Mixed koji for baijiu brewing and fermentation method of mixed koji
By alternating the stacking and contact of mechanical and manual koji, and utilizing the heat transfer from the manual koji, the problem of insufficient aroma substance generation in mechanical koji production is solved, thus achieving high-efficiency and low-cost high-end baijiu brewing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-02
- Publication Date
- 2026-04-10
AI Technical Summary
Mechanically produced koji has insufficient internal density, resulting in a limited amount of aroma substances generated by microbial metabolism during fermentation. This makes it difficult to meet the requirements of high-end baijiu brewing for sensory quality and flavor diversity in koji. On the other hand, manual koji making is labor-intensive and costly, making it unsuitable for large-scale production.
By alternating the stacking and contact of mechanical and manual koji, the heat energy is transferred from the manual koji to the mechanical koji through its heat-retaining capacity. Combined with the principle of heat conduction, this improves the rate of achieving the required temperature for the second turning of mechanical koji, achieves temperature balance, and enriches the variety of aroma substances.
It improves the efficiency of mechanical koji making and the richness of aroma substances, meeting the quality requirements of high-end baijiu, while reducing labor intensity and production costs.
Smart Images
Figure CN121825679A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of baijiu brewing technology, and relates to a mixed koji for baijiu brewing and its fermentation method. Background Technology
[0002] Currently, the koji-making process for baijiu (Chinese liquor) is mainly divided into two types: mechanical koji making and manual koji pressing. Mechanical koji making, utilizing automated equipment, achieves mass production, significantly improving efficiency compared to manual koji pressing. It can quickly meet the needs of large-scale koji production and produces koji blanks with greater uniformity. However, due to limitations in the uniformity of force applied by mechanical pressing and the fixed process parameters, the internal structure of mechanically made koji blanks lacks density. This results in limited generation of aroma substances from microbial metabolism during fermentation, ultimately leading to a weak koji aroma, a single aroma profile, and a significant lack of aroma richness and fullness. This makes it difficult to meet the core requirements of high-end baijiu brewing for sensory quality and flavor diversity in koji making.
[0003] Manual koji-making relies on traditional techniques, where the force and method of treading are manually controlled to create a "tight on the outside, loose on the inside" structure in the koji mold. This structure facilitates the growth, reproduction, and metabolism of microorganisms during fermentation, resulting in a koji mold with a rich and mellow aroma and a wide variety of flavor compounds, providing a high-quality fermentation foundation for high-end baijiu. However, manual koji-making is entirely manual, extremely labor-intensive, and its efficiency in forming the koji mold is low due to factors such as the skill level and physical condition of the operators. This makes it difficult to adapt to the pace of large-scale production. At the same time, the continuously rising labor costs result in high overall production costs, hindering its large-scale promotion and application. Summary of the Invention
[0004] The purpose of this invention is to provide a mixed koji for baijiu brewing and its fermentation method. By alternating the stacking and contact of mechanically made koji and manually made koji, the manually made koji, which has a strong heat retention capacity, transfers heat energy to the mechanically made koji. The principle of heat conduction is used to achieve temperature balance, improve the temperature compliance rate of the second turning of mechanically made koji, and increase the temperature compliance rate of the second turning of koji to 75%. This also improves the aroma of mechanically made koji, enriches the types of aroma substances, and improves the efficiency of koji making.
[0005] Based on this, according to a first aspect of the present invention, the present invention provides a fermentation method for a mixed koji for brewing baijiu (Chinese liquor), comprising the following steps: Storage and stacking: Mechanically produced koji and manually produced koji are mixed and stacked in the fermentation chamber; the mechanically produced koji and manually produced koji are stacked alternately. Fermentation in the warehouse: The fermentation process involves two turnings of the koji. The first turning is carried out 5 to 10 days after the koji is piled up in the warehouse, and the second turning is carried out 5 to 10 days after the first turning. Unpacking: After being stored in the warehouse for 35 to 45 days, the covering material on the surface of the koji blanks is removed to obtain unpacked koji.
[0006] In some embodiments of the present invention, the alternating stacking of mechanically produced koji and artificially produced koji is one of the following: Alternating rows: The mechanically produced koji and the manually produced koji are arranged alternately in a row ratio of 1:1, 1:2, or 2:1; Alternating transport by wagon: The mechanically produced koji and the manually produced koji are transported into the warehouse alternately in a ratio of 1:1, 1:2 or 2:1, with each wagon of koji blanks evenly distributed in different areas of the warehouse; Alternating blocks: The mechanically produced koji and the manually produced koji are stacked alternately in a block ratio of 1:1, 1:2 or 2:1.
