Method for improving quality of sauce-flavor daqu in winter koji-making

Abstract

The application discloses a method for improving the quality of sauce-flavor Daqu in winter, which is improved through the synergistic technology of precise environment temperature control, special functional mother Daqu preparation, warm water mixing, and functional mother Daqu ratio and water mixing, so as to adapt to the winter low-temperature Daqu making scene from the whole dimension of environment, strain and material treatment, greatly improve the richness of the Daqu bacterial community, enzyme activity and physicochemical quality in winter, make the winter Daqu making quality reach the standard of high-quality Daqu in the Dragon Boat Festival, break the technical monopoly of Daqu making in the industry in the Dragon Boat Festival, and realize the whole-year standardized and high-quality production of sauce-flavor Daqu.

Description

Technical Field

[0001] This invention belongs to the field of baijiu (Chinese liquor) koji-making technology, specifically relating to a method for improving the quality of koji-making in winter for sauce-flavored baijiu. Background Technology

[0002] The flavor, quality, and yield of Maotai-flavor liquor depend primarily on the quality of the Maotai-flavor Daqu (fermentation starter). In the 12987 Kunsha brewing process, the ratio of Daqu to grain is approximately 1:1, which is higher than other types of Maotai-flavor liquor. As the saccharification and fermentation agent for Maotai-flavor liquor, the microbial community structure, enzyme activity, and physicochemical quality of Daqu directly determine the intensity, mellowness, and flavor complexity of the liquor. Traditional Maotai-flavor Daqu production follows ancient methods, strictly adhering to the production rhythm of "making Daqu during the Dragon Boat Festival." The core reason is that the temperature and humidity are suitable during the Dragon Boat Festival, and the natural environment is rich in beneficial microorganisms such as Aspergillus, yeast, and bacteria, which have high activity and can meet the core requirements for Daqu fermentation and maturation. During seasons with relatively high temperatures, the proportion of white Daqu is lower and the proportion of yellow Daqu is higher, while yellow Daqu has the best aroma and quality. In winter, there are difficulties in raising the Daqu temperature, damp Daqu cores, strong ammonia and other off-flavors, and a high proportion of white Daqu.

[0003] Currently, the mainstream production model in the industry is concentrated around the Dragon Boat Festival to carry out koji-making operations. Due to the natural environmental limitations in winter, large-scale high-quality koji-making production cannot be carried out. The industry has long faced the technical bottleneck of being able to make koji only during the Dragon Boat Festival, resulting in many production drawbacks: Firstly, the low ambient temperature, large temperature difference between day and night, and dry air in winter lead to a sharp reduction in the number and activity of beneficial koji-making microorganisms in the natural environment, resulting in a high risk of contamination by miscellaneous bacteria. The koji prepared by conventional koji-making processes has quality defects such as insufficient fermentation, simple microbial structure, low saccharification and fermentation enzyme activity, damp koji core, and strong ammonia and other off-flavors, which cannot meet the production standards of sauce-flavored liquor.

[0004] Chen Meimei et al. (Analysis of the Differences in Fermentation Performance of High-Temperature Daqu in Different Production Periods [J]. China Brewing, 2025, 44(6):86-91) introduced that due to the large temperature difference between hot and cold seasons, the fermentation effect of daqu is significantly affected by the ambient temperature. The quality of daqu in the hot season is generally higher than that in the cold season. Firstly, the weather becomes warmer after the Dragon Boat Festival, which allows microorganisms to multiply rapidly; secondly, it is the season when winter wheat matures and is harvested, and the wheat quality is good. After using it to make daqu, it can provide rich nutrients for the growth and reproduction of brewing microorganisms in the daqu blocks. Studies have shown that the aroma of sauce-flavored baijiu produced in summer is significantly better than that produced in winter, while daqu produced in the cold season is white in color and has more obvious off-flavors such as mold and ammonia.

[0005] Secondly, the single-Dragon Boat Festival centralized koji-making model leads to a highly concentrated koji-making cycle for baijiu producers, resulting in limited production capacity and exceeding the optimal storage period for koji (the optimal storage period for sauce-flavored koji is 2 to 6 months), which reduces the quality of the koji and severely restricts the expansion of sauce-flavored baijiu production capacity and the assurance of quality. Thirdly, centralized koji-making leads to short-term overload operation of equipment and manpower, making production control difficult, batch quality instability poor, and wasting equipment resources during idle periods, which significantly increases the production costs of enterprises.

[0006] Under existing conventional process conditions, the proportion of premium grade koji in winter is generally low. Even with optimization of raw material crushing, moisture content, and mother koji dosage, the proportion of premium grade koji in winter remains low using traditional processes. For example, Deng Wanyu et al. (Influence of Key Control Points in Koji Making Process on the Quality of High-Temperature Koji in Winter [J]. China Brewing, 2023, 42(8):153-157) found that in winter, the outside temperature is relatively low, and abnormal temperature rise occurs during high-temperature koji fermentation, leading to quality defects, a significant increase in the proportion of grayish-white koji, and an increase in the growth of miscellaneous bacteria. The optimized conditions for winter koji making process are: 100% old grass content, 37% mixing moisture, 77% raw material crushing degree, and 7.5% mother koji dosage. Under these optimized conditions, the highest proportion of premium grade koji is only 27%, and the koji quality is still not ideal even with simple optimization of the process parameters of sauce-flavored koji.

[0007] Currently, the closest technological examples to this approach, low-temperature koji-making technology, mainly fall into two categories: exogenous microbial inoculation and equipment hardware modification. However, both have significant limitations. Existing measures largely rely on raising the environmental temperature and humidity, which can only slightly improve external conditions and cannot fundamentally solve the core problems of insufficient beneficial microorganisms, weak microbial activity, and poor material fermentation adaptability in winter. CN120484900A discloses a method for enhancing pyrazine compounds in high-temperature Daqu (a type of Chinese liquor) based on mixed-culture fermentation. This method increases pyrazine content by adding multiple artificial mixed strains, exogenous precursors, and using ultrasonic-microwave equipment. However, this method relies on exogenous pure cultures, which can easily disturb the indigenous microbial community of Daqu, conflicting with local standards in the core production areas of Maotai-flavor liquor. Furthermore, it requires specialized equipment, resulting in high production costs. Additionally, it does not address the issue of insufficient heating during winter when heat dissipation is rapid.

[0008] CN121628734A discloses a high-temperature koji cultivation method and apparatus suitable for different climates. By adjusting the temperature of the mixing water and using a special koji support device, it can only improve the initial temperature of the koji when it enters the warehouse. It cannot overcome the problem of weak fermentation microorganisms in winter and continuous heat loss during the heating stage. The oxygenation rack requires modification of existing workshop equipment and has poor compatibility with traditional straw koji stacking process. At the same time, the koji blocks on the rack are more dispersed and dissipate heat faster. The surface moisture of the koji blocks loses faster in the early stage, resulting in a large amount of white koji. In real scenarios, white koji is mostly concentrated on the outer layer of the koji stack. Therefore, this technical solution cannot meet the high temperature and high humidity requirements of high-temperature koji making of soy sauce-flavored koji.

