Brewing method of beer

Abstract

The invention discloses a beer brewing method which comprises the following steps: pretreating tartary buckwheat which is a functional raw material for beer brewing; crushing tartary buckwheat to obtain tartary buckwheat powder; mixing the tartary buckwheat flour, the malt, the humulus lupulus and the drinking water according to a preset proportion; carrying out saccharification treatment on the mixed solution obtained by mixing at a preset temperature for a preset time; boiling saccharified liquid obtained by saccharification treatment, and adding humulus lupulus and a proper amount of enzyme preparation during boiling treatment; and cooling the boiled liquid, and fermenting the cooled liquid to obtain the beer liquid. According to the method and the device, the technical problems that flavonoid substances in the tartary buckwheat cannot be extracted and reserved to the greatest extent in the brewing process and the stability and the taste of the beer cannot be ensured in the prior art are solved, so that the flavor of the beer is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of beer brewing, and particularly to a beer brewing method. BACKGROUND

[0002] In the related art, the efficient extraction and stable retention of flavonoids are technical bottlenecks in the beer brewing process. Specifically, on the one hand, the traditional malt saccharification process does not take the retention of plant flavonoids as the main goal, and the saccharification temperature and pH value are not conducive to the maximum extraction of flavonoids. On the other hand, the control of temperature and oxidative environment during fermentation and pasteurization is insufficient, which easily leads to the destruction of flavonoids, and ultimately results in insufficient functionality and difficulty in standardization.

[0003] In summary, the brewing technology of bitter buckwheat functional beer is not mature, especially in terms of the extraction efficiency of flavonoids and the stability of beer. The beer brewing methods in the related art mostly focus on yeast fermentation and alcohol production, and the extraction of effective ingredients in plants is not fully considered. Due to the sensitivity of flavonoids to temperature and time, if the process is not properly controlled, it is easy to lead to degradation or loss, affecting the health function of the final beer product.

[0004] Therefore, how to maximize the extraction and retention of flavonoids in bitter buckwheat during the brewing process while ensuring the stability and taste of beer is a technical problem to be solved. SUMMARY

[0005] The present application provides a beer brewing method to solve the problem of how to maximize the extraction and retention of flavonoids in bitter buckwheat during the brewing process while ensuring the stability and taste of beer in the related art.

[0006] According to one aspect of the present application, a beer brewing method is provided, comprising: pretreating bitter buckwheat, wherein the bitter buckwheat is a functional raw material for beer brewing; crushing the bitter buckwheat to obtain bitter buckwheat powder; mixing the bitter buckwheat powder and malt according to a predetermined ratio, adding hops and drinking water to obtain a mixed solution; performing saccharification treatment on the mixed solution at a predetermined temperature and for a predetermined time; performing boiling treatment on the saccharification solution, and adding hops and an appropriate amount of enzyme preparation during the boiling treatment; cooling the liquid obtained by the boiling treatment, and performing fermentation treatment on the cooled liquid to obtain beer liquid.

[0007] Preferably, during the saccharification treatment, the saccharification temperature is between 60°C and 70°C, and the saccharification treatment time is 60 minutes to 90 minutes.

[0008] Preferably, the boiling treatment temperature ranges from 95 degrees Celsius to 100 degrees Celsius, and the boiling treatment time is 60 minutes to 90 minutes.

[0009] Preferably, the fermentation process has a temperature range of 9 degrees Celsius to 16 degrees Celsius, and a main fermentation process of the fermentation process has a time greater than or equal to 5 days, and a post-fermentation time greater than or equal to 10 days.

[0010] Preferably, the beer after the fermentation process is subjected to a centrifugation and filtration operation, and the beer is subjected to a pasteurization process after the operation.

[0011] Preferably, the pasteurization process includes heating the beer to 60 degrees Celsius to 65 degrees Celsius, and controlling the pasteurization unit, Pasteurization Unit, PU, to be greater than or equal to 10 within a predetermined time.

[0012] Preferably, the hops include dual-aroma hops.

[0013] Preferably, the malt includes barley malt.

[0014] Preferably, the total flavonoid content of the beer is measured using ultraviolet-visible spectrophotometry, with rutin as a reference, a determination wavelength of 510 nanometers, a sample concentration controlled within an A510 value range of 0.1 to 0.4, and calculated by the following formula: ; wherein c is the total flavonoid concentration, in milligrams per milliliter, X is the concentration value corresponding to the standard curve of ultraviolet-visible spectrophotometry, V is the sampling volume of the beer, in milliliters, and A510 is the absorbance as the ordinate and the concentration as the abscissa to draw the standard curve, and the absorbance is measured at a wavelength of 510 nm.

[0015] Preferably, the flavonoid content of the beer is greater than 30 milligrams per liter.

[0016] Preferably, the preset ratio includes a ratio of the malt between 73% and 85%, and a ratio of the bitter buckwheat flour between 5% and 12%.

[0017] The beer brewing method provided by the present application can extract flavonoids from bitter buckwheat and ensure good retention of the flavonoids in beer by optimizing bitter buckwheat pretreatment, saccharification temperature control, fermentation parameter adjustment, and standardized detection methods. In some preferred embodiments, flavonoid degradation is avoided by optimizing temperature and time control. At the same time, the present application also uses enzyme preparations and pasteurization and other technical means to improve the stability of flavonoids during brewing, solves the problems of insufficient extraction and poor stability of flavonoids in traditional brewing methods, and thus realizes efficient production of functional beer. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings: Figure 1 is a flow chart of a beer brewing method according to an embodiment of the application; Figure 2 is a schematic diagram of a standard curve of a measurement method according to an embodiment of the application. DETAILED DESCRIPTION

[0019] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. In the related art, the beer brewing process mainly focuses on malt saccharification and yeast fermentation. The process and parameter setting of beer brewing in the related art are all targeted at converting starch into fermentation sugar, and lack of pertinence in the extraction and retention of plant-derived active ingredients. In the related art, high-temperature short-time treatment is used in the saccharification stage, resulting in degradation of flavonoids. The oxidative environment and temperature fluctuation in the fermentation process further exacerbate the loss of active ingredients, and the flavonoid content in the final product is difficult to meet the functional standard.

