A frozen storage production process of yellow rice wine

Abstract

The application discloses a kind of frozen storage production process of yellow rice wine, semi-finished liquor after blending filtration is frozen by liquid quick freezer, the temperature of liquor output by liquid quick freezer is controlled at 0~‑3℃, the preservation temperature of the liquor after cooling is transported to low-temperature preservation tank is ≤3℃, and the minimum preservation time is set;Temperature is monitored in real time during the preservation process of liquor, when liquor temperature>3℃, output liquor to liquid quick freezer for cycle recooling, recold is completed after re-calculation preservation timing, liquor enters low-temperature preservation tank 12h, sensory evaluation and physicochemical index detection are carried out, unqualified liquor is reblended or re-filtered;The frozen storage process is completed after the preservation time of qualified liquor reaches the standard, the temperature in tank is uniform and stable, the consistency of clarification effect batch is good, liquor disturbance and dissolved oxygen can be reduced, the original flavor of yellow rice wine is retained, and production efficiency and turnover efficiency are improved, which is suitable for industrialized large-scale production.

Description

Technical Field

[0001] This invention relates to the field of rice wine production technology, and more specifically, to a frozen storage production process for rice wine. Background Technology

[0002] Yellow rice wine is a brewed wine made from grains through microbial fermentation. It contains abundant proteins, polypeptides, polyphenols, polysaccharides, and other colloidal substances, forming a complex colloidal system. During storage, these macromolecules are prone to association, leading to cold turbidity, precipitation, and loss of luster, severely impacting the shelf-life stability and appearance of the wine. Freezing is a common technique for improving the non-biological stability of yellow rice wine. By lowering the wine to a low temperature and maintaining this temperature for a period, unstable macromolecules in the wine flocculate and precipitate prematurely. These are then removed by filtration, significantly reducing the risk of precipitation during subsequent storage.

[0003] Most existing rice wine freezing processes employ an external refrigeration unit with circulating heat exchange. This involves first cooling the wine using a rapid chiller, then pumping it into a standard insulated storage tank for static freezing. This process has significant drawbacks: First, the wine's cooling relies on external piping for circulating heat exchange, resulting in large temperature differences between different areas within the tank, uneven temperature distribution, and significant temperature fluctuations throughout the freezing process, leading to poor low-temperature storage stability. Furthermore, the temperature difference between the wine near the tank wall and the center of the tank causes uneven precipitation of unstable substances, resulting in significant differences in clarification between batches. Second, the external circulation requires continuous wine transport. The pump's agitation disturbs existing flocculated particles, disrupting their settling and hindering the separation of turbid substances. Simultaneously, the wine transport process increases the risk of dissolved oxygen, easily oxidizing and damaging the aroma and flavor of the rice wine. Therefore, a technical solution is needed to address these issues. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a frozen storage production process for rice wine.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention discloses a frozen storage production process for rice wine, comprising the following steps:

[0007] S1. The blended and filtered semi-finished wine liquid is frozen through a liquid quick-cooling machine to control the temperature of the wine liquid output by the liquid quick-cooling machine at 0 to -3℃.

[0008] S2. Transfer the cooled wine to a low-temperature storage tank, control the storage temperature of the wine in the low-temperature storage tank to ≤3℃, and set its minimum storage time according to the nominal volume of the low-temperature storage tank.

[0009] S3. The temperature of the wine is monitored in real time during the storage process. When the temperature of the wine is >3℃, the wine is output to the liquid rapid cooler for circulation and recooling. After the recooling is completed, the storage time is recalculated.

[0010] S4. After the wine has been in the low-temperature storage tank for 12 hours, samples are taken for sensory evaluation and physicochemical index testing. If the wine does not meet the standards, it is re-blended or re-filtered and then S1 to S3 are repeated. If the wine meets the standards, the freezing process is completed.

[0011] Furthermore, in step S1, when the initial temperature of the wine is high, the wine needs to be cooled down in a heat dissipation intermediate tank, and then circulated between the cooling intermediate tank and the liquid rapid chiller for pre-cooling before finally being sent to a low-temperature storage tank.

[0012] Furthermore, the intermediate heat dissipation tank is tilted as a whole and can rotate around its axis. The intermediate heat dissipation tank includes an inlet end and an outlet end. The inlet end is located at the higher end of the intermediate heat dissipation tank, and the outlet end is located at the lower end of the intermediate heat dissipation tank. Multiple heat dissipation fins are arranged on the outer peripheral wall of the intermediate heat dissipation tank.