[0009] CN105969598A discloses a process for producing enhanced Daqu (a type of starter culture) at low temperatures in winter. From the perspective of the Daqu production process, it belongs to the medium-temperature Daqu technology for strong aroma type. It requires the addition of exogenous compound functional microbial agents. Pure Rhizopus preparations and esterified Monascus purpureus are not suitable for sauce-aroma Daqu. Moreover, the addition of exogenous agents does not comply with the local regulations for sauce-aroma liquor. The process system is incompatible with high-temperature sauce-aroma Daqu. At the same time, relying solely on compound functional microbial agents has limited effect and cannot solve the technical problems of low ambient temperature, rapid heat dissipation, and difficulty in heating in winter.

[0010] CN118165835A discloses a soy sauce koji preparation technology, which relies on bacterial suspension inoculation to enhance spore germination ability at low temperatures; it belongs to the thick-layer ventilation koji making system for soy sauce, and its process cycle, target temperature, and microbial system are very different from those of soy sauce high-temperature koji, making it impossible to achieve long-term high-temperature koji for soy sauce, and there is no technology transfer inspiration.

[0011] Therefore, there is an urgent need to develop a koji-making method that is suitable for the low-temperature environment in winter, can stably improve the quality of koji, and breaks the single limitation of koji-making during the Dragon Boat Festival. Summary of the Invention

[0012] This invention aims to address the industry pain points of existing Maotai-flavor Daqu production, which relies on the Dragon Boat Festival, suffers from poor quality during winter production, and cannot achieve continuous production throughout the year. It provides a method to improve the quality of winter Maotai-flavor Daqu production. Through synergistic technological improvements in precise environmental temperature control, specialized functional master koji preparation, warm water mixing, and precise water mixing with functional master koji, this invention adapts to the low-temperature winter koji production scenario from all dimensions—environment, microbial strains, and material processing. This significantly improves the richness of microbial communities, enzyme activity, and physicochemical quality of winter Daqu, enabling winter koji production to meet the standards of high-quality Daqu produced during the Dragon Boat Festival. This breaks the industry's technological monopoly on Dragon Boat Festival koji production and achieves standardized, high-quality production of Maotai-flavor Daqu throughout the year.

[0013] A method for improving the quality of soy sauce-flavored koji during winter koji production includes the following steps: S1. Wheat rinsing: Calculate the required amount of water for rinsing wheat based on its moisture content. It is required to increase the wheat moisture content by 1% to 6% after rinsing. Water temperature: 30℃ to 40℃. The moisture content after rinsing should be 9% to 13%. S2. Crushing: Precisely adjust the spacing of the crushing rollers in the crusher to ensure that the mass ratio of bran, granules and fine powder is (68~72):(10~14):(16~20); S3. Mixing: Add the functional starter culture to an appropriate amount of warm water at 28℃~40℃ and mix evenly. Then mix it evenly with the crushed starter culture and the wheat crushed in step S2. The mass ratio of the crushed starter culture, the crushed wheat material and the functional starter culture is (8~9.5):100:(1~3). Control the moisture content of the mixture to be between 37% and 39%. After mixing, the temperature of the starter culture material is stabilized at 20℃~30℃. S4. Treading the koji: Shovel the mixed koji material into the koji block mold and tread the koji manually. When treading the koji blocks, strictly follow the method of "loose in the middle and tight around the edges". During operation, first use both feet to tread back and forth along both sides of the koji mold twice, and then trim the koji material around the edges to ensure that the weight of a single koji block is controlled within the range of 11.0kg to 12.0kg. S5. Spreading and drying: Place the molded blocks on both sides of the section in sequence. The blocks should be placed neatly, aligned front to back and left to right, and the distance between the blocks should be no less than 2cm. S6. Loading into the fermentation chamber: The fermentation chamber environment must be temperature controlled during the loading process. The temperature of the fermentation chamber should be controlled at 28℃~32℃ and the relative humidity at 75%~80%. The loading should be completed strictly according to the requirement of three rows horizontally and three rows vertically. The number of layers of fermentation blocks should not exceed 5. After three rows of fermentation blocks are loaded into the fermentation chamber, water should be sprinkled on top of the fermentation blocks immediately. The amount of water in a single chamber should be 0.5%~1% of the weight of the fermentation blocks. The water should be evenly sprayed on the surface of the formed fermentation blocks. After spraying, the fermentation blocks should be sent to the temperature-controlled fermentation room for stacking and fermentation. S7. Turning the Fermentation Blocks: Record the temperature of the fermentation blocks in the warehouse daily after they are placed in the warehouse. When the temperature of the middle layer of the third row of fermentation blocks rises to 60℃~65℃ and is maintained for 3 to 4 days, turning the fermentation blocks can be arranged. In winter, the normal time for turning the fermentation blocks is 9 to 12 days after loading. After the first turning, the temperature of the fermentation blocks will drop, and after 3 to 5 days, the temperature will gradually start to rise. When the temperature of the center of the fermentation pile reaches 50℃~60℃ and is maintained for 2 to 3 days, a second turning should be carried out. The temperature and humidity control conditions for the first and second turning are as follows: control the ambient temperature of the fermentation room at 28℃~32℃ and the relative humidity at 75%~100%. S8. Dismantling the koji: The time from when the koji blocks enter the fermentation room to when they leave the fermentation room is 45 to 50 days. When the temperature of the koji pile is close to or equal to the room temperature, the moisture content of the koji blocks is tested. If the moisture content of the koji blocks is ≤13%, the koji blocks are discharged from the warehouse the next day.

[0014] In a preferred embodiment, the pulverized starter culture in step S3 is selected from high-quality yellow starter culture grown in a warehouse where the fermentation temperature reaches above 40°C for 24 hours.

[0015] As a preferred embodiment, the preparation method of the functional masterbatch in step S3 is as follows: high-quality Bacillus isolated from soy sauce-flavored Daqu is selected, and the formula for preparing the functional masterbatch per liter is as follows: take 30g of peptone, 10g of yeast extract, 30g of diammonium hydrogen phosphate, and 4g of dipotassium hydrogen phosphate, dissolve them in 840ml of distilled water, add 160ml of 50% glucose solution, adjust the pH to 6.5 with phosphoric acid, sterilize, take the Bacillus absorptive culture seed liquid and inoculate it at a ratio of 5% of the seed liquid to the culture medium volume, incubate at 37℃ for 60 hours, add diammonium hydrogen phosphate at a ratio of 40g / L, and continue to incubate for 6 to 7 days.

