 h.

[0048] Preparation of functional bacteria enhancer: Mix the above-prepared Aspergillus hanoiensis seeds, Saccharomyces cerevisiae seeds, and Bacillus complex seeds evenly in a weight ratio of 3:3:4.

[0049] Example 2: Preparation of High-Temperature Daqu for Light-Aroma Baijiu Raw material processing and mixing: Take high-quality wheat with a soft to hard wheat ratio of 6:4, and grind it to a fine powder that passes through a 20-mesh sieve, with 45% being fine powder. Add the functional bacteria enhancer to the master koji mixer at a weight ratio of 4:100, mix it evenly with the master koji (5% of the wheat weight), add water and stir, with a material-to-water ratio of 100:38, so that the moisture content of the koji is controlled at 38%.

[0050] Compression molding and horizontal curing stacking: The mixed materials are mechanically compressed into curd blocks. Before horizontal curing, a clean plastic pallet is laid flat on the floor of the curing room, followed by a layer of straw. The curd blocks are then stacked sideways in a three-by-three pattern, with the upper and lower layers also staggered in a three-by-three pattern. The top and last rows of curd blocks are stacked in a straight line. The horizontal curd blocks are stacked to a height of 5 layers, with pallets placed in the middle of the stack to separate them horizontally and vertically. The bottom of the pallets contacts the pallets on the ground, forming a three-dimensional ventilation partition.

[0051] Covering the koji: After the koji piles are separated, they are covered to keep them warm and moist. The covering material uses an alternating mix of dry straw and fresh wet straw: the bottom layer where the koji are attached is covered with fresh wet straw (55% moisture content) that has been sterilized by high-temperature steaming; wet straw with 35% moisture content is used between the koji; and clean dry straw is used for the outer layer and between the koji piles and the trays.

[0052] Precise segmented temperature-controlled bacterial culture: Phase 1: 2-3 days after bending, control the core temperature to slowly rise from room temperature to 42℃, while maintaining the surface temperature between 36℃. 4-6 days after bending, ensure the core temperature reaches 60℃.

[0053] Phase Two: On the 9th day after the koji is laid flat, when the core temperature reaches 63℃, the koji is turned over for the first time. After turning over, the temperature of the koji blocks first decreases and then rises, reaching another temperature peak on the 4th day after turning over. The product temperature is precisely controlled at 61℃ and forcibly maintained for 8 days.

[0054] The third stage involves a second turning of the koji blocks. Any straw adhering to the blocks is removed, all separating trays are removed, and the koji pile is increased to six layers. During this stage, the dehumidification system is activated to maintain relative humidity around 65%, allowing the koji temperature to drop steadily by 2.5℃ daily. The total cultivation time is 42 days. After passing inspection, the koji is removed from the growing chamber and stored.

[0055] Example 3: Storage of Daqu (a type of starter culture) and control of Daqu insects After the finished high-temperature koji (a type of starter culture) passes inspection, it is stored in a warehouse for 6 months. The storage environment should be kept dry, well-ventilated, dark, and odorless, with a storage temperature of 20℃ and a relative humidity controlled between 55%. The storage method is a "layered, height-limited, loose stacking" method: the koji blocks are first stacked in a "well" shape, with a stack height of 6 layers and a spacing of 50cm between new and old stacks; after stacking, a layer of dry straw is covered on top of the stack, which is removed after 15 days. An "audio-visual ecological trapping system" is set up in the koji warehouse: a specific wavelength of ultraviolet light combined with 400Hz low-frequency sound waves, supplemented by pheromone trapping plates for capture.

[0056] Comparison of proportions and effects The physicochemical properties of the light-flavored soy sauce-type high-temperature koji prepared according to this invention (experimental group) were compared with those of ordinary high-temperature koji (control group). The results are as follows: Figure 1 As shown: As can be seen from the table above, the functional bacteria-enhanced Daqu prepared in this invention has significantly improved saccharification power, fermentation power, and acidic protease activity.

[0057] Furthermore, brewing experiments were conducted using the koji blocks of this invention and ordinary high-temperature koji, respectively, selecting 13 fermentation pits for each. The results are as follows: Figure 2 As shown: Alcohol yield: The alcohol yield of the fermentation pits using the Daqu of this invention increased by 4.2% compared with the control pits.

[0058] High-quality product rate: The high-quality product rate of the fermentation pits using the Daqu of this invention increased by 3.5% compared with the control pits.

[0059] Sensory evaluation results Sensory evaluation was conducted on the grain liquor produced in the application pool and the control pool. The results are as follows: Figure 3 As shown: Sauce aroma: The liquor sample using the Daqu of this invention has a more prominent sauce aroma, with a pleasant aroma of roasted sesame and Daqu, and is full-bodied and mellow; while the sauce aroma of the control liquor sample is slightly dull.

[0060] Sweetness and mellowness: The liquor sample using the Daqu of this invention is smoother on the palate, mellow and sweet, and has a cleaner aftertaste; while the control liquor sample is slightly inferior in terms of sweetness and mellowness.

[0061] Cellar bottom: The liquor sample using the Daqu of this invention has a harmonious and delicate aroma without any off-flavors, a relatively mellow taste, a sweet taste, and a clean finish; while the control liquor sample has a stronger cellar aroma, but lacks delicacy.

[0062] In summary, the aroma and taste of the sauce-flavored liquor produced using the high-temperature Daqu of this invention are greatly improved. The sauce aroma is pure and free of impurities, and the taste is smooth and delicate on the palate with better sweetness and a clean finish, perfectly matching the light and elegant style.

