Preparation method of alcohol-free clarified grain sweet wine clear liquor and application thereof

Abstract

The application discloses a preparation method of alcohol-free clarified grain sweet wine supernatant and application thereof, and belongs to the technical field of fermented grain beverage preparation. The alcohol-free clarified grain sweet wine supernatant is prepared by using grain sweet wine with complete grains as raw materials, and through a coupling physical process of grain gentle dilution and dispersion, normal-pressure open system temperature control heat treatment, temperature control flocculation and sedimentation and precision filtration, without any food additive and external alcohol removal process in the whole process, and the structure of the grains is not broken, so that the alcohol-free clarified grain sweet wine supernatant with an alcohol content of less than or equal to 0.4% Vol, which meets the commercial sterility requirement of GB 4789.26-2023, a light transmittance of 80-94% and no precipitation and stratification after cold storage at 4 DEG C for more than 4 days is prepared. The application solves the industry pain point of precipitation and stratification of sweet wine beverage from the source, and is suitable for the clarification requirements of glutinous rice sweet wine and barley wine, and the production cycle is shortened by more than 95%, so that the alcohol-free clarified grain sweet wine supernatant can be directly used for daily drinking, and can be matched with all kinds of coffee liquid and tea liquid, and is suitable for industrialized mass production and popularization.

Description

Technical Field

[0001] This invention belongs to the field of fermented grain beverage preparation technology, specifically relating to a method for preparing alcohol-free clarified grain sweet wine liquid and its application in daily direct drinking and coffee and tea beverage preparation. Background Technology

[0002] Sweet rice wine (also known as fermented glutinous rice, sweet fermented rice, or "jiuniang" or "tianpei" in barley-producing areas) is a traditional Chinese intangible cultural heritage fermented food. Made from grains such as glutinous rice and barley through saccharification and fermentation with yeast, it has a sweet taste and is rich in natural grain aroma and fermented nutrients, making it very popular with consumers. In recent years, with the rapid development of the health beverage market, sweet rice wine-flavored drinks have become a popular trend in the health beverage, new tea, and coffee industries, with annual sales continuing to climb.

[0003] However, existing sweet wine-related products and preparation technologies suffer from the following unresolved industry pain points, which are also the core technical problems that this invention addresses. In particular, for barley wine, it is generally believed in the field that its protein and β-glucan content is much higher than that of glutinous rice sweet wine, making clarification extremely difficult. Clarification can only be achieved by crushing and homogenizing, compound enzymatic hydrolysis, and adding exogenous clarifying agents. No existing technology can achieve alcohol-free high clarity and long-term stability of barley wine without any additives or exogenous de-alcoholization. There is a clear technological gap and technological bias in the industry.

[0004] First, it's impossible to simultaneously achieve compliance with alcohol-free standards and preserve flavor. Most commercially available sweet wines and rice wines contain alcohol, typically between 0.5% and 6% vol. Subject to national regulations on alcoholic beverages, they cannot be sold in prohibited channels such as near primary and secondary schools, gas stations, and high-speed rail stations. Furthermore, there is a legal risk of drunk driving after consumption, severely limiting the consumer base and scenarios. Existing alcohol-free sweet wine products generally use processes like distillation, resin adsorption, and membrane de-alcoholization to remove alcohol. This not only involves significant equipment investment and high production costs but also results in substantial losses of flavor compounds and nutrients, severely damaging the natural aroma of the original grains and failing to retain the core flavor advantages of sweet wine. Relying solely on dilution to control alcohol content leads to poor alcohol-free stability, large batch-to-batch fluctuations, and an inability to meet industrial production requirements. It also fails to meet the commercial sterility requirements stipulated in GB 4789.26-2023, resulting in a short shelf life at room temperature.

[0005] Secondly, the clarification process relies on exogenous additives, lacking the ability to control impurities at the source. Current sweet wine clarification processes generally employ a "grain crushing and homogenization → subsequent addition of clarifying agents for impurity removal" approach. Crushing the grains results in a large amount of polysaccharides, proteins, pectin, β-glucan, etc., entering the solution. The clarification process not only requires the addition of exogenous clarifying agents such as gelatin, bentonite, and pectinase, which does not meet the health requirement of zero additives, but also significantly increases the difficulty of subsequent clarification, making it highly susceptible to sedimentation and stratification during storage. This is especially true for barley wine, whose protein and dietary fiber content is much higher than that of glutinous rice sweet wine, making the clarification process even more difficult with current processes. These processes generally require multiple enzymatic hydrolysis sessions and the addition of complex stabilizers, failing to achieve both zero additives and high clarity.

[0006] Third, the production efficiency is low and the industrial adaptability is poor. Existing clarifying sweet wine processes generally require 24-48 hours of low-temperature static flocculation, which results in a long production cycle, high equipment occupancy rate, and low industrial production efficiency, failing to meet the needs of large-scale mass production. Moreover, long-term low-temperature static flocculation still cannot effectively solve the sedimentation problem during long-term storage, generally only achieving no sedimentation within 72 hours, resulting in poor shelf-life stability.

[0007] Fourth, the adaptability to various scenarios is severely limited. Existing sweet wine products are either used only as cooking ingredients or as side drinks. In the beverage industry, their application is mostly limited to freshly made drinks in chain coffee and tea shops, as a garnish or added in small amounts along with the rice and liquid, making them unsuitable for use as a basic daily beverage. Furthermore, they have poor compatibility with coffee and tea, easily causing flocculation, layering, and flavor clashes when mixed with coffee or tea liquids. Existing solutions are only suitable for hot-brewed coffee and tea, failing to adapt to the currently popular cold-brew coffee and tea market, severely limiting their application scenarios. Additionally, the clear sweet wine products produced by existing technologies generally suffer from poor stability at room temperature, easily exhibiting flocculation, sedimentation, and layering when left at room temperature. They often require continuous cold chain refrigeration, resulting in high storage and transportation costs and limited commercialization channels—a long-standing pain point for the industry.