[0016] In a preferred embodiment, in step S4, the central area is tamped into a standard turtle-back shaped bulge, with the curved edge and the curved mold height being the same as 6cm, the height difference between the curved mold and the bulge being 7cm-8cm, and the overall height of the bulge being controlled at 13cm-14cm; the edges around the bulge should be tamped and tightened, with the short side width being 3cm-4cm and the long side width being 2cm-3cm.

[0017] As a preferred embodiment, the method for preparing the water in step S6 is as follows: (1) Take 30g of peptone, 10g of yeast extract, 30g of diammonium hydrogen phosphate, and 4g of dipotassium hydrogen phosphate, add 840ml of distilled water to dissolve them, add 160ml of 50% glucose solution, adjust the pH to 6.5 with phosphoric acid, sterilize, take the Bacillus propagation seed liquid and inoculate it according to the ratio of seed liquid to culture medium volume of 5%, culture at 37℃ for 60 hours, add 50% diammonium hydrogen phosphate, the amount of addition is 40g / l, continue to culture for 6 to 7 days to obtain functional mother koji; (2) Select mature and high-quality soy sauce koji, crush it and mix it with sterile warm water at 30℃ to 40℃ and the functional mother koji obtained in step (1) at a mass ratio of (2.5 to 3): 100: (1 to 3) to obtain water rich in a variety of active metabolites and bacterial metabolic enzymes.

[0018] In a preferred embodiment, the Bacillus in the Bacillus propagation seed solution is isolated from the soy sauce-flavored koji.

[0019] In a preferred embodiment, in step S2, the mass ratio of bran, granules, and fine powder is 70:12:18.

[0020] The beneficial effects of this invention are: 1. This invention breaks through the industry limitation that traditional soy sauce-flavored koji can only be made during the Dragon Boat Festival. Through the synergistic effect of four core technologies, namely precise temperature control, functional master koji mixing and inoculation, limited range warm water mixing, and functional master koji water addition, it comprehensively solves the koji-making problems of low temperature, low microbial activity, and poor material fermentation in winter. For the first time, it realizes high-quality and standardized production of soy sauce-flavored koji in winter, breaking the seasonal production restrictions.

[0021] 2. High-quality pure yellow koji + functional koji are used as the mother koji. Beneficial koji-making bacteria are artificially and directionally enriched to replace the wild natural bacteria that are scarce in winter. This enriches the microbial community structure of koji from the source, improves the saccharification, fermentation and aroma production capabilities of koji, and solves the core problems of single koji bacteria and low enzyme activity in winter.

[0022] 3. The entire process uses temperature-controlled warm water for mixing and adjusting the master koji, along with gradient environmental temperature and humidity control. This completely avoids the low abundance of beneficial bacteria in winter and the inhibitory effect of low temperature water on the activity of the koji strain, ensuring the continuous activity of the koji strain throughout the entire koji-making process. It effectively prevents the phenomenon of damp koji blocks and cores, strong ammonia and other off-flavors, and high proportion of white koji in winter.

[0023] 4. The process design of combining functional master koji with warm water not only replenishes the koji blocks with moisture, but also introduces the active enzymes, metabolites and trace beneficial bacteria of mature koji, promotes the rapid start of fermentation of the koji blocks, enhances the accumulation of flavor substances in the koji, and makes the quality of winter koji comparable to that of high-quality koji for the Dragon Boat Festival. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention in any way. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of this invention is for describing specific implementation schemes and not for limiting the scope of protection of this invention.

[0025] When a range of values ​​is given, it should be understood that, unless otherwise stated in this invention, the two endpoints of each range and any value between the two endpoints may be selected.

[0026] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly used in the field to which this invention pertains. The terminology used to describe this invention is intended only to describe a particular implementation and is not intended to limit the scope of the teachings. This invention can be implemented using any prior art methods, apparatus, and materials similar to or equivalent to those described, used, or made in the embodiments of this invention.

[0027] The term “and / or” as used herein should be understood to mean any one of the options or any combination of two or more of the options.

[0028] As used herein, the term "about" indicates a range of ±20% of the following value. In some embodiments, the term "about" indicates a range of ±10% of the following value. In some embodiments, the term "about" indicates a range of ±5% of the following value.

[0029] Example 1 This embodiment provides a method for improving the quality of winter-processed soy sauce-flavored koji (fermented soybean curd), the specific steps of which are as follows: 1. Wheat rinsing: Calculate the amount of water required for rinsing wheat based on its moisture content. The requirement is that the moisture content of the wheat increases by 3% after rinsing. Water temperature: 30℃. The moisture content of the wheat after rinsing should be 10%.

[0030] 2. Crushing: Precisely adjust the spacing of the crushing rollers in the crusher to ensure that the mass ratio of bran, granules, and fine powder is 70:12:18. 3. Mixing: Add the functional starter culture to an appropriate amount of warm water at 28℃ and mix evenly. Then mix evenly with the crushed starter culture and the wheat crushed in step S2. The mass ratio of crushed starter culture, crushed wheat material and functional starter culture is 8:100:1. Control the moisture content of the mixture at 38%. After mixing, the temperature of the starter culture material is stabilized at 20℃. 4. Treading the Koji: Scoop the mixed koji material into the koji block mold and tread it manually. When treading the koji blocks, strictly follow the method of "loose in the middle and tight around the edges." First, tread back and forth along both sides of the mold twice with both feet, then trim the koji material around the edges. Tread the central area into a standard turtle-back shaped bulge, with the curved edge and mold height consistent at 6cm, and the height difference between the mold and the bulge at 8cm. The overall height of the koji block should be controlled at 13cm. The edges should be firmly treaded and tightened (short side width 3cm, long side width 3cm), ensuring that the weight of a single koji block is controlled at 12.0 kg.

[0031] 5. Spreading and drying: Place the molded koji blocks in sections on both sides, ensuring that the blocks are placed neatly, aligned front to back and left to right, and that the distance between the blocks is no less than 2cm.