[0007] In some embodiments of the present invention, the alternating stacking of mechanically produced koji and artificially produced koji is one of the following: Alternating by row: The mechanically produced and manually produced koji are arranged alternately in a 1:1 row ratio; Alternating transport by wagon: The mechanically produced koji and the manually produced koji are transported into the warehouse alternately in a ratio of 1:2 or 2:1, with each wagon of koji blanks evenly distributed in different areas of the warehouse.
[0008] In some embodiments of the present invention, when the mechanically made koji and the manually made koji are stacked alternately in rows, the row spacing between two adjacent rows of koji blanks is 35~45cm.
[0009] In some embodiments of the present invention, each row of mechanically made koji and manually made koji are stacked in at least two layers, and the spacing between adjacent layers of koji blanks is 3 to 10 cm.
[0010] In some embodiments of the present invention, the interlayer spacing between mechanically shaped and artificially shaped koji in each row gradually decreases from bottom to top.
[0011] In some embodiments of the present invention, the mechanically made koji and the manually made koji are stacked in a six-row, four-layer structure, with the spacing between the layers of koji blanks from bottom to top being 8cm, 7cm, 6cm, and 5cm respectively.
[0012] In some embodiments of the present invention, the total loading time is ≤5 hours.
[0013] In some embodiments of the present invention, the mechanically produced koji has the same size, weight and appearance as the artificially produced koji.
[0014] According to a second aspect of the present invention, the present invention also provides a mixed koji for brewing baijiu prepared by any of the above methods, including mechanical koji making and manual koji making.
[0015] Compared with the prior art, the present invention has at least the following beneficial effects: By alternating and stacking mechanical and manual koji, the manual koji, with its stronger heat retention, transfers heat to the mechanical koji. This utilizes the principle of heat conduction to achieve temperature balance, thereby increasing the rate of achieving the required temperature during the second turning of the mechanical koji, raising the rate to 75%. This also enhances the aroma of the mechanically produced koji, enriches the variety of aroma compounds, and improves koji-making efficiency. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the stacking of koji blanks in the fermentation chamber in Embodiment 1 of this application. Detailed Implementation
[0017] The following specific embodiments further illustrate the technical solution of the present invention. These specific embodiments do not represent a limitation on the scope of protection of the present invention. Non-essential modifications and adjustments made by others based on the concept of the present invention still fall within the scope of protection of the present invention.
[0018] As described in the background section, mechanical koji making has high production efficiency, and the yellow curvature, curvature rate, and physicochemical data of the koji blanks all meet the requirements. However, the koji blanks have a light aroma and insufficient aroma richness, which makes it difficult to meet the sensory quality requirements of high-end koji making. Although manual koji treading can produce koji blanks with a rich aroma and better quality, the labor intensity is high and the production efficiency is low, resulting in high production costs.
[0019] To address this issue, the industry actively explored the reasons for the aforementioned results. The findings revealed that mechanical koji making, due to the use of machines for treading, resulted in a uniform density of the koji blanks. The tightness of the entire koji blank remained unchanged, and the two ends of the koji blanks could not breathe, which was not conducive to the growth of beneficial bacteria. This may have led to a weak koji aroma and insufficient fragrance.
[0020] When manually treading the koji, workers can only compact the koji material around the edges of the koji blank, while loosening the koji material at one end. This prevents the koji material around the edges from becoming compact while the material at the top and bottom ends is relatively loose. Consequently, the koji blank can only breathe and dissipate heat from one end, which affects the growth of beneficial bacteria inside the koji blank and thus affects its quality.
[0021] To address these issues, the industry has attempted to improve the koji-making molds and processes, making the koji blanks convex at both ends, compact around the edges, and loose in the center. This optimizes the structural permeability of individual koji blanks, thereby increasing the content of beneficial microorganisms within them and shortening the koji-making cycle. However, the problems of reliance on manual labor, extremely high labor intensity, and low koji-forming efficiency still exist.