[0008] Fifth, core indicators cannot be simultaneously met, and there is no mature full-scenario solution. Existing technologies cannot simultaneously achieve the six core indicators of "natural and alcohol-free, zero additives, high clarity, long-term stability, high flavor retention, and short-cycle and efficient production." They can only achieve breakthroughs in a single indicator and cannot simultaneously meet the health needs of C-end consumers for daily direct drinking and the standardized application needs of B-end catering channels. There is a significant technological gap in the industry.

[0009] Therefore, developing a method for preparing sweet wine clear liquid that controls impurities from the source, is additive-free throughout the entire process, has no de-alcoholization step, and achieves alcohol-free stability, high clarity, high flavor retention, short cycle and high efficiency, is suitable for daily direct consumption and standardized blending, and is compatible with various grain raw materials such as glutinous rice and highland barley, is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0010] To overcome the aforementioned deficiencies of the prior art, the present invention aims to provide a method for preparing alcohol-free clarified grain sweet wine and its application. The entire process employs physical processes to control the dissolution of impurities from the source, coupled with a temperature-controlled alternating hot and cold treatment process. There are no additives or de-alcoholization steps. At the same time, it achieves natural alcohol-free, high clarity, long-term stability, high flavor retention, and short-cycle, high-efficiency production. It can be used directly as a basic sweet wine for daily consumption, and it is also perfectly suited to the blending needs of all types of coffee and tea drinks. It is also compatible with various grain sweet wine raw materials such as glutinous rice and highland barley.

[0011] To achieve the above objectives, the present invention adopts the following technical solution.

[0012] A method for preparing alcohol-free clarified grain sweet wine liquid, without any food additives or exogenous de-alcoholization treatment, includes the following steps.

[0013] (1) Raw material dilution and dispersion: Take the finished grain sweet wine with whole grains as raw material, add sterile pure water and gently stir to disperse, avoid structural breakage of grains throughout the process, and obtain sweet wine dilution with grains. The core inventive concept of this step is to abandon the conventional approach of "homogeneous extraction of crushed grains" in existing technologies and adopt a gentle dilution method with whole grains. This avoids structural breakage of the grains throughout the process, reducing the entry of easily precipitated impurities from inside the grains into the solution from the source. This fundamentally reduces the difficulty of subsequent clarification and the risk of precipitation, eliminating the need to add any external clarifying agents while preserving the original sweet flavor of the grains to the greatest extent. Especially for barley wine, it can solve the clarification problem caused by its high fiber and high protein content from the source, achieving a clarification effect that is superior to existing technologies.

[0014] (2) Temperature-controlled heat treatment in an open system under normal pressure: The sweet wine dilution is placed in an open system under normal pressure and heated under controlled temperature. The grains are kept intact and not overcooked throughout the heating process, achieving three core effects simultaneously: ① Protein pre-denaturation and precipitation in the solution; ② The system meets the commercial sterility requirements specified in GB 4789.26-2023 "National Food Safety Standard for Microbiological Testing of Food - Commercial Sterility Test" (i.e., the food has been moderately heat-sterilized and does not contain pathogenic microorganisms, nor does it contain non-pathogenic microorganisms that can multiply in it at normal temperature); ③ Alcohol evaporates to within the limit of 0.5% vol for non-alcoholic beverages specified in GB / T 17204-2021 under an open environment, thus obtaining the heat-treated sweet wine liquid; The core inventive concept of this step is to use an open system with normal pressure for temperature control heating. Under the premise of ensuring that the grains are intact and not overcooked, it simultaneously achieves three core objectives: protein pre-denaturation and sedimentation, commercial sterility to ensure shelf life at room temperature, and alcohol evaporation to achieve alcohol-free production. No de-alcoholization equipment is required, while preserving the original flavor of the grains to the greatest extent and avoiding high temperature damage to flavor substances.

[0015] (3) Temperature-controlled flocculation and sedimentation: The heat-treated sweet wine liquid is cooled down to cause trace macromolecular impurities in the solution to flocculate and settle, keeping the grains intact throughout the process; The core inventive concept of this step is to rapidly form filterable large-particle-size flocs from trace residual macromolecular impurities in the solution by controlling the temperature and cooling down. This is coupled with the technical solutions of source impurity control and heating pre-denaturation sedimentation, which significantly shortens the flocculation and sedimentation time and eliminates the need for the 24-48 hours of long-term standing required by existing technologies, thus significantly improving production efficiency.

[0016] (4) Solid-liquid separation and precision filtration: First, separate and remove the whole grains, take the supernatant and perform precision filtration to remove flocculent precipitates and tiny particles, and obtain alcohol-free clear grain sweet wine liquid; The core inventive concept of this step is to achieve liquid clarification of grain-based sweet wine through physical precision filtration, without any external clarifying agents throughout the process. Depending on product positioning, production costs, and raw material characteristics, physical filtration media such as 2000 mesh or higher precision filter membranes, ultrafiltration membranes, and nanofiltration membranes can be flexibly selected to meet the needs of all scenarios, from laboratory pilot tests to daily direct drinking mass production and large-scale industrial blending of raw materials. It is also compatible with various grain raw materials such as glutinous rice and highland barley.

[0017] The alcohol-free clarified grain sweet wine liquid produced by this invention has a sweet and smooth taste, a pure and natural grain aroma, and no off-flavors or impurities. It can be used directly as a base for daily drinking as a sweet wine beverage, suitable for breakfast, hydration during commutes, afternoon tea, post-workout recovery, as a side dish for hot pot / barbecue, family gatherings, and other scenarios. It is suitable for people of all ages. It can also be used as a beverage base to prepare flavored drinks with coffee or tea, covering both the C-end retail and B-end supply chain markets.

[0018] Furthermore, the grain sweet wine includes glutinous rice sweet wine and barley wine; the barley wine, also known as barley sweet mash or barley lees, is a fermented product with whole barley grains, made from barley through saccharification and fermentation with Rhizopus and Aspergillus oryzae yeast.

[0019] Furthermore, the grain-based sweet wine is glutinous rice wine or barley wine produced using intangible cultural heritage brewing techniques, with an original alcohol content of 1-3% vol, a saccharification and fermentation degree of ≥85%, and no exogenous food additives; furthermore, the volume ratio of the grain-based sweet wine to sterile purified water is 1:5-1:15, the stirring speed is ≤50r / min, and the stirring time is ≤10min.

