A method of brewing a low mineral beer

Abstract

The application discloses a brewing method of low-mineral beer, and belongs to the technical field of beer brewing. The method disclosed by the application reduces from the source, optimizes the process, removes key ions, and compensates for the flavor from multiple angles, so that the final product is not only low in mineral content, but also has coordinated flavor and full taste. Not only can the total mineral content be reduced, but also specific ions which have greater impact on health can be accurately controlled. The method disclosed by the application comprises multiple process modules, and enterprises can select to apply all or part of the technology according to their own conditions (equipment, cost), so that the method is easy to be industrialized and popularized.

Description

Technical Field

[0001] This invention relates to a brewing method for low-mineral beer, belonging to the field of beer brewing technology. Background Technology

[0002] Minerals in beer, such as sodium + (Sodium), K + (Potassium), Ca² + (Calcium), Mg² + (Magnesium), SO4² - (sulfate), PO4³ - Phosphate, oxalate, and other compounds are mainly derived from brewing water, malt, and hops. Excessive intake increases the osmotic burden on the kidneys, affects the body's electrolyte balance, and is associated with certain health risks, such as gout.

[0003] Currently, the "light beer" sold on the market is mainly beer with reduced alcohol and calories, rather than beer specifically designed to reduce minerals. Simply using distilled water for brewing can lead to problems such as a collapse of the beer's flavor structure (e.g., bland taste, unbalanced flavor), insufficient yeast nutrition, and low saccharification efficiency. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides a brewing method for low-mineral beer, aiming to solve the technical problem of the contradiction between "reducing minerals" and "preserving flavor" in existing beer brewing.

[0005] The first technical solution provided by this invention is a brewing method for low-mineral beer, comprising the following steps: (1) Pretreatment of malt and brewing water Select a specialty malt with low mineral content as the base malt; Further acid washing pretreatment is carried out on malt with low mineral content: soak the malt in acidic water with pH 4.0-5.0 at low temperature (<30℃) for 30-60 minutes, and then drain the water; this operation can effectively dissolve some of the potassium, calcium, phosphate and other minerals on the surface of the malt. Brewing water treatment: Use reverse osmosis water or deionized water as the base brewing water, controlling its total dissolved solids (TDS) value to <50 mg / L, total ion concentration to <300 mg / L, and sodium ion concentration to <20 mg / L; then precisely add trace amounts of yeast-essential ions, including at least 5-15 μg / L Zn. 2+ 20-50 mg / L Ca 2+ 10-30 mg / L Mg 2+ ; (2) Brewing Saccharification: Food-grade acid is added to the brewing water to control the pH of the saccharified mash at 5.2-5.4; this environment is conducive to enzyme activity, improves saccharification efficiency, and reduces the dissolution of undesirable substances. Boiling and sedimentation: Dynamic boiling technology is used to control the boiling intensity and promote the full release of thermal coagulated material and protein-polyphenol complex. During this process, thermal coagulated material and protein-polyphenol complex will bind some mineral ions, which are then removed by vortex precipitation. Fermentation process: Inoculate with brewer's yeast and ferment at 10-15℃ for 7-14 days; (3) Post-processing After fermentation and before filtration, the wine is post-treated using ion exchange resin or selective electrodialysis. (4) Flavor compensation and modification Flavor substance recovery: Collect, purify, and concentrate the flavor substances that volatilize from the boiling condensate in the previous process, and add them back to the wine. Before bottling, very low doses of natural hop oils, extracts, or other natural flavor compounds (such as yeast-derived beta-glucan to enhance body) are added to precisely compensate for and modify the flavors lost due to reduced minerality, thus reshaping the body structure of the spirit.

[0006] In some embodiments, the low protein and low mineral content means that the protein content is in the range of 8-10% (dry basis) and the mineral content (as ash) is in the range of 1.0-1.5%.

[0007] In some implementations, the total dissolved solids (TDS) value of the base brewing water is controlled to be <20 mg / L in brewing water treatment.

[0008] In some embodiments, the organic acid includes lactic acid.

[0009] In some embodiments, the dynamic boiling technology controls the boiling intensity by maintaining the boiling temperature at 100-102°C and the boiling time at 60-90 minutes, using intermittent stirring or a circulating pump to promote heat exchange, and controlling the evaporation rate at 8-12% per hour.

[0010] In some embodiments, the cyclone precipitation is carried out at a temperature of 80-90°C for 20-30 minutes.

[0011] In some embodiments, the brewer's yeast is preferably selected from brewer's yeast strains that have low mineral requirements, stable flavor metabolism, and purity, such as brewer's yeast tolerant to low calcium and magnesium ions (e.g., lager yeast strain W34 / 70); the fermentation temperature and cycle are precisely controlled to ensure complete fermentation.