[0022] Based on this, we attempted to explore other methods to improve the sensory quality of mechanically produced koji. First, we measured and statistically analyzed the average temperatures of the first and second turning of the koji during fermentation in five groups of conventionally mechanically produced and manually produced koji. The results are shown in Table 1 below: Table 1. Average temperatures of the first and second turning processes for mechanically produced and manually produced koji. It can be seen that the temperatures for both mechanical and manual koji turning meet the process requirements (≥50℃). During the koji-making process, the optimal growth temperature for microorganisms that play a key role in the flavor of baijiu, such as thermophilic fungi and Bacillus, is concentrated above 50℃. This temperature range promotes microbial reproduction and metabolism, generating aroma precursors such as esters and organic acids. If the temperature is below 50℃, the activity of these microorganisms will be significantly reduced, resulting in insufficient synthesis of aroma substances. At the same time, a high-temperature environment of ≥50℃ can inhibit the growth of acid-producing bacteria, putrefactive microorganisms, and other miscellaneous bacteria, reducing the production of off-flavor substances. There is no significant difference in the average temperature of the first turning. The temperatures for the second turning of mechanical koji both meet the process temperature standard (≥50℃), but the temperatures of manual koji are generally higher than those of mechanical koji.
[0023] Further measurements were taken at multiple points to determine the fermentation temperature during the second turning of the koji. The results are shown in Table 2 below. Table 2 Fermentation temperature for the second turning of the koji. Next, the compliance rate of the fermentation temperature for the second turning of the koji (the ratio of the number of measurement points with a second turning temperature ≥ 50℃ to the total number of measurement points) was analyzed, and the results are shown in Table 3 below: Table 3. Fermentation temperature compliance rate for secondary turning of koji It can be seen that the temperature compliance rate for the second turning of koji made by manual koji production is 75%, while the rate for the second turning of koji made by mechanical koji production is 50%, showing a significant difference between the two.
[0024] Furthermore, the overall concentration of aroma substances at the above-mentioned measurement sites was evaluated and scored based on the mechanical and artificial koji-making processes after fermentation and unpacking. The results are shown in Table 4 below: Table 4 Sensory evaluation results of mechanically made and artificially made koji. It can be seen that the rate of achieving the secondary turning temperature for both artificial and mechanical koji production is weakly positively correlated with the overall intensity of aroma substances in the koji after opening the warehouse. This indicates that the higher the rate of achieving the secondary turning temperature, the higher the correlation between the two, the stronger the aroma, and the richer the aroma substances.
[0025] Based on this, we tried to improve the sensory quality of mechanically made koji by increasing the secondary turning temperature. However, despite trying to increase the secondary turning temperature by increasing the ambient temperature, as well as the materials and processes used in mechanical koji making, the sensory quality of mechanically made koji is still far inferior to that of handmade koji.
[0026] The method for making artificial koji in this application is as follows: Before treading, put a sufficient amount of koji material into the koji mold, filling the mold completely, and press the edges and corners of the koji material firmly. Tread the koji material using the method of "treading more on the four sides and less on the middle" to shape it. Before separating the koji blank from the mold, clean the koji material from the surface of the mold to prevent "rough edges, missing corners" and other phenomena. The resulting koji blank has a tortoise-shell shape, a smooth surface, and the thickest part in the middle is 11-13cm. Arrange the koji blanks neatly to dry, with a 2-4cm gap between each koji blank, in a row both horizontally and vertically.
[0027] The mechanical method for making koji (fermented rice starter) involves: using a roller mill to pulverize wheat into "plum blossom petal" shapes; mixing the wheat flour with 5%-10% of mother koji (aged, high-quality koji powder) using a continuous mixer; and simultaneously adding water (30-35℃) at 40% of the wheat weight to achieve uniform mixing of water, koji, and flour. A hydraulic koji press replaces the traditional manual treading method, with pressure controlled at 10-15MPa. The resulting koji blanks are 37cm × 28cm × 6cm in size, with a density of approximately 1.8g / cm³. 2 .
[0028] The temperature compliance rate mentioned in this application refers to the ratio of the number of temperatures that meet the standard to the total number of temperatures measured when measuring temperature in the fermentation chamber.
[0029] The term "qu pie" as used in this application refers to a block-shaped object formed by pressing (stepping) the raw materials for koji making.
[0030] The turning of koji as described in this application refers to the operation of repositioning the koji blanks during fermentation in the koji room, increasing ventilation and oxygen supply, removing carbon dioxide, and adjusting temperature and humidity to ensure uniform cultivation of the koji blanks. There are two turnings in the koji-making process, namely the first turning and the second turning.