[0020] Experiments have shown that when the dilution ratio is less than 1:5, the soluble solids in the solution are too high, which can easily lead to precipitation during storage; when the dilution ratio is greater than 1:15, the soluble solids in the solution are less than 2g / 100mL, the original flavor of the grains is bland, and there is no commercial drinking value.

[0021] Further, in step (2), the temperature-controlled heat treatment is a two-stage gradient heating; further, first heat up to 60-85℃ and keep warm for 5-20 minutes to complete protein pre-denaturation and precipitation, then heat up to 98-102℃ and keep in a slightly boiling state for 5-20 minutes to complete commercial sterility and alcohol evaporation.

[0022] Furthermore, in step (2), the entire heating rate of the temperature-controlled heat treatment is ≤5℃ / min, the highest temperature of the system during the heating process does not exceed 102℃, and the alcohol content of the sweet wine after heat treatment is ≤0.4% vol, which is lower than the 0.5% vol limit for non-alcoholic beverages specified in GB / T 17204-2021. It is compliantly classified as a common fermented grain beverage, which is not subject to alcohol regulation restrictions and can be covered by all channels and all age groups. At the same time, it fully meets the commercial sterility requirements specified in GB 4789.26-2023 and can achieve a shelf life of more than 6 months at room temperature with sealing.

[0023] Experiments have verified that when the heating rate is greater than 5℃ / min, the temperature difference between the inside and outside of the grain changes drastically, the overcooking rate is greater than 80%, the protein and polysaccharide content in the solution increases by more than 3 times, precipitation occurs after the product is refrigerated for 2 days, the light transmittance is less than 70%, the flavor loss rate is greater than 60%, and it is impossible to achieve a uniform and stable commercial sterility effect, which completely fails to meet commercial requirements.

[0024] Further, in step (3), the temperature-controlled flocculation sedimentation is a gradient cooling; further, the heat-treated sweet wine liquid is first cooled naturally to room temperature of 20-25℃, and then placed in a constant temperature environment of 2-6℃ for refrigeration and standing for 10-60 minutes to complete the impurity flocculation sedimentation.

[0025] Experiments have verified that when the refrigeration time is less than 10 minutes, impurities in the solution are not completely flocculated, and secondary precipitation is likely to occur during the storage of the finished product; when the refrigeration time is more than 60 minutes, the equipment occupancy rate increases significantly, the industrial production cost increases by more than 30%, and the value of large-scale mass production is reduced; when directly cooling from 80-100℃ to 2-6℃, the resulting flocs have a particle size of <1μm, which cannot be intercepted by conventional filter membranes, and precipitation occurs within 3 days of refrigeration; only through gradient cooling can filterable flocs with a particle size >10μm be effectively formed, achieving refrigeration stability for more than 4 days and no precipitation for 6 months at room temperature.

[0026] Furthermore, in step (4), the precision filtration is performed using a physical filter medium with a precision of 2000 mesh or higher; furthermore, the physical filter medium includes any one or more combinations of filter membranes, ultrafiltration membranes, and nanofiltration membranes.

[0027] Preferably, in step (4), the precision filtration adopts a two-stage or higher gradient filtration method; further, a 300-800 mesh filter membrane is first used for pre-filtration to remove large particulate impurities, and then a 2000 mesh or higher precision filter membrane / ultrafiltration membrane is used for final precision filtration. The entire filtration process is carried out at room temperature of 20-25℃ without positive pressure forced pressurization to avoid flocculated impurities from passing through the filter.

[0028] Preferably, in step (4), the pre-filtration uses a 500-mesh filter membrane, and the terminal filtration uses a 2000-5000-mesh filter membrane or an ultrafiltration membrane with a molecular weight cutoff of 10-100kDa.

[0029] Experiments have shown that when the molecular weight cutoff of ultrafiltration membrane is below 10 kDa, small molecule flavor substances in sweet wine are simultaneously retained, resulting in a significant loss of the original grain aroma; when the molecular weight cutoff is above 100 kDa, it cannot effectively retain large molecule proteins and pectin in the solution, resulting in insufficient clarification and stabilization effects.

[0030] Comparison of the effects of different filtration schemes: The transmittance of glutinous rice wine and barley wine liquor prepared by filtration with a 5000-mesh filter membrane was 92% and 86%, respectively, with a shelf life of 8 months at room temperature and an increase in production cost of 80%; The transmittance of glutinous rice wine and barley wine liquor prepared by filtration with a 50kDa ultrafiltration membrane was 94% and 91%, respectively, with a shelf life of 12 months at room temperature and an increase in production cost of 220%.

[0031] The above-mentioned different filtration schemes are all conventional technical means to achieve the precision filtration effect of the present invention. Those skilled in the art can flexibly choose them based on production costs, product positioning, and raw material characteristics without creative labor, and all of them fall within the protection scope of the present invention.

[0032] Furthermore, the final alcohol-free clarified grain sweet wine liquid has a light transmittance of 80-94%, and shows no layering, sedimentation, or flocculation after being refrigerated at 4℃ for 4 days. It has a shelf life of ≥6 months when sealed at room temperature, retains the original sweet flavor of the grains, and can be consumed directly as a basic beverage.

[0033] Preferably, the alcohol-free clarified grain sweet wine liquid prepared by the present invention has a pH value of 3.8-4.5, a soluble solids content of 3-8g / 100mL, strong batch-to-batch uniformity, and stable taste.

[0034] This invention also provides an alcohol-free clarified grain sweet wine, prepared using the above-mentioned method. The alcohol content of the grain sweet wine is ≤0.4% vol, which meets the national standard for alcohol-free beverages. It can be used directly as a base for daily consumption of sweet wine, or as a beverage base for flavored beverage blending.

[0035] This invention also provides applications of the above-mentioned alcohol-free clarified grain sweet wine liquid, including the following scenarios: ① Directly used as a base beverage for daily consumption; ② Used as a beverage base to be combined with any one or more of coffee liquid and tea liquid to prepare sweet wine flavored beverages.

[0036] Furthermore, the coffee liquid includes any one of cold brew coffee liquid, espresso liquid, hot brew coffee liquid, and pour-over coffee liquid; the tea liquid includes any one of cold brew oolong tea liquid, cold brew green tea liquid, cold brew black tea liquid, and hot brew tea liquid.