[0013] Furthermore, multiple baffles are arranged axially at intervals inside the heat dissipation intermediate tank, and adjacent baffles are arranged in a staggered manner on the inner wall of the heat dissipation intermediate tank.

[0014] Furthermore, the inclination angle between the heat dissipation intermediate tank and the horizontal plane is 10° to 20°, the end of the baffle away from the inner wall of the heat dissipation intermediate tank is inclined towards the liquid outlet end, and the angle between the baffle and the radial section of the heat dissipation intermediate tank is 10° to 20°.

[0015] Furthermore, in step S2, the minimum storage time is set as follows: storage time for 5-ton tanks ≥ 24h, storage time for 15-ton tanks ≥ 48h, and storage time for 30-ton tanks ≥ 96h.

[0016] Furthermore, the low-temperature storage tank includes an inner tank body, a heat exchange jacket, and an insulation layer, from the inside out. The heat exchange jacket covers the outer wall and bottom surface of the inner tank body, and the insulation layer completely covers the inner tank body and the heat exchange jacket. A central tank body is provided at the center of the inner tank body, with an opening at the top. The central jacket is installed on the inner wall of the central tank body, and the central tank body is filled with insulation filler. The heat exchange jacket and the central jacket are connected to an external circulating refrigerant, and the top of the central tank body is sealed by a cover plate.

[0017] Furthermore, the inner tank includes a support plate that extends along the inner tank, and the radial ends of the support plate are fixedly connected to the inner wall of the central tank and the inner tank.

[0018] Furthermore, the low-temperature storage tank is equipped with a temperature measuring rod that extends along the axial direction of the inner tank. The temperature measuring rod includes at least three temperature measuring points, one near the bottom of the inner tank, one in the middle of the inner tank, and one near the top of the inner tank.

[0019] Furthermore, in step S4, wines that fail to meet appearance standards are re-filtered or re-blended and then filtered again, and wines that fail to meet physicochemical standards are re-blended.

[0020] The beneficial effects of this invention are:

[0021] 1. This invention constructs a control logic for over-temperature recooling and storage time reset, combined with a composite insulation structure for the tank, to improve the accuracy of low-temperature control and avoid the problem of local overcooling causing the wine to freeze; it sets up a 12-hour mid-storage detection mechanism to identify and dispose of unqualified wine in advance, reduce the occupation of ineffective tanks, and improve the turnover rate of low-temperature storage tanks; it matches different storage times with tanks of different volumes, reducing overall refrigeration energy consumption while ensuring frozen storage quality, and adapting to the needs of industrial-scale production.

[0022] 2. This invention employs a double-sided heat exchange structure formed by an outer wall heat exchange jacket and an inner central jacket, significantly reducing the radial temperature difference within a large-volume tank. Combined with multi-point temperature measurement and control, it solves the problems of uneven temperature distribution and large temperature fluctuations throughout the freezing process in traditional processes, ensuring a consistent degree of flocculation and precipitation of unstable substances such as proteins and polyphenols in the wine. Furthermore, by setting differentiated storage times according to the tank volume, it ensures that tanks of different specifications achieve optimal clarification effects, effectively reducing the risk of cold turbidity during the storage period of the finished product and minimizing batch-to-batch quality differences.

[0023] 3. This invention uses direct heat exchange through the tank wall as the main temperature control method, which greatly reduces the frequency and duration of external circulation of the wine liquid, avoids disturbance to the already formed flocculent particles during the pumping process, and ensures that the flocs are fully settled and separated. Combined with the inclined heat dissipation intermediate tank, it relies on gravity flow to achieve pre-cooling heat exchange, reduces violent pumping and stirring, reduces the risk of dissolved oxygen in the wine liquid, reduces the damage of oxidation to the aroma and flavor of the rice wine, and better preserves the inherent flavor characteristics of the wine. Attached Figure Description

[0024] Figure 1 This is a process flow diagram of this embodiment.

[0025] Figure 2 This is a flowchart of a freezing process in this embodiment.

[0026] Figure 3 This is a schematic diagram of a heat dissipation intermediate tank in this embodiment.

[0027] Figure 4This is a schematic diagram of a cryogenic storage container in this embodiment.