[0012] In some embodiments, the brewer's yeast is a low-sodium, low-mineral brewer's yeast, and the preparation method of the low-sodium, low-mineral brewer's yeast includes the following steps: S1, the activated brewing yeast is inoculated into a culture system containing sterilized wort, cultured to the late logarithmic growth stage, and the pretreated yeast sludge is collected by centrifugation; S2, the pretreated yeast sludge in S1 is washed by centrifugation with deionized water multiple times to obtain washed yeast sludge; S3, the washing yeast sludge in S2 is placed in a potassium-rich washing solution for ion exchange, and centrifuged to obtain the exchanged yeast sludge. S4. The replacement yeast sludge from S3 is washed again by centrifugation with deionized water to obtain low-sodium, low-mineral brewer's yeast.

[0013] In some embodiments, the pretreatment specifically includes the following steps: selecting a suitable brewing yeast strain (Saccharomyces cerevisiae) for beer fermentation, activating it on a plate, inoculating it into an Erlenmeyer flask containing 10-12°P wort, and shaking it at 25-28°C for 18-24 hours to obtain a primary seed culture; Transfer the primary seed culture at an inoculation rate of 5-10% to a fermenter containing sterilized wort and incubate at 20-22℃ for 36-48 hours until the late logarithmic growth stage. Collect the pretreated yeast sludge by centrifugation (centrifugation conditions: 3000-5000 rpm, 5-10 minutes).

[0014] In some embodiments, in S2, the pretreated yeast slurry is suspended in sterile deionized water at 4-10°C at a mass-to-volume ratio of 1:5 to 1:10 (g / mL) and gently stirred for 10-15 minutes.

[0015] In some embodiments, in S2, the yeast is centrifuged (3000-5000 rpm, 5-10 minutes), the supernatant is discarded, and the yeast precipitate is collected. This washing process is repeated 3-5 times to fully remove sodium ions and other mineral ions adsorbed on the surface of yeast cells and the outer layer of the cell wall.

[0016] In some embodiments, a potassium-rich washing solution is prepared: a solution containing 50-200 mmol / L potassium chloride (KCl) is prepared using deionized water. The concentration can be adjusted according to the characteristics of the yeast strain, with a preferred range of 80-150 mmol / L. The solution temperature is controlled at 4-10°C.

[0017] In some embodiments, in S3, the washing yeast sludge is suspended in the above potassium-rich washing solution at a mass-to-volume ratio of 1:5 to 1:20 (g / mL); Treat with gentle stirring at 4-15°C for 30-120 minutes, preferably 60-90 minutes. During this process, potassium ions replace sodium ions bound within the yeast cells through competitive displacement.

[0018] In some implementations, in S3, after the replacement is completed, the replaced yeast slurry is collected by centrifugation (3000-5000 rpm, 5-10 minutes).

[0019] In some embodiments, in S4, the yeast sludge treated with potassium ion replacement is washed again with sterilized deionized water at 4-10°C 1-2 times (washing ratio 1:5~1:10, centrifugation conditions as above) to remove residual potassium ion solution.

[0020] In some embodiments, in step S4, the final low-sodium yeast slurry is suspended in an appropriate amount of sterilized deionized water or low-temperature (0-4°C) diluted wort to achieve a concentration of (1.0-2.0) × 10⁻⁶. 8 1 live cells / mL, stored at 0-4℃ for later use. Storage time should not exceed 72 hours.

[0021] In some embodiments, the brewing yeast is *Saccharomyces cerevisiae* WLP001 or *Lagomonas lagius* W34 / 70.

[0022] In some embodiments, when using an ion exchange resin, para-oxalate ions (C2O4) are used. 2- ), phosphate ions (PO4) 3- A highly selective adsorption resin is packed into a column reactor, allowing the wine to pass through the column for targeted removal of target ions; the resin is effective against oxalate ions (C2O4). 2- ), phosphate ions (PO4) 3- Highly selective adsorption resins can be strong base anion exchange resins such as Amberlite IRA-400, Lewatit MP-500, and Dowex 1x2.

[0023] In some embodiments, when selective electrodialysis is used, under the influence of an electric field, the selective permeability of the ion exchange membrane is utilized to remove ions of a specific valence state (such as K+) from the wine. + Na + SO4 2- The ion exchange membrane can be an anion exchange membrane, such as Neosepta AMX, a cation exchange membrane, such as Neosepta CMX, or a selective membrane, such as Fumasep FAB.

[0024] The second technical solution provided by this invention is a beer brewed using the low-mineral beer brewing method described in the first technical solution. The total dissolved solids content is ≤ 600 mg / L, lower than the 800-1500 mg / L of traditional beer; potassium ion content is ≤ 300 mg / L; sodium ion content is ≤ 50 mg / L; sulfate ion content is ≤ 150 mg / L; and phosphate ion content is ≤ 300 mg / L. Furthermore, the beer's original wort concentration, alcohol content, color, bitterness, and other conventional indicators meet national standards. Sensory evaluation shows that its flavor, body, and carbonation are not significantly different from ordinary beers of the same type, and may even be purer.