[0037] Preferably, the coffee liquid is cold brew coffee liquid prepared by cold brewing whole coffee beans, and the tea liquid is cold brew oolong tea liquid; the volume ratio of the non-alcoholic clarified grain sweet wine liquid to the coffee liquid / tea liquid is 1:0.5-1:3.

[0038] Tests have verified that: 1. When the volume ratio of coffee to tea is less than 1:0.5, the flavor proportion of coffee / tea is too low, making it impossible to achieve flavor balance, resulting in unclear product positioning and low commercial drinking value. 2. When the volume ratio of the blend is higher than 1:3, the tannins and bitterness of the coffee / tea are too strong, the original grain aroma of the sweet wine is completely masked, the flavor conflict is obvious, and the commercial drinking value is low. 3. When whole coffee bean cold brew coffee liquid, cold brew oolong tea liquid and the grain sweet wine liquid of this invention are combined, no flocculation, no sedimentation and no layering are observed after standing at 4°C for 4 days, and the flavor integration is optimal. It is suitable for all scenarios of freshly made and sold as well as pre-packaged bottled beverages. When espresso and hot brew coffee / tea liquid are combined, no visible flocculation is observed after standing at room temperature for 4 hours, which meets the commercial requirements of freshly made and sold scenarios.

[0039] All coffee and tea liquids can be stably blended with the grain sweet wine liquid of this invention, without any insurmountable technical obstacles.

[0040] Furthermore, the sweet wine-flavored beverage includes any one of pre-packaged bottled beverages or freshly made and sold beverages.

[0041] The glutinous rice wine and barley wine mentioned above are both sweet wine products with whole grains, made from grains through saccharification and fermentation with yeast. They are recognized as the same type of fermentation raw materials in the field. Those skilled in the art can apply the core process of this invention to the two types of raw materials without creative labor to achieve the same clarification, alcohol-free, and flavor retention effects.

[0042] Compared with the prior art, the present invention has the following outstanding substantive features and significant progress, and addresses the industry pain points in the background art.

[0043] 1. This invention is the first to propose the technical concept of "source impurity control," abandoning the conventional method of extracting from crushed grains. By gently diluting with intact grains and avoiding structural breakage and overcooking throughout the process, it reduces the amount of large-molecule polysaccharides, proteins, pectin, and other easily precipitating impurities from entering the solution at the source. This fundamentally solves the industry pain point of sedimentation and stratification in sweet wine beverages during long-term storage. No exogenous clarifying agents or preservatives need to be added, perfectly meeting the demand for zero-additive healthy beverages. Especially for barley wine, it overcomes the clarification problem caused by its high protein and high fiber content, achieving a superior clarification effect compared to existing technologies and filling a gap in the industry.

[0044] 2. This invention pioneers an atmospheric pressure open system temperature-controlled heat treatment process. Through a dual approach of dilution and open system alcohol evaporation, the alcohol content of the product can be stably controlled at ≤0.4% vol without any dealcoholization equipment, which is lower than the national alcohol-free standard limit. This eliminates the restrictions on alcohol regulation and can be covered by all channels, all age groups, and all scenarios. At the same time, the gentle temperature control process preserves the original flavor of the grain to the greatest extent, with a flavor retention rate of ≥95%, solving the core pain point of severe flavor loss in existing dealcoholization processes.

[0045] 3. This invention utilizes a synergistic process of source impurity control, temperature-controlled heating for pre-denaturation sedimentation, and temperature-controlled cooling for flocculation. Impurity flocculation and sedimentation can be completed in just 10-60 minutes. Compared with the long standing time of 24-48 hours in the prior art, the production cycle is shortened by more than 95%, significantly reducing equipment occupancy and production costs, and significantly improving industrial production efficiency, making it suitable for large-scale mass production needs.

[0046] 4. The grain-based sweet wine liquid prepared by this invention can be flexibly adapted to physical filtration schemes of different precisions, with a light transmittance of up to 94%. It can be refrigerated at 4°C for up to 10 days without layering, sedimentation, or flocculation, and has a shelf life of up to 12 months when sealed at room temperature. Its stability surpasses that of existing similar products. The product can be consumed directly as a basic daily beverage, or it can be mixed with all types of coffee liquid and tea liquid in appropriate proportions. It is suitable for all scenarios of pre-packaging and on-site preparation and sales, greatly enhancing its commercial potential.

[0047] 5. The solution of the present invention breaks through the long-standing technical bias in the field. It not only realizes the alcohol-free clarification of glutinous rice sweet wine, but also adapts to high-protein and high-fiber barley wine, bringing about technical effects that cannot be expected by those skilled in the art, and filling the gap in the industry's general grain sweet wine clarification technology.

[0048] 6. The preparation process of this invention is simple and controllable, requiring no complex fermentation or de-alcoholization equipment. It uses commercially available intangible cultural heritage grain sweet wine as raw material, exhibiting strong batch stability and low production costs. It can be flexibly adapted to various grain raw materials such as glutinous rice and highland barley, covering different needs from small-scale trials to industrial mass production, and is suitable for promotion and application on multiple scales. At the same time, using intangible cultural heritage grain sweet wine as raw material realizes the modernization and innovation of traditional intangible cultural heritage foods, giving the product a unique cultural premium and differentiated competitiveness.

[0049] 7. The alcohol-free clarified grain sweet wine liquid prepared by this invention exhibits better clarification stability under room temperature storage conditions than that under refrigeration at 4°C after sealed sterilization. Specifically, in Example 1, the glutinous rice sweet wine liquid, after sealed sterilization and storage at room temperature (25°C) for 30 days, still maintains a light transmittance of over 87%, with no stratification or significant visible sediment. In Example 2, the highland barley sweet wine liquid, after sealed sterilization and storage at room temperature (25°C) for 30 days, still maintains a light transmittance of over 80%, demonstrating better stability than refrigerated samples of the same period. It can achieve long-term shelf stability without cold chain storage, significantly reducing the commercial storage and transportation costs of the product.