[0020] In order to solve the above problems, the stable extraction of flavonoids needs to be completed in a specific temperature range, and at the same time, oxidation and high-temperature damage in the subsequent process need to be avoided. In the present application, the temperature and time parameters of the saccharification stage are adjusted to establish an environment conducive to the dissolution of flavonoids; the fermentation control strategy is optimized to reduce the intensity of oxidation reaction; and the sterilization process parameters are improved to reduce thermal damage under the premise of ensuring microbial safety. This phased control strategy can systematically solve the problems of flavonoid extraction efficiency and stability.

[0021] The present embodiment provides a beer brewing method, Figure 1 is a flow chart of a beer brewing method according to an embodiment of the application, as Figure 1 shown, the method comprises the following steps S102 to S206.

[0022] Step S102, pretreating tartary buckwheat, wherein the tartary buckwheat is a functional raw material for beer brewing.

[0023] Step S104, crushing the tartary buckwheat to obtain tartary buckwheat powder.

[0024] Step S106, mixing the tartary buckwheat powder, malt, hops and drinking water according to a preset ratio; Step S108, saccharifying the mixed liquid obtained by mixing at a preset temperature and for a preset time; Step S110, the saccharification liquid obtained by the saccharification treatment is boiled, and hops and an appropriate amount of enzyme preparation are added during the boiling treatment; Step S112, the liquid obtained by the boiling treatment is cooled, and the cooled liquid is subjected to fermentation treatment to obtain beer liquid.

[0025] In this embodiment, by optimizing the selection of raw materials in beer brewing, and the steps of saccharification, boiling, fermentation and other links in beer brewing, flavonoids in tartary buckwheat can be extracted, and good retention in beer can be ensured. The problem of insufficient extraction and poor stability of flavonoids in traditional brewing method is solved, thereby realizing efficient production of functional beer.

[0026] The pretreatment of tartary buckwheat can include cleaning and drying treatment. The cleaning and drying treatment refers to removing impurities on the surface of tartary buckwheat and reducing the water content by physical methods. A vibrating screen combined with a hot air drying device can be used to achieve this step, which ensures the purity of the raw material and prevents microbial contamination. The pulverization into powder refers to breaking the dried tartary buckwheat particles to a predetermined particle size range, which can be treated by a hammer mill to increase the specific surface area of the material to promote the dissolution of subsequent components. The saccharification treatment refers to promoting enzymatic hydrolysis of starch and release of flavonoids under temperature control. A gradient temperature program can be used to maintain enzyme activity. The temperature and time of this stage are matched with the optimal dissolution conditions of flavonoids. The enzyme preparation addition refers to the introduction of protein-decomposing enzymes during the boiling stage. Liquid enzyme preparation can be pumped into the system by a quantitative pump to promote the flocculation of colloidal substances and improve the clarity of beer. The fermentation parameter control refers to adjusting the yeast metabolism environment through temperature sensors and aeration devices. A constant-temperature fermentation tank can be used in combination with oxygen content monitoring equipment to maintain yeast activity while inhibiting oxidation reactions.

[0027] Specifically, after cleaning and drying, the raw material is pulverized to a predetermined fineness and mixed with malt in a certain proportion to form a homogeneous material. The mixed material is treated in a temperature-controlled saccharification tank with a preset temperature curve. While starch is hydrolyzed to produce fermentable sugars, the cell wall of tartary buckwheat is broken to release flavonoids. The saccharification liquid is separated from the solids by a filter screen and then enters the boiling tank. High-temperature inactivation of enzyme activity and the addition of hops impart flavor, and enzyme preparation promotes the decomposition of high-molecular substances. The cooled wort is introduced into the fermentation tank, and a low-temperature environment is maintained by a temperature control system. The yeast completes the main fermentation and maturation process under low-oxygen conditions.

[0028] Compared with the prior art, the traditional process uses single high-temperature rapid treatment in the saccharification stage, which results in low extraction rate and structural damage of flavonoids. The present application prolongs the dissolution time of flavonoids by controlling the temperature in stages, and forms a protection chain by combining low-temperature fermentation and mild sterilization, effectively reducing thermal degradation and oxidation loss. The existing method directly sterilizes at high temperature after boiling, causing secondary damage to the extracted flavonoids. In the present application, centrifugal filtration is used after fermentation to remove easily oxidizable substances, reducing the heat load demand of the sterilization link.

[0029] By the technical scheme, efficient extraction and stable reservation of the tartary buckwheat flavonoids are realized, the flavonoid content in the finished product reaches the functional standard and the physicochemical properties are stable. The temperature control in the saccharification stage improves the flavonoid dissolution rate, and the optimization of the fermentation parameters inhibits the oxidation side reaction. The method significantly improves the health function properties of the product under the premise of ensuring the taste and shelf life of the beer.

[0030] In implementation, the preset proportion of the tartary buckwheat flour and the malt in step S106 can include that the proportion of the malt is between 73% and 85%, and the proportion of the tartary buckwheat flour is between 5% and 12%.

[0031] The technical features can achieve the following technical effects: (1) Balance of nutritional functionality and sensory quality.

[0032] Although tartary buckwheat is good, it has a bitter taste and a rough texture, and a too high proportion will seriously affect the acceptability of the product; the proportion between 5% and 12% is to ensure the intake of functional ingredients without causing too strong bitterness of the product. The natural sweetness and flavor compatibility of the malt can alleviate the astringency of the tartary buckwheat and improve the overall mouthfeel pleasure.

[0033] (2) The processing performance can be guaranteed. High proportion of malt (73%-85%) can ensure good processing performance, especially in saccharification, heat treatment, pressing, baking and other processes. The malt itself has certain gelation and stability, and when compounded with tartary buckwheat flour, it can improve the texture stability of the product. Tartary buckwheat flour in a high proportion may cause poor dough adhesion, strong fracture, and decreased swelling, so controlling it below 12% is a guarantee of process stability.

[0034] Although the technical features of the preferred embodiment are a proportion setting, it actually involves a complex trade-off mechanism: functionality and sensory acceptability, nutritional density and processing stability.