[0032] 6. Loading: The fermentation chamber environment must be temperature-controlled during loading, maintaining a temperature of 28℃ and a relative humidity of 75%. Loading must strictly adhere to the "three horizontal, three vertical" loading requirement. The number of layers of fermented blocks should not exceed 5 (each layer of fermented blocks in the first column, each layer in the sixth column, and the bottom and top layers of each row should be placed in a "side-up, forward-facing" manner; the remaining rows and layers should be staggered in a "three horizontal, three vertical" pattern, with the backs of the fermented blocks not facing each other; "same hole" phenomena between upper and lower layers are prohibited). After loading three rows of fermented blocks into the fermentation chamber, immediately place a... The preparation method for the sprayed water is as follows: High-quality Bacillus isolated from the soy sauce-flavored koji is selected. The formula for each liter of functional koji is as follows: Take 30g of peptone, 10g of yeast extract, 30g of diammonium hydrogen phosphate, and 4g of dipotassium hydrogen phosphate, dissolve in 840ml of distilled water, add 160ml of 50% glucose solution, adjust the pH to 6.5 with phosphoric acid, sterilize, and inoculate with the Bacillus seed culture at a ratio of 5% (seed culture to culture medium volume). Incubate at 37℃ for 60 hours, then add 50% diammonium hydrogen phosphate at a dosage of 40g / L, and continue incubation for 7 days. Select mature, high-quality soy sauce-flavored koji, pulverize it, and mix it with 30℃ sterile warm water and functional koji at a mass ratio of 2.5:100:1 to obtain a sprayed water rich in various active metabolites and microbial metabolic enzymes. The sprayed water per compartment is approximately 0.5% of the koji block weight, and is evenly sprayed onto the surface of the formed koji blocks, with more spray around the edges and less in the center, ensuring that the water does not flow into the koji blocks. After spraying, the koji blocks are sent to a temperature-controlled koji-making room for stacking and fermentation.

[0033] 7. Turning the Kou blocks: Record the temperature of the Kou blocks in the warehouse daily after they are placed in the warehouse. When the temperature of the middle layer of the third row of Kou blocks reaches 62℃ and is maintained for 3 days, turning the Kou blocks can be arranged. In winter, the normal time for turning the Kou blocks is 10 days after loading. The specific turning time can be determined based on the fermentation temperature and the appearance of the Kou blocks (the surface of the middle and lower layers of Kou blocks is brownish-yellow, the cross-section is like a goose egg yolk, with a distinct yellow rice cake flavor, a sweet and sour flavor, and no raw wheat flavor). Temperature and humidity control for each turning: After loading the Kou blocks into the warehouse, close the temperature control equipment and doors and windows, allowing the Kou blocks to ferment and heat up naturally. One turning process takes about 4 hours. Temperature and humidity control must be turned on throughout the process, maintaining the ambient temperature of the fermentation room at 28℃ and the relative humidity at 75%. After one turning, close the temperature control equipment and doors and windows.

[0034] After the first turning of the fermentation chamber, the temperature of the fermentation blocks drops, but gradually begins to rise after 3 days. When the center temperature of the fermentation pile reaches 50℃ and remains there for 2 days, a second turning can be arranged (the second turning time is the number of days of the first turning × 2 + 1 days). Temperature and humidity control for the second turning: The second turning process takes about 4 hours. Temperature and humidity control must be turned on throughout the process, maintaining the ambient temperature in the fermentation room at 28℃ and the relative humidity at 75%. After the second turning, the temperature control equipment is turned off, the chamber door is closed, and the ventilation louvers are opened.

[0035] 8. Dismantling the Koji: The time from when the koji blocks enter the fermentation room to when they leave is 45 days. When the temperature of the koji pile is close to or equal to room temperature, the management personnel must test the moisture content of the koji blocks before they leave the warehouse. If the moisture content of the koji blocks is ≤13%, the large koji blocks can be removed from the warehouse the next day. Workers must handle the koji blocks gently to prevent them from breaking and becoming fragmented koji. They must also clean off any koji grass adhering to the surface of the koji blocks. Koji grass adhering to the koji blocks is prohibited.

[0036] Example 2 This embodiment provides a method for improving the quality of winter-processed soy sauce-flavored koji (fermented soybean curd), the specific steps of which are as follows: 1. Wheat rinsing: Calculate the required amount of water for rinsing wheat based on its moisture content. The goal is to increase the wheat's moisture content by 1% after rinsing. Water temperature: 35℃. The moisture content after rinsing should be 9%.

[0037] 2. Crushing: Precisely adjust the spacing of the crushing rollers in the crusher to ensure that the mass ratio of bran, granules, and fine powder is 68:10:16. 3. Mixing: Add the functional starter culture to an appropriate amount of warm water at 35℃ and mix evenly. Then mix evenly with the crushed starter culture and the wheat crushed in step S2. The mass ratio of crushed starter culture, crushed wheat material and functional starter culture is 9:100:2. Control the moisture content of the mixture at 37%. After mixing, the temperature of the starter culture material is stabilized at 25℃. 4. Treading the Koji: Scoop the mixed koji material into the koji block mold and tread it manually. When treading the koji blocks, strictly follow the method of "loose in the middle and tight around the edges." First, tread back and forth along both sides of the mold twice with both feet, then trim the koji material around the edges. Tread the central area into a standard turtle-back shaped bulge, with the curved edge and mold height consistent at 6cm, and the height difference between the mold and the bulge at 7cm. The overall height of the koji block should be controlled at 14cm. The edges should be firmly treaded and tightened (short side width 4cm, long side width 4cm), ensuring that the weight of a single koji block is controlled at 12.0 kg.

[0038] 5. Spreading and drying: Place the molded koji blocks in sections on both sides, ensuring that the blocks are placed neatly, aligned front to back and left to right, and that the distance between the blocks is no less than 2cm.

[0039] 6. Loading: The fermentation chamber environment must be temperature-controlled during loading, maintaining a temperature of 28℃ and a relative humidity of 75%. Loading must strictly adhere to the "three horizontal, three vertical" loading requirement. The number of layers of fermented blocks should not exceed 5 (each layer of fermented blocks in the first column, each layer in the sixth column, and the bottom and top layers of each row should be placed in a "side-up, forward-facing" manner; the remaining rows and layers should be staggered in a "three horizontal, three vertical" pattern, with the backs of the fermented blocks not facing each other; "same hole" phenomena between upper and lower layers are prohibited). After loading three rows of fermented blocks into the fermentation chamber, immediately place a... The preparation method for the sprayed water is as follows: High-quality Bacillus isolated from the soy sauce-flavored koji is selected. The formula for each liter of functional koji is as follows: Take 30g of peptone, 10g of yeast extract, 30g of diammonium hydrogen phosphate, and 4g of dipotassium hydrogen phosphate, dissolve in 840ml of distilled water, add 160ml of 50% glucose solution, adjust the pH to 6.5 with phosphoric acid, sterilize, and inoculate with the Bacillus seed culture at a ratio of 5% (seed culture to culture medium volume). Incubate at 37℃ for 60 hours, then add 50% diammonium hydrogen phosphate at a dosage of 40g / L, and continue incubation for 6 days. Select mature, high-quality soy sauce-flavored koji, pulverize it, and mix it with 30℃ sterile warm water and functional koji at a mass ratio of 3:100:2 to obtain sprayed water rich in various active metabolites and microbial metabolic enzymes. The amount of sprayed water per compartment is approximately 1% of the koji block weight, and is evenly sprayed onto the surface of the formed koji block, with more spray around the edges and less in the center, ensuring that the water does not flow into the koji block. After spraying, the koji blocks are sent to a temperature-controlled koji-making room for stacking and fermentation.