[0050] Any equivalent substitutions or simple adjustments made by those skilled in the art to the process parameters, filter media, heating methods, and cooling methods of this invention without departing from the core principles of this invention shall fall within the protection scope of this invention. Detailed Implementation

[0051] The present invention will be further described in detail below with reference to specific embodiments and comparative examples. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Example 1: Basic Optimal Proportion Example - Glutinous Rice Sweet Wine (Basic Drink)

[0052] This embodiment provides a method for preparing alcohol-free clarified grain sweet wine liquid, the specific steps of which are as follows: (1) Raw material dilution and dispersion: Hunan intangible cultural heritage glutinous rice sweet wine is used as raw material, with whole rice grains, original alcohol content of 2% vol, saccharification and fermentation degree of 90%, and no external additives; add sterile pure water according to the mass ratio of sweet wine raw material: sterile pure water = 1:8, stir gently at 25 r / min for 3 min, disperse evenly, without structural breakage of rice grains throughout the process, and no visible structural damage to rice grains, to obtain sweet wine dilution with rice grains; (2) Temperature-controlled heat treatment in an open system under normal pressure: The diluted sweet wine was placed in an open heating pot under normal pressure, and the heating rate was controlled at 3℃ / min. The temperature was first raised to 70℃ and held for 10min to complete the pre-denaturation and precipitation of proteins. Then the temperature was raised to 100℃ and held at a slight boil for 12min. No rice grains were overcooked throughout the process, and commercial sterility and alcohol evaporation were achieved simultaneously. After the heat treatment, the alcohol content of the sweet wine was 0.22% vol, which met the commercial sterility requirements specified in GB 4789.26-2023. (3) Temperature-controlled flocculation and sedimentation: Take out the heat-treated sweet wine liquid with rice grains, let it stand naturally at normal pressure to 22°C room temperature for 55 minutes, and then place it in a constant temperature refrigeration environment of 3°C for 35 minutes. During the standing process, there is no stirring or shaking, and the flocculation and sedimentation of trace impurities are completed. (4) Solid-liquid separation and precision filtration: After cooling, the whole rice grains of the sweet wine liquid are first screened out. The supernatant is first pre-filtered at room temperature using a 500-mesh filter membrane, and then finely filtered at the end using a 2000-mesh filter membrane. There is no positive pressure forced pressurization, no additives, and no de-alcoholization treatment throughout the process, resulting in alcohol-free clear sweet wine liquid. 1 part by mass of sweet wine raw material is finally used to produce 4 parts by mass of clear sweet wine liquid.

[0053] The alcohol-free clarified sweet wine liquid prepared in this embodiment, after testing, showed the following: alcohol content 0.22% vol, meeting the GB / T17204-2021 standard for alcohol-free beverages; light transmittance 89%; pH value 4.1; soluble solids content 4.8g / 100mL; after standing at 4℃ for 4 days without layering, precipitation, or flocculation, and with no change in flavor; shelf life of 6 months at room temperature when sealed, fully meeting the commercial sterility requirements of GB 4789.26-2023; perfectly retaining the original sweet rice aroma of intangible cultural heritage sweet wine, with a refreshing and smooth taste, suitable sweetness, and no off-flavors, it can be directly consumed as a basic daily beverage, and the aroma of the sweet wine is not significantly different from that of directly brewed sweet wine. Example 2: Basic Optimal Formulation Example - Barley Wine Rice Drink (Basic Version)

[0054] This embodiment provides a method for preparing alcohol-free clarified barley wine liquor, the specific steps of which are as follows: (1) Raw material dilution and dispersion: Qinghai intangible cultural heritage barley wine maker is used as raw material, with whole barley grains, original alcohol content of 1.8% vol, saccharification and fermentation degree of 88%, and no external additives; add sterile purified water according to the mass ratio of barley wine maker raw material: sterile purified water = 1:8, and gently stir at 25r / min for 3min to disperse evenly. There is no structural breakage of barley grains throughout the process, and no visible structural damage to grains, to obtain sweet wine dilution with grains; (2) Temperature-controlled heat treatment in an open system under normal pressure: The sweet wine dilution was placed in an open heating pot under normal pressure, and the heating rate was controlled at 3℃ / min. The temperature was first raised to 70℃ and kept for 10min to complete the protein pre-denaturation and precipitation. Then the temperature was raised to 100℃ and kept at a slight boiling state for 12min. No grains were cooked throughout the process, and commercial sterility and alcohol evaporation were achieved simultaneously. After the heat treatment, the alcohol content of the sweet wine was 0.20% vol, which met the commercial sterility requirements specified in GB 4789.26-2023. (3) Temperature-controlled flocculation and sedimentation: Take out the heat-treated sweet wine liquid with grains, let it stand naturally at normal pressure to 22°C room temperature for 55 minutes, and then place it in a constant temperature refrigeration environment of 3°C for 35 minutes. During the standing process, there is no stirring or shaking, and the flocculation and sedimentation of trace impurities are completed. (4) Solid-liquid separation and precision filtration: After cooling, the whole barley grains are first screened out of the sweet wine liquid. The supernatant is first pre-filtered at room temperature using a 500-mesh filter membrane, and then finely filtered at the end using a 2000-mesh filter membrane. There is no positive pressure forced pressurization, no additives, and no de-alcoholization treatment throughout the process, resulting in alcohol-free clear barley wine liquid. 1 part by mass of barley wine raw material finally yields 4 parts by mass of clear liquid.