[0035] Through the proportion setting of the preferred embodiment, in beer brewing, a good product is not only the addition of ingredients, but also the proportion of raw materials (malt and tartary buckwheat flour), which will affect the stability and flavor compatibility of the beer. In implementation, in the saccharification process in step S108, the saccharification temperature is between 60°C and 70°C, and the saccharification time is 60 minutes to 90 minutes.

[0036] This preferred embodiment allows for precise control of the saccharification temperature range, improving the dissolution efficiency of flavonoids. Specifically, flavonoids (such as rutin and quercetin) typically exist in plant cell wall structures as glycosomes or bound forms, and their dissolution depends on cell wall disruption and polysaccharide degradation. The temperature range of 60°C to 70°C represents the peak activity range for α-amylase and β-amylase. These enzymes effectively degrade starch in buckwheat and malt into soluble sugars, while also helping to disrupt cell wall structures and release flavonoids encapsulated in plant tissues. Furthermore, within this temperature range, the activity of residual endogenous polyphenol oxidase in buckwheat cells is low, preventing flavonoids from being oxidized and degraded in the early stages of saccharification, thus increasing the extraction and retention rate. Saccharification within this temperature range not only achieves efficient sugar conversion but also creates an optimal environment for flavonoid extraction. Secondly, the saccharification time in this preferred embodiment is set to 60 to 90 minutes, effectively balancing the extraction rate and enzyme activity stability.

[0037] Specifically, the extraction of flavonoids from plant raw materials into the saccharification liquid requires a certain amount of time. Less than 60 minutes is insufficient to release bound flavonoids, while more than 90 minutes can cause some enzymes to become inactive or lead to thermal degradation of flavonoids, resulting in precipitation or color changes. Furthermore, a longer saccharification time is beneficial for protein hydrolysis, reducing protein turbidity during subsequent fermentation and improving beer clarity. By controlling the time between 60 and 90 minutes, an optimal balance is achieved between enzyme efficiency, flavonoid extraction rate, and flavor harmony.

[0038] In a preferred embodiment, the boiling treatment temperature range can be 95 degrees Celsius to 100 degrees Celsius, and the boiling treatment time can be 60 minutes to 90 minutes.

[0039] This preferred embodiment is a crucial part of the beer brewing process, affecting not only flavor formation and microbial safety, but also directly determining the stability and activity release of functional components (especially flavonoids).

[0040] The temperature range and time in this step ensure complete inactivation of enzyme preparations and endogenous enzyme systems, terminating the saccharification reaction and preventing the accumulation of byproducts. Thorough boiling for 60-90 minutes completely terminates all enzymatic reactions, locking in the nutritional composition of the wort and the extraction state of buckwheat flavonoids, providing a material basis for fermentation stability. Furthermore, boiling at 95-100°C for over 60 minutes provides excellent sterilization conditions, effectively killing common beer bacteria (lactic acid bacteria, acetic acid bacteria, etc.), preventing fermentation contamination by other microorganisms, and providing a highly hygienic wort base for subsequent low-temperature fermentation, reducing the need for preservatives.

[0041] In a preferred embodiment, the fermentation temperature range is 9 to 16 degrees Celsius, the main fermentation time is greater than or equal to 5 days, and the post-fermentation time is greater than or equal to 10 days.

[0042] In this preferred embodiment, the fermentation processing parameters are related to fermentation efficiency and brewing stability, and are key parameters that determine the final taste, flavonoid retention rate, foam structure, flavor purity, and functional health activities.

[0043] This preferred embodiment ensures that the yeast ferments within a stable metabolic range, improving product purity and fermentation integrity. The 9°C–16°C control range precisely maintains a balance between optimal yeast metabolic efficiency and byproduct control, achieving a pure flavor and harmonious body.

[0044] In addition, the primary fermentation time is extended to more than 5 days to ensure that the sugar is completely consumed and that the flavonoids and metabolites are fully integrated. Buckwheat beer contains a large amount of non-malt ingredients (i.e., buckwheat flour), whose sugar source structure is more complex than that of traditional malt, containing more difficult-to-ferment sugars and polysaccharide residues. Extending the primary fermentation time to more than 5 days (e.g., 6-7 days) ensures that the yeast has enough time to complete the conversion of fermentable sugars, reducing the sweet aftertaste and avoiding secondary fermentation or clarification problems in the bottle after bottling.

[0045] Secondly, a post-fermentation (aging) time of ≥10 days can stabilize flavor, precipitate impurities, and improve the clarity of the finished product. Post-fermentation is mainly used to: remove fermentation byproducts such as thiols and aldehydes; promote the sedimentation of protein-polyphenol complexes; complete the flavor blending and foam structure formation of beer; especially for functional beers containing more plant flavonoids and natural proteins, insufficient post-fermentation time will result in cloudy, unstable, and rough-flavored final products; extending the aging time allows the flavonoid and protein complex system to gradually settle, resulting in a bright and clear visual effect. In this embodiment, an aging period of ≥10 days ensures a significant improvement in sensory indicators (color, clarity, foam stability) while enhancing the non-biological stability of the product during shelf life.

[0046] In this preferred embodiment, the temperature range of the fermentation treatment refers to the ambient temperature range in which the yeast's metabolic activity occurs. Specifically, this can be achieved using a constant-temperature fermenter or a segmented temperature control device. This temperature range maintains the yeast's basal metabolic rate while preventing high temperatures from accelerating the oxidative decomposition of flavonoids. The primary fermentation time refers to the main metabolic cycle in which the yeast completes sugar conversion and alcohol production. Specifically, the endpoint can be determined by monitoring changes in the specific gravity of the fermentation broth or the amount of carbon dioxide released. This lower limit ensures that the yeast completes its basal metabolic process. The secondary fermentation time refers to the maturation cycle in which the yeast enters the secondary metabolic stage and promotes the formation of flavor compounds. Specifically, this can be adjusted by controlling the fermenter pressure or periodically sampling and testing the content of flavor compounds. This time setting provides a buffer period for the stable retention of flavonoids.