[0040] 7. Turning the Kou blocks: Record the temperature of the Kou blocks in the warehouse daily after they are placed in the warehouse. When the temperature of the middle layer of the third row of Kou blocks reaches 62℃ and is maintained for 3 days, turning the Kou blocks can be arranged. In winter, the normal time for turning the Kou blocks is the 9th day after loading. The specific turning time can be determined based on the fermentation temperature and the appearance of the Kou blocks (the surface of the middle and lower layers of Kou blocks is brownish-yellow, the cross-section is like a goose egg yolk, with a distinct yellow rice cake flavor, a sweet and sour flavor, and no raw wheat flavor). Temperature and humidity control for each turning: After loading the Kou blocks into the warehouse, close the temperature control equipment and doors and windows, allowing the Kou blocks to ferment and heat up naturally. One turning process takes about 4 hours. Temperature and humidity control must be turned on throughout the process, maintaining the ambient temperature of the fermentation room at 30℃ and the relative humidity at 85%. After one turning, close the temperature control equipment and doors and windows.

[0041] After the first turning of the fermentation chamber, the temperature of the fermentation blocks drops, but gradually begins to rise after 3 days. When the center temperature of the fermentation block reaches 55℃ and remains at that temperature for 2 days, a second turning of the fermentation chamber can be arranged (the second turning time is the number of days of the first turning × 2 + 1 days). Temperature and humidity control for the second turning: The second turning process takes about 4 hours. Temperature and humidity control must be turned on throughout the process, maintaining the ambient temperature of the fermentation room at 32℃ and the relative humidity at 85%. After the second turning, the temperature control equipment is turned off, the chamber door is closed, and the dehumidification louvers are opened.

[0042] 8. Dismantling the Koji: The time from when the koji blocks enter the fermentation room to when they exit is 48 days. When the temperature of the koji pile approaches or equals room temperature, the management personnel must test the moisture content of the koji blocks before they leave the warehouse. If the moisture content is ≤13%, the large koji blocks can be removed from the warehouse the next day. Workers must handle the koji blocks gently to prevent them from breaking and becoming fragmented koji. They must also clean off any koji grass adhering to the surface of the koji blocks, and it is forbidden for any koji grass to remain on the surface of the koji blocks.

[0043] Example 3 This embodiment provides a method for improving the quality of winter-processed soy sauce-flavored koji (fermented soybean curd), the specific steps of which are as follows: 1. Wheat rinsing: Calculate the required amount of water for rinsing wheat based on its moisture content. The goal is to increase the wheat's moisture content by 6% after rinsing. Water temperature: 40℃. The moisture content after rinsing should be 13%.

[0044] 2. Crushing: Precisely adjust the spacing of the crushing rollers in the crusher to ensure that the mass ratio of bran, granules, and fine powder is 72:14:20. 3. Mixing: Add the functional starter culture to an appropriate amount of warm water at 28℃ and mix evenly. Then mix evenly with the crushed starter culture and the wheat crushed in step S2. The mass ratio of crushed starter culture, crushed wheat material and functional starter culture is 9.5:100:3. Control the moisture content of the mixture at 39% and stabilize the temperature of the starter culture material at 30℃ after mixing. 4. Treading the Koji: Scoop the mixed koji material into the koji block mold and tread it manually. When treading the koji blocks, strictly follow the method of "loose in the middle and tight around the edges." First, tread back and forth along both sides of the mold twice with both feet, then trim the koji material around the edges. Tread the central area into a standard turtle-back shaped bulge, with the curved edge and mold height consistent at 6cm, and the height difference between the mold and the bulge at 8cm. The overall height of the koji block should be controlled at 13cm. The edges should be firmly treaded and tightened (short side width 3.5cm, long side width 3.5cm), ensuring that the weight of a single koji block is controlled at 12.0 kg.

[0045] 5. Spreading and drying: Place the molded koji blocks in sections on both sides, ensuring that the blocks are placed neatly, aligned front to back and left to right, and that the distance between the blocks is no less than 2cm.

[0046] 6. Loading: The fermentation chamber environment must be temperature-controlled during loading, maintaining a temperature of 32℃ and a relative humidity of 95%. Loading must strictly adhere to the "three horizontal, three vertical" loading requirement. The number of layers of fermented blocks should not exceed 5 (each layer of fermented blocks in the first column, each layer in the sixth column, and the bottom and top layers of each row should be placed in a "side-up, forward-facing" manner; the remaining rows and layers should be staggered according to the "three horizontal, three vertical" rule, with the backs of the fermented blocks not facing each other; "same hole" phenomena between upper and lower layers are prohibited). After loading three rows of fermented blocks into the fermentation chamber, immediately place a... The preparation method for the sprayed water is as follows: High-quality Bacillus isolated from the soy sauce-flavored koji is selected. The formula for each liter of functional koji is as follows: Take 30g of peptone, 10g of yeast extract, 30g of diammonium hydrogen phosphate, and 4g of dipotassium hydrogen phosphate, dissolve in 840ml of distilled water, add 160ml of 50% glucose solution, adjust the pH to 6.5 with phosphoric acid, sterilize, and inoculate with the Bacillus seed culture at a ratio of 5% (seed culture to culture medium volume). Incubate at 37℃ for 60 hours, then add 50% diammonium hydrogen phosphate at a dosage of 40g / L, and continue incubation for 7 days. Select mature, high-quality soy sauce-flavored koji, pulverize it, and mix it with 30℃ sterile warm water and functional koji at a mass ratio of 3:100:2 to obtain sprayed water rich in various active metabolites and microbial metabolic enzymes. The amount of sprayed water per compartment is approximately 1% of the koji block weight, and is evenly sprayed onto the surface of the formed koji blocks, with more spray around the edges and less in the center, ensuring that the water does not flow into the koji blocks. After spraying, the koji blocks are sent to a temperature-controlled koji-making room for stacking and fermentation.

[0047] 7. Turning the Kou blocks: Record the temperature of the Kou blocks in the warehouse daily after they are placed in the warehouse. When the temperature of the middle layer of the third row of Kou blocks reaches 65℃ and is maintained for 3 days, turning the Kou blocks can be arranged. In winter, the normal time for turning the Kou blocks is 12 days after loading. The specific turning time can be determined based on the fermentation temperature and the appearance of the Kou blocks (the surface of the middle and lower layers of Kou blocks is brownish-yellow, the cross-section is like a goose egg yolk, with a distinct yellow rice cake flavor, a sweet and sour flavor, and no raw wheat flavor). Temperature and humidity control for each turning: After loading the Kou blocks into the warehouse, close the temperature control equipment and doors and windows, allowing the Kou blocks to ferment and heat up naturally. One turning process takes about 4 hours. Temperature and humidity control must be turned on throughout the process, maintaining the ambient temperature of the fermentation room at 32℃ and the relative humidity at 95%. After one turning, close the temperature control equipment and doors and windows.