[0055] The alcohol-free clarified barley wine liquid prepared in this embodiment, after testing, showed the following: alcohol content 0.20% vol, meeting the GB / T 17204-2021 standard for alcohol-free beverages; light transmittance 81%, slightly lower than the glutinous rice sweet wine liquid of Example 1; pH value 3.9; soluble solids content 6.3g / 100mL; after standing at 4℃ for 4 days without layering, precipitation, or flocculation, and with no change in flavor; shelf life of 6 months at room temperature when sealed, fully meeting the commercial aseptic requirements of GB 4789.26-2023; perfectly retaining the natural malt aroma and sweet taste of barley, with a rich and unique flavor, a refreshing and smooth taste, and no off-flavors, it can be directly consumed as a basic daily beverage. Example 3: Xiaogan Glutinous Rice Sweet Wine Example

[0056] This embodiment provides a method for preparing alcohol-free clarified sweet wine liquid, the specific steps of which are as follows: (1) Raw material dilution and dispersion: Xiaogan intangible cultural heritage glutinous rice sweet wine is taken as raw material, with whole rice grains, original alcohol content of 1.5% vol, saccharification and fermentation degree of 88%, and no external additives; add sterile pure water at a mass ratio of sweet wine raw material: sterile pure water = 1:10, stir gently at 30 r / min for 5 min, disperse evenly, with no structural breakage of rice grains throughout the process, and no visible structural damage to rice grains, to obtain sweet wine dilution with rice grains; (2) Temperature-controlled heat treatment in an open system under normal pressure: The diluted sweet wine was placed in an open heating pot under normal pressure, and the heating rate was controlled at 4℃ / min. The temperature was first raised to 65℃ and held for 10min, and then raised to 100℃ and kept at a slight boiling state for 15min. No rice grains were overcooked during the whole process. After the heat treatment, the alcohol content of the sweet wine was 0.18% vol, which met the requirements for commercial sterility. (3) Temperature-controlled flocculation and sedimentation: Take out the heat-treated sweet wine liquid with rice grains, let it stand naturally at normal pressure to 20°C room temperature for 50 minutes, and then place it in a constant temperature refrigeration environment at 2°C for 30 minutes to complete the flocculation and sedimentation of trace impurities. (4) Solid-liquid separation and precision filtration: After cooling, the whole rice grains are first screened out of the sweet wine liquid. The supernatant is then filtered at room temperature using a 2000-mesh filter membrane. There is no positive pressure forced pressurization, no additives, and no de-alcoholization treatment throughout the process, resulting in alcohol-free clear sweet wine liquid.

[0057] The alcohol-free clarified sweet wine liquid prepared in this embodiment was tested and found to have the following characteristics: alcohol content of 0.18% vol, which meets the national standard for alcohol-free beverages; light transmittance of 87%; pH value of 4.2; soluble solids content of 5.7g / 100mL; no layering, sedimentation, or flocculation, and no change in flavor after standing at 4℃ for 4 days; shelf life of 6 months when sealed at room temperature; fresh rice aroma, sweet and refreshing taste, suitable for direct daily consumption. Example 4: Mass Production Example of Highland Barley Wine Brewery Ultrafiltration Membrane

[0058] The only difference between this embodiment and embodiment 2 is that in step (4), the supernatant after solid-liquid separation is first pre-filtered with a 500-mesh filter membrane, and then filtered at room temperature using a polyethersulfone ultrafiltration membrane with a molecular weight cutoff of 50kDa. The remaining steps and parameters are exactly the same.

[0059] The alcohol-free clarified barley wine liquor prepared in this embodiment has the following characteristics: 91% light transmittance; no layering, sedimentation, or flocculation after 10 days of refrigeration at 4°C; 12-month shelf life under sealed conditions at room temperature; 99.98% retention rate of large molecular proteins; and no flocculation after mixing with coffee or tea. It perfectly meets the standardized raw material requirements of tea / coffee chain brands and is also suitable for large-scale production of bottled direct-drink beverages. It has a rich barley aroma and a smooth taste. Example 5: Targeted Application Example - Whole Coffee Bean Cold Brew Sweet Wine Black Coffee

[0060] Take the non-alcoholic clear sweet wine liquid obtained in Example 1, mix it with whole coffee bean cold brew coffee liquid at a mass ratio of 2:1, add an appropriate amount of ice cubes, and obtain a non-alcoholic sweet wine clear coffee beverage. The preparation method of cold brew coffee liquid from whole coffee beans is as follows: Take whole Arabica coffee beans, without grinding, and place them in an environment of 2-4℃ for 12 hours at a mass ratio of coffee beans to purified water of 1:10. Filter to obtain cold brew coffee liquid.

[0061] The sweet rice wine and coffee beverage prepared in this embodiment has no layering, no flocculation, and no sediment. The aroma of coffee and sweet rice wine are perfectly blended, with no flavor conflict. The taste is refreshing and smooth, without any graininess, and the flavor is uniform and stable. After being refrigerated at 4°C for 4 days, there is no visible flocculation, no layering, and no sediment. It can be used directly as a standardized finished beverage for chain coffee shops, or it can be prepared as a pre-packaged bottled beverage. Example 6: Targeted Application Example - Cold-brewed Oolong Sweet Wine and Green Tea

[0062] Take the alcohol-free clarified barley wine liquid obtained in Example 2, mix it with cold-brewed oolong tea liquid at a mass ratio of 1:1, add an appropriate amount of ice cubes, and obtain an alcohol-free barley sweet wine clear tea beverage. The preparation method of cold-brewed oolong tea liquid is as follows: take Anxi Tieguanyin oolong tea, and according to the mass ratio of tea leaves to purified water = 1:80, place it in an environment of 2-4℃ for cold brewing for 8 hours, and filter to obtain cold-brewed oolong tea liquid.

[0063] The highland barley sweet wine and green tea beverage prepared in this embodiment has no layering, no flocculation, and no sediment. The aroma of oolong orchid and highland barley blend harmoniously, with a sweet and refreshing taste, no bitterness, and a uniform and stable flavor. After being refrigerated at 4℃ for 4 days, there is no visible flocculation, no layering, and no sediment. It can be used directly as a standardized finished beverage in new tea shops, or it can be prepared as a pre-packaged bottled beverage with a prominent differentiated flavor. Example 7: General Compatibility Example - Italian Espresso Black Coffee

[0064] Take the alcohol-free clarified barley wine liquid obtained in Example 2, mix it with espresso liquid at a volume ratio of 3:1, add an appropriate amount of ice cubes, and you will get a freshly made and sold barley sweet wine coffee drink.