[0047] Specifically, within a low-temperature environment of 9-16 degrees Celsius, the yeast's metabolic rate remains within a controllable range. This avoids the thermal decomposition of flavonoids caused by high temperatures while maintaining sufficient metabolic activity to complete alcohol conversion. The primary fermentation stage, set at at least 5 days, ensures that the yeast fully consumes fermentable sugars and generates the target alcohol content; for example, the specific gravity of the fermentation broth can drop below a preset threshold by the fifth day. The secondary fermentation stage is extended to over 10 days, allowing the yeast to enter a slow ester synthesis phase after completing its primary metabolism. For example, the accumulation rate of flavor compounds such as ethyl acetate is significantly increased during this stage. Simultaneously, the low-temperature environment reduces oxidase activity; for instance, the activity of polyphenol oxidase is inhibited, thereby reducing the oxidative loss of flavonoids.

[0048] Compared to related technologies, traditional beer fermentation processes typically employ a single fermentation stage with a wide temperature control range. For example, the fermentation temperature for conventional ale yeast is often set between 18-22 degrees Celsius, and the total fermentation cycle is generally shorter than 10 days. While this type of process can achieve alcohol production, the high-temperature environment accelerates the degradation of flavonoids, and the short fermentation cycle cannot create a sufficiently reducing environment to protect the active ingredients. This solution, through the synergistic effect of staged time control and precise temperature range, constructs process conditions conducive to flavonoid retention while ensuring fermentation efficiency.

[0049] Through the above technical solution, this preferred embodiment effectively reduces the thermal degradation rate and oxidative loss of flavonoids while maintaining normal fermentation, solving the technical problem of low retention rate of functional components in traditional processes. By controlling the fermentation cycle in stages, it not only meets the basic metabolic needs but also provides dual protection for the formation of flavor substances and the stability of active ingredients, achieving a balanced optimization of beer quality and functional characteristics.

[0050] In practice, the fermented beer is centrifuged and filtered, and then pasteurized.

[0051] This technological feature is a key aspect of ensuring cleanliness, biostability, taste purity, flavonoid retention, and product shelf life during the preparation of functional beers (especially beers rich in natural plant active ingredients such as flavonoids).

[0052] Centrifugation and filtration effectively remove suspended impurities and residual yeast, improving clarity and visual purity. After fermentation, beer often still contains a large number of dead yeast cells, protein-polyphenol complexes, and incompletely settled fiber particles (especially from buckwheat). Centrifugation pre-clarification quickly removes large particles and high-density turbidity. This improves the beer's color clarity and translucency, enhances sensory grading quality, and ensures controllable final product appearance.

[0053] In this preferred embodiment, centrifugation refers to the removal of yeast cells and large molecular suspensions from the fermentation broth through mechanical separation. Specifically, a disc centrifuge at a speed of 3000-5000 rpm can be used to achieve solid-liquid separation, which reduces the contact area between impurities and the heat source during subsequent sterilization. Filtration refers to the use of porous media to trap small particles. Specifically, a diatomaceous earth filter or membrane filtration device can be used to clarify the liquid, which improves the light transmittance and non-biological stability of the beer and prevents the generation of off-flavor substances from heated particles during sterilization. Pasteurization is a heat treatment process with precise temperature control. Specifically, a plate heat exchanger can be used to heat the beer to 60-65 degrees Celsius and maintain this temperature for 10-30 minutes. This process inactivates microorganisms while reducing the thermal decomposition rate of flavonoids by shortening the high-temperature exposure time.

[0054] Specifically, after primary and secondary fermentation, the beer liquor contains residual yeast and protein aggregates. After centrifuging to remove over 80% of the solid impurities, a filtration system with a pore size of 1-5 microns is used to further remove submicron particles, reducing the liquid turbidity to below 1.0 EBC. The clarified liquid is then introduced into a pasteurization unit, where a PID temperature control module raises the liquid temperature to the target temperature at a rate of 2-3 degrees Celsius per minute and maintains it at that temperature for a preset time to achieve a cumulative PU value of 10-15. This staged treatment method reduces the sterilization load through physical purification, while gradient heating prevents flavonoids from undergoing structural isomerization due to rapid heating.

[0055] Compared to related technologies, traditional pasteurization processes typically involve treatment at temperatures above 70 degrees Celsius for over 30 minutes, resulting in a flavonoid loss rate exceeding 40%. This solution, however, reduces the microbial load through pre-centrifugal filtration, allowing for a 5-10 degree Celsius reduction in sterilization temperature and a more than 50% reduction in processing time. While maintaining the same sterilization efficiency, it increases the flavonoid retention rate to over 85%. Related technologies do not disclose the synergistic application of centrifugal filtration and low-temperature short-time sterilization, and particularly do not address the technical means of dynamically controlling and balancing sterilization intensity and component retention through PU value.

[0056] Through the above technical solution, the technical solution in this embodiment achieves the goal of increasing the retention rate of total flavonoids from 50-60% in traditional processes to over 80% while ensuring that the microbial indicators of beer meet the GB4927-2008 standard. At the same time, it ensures that the turbidity increase of the finished beer after 6 months of storage at 25 degrees Celsius does not exceed 0.5 EBC (European brewing units), effectively solving the contradiction between the retention of functional components and the shelf life of the product.

[0057] Preferably, pasteurization involves heating the beer to 60-65°C and controlling the pasteurization unit (PU) to be greater than or equal to 10 within a predetermined time. Furthermore, pasteurization is controlled at 60-65°C, which effectively sterilizes while preserving the activity of functional components. Pasteurization is a classic thermal sterilization method suitable for products with high requirements for heat-sensitive substances. By controlling the temperature within the range of 60-65°C and a PU value ≥10, residual pathogenic and spoilage bacteria in the beer can be effectively killed without damaging the following components: flavonoid polyphenol structures; dietary fiber-related metabolites from buckwheat; and volatile aroma components derived from hops. This embodiment balances microbial safety and functional activity preservation, minimizing nutrient loss and flavor deterioration during the sterilization process.

[0058] The pasteurization temperature range refers to controlling the temperature of the beer during the pasteurization stage between 60°C and 65°C. This can be achieved using segmented heating or a constant temperature control device. This temperature range can inhibit microbial activity while preventing the thermal decomposition of flavonoids. The PU value refers to Pasteurization Units, which are calculated by integrating temperature and time. For example, maintaining a temperature of 62°C for 20 minutes or 65°C for 10 minutes. This parameter quantifies the pasteurization intensity to ensure that the microbial inactivation effect meets the standards.