[0031] The mechanical koji-making process described in this application refers to the operation of processing, shaping, fermenting, and other steps of koji-making raw materials through mechanical equipment to achieve the cultivation and production of koji.
[0032] The term "artificial koji" as used in this application refers to the process of making koji through manual operation during the brewing of baijiu (Chinese liquor).
[0033] The aroma richness mentioned in this application refers to the diversity and complexity of aroma components produced by the koji-making process. In the brewing process of baijiu, koji is a key fermentation agent, and its quality directly affects the aroma and flavor of the final product.
[0034] The temperature measurement mentioned in this application refers to the temperature of the koji blanks being measured by specific personnel on the day of turning the koji (the measurement method is to measure the temperature of the second layer of koji blanks after removing the upper layer from the fermentation chamber). The term "dismantling koji" as used in this application refers to the process of removing the straw from the koji blanks that have been fermented in the fermentation chamber for a period of time and transferring them to the dry koji chamber. "Dismantling koji" refers to the koji blanks that are taken out during the "dismantling" process and prepared for subsequent processing.
[0035] The sweating compliance rate of the koji blanks mentioned in this application refers to the ratio of the number of koji blanks that have reached the sweating compliance rate in the fermentation chamber to the total number of koji blanks after they have been shaped and spread out for a certain period of time.
[0036] To address the aforementioned issues, this application provides a mixed starter culture for brewing baijiu (Chinese liquor) and its fermentation method.
[0037] A fermentation method for using mixed yeast in Baijiu brewing includes the following steps: Storage and stacking: Mechanically produced koji and manually produced koji are mixed and stacked in the fermentation chamber; mechanically produced koji and manually produced koji are stacked alternately. Fermentation in the warehouse: The fermentation process involves two turnings of the koji. The first turning is carried out 5 to 10 days after the koji is piled up in the warehouse, and the second turning is carried out 5 to 10 days after the first turning. Unpacking: After being stored in the warehouse for 35 to 45 days, the covering material on the surface of the koji blanks is removed to obtain unpacked koji.
[0038] Since the richness of the aroma of Daqu (a type of starter culture) is closely related to the fermentation temperature, in production practice, the better the fermentation of the starter culture, the richer the aroma substances. In particular, the initial and secondary temperature increases during the fermentation process in the starter culture storage directly affect the quality of the Daqu. Insufficient initial temperature increases or low secondary temperature increases can lead to weak aroma, faint fragrance, or even off-odors in the Daqu after it is removed from the storage.
[0039] This application utilizes a mixed fermentation process combining mechanically produced and manually produced koji (fermentation starter). Employing the principle of heat conduction, the mechanically produced and manually produced koji are simultaneously placed in a fermentation chamber in a specific ratio. The more heat-retaining manually produced koji transfers heat to the mechanically produced koji, increasing the temperature compliance rate for the second turning of the koji to 75%, enhancing the aroma of the mechanically produced koji, and enriching the variety of aroma compounds. This koji-making method not only improves efficiency but also ensures the sensory quality of the koji.
[0040] Furthermore, the alternating layering of mechanically produced and manually produced koji can be achieved through one of the following methods: Alternating rows: The mechanically produced koji and the manually produced koji are arranged alternately in a row ratio of 1:1, 1:2, or 2:1; Alternating transport by wagon: The mechanically produced koji and the manually produced koji are transported into the warehouse alternately in a ratio of 1:1, 1:2 or 2:1, with each wagon of koji blanks evenly distributed in different areas of the warehouse; Alternating blocks: The mechanically produced koji and the manually produced koji are stacked alternately in a block ratio of 1:1, 1:2 or 2:1.
[0041] The above arrangement can better balance the temperature conduction between mechanical and manual koji making, increase the temperature of the second turning of mechanical koji, reduce the storage time, improve the sweating rate of the koji after dismantling, and ultimately improve the sensory quality of the koji after mechanical fermentation.
[0042] Furthermore, the alternating layering of mechanically produced and manually produced koji can be achieved through one of the following methods: Alternating by row: The mechanically produced and manually produced koji are arranged alternately in a 1:1 row ratio; Alternating transport by wagon: The mechanically produced koji and the manually produced koji are transported into the warehouse alternately in a ratio of 1:2 or 2:1, with each wagon of koji blanks evenly distributed in different areas of the warehouse.