[0048] After the first turning of the fermentation chamber, the temperature of the fermentation blocks drops, but gradually begins to rise after 3 days. When the center temperature of the fermentation pile reaches 60℃ and remains there for 2 days, a second turning can be arranged (the second turning time is the number of days of the first turning × 2 + 1 days). Temperature and humidity control for the second turning: The second turning process takes about 4 hours. Temperature and humidity control must be turned on throughout the process, maintaining the ambient temperature in the fermentation room at 32℃ and the relative humidity at 95%. After the second turning, the temperature control equipment is turned off, the chamber door is closed, and the ventilation louvers are opened.

[0049] 8. Dismantling the Koji: The time from when the koji blocks enter the fermentation room to when they leave is 50 days. When the temperature of the koji pile approaches or equals room temperature, the management personnel must test the moisture content of the koji blocks before they leave the warehouse. If the moisture content of the koji blocks is ≤13%, the large koji blocks can be removed from the warehouse the next day. Workers must handle the koji blocks gently to prevent them from breaking and becoming fragmented koji. They must also clean off any koji grass adhering to the surface of the koji blocks, and it is forbidden for any koji grass to adhere to the koji blocks.

[0050] Comparative Example 1 This comparative example provides a traditional winter koji-making process, including the following steps: 1. Wheat rinsing: Calculate the amount of water required for rinsing wheat based on its moisture content. It is required to increase the moisture content of wheat by 3% after rinsing. Water temperature: room temperature water. The moisture content of wheat after rinsing should be 10%.

[0051] 2. Crushing: Precisely adjust the spacing of the crushing rollers in the crusher to ensure that the mass ratio of bran, granules, and fine powder is 70:12:18. 3. Mixing: Mix the crushed mother koji (high-quality yellow koji), crushed wheat, and room temperature water. The mass ratio of crushed mother koji to crushed wheat is 8:100. Control the moisture content of the mixture at 38%. Mix at a uniform speed to ensure that the mother koji, room temperature water, and koji are fully and evenly mixed. The temperature of the koji after mixing is 10℃.

[0052] 4. Treading the Koji: Scoop the mixed koji material into the koji block mold and tread it manually. When treading the koji blocks, strictly follow the method of "loose in the middle and tight around the edges." First, tread back and forth along both sides of the mold twice with both feet, then trim the koji material around the edges. Tread the central area into a standard turtle-back shaped bulge, with the curved edge and mold height consistent at 6cm, and the height difference between the mold and the bulge at 8cm. The overall height of the koji block should be controlled at 13cm. The edges should be firmly treaded and tightened (short side width 3cm, long side width 3cm), ensuring that the weight of a single koji block is controlled within 12.0 kg.

[0053] 5. Spreading and drying: Place the molded koji blocks in sections on both sides, ensuring that the blocks are placed neatly, aligned front to back and left to right, and that the distance between the blocks is no less than 2cm.

[0054] 6. Loading: Loading must be strictly completed according to the requirement of three rows and three columns. The number of layers of fermented koji blocks should not exceed 5 (each layer of koji blocks in the first column, each layer of koji blocks in the sixth column, and the bottom and top layers of koji blocks in each row should be placed in a "side-up and forward" manner; the remaining rows and layers should be placed in a staggered "three rows and three columns" manner, and the backs of the koji blocks should not face each other; the phenomenon of "same hole" between upper and lower layers is prohibited; after three rows of koji blocks are loaded in the fermentation chamber, immediately sprinkle a small amount of water on top of the koji blocks. The water should be room temperature tap water, and the amount of water in each chamber should be about 0.5% of the weight of the koji blocks. Spray evenly on the surface of the formed koji blocks, with more water around the edges and less in the center, so that the water does not flow into the koji blocks. After spraying, send the koji blocks into the fermentation room for stacking and fermentation.

[0055] 7. Turning the Kou Blocks: After the Kou blocks are placed in the warehouse, record the temperature of the Kou blocks in the warehouse daily. When the temperature of the middle layer of the third row of Kou blocks rises to 55℃ and is maintained for 3 days, turning the Kou blocks can be arranged. In winter, the normal time for turning the Kou blocks is 10 days after loading. The specific turning time can be judged and determined based on the fermentation temperature and the sensory characteristics of the Kou blocks (the surface of the middle and lower layers of Kou blocks is brownish-yellow, the cross-section is like a goose egg yolk, with a distinct yellow rice cake smell, a sweet and sour smell, and no raw wheat smell). After the first turning, close the doors and windows. After the first turning, the temperature of the Kou blocks drops, and after 3 days, the temperature gradually begins to rise. When the temperature of the center of the Kou pile reaches 50℃ and is maintained for 2 days, personnel can arrange for a second turning (the time for the second turning is the number of days of the first turning × 2 + 1 days). After the second turning, close the warehouse door and open the ventilation louvers.

[0056] 8. Dismantling the Koji: The time from when the koji blocks enter the fermentation room to when they leave is 45 days. When the temperature of the koji pile is close to or equal to room temperature, the management personnel must test the moisture content of the koji blocks before they leave the warehouse. If the moisture content of the koji blocks is ≤13%, the large koji blocks can be removed from the warehouse the next day. Workers must handle the koji blocks gently to prevent them from breaking and becoming fragmented koji. They must also clean off any koji grass adhering to the surface of the koji blocks. Koji grass adhering to the koji blocks is prohibited.

[0057] Comparative Example 2 This comparative example provides a traditional winter koji-making process, including the following steps: 1. Wheat rinsing: Calculate the required amount of water for rinsing wheat based on its moisture content. It is required to increase the wheat moisture content by 1% after rinsing. Water temperature: room temperature water. The moisture content after rinsing wheat should be 9%.

[0058] 2. Crushing: Precisely adjust the spacing of the crushing rollers in the crusher to ensure that the mass ratio of bran, granules, and fine powder is 68:10:16. 3. Mixing: Mix the crushed mother koji (high-quality yellow koji), crushed wheat, and room temperature water. The mass ratio of crushed mother koji to crushed wheat is 9:100. Control the moisture content of the mixture at 37%. Mix at a uniform speed to ensure that the mother koji, room temperature water, and koji are fully and evenly mixed. The temperature of the koji after mixing is 12℃.

[0059] 4. Treading the Koji: Scoop the mixed koji material into the koji block mold and tread it manually. When treading the koji blocks, strictly follow the method of "loose in the middle and tight around the edges." First, tread back and forth along both sides of the mold twice with both feet, then trim the koji material around the edges. Tread the central area into a standard turtle-back shaped bulge, with the curved edge and mold height consistent at 6cm, and the height difference between the mold and the bulge at 7cm. The overall height of the koji block should be controlled at 14cm. The edges should be firmly treaded and tightened (short side width 4cm, long side width 4cm), ensuring that the weight of a single koji block is controlled within 12.0 kg.