[0059] Specifically, during pasteurization, the temperature is limited to a low range of 60 to 65 degrees Celsius. Within this range, the duration is adjusted to maintain a PU value of 10 or higher. For example, when the pasteurization temperature is set to 62 degrees Celsius, the time required to maintain this temperature needs to be extended to 20 minutes to meet the PU ≥ 10 requirement; when the temperature is increased to 65 degrees Celsius, the maintenance time can be shortened to 10 minutes. This dynamic temperature-time matching mechanism ensures sterilization efficiency while reducing the risk of thermal degradation of flavonoids by shortening the high-temperature exposure time. Plate heat exchangers are used for precise temperature control during the sterilization process to ensure consistency of processing parameters across batches of products.

[0060] Compared to related technologies, traditional pasteurization typically involves high-temperature treatment at above 70 degrees Celsius for 15-30 minutes. While effective sterilization, this results in a loss of over 30% of flavonoids. This solution, by lowering the processing temperature and introducing PU value control, achieves a flavonoid retention rate of over 85% while maintaining the same sterilization effect. Existing technologies lack a quantitative relationship between sterilization intensity and functional component retention; this solution, for the first time, uses PU value as a core indicator for process control, achieving dual optimization of sterilization effect and component protection.

[0061] Through the above technical solution, this application effectively solves the problem of flavonoid degradation caused by high-temperature sterilization, ensuring the microbial safety of beer while maintaining the functional index requirements for flavonoid retention in the finished product. Testing showed that beer samples using this sterilization process maintained over 90% of their initial flavonoid content after three months of storage, confirming the stabilizing and protective effect of this method on functional components.

[0062] In practice, hops can include blended-aroma hops. Blended-aroma hops can harmonize the unique botanical flavor of buckwheat, achieving a flavor balance in functional beers. Buckwheat itself has a distinct vegetal astringency and mild bitterness, sometimes with a slight roasted or grainy aroma. If the hop selection is inappropriate, it can easily lead to flavor clashes, disordered aroma layers, or a thin mouthfeel. Blended-aroma hops possess both bitterness intensity and aromatic substance release capabilities. They can provide a balanced bitterness while also creating a synergistic effect with the grainy aroma of buckwheat. Blended-aroma hops can avoid excessive bitterness caused by the superposition of the botanical bitterness of buckwheat and the bitterness of hops, achieving a smoother mouthfeel and a more complex flavor profile, enhancing the drinking pleasure of functional products.

[0063] Preferably, the malt includes barley malt. Barley malt has good fermentation properties, can provide sufficient sugar source for yeast, ensure the smooth progress of the fermentation process, and further improve the brewing efficiency and final taste of beer.

[0064] Barley malt refers to raw materials prepared from barley through germination, drying, and roasting processes. This can be achieved by controlling the soaking degree, germination temperature, and drying temperature during the malting process. Barley malt is rich in amylase and fermentable sugars, which can synergistically work with buckwheat flour during the saccharification stage, promoting the dissolution of flavonoids from the buckwheat cell walls. The protein content of barley malt is well-matched to the saccharification temperature, preventing the formation of turbid substances due to excessive protein decomposition.

[0065] Specifically, when barley malt and buckwheat flour are mixed, during the saccharification process, the amylase in the barley malt converts starch into fermentable sugars. Simultaneously, the released sugars form stable bonds with the flavonoids in the buckwheat flour. The protein content of the barley malt is controlled within a specific range to prevent excessive decomposition at the saccharification temperature, reducing the formation of turbidity precursors and ensuring the clarity of the fermentation liquid. The unique flavor compounds of barley malt interact with the flavonoids in buckwheat to create a harmonious and complex aroma, enhancing the taste while preserving the functional components.

[0066] Compared to related technologies, traditional brewing methods often use wheat malt or other grain malts, which have a high protein content and are prone to producing excessive soluble nitrogen compounds during saccharification, leading to turbidity in the fermentation broth and flavor imbalance. The enzyme activity and protein composition of barley malt have been optimized to promote flavonoid extraction while maintaining system stability and avoiding interference from non-target components.

[0067] Through the above technical solution, this application solves the problem of the impact of malt selection on flavonoid extraction efficiency and beer quality stability, achieves efficient dissolution of flavonoids, maintains the clarity of fermentation liquid, and enhances the harmony of beer flavor.

[0068] Barley malt refers to raw materials prepared from barley through germination, drying, and roasting processes. This can be achieved by controlling the soaking degree, germination temperature, and drying temperature during the malting process. Barley malt is rich in amylase and fermentable sugars, which can synergistically work with buckwheat flour during the saccharification stage, promoting the dissolution of flavonoids from the buckwheat cell walls. The protein content of barley malt is well-matched to the saccharification temperature, preventing the formation of turbid substances due to excessive protein decomposition.

[0069] Specifically, when barley malt and buckwheat flour are mixed, during the saccharification process, the amylase in the barley malt converts starch into fermentable sugars. Simultaneously, the released sugars form stable bonds with the flavonoids in the buckwheat flour. The protein content of the barley malt is controlled within a specific range to prevent excessive decomposition at the saccharification temperature, reducing the formation of turbidity precursors and ensuring the clarity of the fermentation liquid. The unique flavor compounds of barley malt interact with the flavonoids in buckwheat to create a harmonious and complex aroma, enhancing the taste while preserving the functional components.

[0070] Compared to related technologies, traditional brewing methods often use wheat malt or other grain malts, which have a high protein content and are prone to producing excessive soluble nitrogen compounds during saccharification, leading to turbidity in the fermentation broth and flavor imbalance. The enzyme activity and protein composition of barley malt have been optimized to promote flavonoid extraction while maintaining system stability and avoiding interference from non-target components.

[0071] Through the above technical solution, this application solves the problem of the impact of malt selection on flavonoid extraction efficiency and beer quality stability, achieves efficient dissolution of flavonoids, maintains the clarity of fermentation liquid, and enhances the harmony of beer flavor.