[0043] A 1:1 row ratio ensures even distribution of mechanical and manual koji production, resulting in more balanced heat transfer. A 1:2 or 2:1 vehicle ratio adapts to transfer efficiency and ensures effective heat transfer from manual to mechanical koji production. This improves operational convenience while guaranteeing a secondary turning temperature compliance rate of ≥75% and optimizing the aroma intensity of the koji after storage.
[0044] Furthermore, when mechanically made koji and manually made koji are stacked alternately in rows, the row spacing between two adjacent rows of koji blanks is 35~45cm.
[0045] The row spacing is 35-45cm, such as 35cm, 36cm, 37cm, 38cm, 39cm, and 45cm. This spacing range ensures ventilation and oxygen supply within the fermentation chamber to meet the growth needs of microorganisms, while avoiding excessive heat loss due to large spacing, thus ensuring stable fermentation temperature of the koji. It also facilitates better heat transfer between manual and mechanical koji making, increases the secondary turning temperature of mechanically made koji, and optimizes sensory quality. Furthermore, it adapts to the spatial layout of the fermentation chamber, facilitating turning operations, reducing collision damage to the koji, and ensuring the integrity of the koji.
[0046] Furthermore, each row of mechanically made koji and manually made koji are stacked in at least two layers, with a spacing of 3 to 10 cm between adjacent layers.
[0047] The spacing between adjacent layers of koji is 3-10cm, such as 3cm, 5cm, 6cm, 8cm, 9cm, 10cm, etc. Multi-layer stacking improves the space utilization of the fermentation chamber and meets the needs of mass production. The spacing between layers takes into account both heat retention and air circulation, avoiding poor air permeability of the lower koji due to compression, or insufficient temperature of the upper koji due to excessive spacing, ensuring uniform fermentation of each layer of koji and improving the consistency of the overall koji production quality.
[0048] Furthermore, the spacing between mechanically produced and manually produced layers gradually decreases from bottom to top.
[0049] In accordance with the natural temperature distribution pattern inside the fermentation chamber (temperature tends to accumulate in the lower layer and dissipate in the upper layer), the temperature of each layer is balanced through a gradient design of the interlayer spacing. This prevents the lower layer of fermented koji from overheating and the upper layer from becoming too cold, ensuring that all koji are within the appropriate fermentation temperature range and further improving the uniformity of aroma synthesis.
[0050] Furthermore, mechanically made koji and manually made koji are stacked in a six-row, four-layer structure, with the spacing between the layers from bottom to top being 8cm, 7cm, 6cm, and 5cm respectively.
[0051] The spacing between the layers of the koji blanks from bottom to top is 8cm, 7cm, 6cm, and 5cm, which allows for precise control of temperature and humidity inside the warehouse. The six-row, four-layer layout is suitable for standard fermentation warehouse space, and the gradient design of the layer spacing can maximize heat transfer efficiency, so that the temperature of the second turning of the koji blanks can be kept above the target value. At the same time, it ensures that the koji blanks can be sweated at a rate of ≥95%, and improves the yellow curvature and saccharification power of the koji blanks after the warehouse is opened.
[0052] Furthermore, the total loading time is ≤5 hours.
[0053] Controlling the loading time can prevent the koji blanks from being exposed for a long time, resulting in "dry outside and wet inside" or excessive temperature drop, thus ensuring the koji blanks' sweating effect and initial fermentation temperature. At the same time, matching the production rhythm can avoid chaotic loading layout and ensure the standardization of alternating stacking of mechanically made and manually made koji, laying the foundation for subsequent heat transfer fermentation and quality stability.
[0054] Furthermore, mechanically made koji has the same size, weight, and appearance as handmade koji.
[0055] The same size, weight and appearance can ensure the fit when stacked alternately, improve heat conduction efficiency; avoid excessive stacking gaps or uneven stress caused by differences in shape, reduce the risk of deformation and collapse of the koji blanks, and at the same time ensure the consistency of nutrient supply and microbial growth environment of each koji blank during fermentation, and improve the uniformity of koji quality after unpacking.
[0056] Furthermore, this application provides a mixed starter culture for brewing baijiu prepared by the above method, including mechanical starter culture and manual starter culture.
[0057] Combining the high efficiency of mechanical koji making with the high quality of manual koji, the mixed koji has both production efficiency and quality advantages. After being treated by a specific fermentation method, it has a high richness of aroma substances and stable physicochemical indicators, which can improve the yield and flavor quality of baijiu brewing and meet the quality requirements of koji for high-end baijiu production.