[0060] 5. Spreading and drying: Place the molded koji blocks in sections on both sides, ensuring that the blocks are placed neatly, aligned front to back and left to right, and that the distance between the blocks is no less than 2cm.

[0061] 6. Loading: Loading must be completed strictly according to the three-by-three horizontal and three-by-three vertical loading requirement. The number of layers of fermented koji blocks should not exceed 5 (each layer of koji blocks in the first column, each layer of koji blocks in the sixth column, and the bottom and top layers of each row should be placed in a "side-up and forward-facing" manner; the remaining rows and layers should be placed in a staggered "three-by-three horizontal and three-by-three" manner, and the backs of the koji blocks should not face each other; the phenomenon of "same hole" between upper and lower layers is prohibited; after three rows of koji blocks are loaded into the fermentation chamber, immediately sprinkle a small amount of water on top of the koji blocks. The water should be room temperature tap water, and the amount of water per chamber should be about 1% of the weight of the koji blocks. Spray evenly on the surface of the formed koji blocks, with more water around the edges and less in the center, so that the water does not flow into the koji blocks. After spraying, send the koji blocks into the fermentation room for stacking and fermentation.

[0062] 7. Turning the Kou Blocks: After the Kou blocks are placed in the warehouse, record the temperature of the Kou blocks in the warehouse daily. When the temperature of the middle layer of the third row of Kou blocks rises to 57℃ and is maintained for 3 days, turning the Kou blocks can be arranged. In winter, the normal time for turning the Kou blocks is 9 days after loading. The specific turning time can be judged and determined based on the fermentation temperature and the sensory characteristics of the Kou blocks (the surface of the middle and lower layers of Kou blocks is brownish-yellow, the cross-section is like a goose egg yolk, with a distinct yellow rice cake smell, a sweet and sour smell, and no raw wheat smell). After the first turning, close the doors and windows. After the first turning, the temperature of the Kou blocks drops, and the temperature gradually begins to rise after 3 days. When the temperature of the center of the Kou pile reaches 57℃ and is maintained for 2 days, personnel can arrange for a second turning (the time for the second turning is the number of days of the first turning × 2 + 1 days). After the second turning, close the warehouse door and open the ventilation louvers.

[0063] 8. Dismantling the Koji: The time from when the koji blocks enter the fermentation room to when they exit is 48 days. When the temperature of the koji pile approaches or equals room temperature, the management personnel must test the moisture content of the koji blocks before they leave the warehouse. If the moisture content is ≤13%, the large koji blocks can be removed from the warehouse the next day. Workers must handle the koji blocks gently to prevent them from breaking and becoming fragmented koji. They must also clean off any koji grass adhering to the surface of the koji blocks, and it is forbidden for any koji grass to remain on the surface of the koji blocks.

[0064] Comparative Example 3 This comparative example provides a traditional winter koji-making process, including the following steps: 1. Wheat rinsing: Calculate the required amount of water for rinsing wheat based on its moisture content. It is required to increase the wheat moisture content by 6% after rinsing. Water temperature: room temperature water. The moisture content after rinsing wheat should be 13%.

[0065] 2. Crushing: Precisely adjust the spacing of the crushing rollers in the crusher to ensure that the mass ratio of bran, granules, and fine powder is 72:14:20. 3. Mixing: Mix the crushed mother koji (high-quality yellow koji), crushed wheat, and room temperature water. The mass ratio of crushed yellow koji to crushed wheat is 9.5:100. Control the moisture content of the mixture at 39%. Mix at a uniform speed to ensure that the mother koji, room temperature water, and koji are fully and evenly mixed. The temperature of the koji after mixing is 15℃.

[0066] 4. Treading the Koji: Scoop the mixed koji material into the koji block mold and tread it manually. When treading the koji blocks, strictly follow the method of "loose in the middle and tight around the edges." First, tread back and forth along both sides of the mold twice with both feet, then trim the koji material around the edges. Tread the central area into a standard turtle-back shaped bulge, with the curved edge and mold height consistent at 6cm, and the height difference between the mold and the bulge at 8cm. The overall height of the koji block should be controlled at 13cm. The edges should be firmly treaded and tightened (short side width 3.5cm, long side width 3.5cm), ensuring that the weight of a single koji block is controlled within 12.0 kg.

[0067] 5. Spreading and drying: Place the molded koji blocks in sections on both sides, ensuring that the blocks are placed neatly, aligned front to back and left to right, and that the distance between the blocks is no less than 2cm.

[0068] 6. Loading: Loading must be completed strictly according to the three-by-three horizontal and three-by-three vertical loading requirement. The number of layers of fermented koji blocks should not exceed 5 (each layer of koji blocks in the first column, each layer of koji blocks in the sixth column, and the bottom and top layers of each row should be placed in a "side-up and forward-facing" manner; the remaining rows and layers should be placed in a staggered "three-by-three horizontal and three-by-three" manner, and the backs of the koji blocks should not face each other; the phenomenon of "same hole" between upper and lower layers is prohibited; after three rows of koji blocks are loaded into the fermentation chamber, immediately sprinkle a small amount of water on top of the koji blocks. The water should be room temperature tap water, and the amount of water per chamber should be about 1% of the weight of the koji blocks. Spray evenly on the surface of the formed koji blocks, with more water around the edges and less in the center, so that the water does not flow into the koji blocks. After spraying, send the koji blocks into the fermentation room for stacking and fermentation.

[0069] 7. Turning the Kou Blocks: After the Kou blocks are placed in the warehouse, record the temperature of the Kou blocks in the warehouse daily. When the temperature of the middle layer of the third row of Kou blocks rises to 58℃ and is maintained for 3 days, turning the Kou blocks can be arranged. In winter, the normal time for turning the Kou blocks is 12 days after loading. The specific turning time can be judged and determined based on the fermentation temperature and the sensory characteristics of the Kou blocks (the surface of the middle and lower layers of Kou blocks is brownish-yellow, the cross-section is like a goose egg yolk, with a distinct yellow rice cake smell, a sweet and sour smell, and no raw wheat smell). After the first turning, close the doors and windows. After the first turning, the temperature of the Kou blocks drops, and after 3 days, the temperature gradually begins to rise. When the temperature of the center of the Kou pile reaches 58℃ and is maintained for 2 days, personnel can arrange for a second turning (the time for the second turning is the number of days of the first turning × 2 + 1 days). After the second turning, close the warehouse door and open the ventilation louvers.

[0070] 8. Dismantling the Koji: The time from when the koji blocks enter the fermentation room to when they leave is 50 days. When the temperature of the koji pile approaches or equals room temperature, the management personnel must test the moisture content of the koji blocks before they leave the warehouse. If the moisture content of the koji blocks is ≤13%, the large koji blocks can be removed from the warehouse the next day. Workers must handle the koji blocks gently to prevent them from breaking and becoming fragmented koji. They must also clean off any koji grass adhering to the surface of the koji blocks, and it is forbidden for any koji grass to adhere to the koji blocks.