[0065] The beverage prepared in this embodiment is freshly made and consumed without flocculation or sedimentation. The aroma of barley can neutralize the bitter taste of coffee, resulting in a smooth texture. After being left at room temperature for 4 hours, there is no visible flocculation or layering, which fully meets the food safety and commercial requirements for freshly made beverages and is suitable for freshly made and sold coffee shops. Example 8: Verification of the Basic Sweet Wine Drink (Straight Drink)

[0066] The alcohol-free clarified grain sweet wine liquids prepared in Examples 1 and 2 were used as the base for sweet wine drinking. These liquids were then consumed daily for 7 consecutive days by 10 testers who had received food sensory evaluation training. The test results are as follows: 1. Sensory evaluation: Both products received a score of 8.5 or higher (out of 10). Among them, the barley wine liquid of Example 2 received an average score of 9.2. The testers generally commented that it had a "sweet and smooth taste, without being overly sweet or having any off-flavors. It has a rich and unique barley aroma and is easy to drink daily." 2. Scene adaptability: All testers agreed that both products are suitable for all scenarios such as breakfast, commuting, post-workout, and as a side dish, and can be consumed daily as beverages; 3. Stability: During the test, the product showed no flavor change when left open at room temperature for 4 hours, and no sedimentation, layering, or flavor deterioration when refrigerated and sealed for 7 days, fully meeting the storage requirements for daily drinking. Comparative Example 1: Comparison of Broken Grains - Glutinous Rice Sweet Wine

[0067] The only difference between this comparative example and Example 1 is that: in step (1), high-speed homogenizing is used to completely break the rice grains, while the rest of the steps and parameters are exactly the same.

[0068] The sweet wine liquid prepared in this comparative example was tested and found to contain 4.2 times more protein and polysaccharide than that of Example 1. The transmittance was 70%. Slight precipitation appeared after standing at 4°C for 12 hours, significant precipitation appeared after 48 hours, and stratification occurred after 72 hours. The stability was far lower than that of Example 1. In addition, multiple filtrations were required to achieve a basic clarification effect, the filter membrane was severely clogged, industrial production was difficult, the taste was rough and lacked smoothness, and it was not suitable for daily direct drinking. Comparative Example 2: Comparison of Broken Grains - Highland Barley Wine

[0069] The only difference between this comparative example and Example 2 is that: in step (1), high-speed homogenizing is used to completely break down the barley grains; the remaining steps and parameters are exactly the same.

[0070] The barley wine liquor prepared in this comparative example was tested and found to contain 5.8 times more protein and β-glucan than that of Example 2. The transmittance was only 62%. Obvious precipitation occurred after standing at 4°C for 6 hours, and stratification occurred after 24 hours. The stability was poor and could not meet commercial requirements. This verifies the core role of the "grain preservation and impurity control" process of this invention in barley wine liquor. Comparative Example 3: Closed Heating Comparison

[0071] The only difference between this comparative example and Example 1 is that a closed system is used for heating in step (2), while the other steps and parameters are exactly the same.

[0072] The sweet wine liquid prepared in this comparative example was tested and found to have an alcohol content of 0.48% vol, which is close to the alcohol-free standard limit specified in GB / T 17204-2021. However, the batch-to-batch variation was large, and the alcohol-free stability was poor, failing to consistently meet the compliance requirements for alcohol-free beverages. Furthermore, the sealed heating caused the rice grains to overcook, resulting in the dissolution of a large amount of impurities. The light transmittance was 75%, and slight precipitation occurred after standing at 4°C for 2 days. The stability and alcohol-free guarantee capability were far lower than those of Example 1. The flavor exhibited a stale or musty taste, making it unsuitable for daily direct consumption, and it could not consistently meet the commercial sterility requirements specified in GB 4789.26-2023. Comparative Example 4: Rapid Heating Comparison

[0073] The only difference between this comparative example and Example 2 is that the heating rate in step (2) is 10℃ / min, and the temperature is directly and rapidly raised to 100℃ and held for 22min. The other steps and parameters are exactly the same.

[0074] The barley wine liquor prepared in this comparative ratio was tested and found to have the following characteristics: 95% of the barley grains were thoroughly cooked; the impurity content in the solution was significantly increased; the light transmittance was 65%; precipitation occurred after standing at 4℃ for 1 day; the flavor loss rate was 70%; a burnt taste appeared; and the product had low commercial value and was not suitable for daily direct consumption. Comparative Example 5: Direct Sudden Cooling Comparison

[0075] The only difference between this comparative example and Example 1 is that the natural cooling step is omitted in step (3), and after heat treatment, the sample is placed directly in a 3°C environment for refrigeration and stand for 35 minutes. The remaining steps and parameters are exactly the same.

[0076] The sweet wine liquid prepared in this comparative example had a light transmittance of 82% and showed slight precipitation after standing at 4°C for 3 days. The precipitation was obvious after 4 days, and the long-term stability was significantly lower than that of Example 1. Comparative Example 6: Exogenous Dehydrolution Comparison

[0077] The only difference between this comparative example and Example 2 is that commercially available 5% vol ordinary highland barley wine was used as raw material, and after dilution, the alcohol content was reduced to 0.20% vol using a reverse osmosis membrane de-alcoholization process. The remaining steps and parameters are exactly the same.

[0078] The barley wine liquor prepared in this comparative example was tested and found to have a retention rate of only 38% for the original malt aroma, a light flavor, and lack of the original sweet taste of barley sweet wine. At the same time, the equipment investment and production cost were more than three times that of Example 2, and the product could not reflect its core flavor advantages, making it unsuitable for daily direct consumption.

[0079] Both the glutinous rice sweet wine and the highland barley wine recipe achieve the same technical effect through the same core process of this invention. They share the same inventive concept and solve the industry pain points of existing technologies for different grain raw materials. They are parallel implementation schemes of the same invention.

[0080] Table 1 below shows a comparison of the light transmittance and stability days at 4°C for the products prepared in the examples and comparative examples: Table 1. Effect of Product Light Transmittance on Stability Days at 4℃ Refrigeration Sample number Light transmittance (%) Stable days at 4℃ Example 1 89 4 Example 2 81 4 Comparative Example 1 70 0.5 Comparative Example 2 62 0.25 Comparative Example 3 75 2 Comparative Example 4 65 1 Comparative Example 5 82 3

[0081] Through the comparative experiments of the above embodiments and comparative examples, it is clear that the various process steps of the present invention are mutually coupled and synergistic, and each step is indispensable. Together, they achieve the core effects of "source impurity control, dual alcohol-free guarantee, alternating hot and cold temperature control to promote sedimentation, short cycle and high-efficiency production, high flavor retention, long-term clarification and stability, and full-scenario adaptability". This solves many industry pain points of the prior art and achieves clarification effects and flavor advantages for barley wine that cannot be predicted by those skilled in the art. It has outstanding substantive features and significant progress.