[0058] Example 1 A fermentation method for using mixed yeast in Baijiu brewing includes the following steps: Warehouse stockpiling: such as Figure 1 As shown, mechanically produced koji and artificially produced koji are mixed and piled up to an area of 37.8 m².2 In the fermentation chamber, the dimensions of both mechanically made and manually made koji are 37cm×28cm×6cm. Mechanically made and manually made koji are stacked alternately in a 2:1 ratio, for a total of 6 rows. The spacing between each row of koji is 40cm, and each row of koji is stacked with 4 layers. The spacing between the layers of mechanically made and manually made koji in each row from bottom to top is 8cm, 7cm, 6cm, and 5cm, respectively.
[0059] Fermentation in the warehouse: The fermentation process involves two turnings of the koji. The first turning is carried out on the 7th day after the koji is piled up in the warehouse, and the second turning is carried out on the 7th day after the first turning. Unpacking: On the 40th day after being stored in the warehouse, the covering material on the surface of the koji blanks is removed to obtain unpacked koji.
[0060] Example 2 A fermentation method for mixed koji for brewing baijiu (Chinese liquor) involves mixing and stacking mechanically made koji and manually made koji in a fermentation chamber during the stacking step. The mechanically made koji and manually made koji are stacked alternately in rows at a mass ratio of 1:1, and the remaining conditions are the same as in Example 1.
[0061] Example 3 A fermentation method for mixed koji for brewing baijiu (Chinese liquor) involves mixing and stacking mechanically made koji and manually made koji in a fermentation chamber during the stacking step. The mechanically made koji and manually made koji are stacked alternately in rows at a mass ratio of 1:2, and the remaining conditions are the same as in Example 1.
[0062] Example 4 A fermentation method for mixed koji (Chinese liquor) is disclosed. In the stacking step, mechanically produced koji and manually produced koji are mixed and stacked in the fermentation chamber. The mechanically produced koji and manually produced koji are stacked alternately in a 1:1 mass ratio in carts, with the remaining conditions being the same as in Example 1. Specifically, the 1:1 ratio refers to the ratio of the number of times the carts carrying the mechanically produced koji and manually produced koji blanks are loaded into the chamber.
[0063] Example 5 A fermentation method for mixed koji (Chinese liquor) is disclosed. In the stacking step, mechanically produced koji and manually produced koji are mixed and stacked in a fermentation chamber. The mechanically produced koji and manually produced koji are stacked alternately in a mass ratio of 1:2, and the remaining conditions are the same as in Example 1. Specifically, the 1:2 ratio refers to the ratio of the number of times the omnidirectional wheeled carts carrying the mechanically produced koji and manually produced koji blanks are loaded into the chamber.
[0064] Example 6 A fermentation method for mixed koji (Chinese liquor) is disclosed. In the stacking step, mechanically produced koji and manually produced koji are mixed and stacked in the fermentation chamber. The mechanically produced koji and manually produced koji are stacked alternately in a 2:1 mass ratio in carts, with the remaining conditions being the same as in Example 1. Specifically, the 2:1 ratio refers to the ratio of the number of times the carts carrying the mechanically produced koji and manually produced koji blanks are loaded into the chamber being 2:1.
[0065] Example 7 A fermentation method for mixed koji (Chinese liquor) is disclosed. In the stacking step, mechanically made koji and manually made koji are mixed and stacked in the fermentation chamber. The mechanically made koji and manually made koji are stacked alternately in a 1:1 mass ratio, and the remaining conditions are the same as in Example 1. Specifically, the 1:1 ratio means that the ratio of mechanically made koji to manually made koji blocks when loading the chamber is 1:1.
[0066] Example 8 A fermentation method for mixed koji (Chinese liquor) is disclosed. In the stacking step, mechanically made koji and manually made koji are mixed and stacked in the fermentation chamber. The mechanically made koji and manually made koji are stacked alternately at a mass ratio of 1:2, and the remaining conditions are the same as in Example 1. Specifically, the 1:2 ratio refers to the ratio of the number of mechanically made koji and manually made koji blocks placed in the chamber being 1:2 during loading.
[0067] Example 9 A fermentation method for mixed koji (Chinese liquor) is disclosed. In the stacking step, mechanically made koji and manually made koji are mixed and stacked in the fermentation chamber. The mechanically made koji and manually made koji are stacked alternately in a mass ratio of 2:1, and the remaining conditions are the same as in Example 1. Specifically, the 2:1 ratio refers to the ratio of the number of mechanically made koji and manually made koji blocks placed in the chamber being 2:1 during loading.