[0071] Experimental Example The sampling method involved taking one piece of Daqu (a type of starter culture) from different positions at the top, middle, and bottom of each column in the entire warehouse, mixing and crushing it, and then testing and grading it. The moisture content, acidity, saccharification power, fermentation power, microbial richness, and finished product qualification rate of the winter Daqu prepared in Examples 1, 2, 3, and the comparative example were tested respectively. The results showed that the Daqu prepared in Examples 1, 2, and 3 of this invention had a 100% qualification rate, with no defects such as damp core, strong ammonia smell and other off-flavors, or high proportion of white Daqu. The Daqu grade of Grade 1 and above was 100% higher than that of traditional winter Daqu production.

[0072]

[0073] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A method for improving the quality of winter-processed soy sauce-flavored koji, characterized in that, Includes the following steps: S1. Wheat rinsing: Calculate the required amount of water for rinsing wheat based on its moisture content. It is required to increase the wheat moisture content by 1% to 6% after rinsing. Water temperature: 30℃ to 40℃. The moisture content after rinsing should be 9% to 13%. S2. Crushing: Precisely adjust the spacing of the crushing rollers in the crusher to ensure that the mass ratio of bran, granules and fine powder is (68~72):(10~14):(16~20); S3. Mixing: Add the functional starter culture to an appropriate amount of warm water at 28℃~40℃ and mix evenly. Then mix it evenly with the crushed starter culture and the wheat crushed in step S2. The mass ratio of the crushed starter culture, the crushed wheat material and the functional starter culture is (8~9.5):100:(1~3). Control the moisture content of the mixture to be between 37% and 39%. After mixing, the temperature of the starter culture material is stabilized at 20℃~30℃. S4. Treading the koji: The mixed koji material is shoveled into the koji block mold and treaded manually. When treading the koji blocks, the method of "loose in the middle and tight around the edges" must be strictly followed. During operation, first use both feet to tread back and forth along both sides of the koji mold twice, and then trim the koji material around the edges to ensure that the weight of a single koji block is controlled within the range of 11.0kg to 12.0kg. S5. Spreading and drying: Place the molded blocks on both sides of the section in sequence. The blocks should be placed neatly, aligned front to back and left to right, and the distance between the blocks should be no less than 2cm. S6. Loading into the fermentation chamber: The fermentation chamber environment must be temperature controlled during the loading process. The temperature of the fermentation chamber should be controlled at 28℃~32℃ and the relative humidity at 75%~80%. The loading should be completed strictly according to the requirement of three rows horizontally and three rows vertically. The number of layers of fermentation blocks should not exceed 5. After three rows of fermentation blocks are loaded into the fermentation chamber, water should be sprinkled on top of the fermentation blocks immediately. The amount of water in a single chamber should be 0.5%~1% of the weight of the fermentation blocks. The water should be evenly sprayed on the surface of the formed fermentation blocks. After spraying, the fermentation blocks should be sent to the temperature-controlled fermentation room for stacking and fermentation. S7. Turning the Fermentation Blocks: Record the temperature of the fermentation blocks in the warehouse daily after they are placed in the warehouse. When the temperature of the middle layer of the third row of fermentation blocks rises to 60℃~65℃ and is maintained for 3 to 4 days, turning the fermentation blocks can be arranged. In winter, the normal time for turning the fermentation blocks is 9 to 12 days after loading. After the first turning, the temperature of the fermentation blocks will drop, and after 3 to 5 days, the temperature will gradually start to rise. When the temperature of the center of the fermentation pile reaches 50℃~60℃ and is maintained for 2 to 3 days, a second turning should be carried out. The temperature and humidity control conditions for the first and second turning are as follows: control the ambient temperature of the fermentation room at 28℃~32℃ and the relative humidity at 75%~100%. S8. Dismantling the koji: The time from when the koji blocks enter the fermentation room to when they leave the fermentation room is 45 to 50 days. When the temperature of the koji pile is close to or equal to the room temperature, the moisture content of the koji blocks is tested. If the moisture content of the koji blocks is ≤13%, the koji blocks are discharged from the warehouse the next day.

2. The method according to claim 1, characterized in that, The pulverized starter culture in step S3 is selected from high-quality yellow starter culture grown in warehouses where fermentation temperature reaches above 40°C for 24 hours.

3. The method according to claim 1, characterized in that, The preparation method of the functional masterbatch in step S3 is as follows: Select high-quality Bacillus isolated from soy sauce-flavored Daqu. The formula for preparing the functional masterbatch per liter is as follows: Take 30g of peptone, 10g of yeast extract, 30g of diammonium hydrogen phosphate, and 4g of dipotassium hydrogen phosphate, dissolve them in 840ml of distilled water, add 160ml of 50% glucose solution, adjust the pH to 6.5 with phosphoric acid, sterilize, take the Bacillus seed culture and inoculate it at a ratio of 5% of the seed culture to the culture medium volume, incubate at 37℃ for 60 hours, add diammonium hydrogen phosphate at a ratio of 40g / L, and continue to incubate for 6 to 7 days.

4. The method according to claim 1, characterized in that, In step S4, the central area is tamped into a standard turtle-back shaped bulge, with the curved edge and the curved mold at the same height of 6cm. The height difference between the curved mold and the bulge is 7cm-8cm, and the overall height of the bulge is controlled at 13cm-14cm. The edges should be tamped and tightened around the bulge, with the short side being 3cm-4cm wide and the long side being 2cm-3cm wide.

5. The method according to claim 1, characterized in that, The preparation method of the water in step S6 is as follows: (1) Take 30g of peptone, 10g of yeast extract, 30g of diammonium hydrogen phosphate and 4g of dipotassium hydrogen phosphate, add 840ml of distilled water to dissolve, add 160ml of 50% glucose solution, adjust the pH to 6.5 with phosphoric acid, sterilize, take the Bacillus propagation seed liquid and inoculate it according to the ratio of seed liquid to culture medium volume of 5%, culture at 37℃ for 60 hours, add 50% diammonium hydrogen phosphate, the amount of addition is 40g / l, continue to culture for 6 to 7 days to obtain functional mother koji; (2) Select mature high-quality soy sauce koji, crush it and mix it with sterile warm water at 30℃~40℃ and the functional mother koji obtained in step (1) at a mass ratio of (2.5~3):100:(1~3) to obtain water rich in a variety of active metabolites and bacterial metabolic enzymes.

6. The method according to claim 5, characterized in that, Bacillus in the Bacillus propagation seed liquid was isolated from soy sauce-flavored koji.

7. The method according to claim 1, characterized in that, In step S2, the mass ratio of bran, granules, and fine powder is 70:12:18.

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