[0028] Reference numerals: 1. Intermediate heat dissipation tank; 11. Liquid inlet; 12. Liquid outlet; 13. Baffle plate; 14. Heat dissipation fins; 2. Low-temperature storage tank; 21. Inner tank body; 22. Heat exchange jacket; 23. Insulation layer; 24. Central tank body; 241. Central jacket; 242. Insulation packing; 25. Support plate; 26. Temperature measuring rod. Detailed Implementation

[0029] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figures 1 to 4 As shown, the frozen storage production process of rice wine in this embodiment is based on a frozen storage system consisting of a heat dissipation intermediate tank 1, a liquid rapid chiller, a cooling intermediate tank, a low-temperature storage tank 2, a pipeline valve group, and a monitoring and control unit. The specific implementation process is as follows:

[0031] S1. Pre-cooling and freezing process:

[0032] When the initial temperature of the wine is high (e.g., the ambient wine temperature in summer > 25°C), the blended and coarsely filtered semi-finished rice wine is sent to the heat dissipation intermediate tank 1 for preliminary heat dissipation and cooling. The heat dissipation intermediate tank 1 is tilted as a whole, with an inclination angle of 10° to 20° with respect to the horizontal plane. In this embodiment, 15° is preferred. The higher end of the heat dissipation intermediate tank 1 is the liquid inlet 11, which is connected to the liquid inlet pipeline through a rotary joint. The lower end of the heat dissipation intermediate tank 1 is the liquid outlet 12, which is connected to the liquid outlet pipeline and then to the liquid rapid cooling machine through a rotary joint. After the wine enters from the liquid inlet 11, it flows slowly towards the liquid outlet 12 along the tilted tank body by gravity, increasing the contact time and area between the wine and the tank wall of the heat dissipation intermediate tank 1. Multiple heat dissipation fins 14 are arranged on the outer peripheral wall of the heat dissipation intermediate tank 1. The air cooler blows air onto the surface of the heat dissipation intermediate tank 1 to cool it down. The heat dissipation fins 14 can increase the heat exchange area and enhance the natural convection heat exchange with the outside, so that the temperature of the wine flowing through the inner wall of the heat dissipation intermediate tank 1 can be significantly reduced.

[0033] Multiple baffles 13 are arranged axially at intervals inside the tank. Adjacent baffles 13 are staggered circumferentially on the inner wall of the tank, and the inner end of the baffle 13 is inclined towards the liquid outlet 12, with an angle of 10° to 20° with the radial section of the tank. In this embodiment, the angle of the baffle 13 is preferably 15°, which can extend the flow path of the wine, extend the heat exchange time, and ensure uniform pre-cooling. The intermediate heat dissipation tank 1 can rotate at low speed around its own axis. During rotation, some of the wine will flow along the baffles 13. The wine flows a long distance with the rotation of the intermediate heat dissipation tank 1, which further improves the heat exchange efficiency of the wall surface without violently agitating the wine and avoiding dissolved oxygen.

[0034] The pre-cooled or low-temperature wine enters a liquid rapid chiller for further cooling. The cooled wine then enters a cooling intermediate tank. The temperature of the wine in the intermediate tank is monitored, and a circulation pump is activated to circulate the wine between the intermediate tank and the liquid rapid chiller until the overall temperature of the wine drops to a preset range. The pre-cooled wine undergoes deep freezing treatment in the liquid rapid chiller, controlling the outlet temperature of the cooling intermediate tank to be stable at 0 to -3°C. In this embodiment, -1 to -2°C is preferred. This ensures that the wine does not freeze while rapidly reducing its temperature, promoting the flocculation and precipitation of unstable macromolecules such as proteins and polyphenols. The output pipeline maintains its insulation performance to prevent the wine from heating up within the pipeline.

[0035] S2, Low-temperature preservation

[0036] The wine, cooled to 0 to -3°C, is transferred to the low-temperature storage tank 2 for static storage. The low-temperature storage tank 2 has a vertical structure and consists of an inner tank body 21, a heat exchange jacket 22, and an insulation layer 23 from the inside out. The heat exchange jacket 22 covers the outer wall and bottom surface of the inner tank body 21. Circulating refrigerant is introduced into the heat exchange jacket 22 and exchanges heat directly with the wine through the tank wall to ensure that the temperature of the wine inside the low-temperature storage tank 2 does not exceed 3°C. The insulation layer 23 completely covers the outside of the heat exchange jacket 22 and adopts a composite insulation structure of polyurethane rigid foam and aerogel to block the intrusion of ambient heat and reduce cold loss.