Claims

1. A method for preparing an alcohol-free clarified grain sweet wine liquid, characterized in that, The entire process involves no food additives and no exogenous dealcoholization treatment, and includes the following steps: (1) Raw material dilution and dispersion: Take the finished grain sweet wine with whole grains as raw material, add sterile pure water and gently stir to disperse, avoid structural breakage of grains throughout the process, and obtain sweet wine dilution with grains. (2) Temperature-controlled heat treatment in an open system under normal pressure: The sweet wine dilution is placed in an open system under normal pressure and heated under controlled temperature. The grains are kept intact and not overcooked throughout the heating process, achieving three core effects simultaneously: ① protein pre-denaturation and precipitation in the solution, ② the system meets the commercial sterility requirements specified in GB 4789.26-2023, and ③ alcohol evaporates to within the limit of 0.5% vol non-alcoholic beverage specified in GB / T 17204-2021 under an open environment, thus obtaining the heat-treated sweet wine liquid; (3) Temperature-controlled flocculation and sedimentation: The heat-treated sweet wine liquid is cooled down to cause trace macromolecular impurities in the solution to flocculate and settle, keeping the grains intact throughout the process; (4) Solid-liquid separation and precision filtration: First, separate and remove the whole grains, then take the supernatant and perform precision filtration to obtain alcohol-free clear sweet wine liquid.

2. The preparation method according to claim 1, characterized in that, The grain-based sweet wines include glutinous rice sweet wine and barley wine; the barley wine, also known as barley sweet mash or barley lees, is a fermented product made from barley through saccharification and fermentation with yeast, containing whole barley grains.

3. The preparation method according to claim 2, characterized in that, The grain-based sweet wine is a glutinous rice wine or barley wine made using intangible cultural heritage brewing techniques. Its original alcohol content is 1-3% vol, saccharification and fermentation degree is ≥85%, and it contains no exogenous food additives. Furthermore, the volume ratio of the grain-based sweet wine to sterile purified water is 1:5-1:15, the stirring speed is ≤50 r / min, and the stirring time is ≤10 min.

4. The preparation method according to claim 1, characterized in that, In step (2), the temperature-controlled heat treatment is a two-stage gradient heating; further, the temperature is first raised to 60-85℃ and held for 5-20 minutes to complete the protein pre-denaturation and precipitation, and then the temperature is raised to 98-102℃ and held at a slight boiling state for 5-20 minutes to complete commercial sterility and alcohol evaporation.

5. The preparation method according to claim 1, characterized in that, In step (2), the heating rate of the temperature-controlled heat treatment is ≤5℃ / min, the maximum temperature of the system during the heating process does not exceed 102℃, and the alcohol content of the sweet wine is ≤0.4%vol after the heat treatment is completed.

6. The preparation method according to claim 1, characterized in that, In step (3), the temperature-controlled flocculation sedimentation is a gradient cooling process; furthermore, the heat-treated sweet wine liquid is first cooled naturally to room temperature of 20-25℃, and then placed in a constant temperature environment of 2-6℃ for refrigeration and standing for 10-60 minutes to complete the impurity flocculation sedimentation.

7. The preparation method according to claim 1, characterized in that, In step (4), the precision filtration is performed using a physical filter medium with a precision of 2000 mesh or higher; further, the physical filter medium includes any one or more combinations of filter membranes, ultrafiltration membranes, and nanofiltration membranes.

8. The preparation method according to claim 7, characterized in that, The precision filtration adopts a two-stage or higher gradient filtration method; furthermore, a 300-800 mesh filter membrane is first used for pre-filtration to remove large particulate impurities, and then a 2000 mesh or higher precision filter membrane / ultrafiltration membrane is used for final precision filtration. The entire filtration process is carried out at room temperature of 20-25℃ without positive pressure forced pressurization to avoid flocculated impurities from passing through the filter.

9. The preparation method according to claim 8, characterized in that, Preferably, the pre-filtration uses a 500-mesh filter membrane, and the terminal filtration uses a 2000-5000-mesh filter membrane, or an ultrafiltration membrane with a molecular weight cutoff of 10-100 kDa.

10. The preparation method according to claim 1, characterized in that, The final alcohol-free clarified sweet wine liquid has a light transmittance of 80-94%. It shows no layering, sedimentation, or flocculation after being refrigerated at 4℃ for 4 days. It has a shelf life of ≥6 months when sealed at room temperature, retains the original sweet flavor of the grains, and can be consumed directly as a base beverage.

11. A non-alcoholic clarified grain sweet wine liquid, characterized in that, The grain sweet wine liquid prepared by any one of claims 1-10 has an alcohol content of ≤0.4% vol, which meets the national standard for non-alcoholic beverages. It can be used directly as a base for daily consumption of sweet wine drinks, or as a base for flavored beverages.

12. The application of the alcohol-free clarified grain sweet wine liquid according to claim 11, characterized in that, Including the following scenarios: ① Directly consumed as a non-alcoholic base beverage for daily drinking; ② As a beverage base, combined with any one or more of coffee liquid and tea liquid to prepare sweet wine-flavored beverages.

13. The application according to claim 12, characterized in that, The coffee liquid includes any one of cold brew coffee liquid, espresso liquid, hot brew coffee liquid, and pour-over coffee liquid; the tea liquid includes any one of cold brew oolong tea liquid, cold brew green tea liquid, cold brew black tea liquid, and hot brew tea liquid.

14. The application according to claim 13, characterized in that, Preferably, the coffee liquid is cold brew coffee liquid prepared by cold brewing whole coffee beans, and the tea liquid is cold brew oolong tea liquid; the volume ratio of the non-alcoholic clarified sweet wine liquid to the coffee liquid / tea liquid is 1:0.5-1:

3.

15. The application according to claim 12, characterized in that, The sweet wine-flavored beverages include any one of pre-packaged bottled beverages or freshly made and sold beverages.