[0068] Comparative Example 1 A fermentation method for mixed koji for brewing baijiu (Chinese liquor) involves mixing and stacking mechanically made koji and manually made koji in a fermentation chamber during the stacking step. The mechanically made koji and manually made koji are stacked alternately in rows at a mass ratio of 3:1, and the remaining conditions are the same as in Example 1.
[0069] Performance testing 1. Following the stacking method described in the embodiment, three warehouses with different stacking orders were selected for follow-up tests. The number of koji bricks that met the sweating standard and the loading time were recorded. The sweating standard compliance rate of the koji bricks was calculated. The results are shown in Table 5-13 below: Table 5. Yield and storage time of koji blanks in Example 1 Table 6. Yield and storage time of koji blanks in Example 2 Table 7. Yield and storage time of koji blanks in Example 3 Table 8. Yield and storage time of koji blanks in Example 4 Table 9. Yield and storage time of koji blanks in Example 5 Table 10. Yield and Storage Time of Cured Rice in Example 6 Table 11. Yield and storage time of koji blanks in Example 7 Table 12. Yield and storage time of koji blanks in Example 8 Table 13. Yield and storage time of koji blanks in Example 9 The "sweating" process is a crucial step in the koji-making process after the koji has been shaped by pressing. It refers to the process where, after the freshly shaped koji is spread out to dry, the surface moisture gradually evaporates while the internal moisture slowly penetrates, eventually resulting in a dry, hardened surface and a more uniform internal moisture content. Freshly pressed koji contains a significant amount of moisture and is relatively soft. "Sweating" allows the koji to naturally dry its surface and simultaneously ensures a more even distribution of internal moisture, preventing mold, sticking, or uneven fermentation during subsequent storage. After sweating, the koji should reach a state where it is "dry and not sticky to the touch, and its shape is fixed and does not collapse." This is the core criterion for judging the "sweating compliance rate" of koji; the percentage of compliant pieces should be ≥95% to better guarantee the subsequent fermentation effect and the quality of the koji.
[0070] If the storage time is too long, the koji blanks will be exposed to the air for an extended period, causing the surface moisture to evaporate too quickly, resulting in a "dry outside, wet inside" situation. This can lead to cracking, mold growth, or uneven fermentation due to uneven moisture distribution during subsequent fermentation. Furthermore, mechanically made koji blanks have micropores in the center, while manually made koji blanks have a "tight outside, loose inside" structure. Prolonged exposure will damage their internal permeability, affecting the initial reproduction of microorganisms and thus reducing the aroma richness of the koji blanks. Therefore, a storage time of ≤5 hours is beneficial for improving the koji blanks' sweat absorption rate and the aroma richness of the koji after storage.
[0071] Furthermore, statistics were compiled on the above-mentioned koji blanks with a sweating rate ≥95% and a storage time ≤5h for storage, and the compliance rate of the dismantled koji was calculated (the proportion of fermentation chambers that simultaneously meet the requirements of a sweating rate ≥95% and a storage time ≤5h to the total number of fermentation chambers stored). The results are shown in Table 14 below: Table 14. Compliance rate of dismantling process in Examples 1-9 It is evident that the compliance rate was higher in fermentation chambers where fermentation ratios of 1:1 row (Example 2), 1:2 cart (Example 5), and 2:1 cart (Example 6) were alternately stacked. Based on this, the physicochemical properties of mechanically produced and manually produced koji (fermented and dismantled) using alternating stacking ratios of 1:1 row, 1:2 cart, and 2:1 cart were tested after fermentation and dismantling. The results are shown in Table 15 below: Table 15 Test Results of Physicochemical Indicators The physicochemical data of the dismantled koji were calculated according to the following standards to achieve the following compliance rates: acidity 1.0-3.5 (0.1 mol·L⁻¹ NaOH, ml / g koji); sugar content 0.5-1.5%; moisture ≤12%; starch 52-60%; saccharification power 100-300 (mg glucose / 35℃·hour·gram koji). The results are shown in Table 16 below. Table 16 Compliance Rate of Physicochemical Indicators As shown in the table above, the physicochemical indicators of dismantled koji loaded at a ratio of 1:2 vehicles achieved the highest compliance rate. Based on this, further statistical analysis of the sensory indicators of dismantled koji was conducted, and the results are shown in Table 17 below: Table 17 Sensory Indicator Results of Warehouse Dismantling Note: The more ideal the result, the more asterisks (*) there will be. More asterisks indicate slight stickiness, rich and strong aroma, neat cross-section, and a high proportion of yellow koji.