[0037] A central tank 24 is located at the center of the inner tank 21. A central jacket 241 is installed on the inner wall of the central tank 24. Both the heat exchange jacket 22 and the central jacket 241 are connected to the external refrigerant circulation system, allowing refrigerant to be introduced independently or simultaneously, forming a double-sided heat exchange structure for the liquid. The central tank 24 is filled with insulating filler 242 to reduce heat loss. The diameter of the central tank 24 is 1 / 5 to 1 / 6 of the diameter of the inner tank 21. The larger the volume of the inner tank 21, the larger its diameter, and the greater the ratio of the diameter of the central tank 24 to the diameter of the inner tank 21. The inner tank 21 and the central tank 24 are fixedly connected by multiple axially extending support plates 25. The support plates 25 are used to support and stabilize the structural strength of the central tank 24. The support plates 25 are located below the manhole at the top of the inner tank 21 for easy cleaning. The double-sided heat exchange structure can significantly reduce the radial temperature difference inside large-volume tanks, which is particularly effective for large-volume tanks. It avoids the problem of excessively cold tank walls and excessively high temperatures in the central area, ensuring a uniform temperature field for the wine inside the tank and improving batch consistency of the frozen clarification effect.

[0038] The temperature and flow rate of the refrigerant in the heat exchange jacket 22 and the central jacket 241 are controlled to maintain the storage temperature of the wine in the tank at ≤3℃. The minimum storage time is set according to the nominal volume of the low-temperature storage tank 2: for a tank with a nominal volume of 5 tons, the minimum storage time is ≥24h; for a tank with a nominal volume of 15 tons, the minimum storage time is ≥48h; and for a tank with a nominal volume of 30 tons, the minimum storage time is ≥96h. This embodiment uses a 5-ton low-temperature storage tank and sets the minimum storage time to 24h to ensure sufficient flocculation and precipitation of colloidal substances in a large volume of wine. By setting the storage time according to the tank volume, the problems of excessive freezing of small tanks leading to energy waste and insufficient freezing time in large tanks leading to inadequate clarification are avoided, thus balancing clarification effect and production energy efficiency.

[0039] S3, Temperature Monitoring and Cyclic Recooling:

[0040] During the storage process, the temperature of the wine is monitored in real time by a temperature measuring rod 26 inserted into the low-temperature storage tank 2. The temperature measuring rod 26 is vertically arranged along the axial direction of the inner tank body 21, and at least three temperature measuring points are set on the rod 26, located near the bottom of the tank, the middle of the tank body, and near the top of the tank, respectively, so as to collect the temperature data of the wine at different heights inside the tank in real time. The control unit uses the highest temperature among all temperature measuring points as the temperature control trigger to avoid local temperature exceedances going undetected, and ensures that the storage temperature is ≤3℃ throughout the process. There are 2 to 3 temperature measuring rods 26 along the axial direction of the low-temperature storage tank 2 to ensure the uniformity of the circumferential temperature.

[0041] When the temperature of the liquid at any temperature measuring point exceeds 3℃, it is determined that the temperature has exceeded the limit. The bottom valve is opened, and the circulation pump is started to output the liquid in the tank to the liquid rapid cooler for recirculation and recooling. At the same time, the refrigerant flow rate of the heat exchange jacket 22 and the central jacket 241 can be increased to enhance refrigeration and assist in the rapid cooling of the liquid until the temperature at all points in the tank drops below 3℃. After recooling is completed, the storage time is reset to zero and recalculated to ensure that the effective low-temperature storage time meets the process requirements; at the same time, the external circulation time of the liquid is shortened to minimize disturbance to the already formed precipitates and flocs.

[0042] S4. Mid-process inspection and finished product output:

[0043] After the wine is stored in the low-temperature storage tank 2 for 12 hours, a sample is taken from the sterile sampling valve on the side wall of the low-temperature storage tank 2. The sensory appearance is evaluated by the workshop wine tasting team, and at the same time, it is sent to the quality inspection department to test the physicochemical indicators such as alcohol content, total acid, total sugar, amino acid nitrogen, non-sugar solids, and calcium oxide. The qualified judgment is made according to the national standard GB / T13662-2018 "Huangjiu" and product requirements.

[0044] For wines that do not meet the appearance requirements (such as turbidity or abnormal sedimentation), they should be filtered again or re-blended and then filtered again. Then, steps S1 to S3 should be repeated for freezing again. For wines that do not meet the physicochemical requirements, they should be re-blended until the requirements are met and then the freezing process should be repeated.

[0045] Wine that has reached the minimum storage time set for the corresponding tank and whose sensory and physicochemical indicators are qualified completes the freezing process and is then transported to the subsequent membrane filtration and bottling processes.