[0063] Working principle: When using this method for producing light-flavored soy sauce-flavored baijiu with high-temperature koji, a series of steps are first taken to complete the process. Content not described in detail in this manual is prior art known to those skilled in the art.

[0064] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing a light-aroma baijiu using high-temperature Daqu (a type of starter culture), characterized by: Includes the following steps: Preparation of functional microbial enhancers: Preparation of Aspergillus hanoiensis seeds, Saccharomyces cerevisiae seeds and compound Bacillus seeds; Preparation of high-temperature Daqu: The functional bacteria enhancer is mixed with the raw materials for making Daqu, and then pressed into shape, stacked horizontally, covered and kept warm, and managed for cultivation to produce high-temperature Daqu; Storage of Daqu and control of Daqu pests: The high-temperature Daqu produced is stored in warehouses and physical control is carried out to prevent Daqu pests from entering the warehouse. The functional microbial enhancer is composed of Hanoi white aspergillus seeds, brewer's yeast seeds, and compound Bacillus seeds in a weight ratio of 3:3:4; the weight ratio of the functional microbial enhancer to the koji-making raw materials is (3-5):

100.

2. The method for producing a light-aroma baijiu using high-temperature koji as described in claim 1, characterized in that: The sources and characteristics of each bacterial species in the aforementioned functional bacterial enhancer are as follows: Hanoi white aspergillus: derived from the isolation and screening of Taishan Winery's space Hanoi white aspergillus bran koji, and after directional screening and gradual temperature acclimatization from 40℃ to 52℃, it has the characteristics of high temperature resistance, high production of saccharifying enzymes and acidic proteases; Saccharomyces cerevisiae: Saccharomyces cerevisiae with preservation number CICC 1421 was selected; Complex Bacillus species include Bacillus licheniformis (accession number CICC 10037), Bacillus subtilis (accession number CICC 10071), and Bacillus coagulans (accession number CICC 24625).

3. The method for producing a light-aroma baijiu using high-temperature koji as described in claim 1, characterized in that: In the preparation steps of the high-temperature Daqu (a type of starter culture), the specific parameters for raw material processing and mixing are as follows: The main raw material is high-quality wheat, with a soft to hard wheat ratio of 6:

4. After grinding, the fine powder that passes through a 20-mesh sieve accounts for 42%-47%. The amount of mother yeast used is 5% of the amount of wheat used; The material-to-water ratio is 100:(37-40), and the moisture content of the koji is controlled at 37%-40%.

4. The method for producing a high-temperature Daqu (fermented starter culture) for a light-aroma baijiu according to claim 1, characterized in that: The specific method of horizontal stacking is as follows: Plastic pallets and straw were laid on the floor of the curing room, and the curing blocks were stacked sideways in a "three horizontal blocks and three vertical blocks" manner. The upper and lower layers are stacked alternately in a "three horizontal and three vertical" pattern, while the top and last rows are stacked in a side-standing, straight-line manner. The stack of curved blocks is 5 layers high. A pallet is placed in the middle of the stack to separate them horizontally and vertically. The bottom of the pallet contacts the pallet on the ground to form a three-dimensional ventilation partition.

5. The method for producing a light-aroma baijiu using high-temperature koji according to claim 1, characterized in that: The insulation covering uses an alternating mixture of dry straw and fresh, wet straw. The bottom layer of the curved section is covered with fresh, wet rice straw that has been sterilized by high-temperature steaming, with a moisture content of 50-60%. Wet rice straw with a moisture content of 30%-40% is used between the clumps; The outer layer and the area between the pile and the tray are covered with clean, dry straw.

6. The method for producing a light-aroma baijiu using high-temperature koji according to claim 1, characterized in that: The fermentation management adopts a precise segmented temperature control process of "slow initial release, moderate middle release, and slow final release," which specifically includes three stages: First stage (heating and color change period): After the crepe is laid down, the core temperature is controlled to slowly rise to 40-45℃ for 2-3 days, and the crepe block temperature reaches about 60℃ in 4-6 days. The second stage (aroma development period): When the temperature of the koji core reaches 62-65℃, the koji is turned over for the first time. After turning the koji, the temperature is precisely controlled at 60℃-62℃ for 3-5 days and maintained for 7-8 days. Third stage (drying period): Perform the second turning of the koji, remove the dividing trays, increase the koji stack to 6 layers, control the relative humidity at 60%-70%, and make the koji temperature drop steadily by 2-3℃ every day until it drops back to 40-45℃. The total cultivation time is 40-45 days.

7. The method for producing a high-temperature Daqu (fermented starter culture) for a light-aroma baijiu according to claim 1, characterized in that: The storage method for the Daqu (a type of starter culture) is as follows: The finished high-temperature koji should be stored in the warehouse for at least 6 months at an ambient temperature of 15-25℃ and a relative humidity of 50%-60%. The "layered height-limited scattered stacking" method is adopted, and the stacks are stacked in a "well" shape, with a stack height not exceeding 7 layers and a spacing of 50cm between new and old stacks; After the stacking is completed, cover the top of the stack with a layer of dry straw, and remove it after about 15 days.

8. The method for producing high-temperature Daqu (a type of starter culture) for a light-aroma baijiu (Chinese liquor) according to claim 1, characterized in that: The method for controlling Aspergillus is as follows: An "audio-visual ecological trapping system" was set up in the worm storage area. It uses ultraviolet light of a specific wavelength combined with low-frequency sound waves of 300-500Hz to interfere with the behavior of worms, and is supplemented by pheromone trapping boards for sticky trapping.

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