[0072] Preferably, the total flavonoid content of beer is measured using ultraviolet-visible spectrophotometry, with rutin as a reference, a measurement wavelength of 510 nm, and the sample concentration controlled within the range of 0.1 to 0.4 (a standard curve is plotted with absorbance as the ordinate and concentration as the abscissa, and absorbance is measured at a wavelength of 510 nm). The concentration is calculated using the following formula: ; Where c is the total flavonoid concentration in mg / mL, X is the concentration value corresponding to the standard curve of UV-Vis spectrophotometry, and V is the sampling volume of beer in mL.

[0073] The ultraviolet-visible spectrophotometry method is a quantitative analysis method based on the characteristic of flavonoids reacting with chromogenic agents to form colored complexes. Specifically, it can be achieved by using rutin as a standard substance to establish a standard curve. This method enables rapid detection through the linear relationship between absorbance and concentration. Using rutin as a reference means using rutin as a reference standard for flavonoids. This can be achieved by preparing rutin standard solutions of different concentrations and plotting a standard curve, ensuring the comparability and universality of the detection results. The measurement wavelength of 510 nm refers to selecting the maximum absorption wavelength of the colorimetric reaction product as the detection wavelength. This can be achieved by determining the maximum absorption peak of the rutin-aluminum nitrate complex through spectral scanning, avoiding interference from other components. The A510 value range of 0.1–0.4 means controlling the sample absorbance within the linear range of Lambert-Beer's law. This can be achieved by adjusting the sample dilution factor or sampling volume, avoiding precipitation errors caused by excessive concentration. The calculation formula C=X×25 / V refers to converting the concentration value corresponding to the standard curve into the total flavonoid concentration of the actual sample. Specifically, it can be calculated by the ratio of the fixed volume to the sampling volume. This formula can establish a mathematical relationship between absorbance and concentration.

[0074] Specifically, after adding a colorimetric reagent to the beer sample, flavonoids form a stable complex with aluminum nitrate. By measuring the absorbance at a wavelength of 510 nm and combining this with a pre-established rutin standard curve, the concentration of total flavonoids in the sample can be calculated. The sample dilution factor is controlled within the A510 value range of 0.1 to 0.4 to ensure that the detection is within the linear response range. The X value in the standard curve is converted into the actual concentration using the formula C = X × 25 / V, achieving accurate conversion from absorbance to functional component content. This method, through standardized colorimetric reaction conditions and the establishment of a mathematical model, solves the problem of the inability to quantitatively verify flavonoid content in traditional processes.

[0075] In some specific embodiments, after degassing, 2 ml of the beer sample is taken, and sodium nitrite and aluminum nitrate are added for colorimetric reaction. The volume is then adjusted to 25 ml, and the absorbance is measured. The standard curve is plotted by preparing a 0.25 mg / ml rutin working solution, serially diluting it, developing the color, and measuring the absorbance. Its linear equation is y = 8.002x + 0.0329, and the correlation coefficient R0 is [missing value]. 2 It is 0.9965.

[0076] Compared to related technologies, the latter lacks a clearly defined absorbance range for the colorimetric reaction, leading to precipitation interference in high-concentration samples. Furthermore, the absence of standardized calculation formulas results in a lack of comparability between different batches of test results. This proposed solution improves the accuracy and repeatability of test results by defining the A510 detection range and establishing a clear mathematical conversion formula. Simultaneously, the use of rutin as a unified reference material ensures cross-laboratory comparability of the test data.

[0077] Through the above technical solution, this embodiment achieves accurate quantitative detection of flavonoids in beer, ensuring that the flavonoid content of each batch of products meets the functional standards, providing data support for process parameter optimization, and meeting the industry standard requirements for traceability of detection methods.

[0078] Preferably, the flavonoid content of the beer is greater than 30 mg per liter. This target of increasing flavonoid content ensures the antioxidant and immune-enhancing functions of the beer, meeting market demand for healthy beverages.

[0079] Flavonoid content refers to the concentration of total flavonoids with rutin as a reference, determined by ultraviolet-visible spectrophotometry. Quantitative analysis can be performed using a standard curve method, such as measuring absorbance at a wavelength of 510 nm and calculating the concentration value, which serves as a quality control indicator. 30 mg / L is the minimum threshold for flavonoid content in the finished beer product. This can be achieved by adjusting the raw material ratio, saccharification temperature and time, fermentation conditions, and sterilization parameters. For example, controlling the proportion of buckwheat flour between 5% and 12% and maintaining the saccharification temperature between 60°C and 70°C optimizes flavonoid dissolution.

[0080] Specifically, the quantitative standard for flavonoid content is achieved through the following collaborative processes: In the raw material selection stage, buckwheat is the main source of flavonoids, and its particle size affects the dissolution efficiency; in the saccharification stage, temperature and time control balances amylase activity and flavonoid stability; in the fermentation stage, low-temperature, long-term fermentation reduces flavonoid degradation; and in the sterilization stage, pasteurization is employed and the PU value is controlled to reduce the loss of heat-sensitive components. Through precise control of parameters at each stage, the flavonoid content ultimately exceeds the limits set by traditional processes.

[0081] Compared to related technologies, traditional beer brewing processes do not set standards for flavonoid content, and the saccharification and fermentation parameters are not optimized for the retention of plant active ingredients, resulting in low flavonoid extraction rates and large fluctuations in the content of the finished product. This solution, by setting a clear lower limit for flavonoid content and combining it with targeted adjustments to process parameters, achieves stable retention of functional components, solving the problem of uncontrollable functional indicators caused by insufficient process control in traditional methods.

[0082] Through the above technical solution, this application effectively solves the problem of degradation and loss of flavonoids in beer caused by improper process conditions, and ensures the verifiability of the product's antioxidant and health functions through quantitative indicators. This standard provides a clear testing benchmark for the production process, enabling the quality of functional beer to be controlled through standardized testing methods, thereby meeting the market's functional demand for healthy beverages.