[0046] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A frozen storage production process for Shaoxing rice wine, characterized in that, Includes the following steps: S1. The blended and filtered semi-finished wine liquid is frozen through a liquid quick-cooling machine to control the temperature of the wine liquid output by the liquid quick-cooling machine at 0 to -3℃. S2. The cooled wine is transferred to the low-temperature storage tank (2), and the storage temperature of the wine in the low-temperature storage tank (2) is controlled to be ≤3℃. The minimum storage time is set according to the nominal volume of the low-temperature storage tank (2). S3. The temperature of the wine is monitored in real time during the storage process. When the temperature of the wine is >3℃, the wine is output to the liquid rapid cooler for circulation and recooling. After the recooling is completed, the storage time is recalculated. S4. After the wine enters the low-temperature storage tank (2) for 12 hours, samples are taken for sensory evaluation and physicochemical index testing. Unqualified wine is re-blended or re-filtered and then S1 to S3 are repeated. Qualified wine is stored for the required time and the freezing process is completed.

2. The frozen storage production process for rice wine according to claim 1, characterized in that, In step S1, when the initial temperature of the wine is high, the wine needs to be cooled down by passing through the heat dissipation intermediate tank (1), and then circulated between the cooling intermediate tank and the liquid rapid chiller for pre-cooling, and finally sent to the low temperature storage tank (2).

3. The frozen storage production process for rice wine according to claim 2, characterized in that, The heat dissipation intermediate tank (1) is inclined as a whole. The heat dissipation intermediate tank (1) can rotate around its axis. The heat dissipation intermediate tank (1) includes an inlet end (11) and an outlet end (12). The inlet end (11) is located at the higher end of the heat dissipation intermediate tank (1), and the outlet end (12) is located at the lower end of the heat dissipation intermediate tank (1). Multiple heat dissipation fins (14) are arranged on the outer peripheral wall of the heat dissipation intermediate tank (1).

4. The frozen storage production process for rice wine according to claim 3, characterized in that, Multiple baffles (13) are arranged axially at intervals inside the heat dissipation intermediate tank (1), and two adjacent baffles (13) are arranged circumferentially staggered on the inner wall of the heat dissipation intermediate tank (1).

5. The frozen storage production process for rice wine according to claim 4, characterized in that, The inclination angle between the heat dissipation intermediate tank (1) and the horizontal plane is 10° to 20°. The end of the baffle plate (13) away from the inner wall of the heat dissipation intermediate tank (1) is inclined towards the liquid outlet (12). The angle between the baffle plate (13) and the radial section of the heat dissipation intermediate tank (1) is 10° to 20°.

6. The frozen storage production process for rice wine according to claim 1, characterized in that, In step S2, the minimum storage time is set as follows: storage time for 5-ton tanks ≥ 24h, storage time for 15-ton tanks ≥ 48h, and storage time for 30-ton tanks ≥ 96h.

7. The frozen storage production process for rice wine according to claim 1, characterized in that, The low-temperature storage tank (2) includes an inner tank (21), a heat exchange jacket (22), and an insulation layer (23) from the inside out. The heat exchange jacket (22) covers the outer side wall and the outer bottom surface of the inner tank (21). The insulation layer (23) completely covers the inner tank (21) and the heat exchange jacket (22). A central tank (24) is provided in the center of the inner tank (21). The upper end of the central tank (24) is open. The inner wall of the central tank (24) is fitted with a central jacket (241). The central tank (24) is filled with insulation filler (242). The heat exchange jacket (22) and the central jacket (241) are connected to an external circulating refrigerant. The top of the central tank (24) is closed by a cover plate.

8. The frozen storage production process for rice wine according to claim 7, characterized in that, The inner tank (21) includes a support plate (25) that extends along the inner tank (21). The radial ends of the support plate (25) are fixedly connected to the inner walls of the central tank (24) and the inner tank (21).

9. The frozen storage production process for rice wine according to claim 7, characterized in that, The low-temperature storage container (2) is equipped with a temperature measuring rod (26), which extends along the axial direction of the inner container (21). The temperature measuring rod (26) includes at least three temperature measuring points, including one near the bottom of the inner container (21), one in the middle of the inner container (21), and one near the top of the inner container (21).

10. The frozen storage production process for rice wine according to claim 1, characterized in that, In step S4, wines that fail to meet appearance standards are either re-filtered or re-blended and then filtered again, while wines that fail to meet physicochemical standards are re-blended.

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