[0072] As shown in the table above, there is little difference in the stickiness of mechanically made koji and manually made koji when they are stacked alternately in a 1:1 ratio, a 1:2 ratio, and a 2:1 ratio. However, the koji stacked in a 1:2 ratio has the richest and most intense aroma, a more uniform cross-section, and the highest proportion of yellow koji.
[0073] 2. On the day of the second turning of the koji, the temperature of the koji in the fermentation chambers of Example 1 and Comparative Example 1 was measured. The temperature at 8 measurement points was recorded, and the compliance rate of the second turning temperature in mechanical koji making was calculated. The results are shown in Table 18 below: Table 18. Compliance Rate of Mechanically Produced Koji As shown in the table above, when mechanically made koji and artificially made koji are stacked alternately in a row ratio of 2:1 or 3:1 for mixed fermentation, the temperature of the second turning of mechanically made koji can be increased. However, when stacked alternately in a row ratio of 2:1, the effect of increasing the temperature is more obvious, and the temperature compliance rate of the second turning of koji is increased to 75%.
[0074] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.
Claims
1. A fermentation method for mixed yeast used in Baijiu brewing, characterized in that, Includes the following steps: Storage and stacking: The mechanically produced koji and the manually produced koji are mixed and stacked in the fermentation chamber; The mechanically produced koji and the manually produced koji are stacked alternately; Fermentation in the warehouse: The fermentation process involves two turnings of the koji. The first turning is carried out 5 to 10 days after the koji is piled up in the warehouse, and the second turning is carried out 5 to 10 days after the first turning. Unpacking: After being stored in the warehouse for 35 to 45 days, the covering material on the surface of the koji blanks is removed to obtain unpacked koji.
2. The fermentation method of mixed koji for brewing baijiu as described in claim 1, characterized in that, The alternating stacking method of mechanically produced koji and manually produced koji is one of the following: Alternating rows: The mechanically produced koji and the manually produced koji are arranged alternately in a row ratio of 1:1, 1:2, or 2:1; Alternating transport by wagon: The mechanically produced koji and the manually produced koji are transported into the warehouse alternately in a ratio of 1:1, 1:2 or 2:1, with each wagon of koji blanks evenly distributed in different areas of the warehouse; Alternating blocks: The mechanically produced koji and the manually produced koji are stacked alternately in a block ratio of 1:1, 1:2 or 2:
1.
3. The fermentation method of mixed koji for brewing baijiu as described in claim 1, characterized in that, The alternating stacking method of mechanically produced koji and manually produced koji is one of the following: Alternating by row: The mechanically produced and manually produced koji are arranged alternately in a 1:1 row ratio; Alternating transport by wagon: The mechanically produced koji and the manually produced koji are transported into the warehouse alternately in a ratio of 1:2 or 2:1, with each wagon of koji blanks evenly distributed in different areas of the warehouse.
4. The fermentation method of mixed koji for brewing baijiu as described in claim 2, characterized in that, When mechanically made koji and manually made koji are stacked alternately in rows, the row spacing between two adjacent rows of koji blanks is 35~45cm.
5. The fermentation method of mixed koji for brewing baijiu as described in claim 4, characterized in that, Each row of mechanically made koji and manually made koji are stacked in at least two layers, with a spacing of 3 to 10 cm between adjacent layers.
6. The fermentation method of the mixed koji for brewing baijiu as described in claim 5, characterized in that, The spacing between mechanically produced and artificially produced koji in each row gradually decreases from bottom to top.
7. The fermentation method of mixed koji for brewing baijiu as described in claim 6, characterized in that, The mechanically made koji and the manually made koji are stacked in a six-row, four-layer structure, with the spacing between the layers from bottom to top being 8cm, 7cm, 6cm, and 5cm respectively.
8. The fermentation method of mixed koji for brewing baijiu as described in claim 1, characterized in that, The total loading time is ≤5 hours.
9. The fermentation method of mixed koji for brewing baijiu as described in claim 1, characterized in that, The mechanically produced koji has the same dimensions, weight, and appearance as the manually produced koji.
10. A mixed koji prepared by the fermentation method of the mixed koji for brewing baijiu according to any one of claims 1-9, characterized in that, This includes both mechanical and manual music production.