[0083] This application provides a brewing method for a high-flavonoid-content functional beer based on buckwheat. The method includes the following steps: First, high-quality buckwheat is selected as the main raw material and subjected to washing and drying. Then, the treated buckwheat is pulverized to obtain buckwheat flour. Next, the buckwheat flour is mixed with malt, hops, and water in a certain proportion and subjected to saccharification treatment, controlling the saccharification temperature and time to ensure the effective extraction of flavonoids from the buckwheat. Next, a filtration and boiling process is carried out, adding hops and, during the boiling process, adding enzyme preparations as needed to improve enzymatic hydrolysis efficiency. Subsequently, cooling and fermentation steps are performed, controlling the fermentation temperature and time to ensure full fermentation. Finally, the fermented beer is filtered and pasteurized, and then bottled. The brewing method of this application can effectively retain the flavonoids in buckwheat, producing a functional beer with a high flavonoid content, good taste and nutritional value, and suitable for general consumption.

[0084] This embodiment provides a beer brewing method that can brew functional beer with high flavonoid content based on buckwheat. This embodiment may include the following steps: Step a. Select buckwheat as the main raw material and clean and dry it.

[0085] Step b. Grind the dried buckwheat into buckwheat powder using a grinding equipment.

[0086] Step c. Mix buckwheat flour with malt, hops and water in a preset ratio, and perform saccharification to extract flavonoids from buckwheat.

[0087] Step d. Perform the filtration and boiling process, add hops, and add enzyme preparations as needed.

[0088] Step e. Cool the mixture and ferment it, controlling the yeast inoculation amount, yeast contact time with oxygen, fermentation temperature and time to ensure yeast activity.

[0089] Step f. Centrifuge and filter the fermented beer, then pasteurize it after bottling.

[0090] In a preferred embodiment, the hops used in this example are mixed-aroma hops.

[0091] During implementation, the malt can be barley malt.

[0092] In a preferred embodiment, the saccharification process in this example includes controlling the saccharification temperature between 60°C and 70°C for a time of 60 to 90 minutes.

[0093] During implementation, in step d, the boiling temperature can be between 95°C and 100°C, and the time can be between 60 and 90 minutes.

[0094] In step e, the fermentation temperature can be between 9°C and 16°C, the primary fermentation time can be greater than or equal to 5 days, and the secondary fermentation time can be greater than or equal to 10 days.

[0095] Preferably, pasteurization may include heating the beer to 60°C to 65°C and holding it for the corresponding time so that the pasteurization PU calculation result is greater than or equal to 10.

[0096] Preferably, the beer contains more than 30 mg of flavonoids per liter.

[0097] The beer brewed through the above embodiments has a high flavonoid content, giving it antioxidant properties and the ability to enhance the function of the immune system.

[0098] This embodiment provides a beer brewing method based on the high flavonoid content of buckwheat to create a functional beer. The method is described in detail below.

[0099] In this embodiment, beer brewing may include the following steps: Step 1: Raw material selection and processing.

[0100] In this step, high-quality buckwheat is selected as the main raw material, thoroughly cleaned and dried, and then pulverized into buckwheat flour.

[0101] Step 2: Mix the raw materials.

[0102] In this step, buckwheat flour is mixed with malt, hops and water in a preset ratio.

[0103] Step 3, saccharification.

[0104] In this step, saccharification is performed at a preset temperature and time to release flavonoids from tartary buckwheat.

[0105] Step 4, Boil and add.

[0106] In this step, the mixture is boiled, and appropriate amounts of hops and enzymes are added to enhance aroma and extraction, promote the flocculation of polyphenols, proteins and other substances, and ensure the non-biological stability of the liquid.

[0107] Step 5, fermentation.

[0108] In this step, the treated mixture is cooled and fermented, with control over the yeast inoculation amount, yeast-oxygen contact time, fermentation temperature, and time.

[0109] Step 6, filtration and processing.

[0110] In this step, the fermented beer is centrifuged and filtered to obtain a clear, stable clear beer liquid for bottling and pasteurization to ensure product stability and food safety.

[0111] Through the technical solutions in the above embodiments and their preferred embodiments, the brewed beer has a relatively high flavonoid content, which can possess antioxidant and other health functional properties, thus meeting consumers' demand for functional beverages.

[0112] As a preferred embodiment, the total flavonoid content of brewed beer can be measured, for example, by using ultraviolet-visible spectrophotometry. The detection method (measurement of total flavonoid content (calculated as rutin) by ultraviolet-visible spectrophotometry) is described in detail below.

[0113] In this embodiment, the measurement can be performed using the following steps: Step 1: Solution Preparation. In this step, the rutin stock solution and the rutin working solution are prepared.

[0114] In this step, the rutin stock solution is prepared. Accurately weigh 0.1000g of anhydrous rutin into a 100mL volumetric flask, add an appropriate amount of 60% ethanol, dissolve in a 45℃ water bath, cool, and dilute to volume with 60% ethanol. The resulting rutin stock solution is 1mg / mL.

[0115] In this step, the rutin working solution is prepared. Accurately transfer 12.5 mL of rutin stock solution into a 50 mL volumetric flask, dilute to the mark with 60% ethanol, and shake well to obtain a 0.25 mg / mL rutin working solution.

[0116] Step 2: Creating the standard curve.

[0117] In this step, ten 25 mL volumetric flasks were divided into two groups, A and B. Group A was filled with 1.0, 2.0, 3.0, 4.0, and 5.0 mL of rutin working solution, respectively, and diluted to 25 mL with 60% ethanol as a reference solution. Group B was filled with 1.0, 2.0, 3.0, 4.0, and 5.0 mL of rutin working solution, followed by the addition of 1 mL of 4% NaNO₂ solution. After reacting for 6 minutes, 1 mL of 10% Al(NO₃)₃ solution was added, and the reaction was continued for another 6 minutes. Finally, 10 mL of 4% NaOH solution was added. The mixture was then diluted to volume with 60% ethanol, shaken well, and allowed to stand for 12 minutes before measuring A510.

[0118] like Figure 2 As shown, Figure 2 The standard curve is: y = 8.002x + 0.0329; R0 2 = 0.9965 Y: A510 X: Total flavonoid content (mg / mL), R 2 It is the correlation coefficient of the linear regression equation, used to determine the linear correlation of the standard curve. Generally, R0... 2 The value is greater than 0.99.

[0119] The detection limit for A is 0.1-0.6, and it is generally diluted between 0.1-0.4. If the concentration is too high, red flocculent precipitate will be produced, which will affect the measurement data.

[0120] Step 3. Sample Determination This step may include the following steps: (1) Blank: Take 2 mL of wine sample (shake well and degas), and dilute to 25 mL with 60% ethanol.

[0121] (2) Sample measurement: Take 2 mL of wine sample (shake well and degas), put it into a 25 mL volumetric flask, then add 1 mL of 4% NaNO2 solution, react for 6 minutes, then add 1 mL of 10% Al(NO3)3 solution, react for another 6 minutes, then add 10 mL of 4% NaOH solution. Make up to volume with 60% ethanol, shake well and let stand for 12 minutes, then measure A510.

[0122] It should be noted that in the above embodiments, the total flavonoid concentration was calculated using the following formula: , The corresponding units are explained below: C—Total flavonoid concentration, mg / mL; X—Content obtained from the standard curve, mg / mL; 25 — Fixed volume, mL; V — Sampling volume, mL.

[0123] Preferred embodiment In this embodiment, a beer brewing method is provided, which may include the following steps: Step 1: Select 500 grams of high-quality buckwheat, wash, dry and grind it into powder.

[0124] Step 2: Mix 1000g of buckwheat flour with 2000g of barley malt, 200g of hops and 5000ml of water.

[0125] Step 3: Saccharify the above mixture at 60°C for 90 minutes.

[0126] Step 4: Heat the mixture to 90°C and bring it to a boil, then add 100 grams of hops and an appropriate amount of enzyme preparation.

[0127] Step 5: After cooling to 9°C, add brewer's yeast and start fermentation at 18°C ​​for 17 days.

[0128] Step 6: Filter the beer and pasteurize it with a PU of 10 to ensure biological stability.

[0129] Preferably, the beer brewed using the technical solution of this embodiment is tested for total flavonoids (calculated as rutin) using ultraviolet spectrophotometry. The absorbance value is 0.23946, and the result calculated according to the standard curve is 0.0258 mg / mL. The final result is 0.0258*25 / 2=0.3225 mg / mL, which means that the final product contains 322.5 mg / L of flavonoids. The final product contains more than 30 mg of flavonoids per liter, and has antioxidant and immune-enhancing functions.

[0130] This invention provides a brewing method for a functional beer with high flavonoid content based on buckwheat, which can effectively improve the functional properties of beer and meet market demand.

[0131] Through the above embodiments and preferred embodiments, this application provides a beer brewing method. The method involves selecting high-quality buckwheat as the main raw material, washing and drying it; then, pulverizing the treated buckwheat to obtain buckwheat flour; next, mixing the buckwheat flour with malt, hops, and water in a certain proportion and performing saccharification treatment, controlling the saccharification temperature and time to ensure the effective extraction of flavonoids from the buckwheat; next, performing a filtration and boiling process, adding hops, and adding enzyme preparations at appropriate times during boiling to improve enzymatic hydrolysis efficiency; subsequently, performing cooling and fermentation steps, controlling the fermentation temperature and time to ensure full fermentation; finally, filtering and pasteurizing the fermented beer, and then bottling it. This brewing method effectively retains the flavonoids in buckwheat, producing a functional beer with high flavonoid content, good taste and nutritional value, suitable for general consumption.

[0132] Through the above technical solution, this application effectively solves the problem of degradation and loss of flavonoids in beer caused by improper process conditions, and ensures the verifiability of the product's antioxidant and health functions through quantitative indicators. This standard provides a clear testing benchmark for the production process, enabling the quality of functional beer to be controlled through standardized testing methods, thereby meeting the market's functional demand for healthy beverages.

[0133] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for brewing beer, characterized in that, include: The buckwheat is pretreated, wherein the buckwheat is a functional raw material for beer brewing; The tartary buckwheat is crushed to obtain tartary buckwheat powder; The buckwheat powder and malt are mixed in a preset ratio, and hops and drinking water are added to obtain a mixture. The mixture is subjected to saccharification at a preset temperature and a preset time. The saccharified liquid obtained by the saccharification process is boiled, wherein hops and enzyme preparations are added during the boiling process. The liquid obtained from the boiling process is cooled, and the cooled liquid is fermented to obtain beer.

2. The brewing method according to claim 1, characterized in that, During the saccharification process, the saccharification temperature is between 60°C and 70°C, and the saccharification time is between 60 minutes and 90 minutes.

3. The brewing method according to claim 1, characterized in that, The boiling treatment is performed at a temperature range of 95 degrees Celsius to 100 degrees Celsius for a duration of 60 to 90 minutes.

4. The brewing method according to claim 1, characterized in that, The temperature range of the fermentation treatment is 9 degrees Celsius to 16 degrees Celsius, the main fermentation time is greater than or equal to 5 days, and the post-fermentation time is greater than or equal to 10 days.

5. The brewing method according to claim 1, characterized in that, Also includes: The fermented beer is centrifuged and filtered, and then pasteurized.

6. The brewing method according to claim 5, characterized in that, The pasteurization process includes heating the beer to 60 to 65 degrees Celsius and controlling the pasteurization process within a predetermined time to achieve a pasteurization unit (PU) greater than or equal to 10.

7. The brewing method according to any one of claims 1 to 6, characterized in that, The hops include mixed-aroma hops.

8. The brewing method according to any one of claims 1 to 6, characterized in that, The malt includes barley malt.

9. The brewing method according to any one of claims 1 to 6, characterized in that, The total flavonoid content of the beer was measured using ultraviolet-visible spectrophotometry, with rutin as a reference. The measurement wavelength was 510 nm, and the sample concentration was controlled within the range of A510 value from 0.1 to 0.

4. The content was calculated using the following formula: ； Where c is the total flavonoid concentration in mg / mL, X is the concentration value corresponding to the standard curve of UV-Vis spectrophotometry, V is the sampling volume of the beer in mL, and A510 is the absorbance measured at a wavelength of 510 nm on the standard curve obtained with absorbance as the ordinate and concentration as the abscissa.

10. The brewing method according to any one of claims 1 to 6, characterized in that, The beer contains more than 30 milligrams of flavonoids per liter.

11. The brewing method according to any one of claims 1 to 6, characterized in that, The preset ratio of buckwheat flour and malt includes: the proportion of malt is between 73% and 85%, and the proportion of buckwheat flour is between 5% and 12%.

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