[0025] The third technical solution provided by this invention is the application of the method described in the first technical solution in the field of brewing.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: The method disclosed in this invention addresses this issue from multiple angles, including source reduction, process optimization, targeted removal of key ions, and flavor compensation, ensuring that the final product not only has low mineral content but also a harmonious flavor and full-bodied taste. It not only reduces total minerals but also precisely controls specific ions that have a significant impact on health.

[0027] The method disclosed in this invention includes multiple process modules, and enterprises can choose to apply all or part of the technology according to their own conditions (equipment, cost), which is easy to promote industrialization. Detailed Implementation

[0028] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0029] Test method: 1. Methods for detecting ions: Ion content (Na) + , K + , Ca² + Mg² + ) Standard: GB / T 35876-2018 "Grain and Oil Inspection - Determination of Sodium, Magnesium, Potassium, Calcium, Chromium, Manganese, Iron, Copper, Zinc, Arsenic, Selenium, Cadmium and Lead in Cereals and Their Products - Inductively Coupled Plasma Mass Spectrometry".

[0030] Core of the method: Sample pretreatment: Digest the sample (such as the supernatant after centrifugation of fermentation broth) with nitric acid to completely dissolve the target element.

[0031] Instrument measurement: The treated solution was injected into an inductively coupled plasma mass spectrometer (ICP-MS).

[0032] Quantitative analysis: Quantitative analysis was performed using the internal standard method. A series of standard solutions of the target elements (Na, K, Ca, Mg) were prepared to construct calibration curves. Internal standard elements (such as Sc, Ge, Y, etc.) were added to correct for instrument fluctuations and matrix effects. Finally, the concentration of the analyte ions in the sample was calculated.

[0033] 2. Sensory evaluation: The sensory evaluation of this invention is conducted in accordance with the requirements for sensory evaluation in the national standard GB / T 4928 "Methods for Analysis of Beer", and is combined with quantitative descriptive analysis (QDA). The specific steps are as follows: (1) Selection and training of evaluators Select 8–12 tasters who have undergone basic sensory training. All personnel should have no olfactory or gustatory impairments and should have a basic ability to identify beer flavors.

[0034] Training phase: Flavor identification training is conducted using beer samples of different styles, focusing on distinguishing characteristics such as malt aroma, hop aroma, body, bitterness, sourness, and astringency, and consistency calibration is performed to ensure uniformity of evaluation standards.

[0035] (2) Evaluation of the environment Sensory evaluation should be conducted in a sensory evaluation room that conforms to GB / T 13868 "General Guidelines for Establishing Sensory Analysis Laboratories". The environment should be quiet, odorless, with uniform and soft lighting (generally white neutral light), and the temperature should be controlled at 20–22℃.

[0036] (3) Sample preparation Store the beer samples to be evaluated in a refrigerator at 4–6℃. Shake gently before tasting to avoid agitation.

[0037] Each sample was poured into a clean, odorless, transparent tasting cup, approximately 100 mL per cup, and randomly numbered (e.g., three random numbers).

[0038] The evaluation order is randomized to avoid the order effect.

[0039] (4) The evaluation indicators and scoring criteria adopt a 10-point scoring system (1 point is very poor, and 10 points is excellent). The main evaluation dimensions are as follows:

[0040] (5) Evaluation procedure Each taster independently evaluated the appearance, aroma, and taste of each sample in turn.

[0041] After tasting each sample, rinse your mouth with water and wait at least 2 minutes before tasting the next sample.

[0042] Fill out the standardized sensory evaluation form and record the scores and textual descriptions for each item.

[0043] After all samples have been evaluated, the scoring sheets are collected for data analysis.

[0044] (6) Data processing and result presentation After removing extreme scores (such as the highest and lowest scores), calculate the mean score and standard deviation of each attribute.

[0045] Analysis of variance (ANOVA) or paired t-tests can be used to compare the significance of differences between different samples (p<0.05 is considered significant).

[0046] The results are presented in the form of "mean score ± standard deviation" and accompanied by a representative textual evaluation summary.

[0047] Materials used in the examples: 1. The Lager yeast strain W34 / 70 was purchased from Fermentis.

[0048] 2. Aleurone WLP001 was purchased from Fermentis.

[0049] Example 1 The yeast strain WLP001 was selected, activated with wort, and cultured in a fermenter at 20°C until the late logarithmic phase. The pretreated yeast sludge was then collected by centrifugation.

[0050] The pretreated yeast slurry was suspended in sterile deionized water at 6°C at a ratio of 1:8 (g / mL), gently stirred for 12 minutes, centrifuged, and the supernatant was discarded. This washing process was repeated 4 times to obtain washed yeast slurry.

[0051] Prepare a 100 mmol / L KCl solution (using deionized water) and cool it to 8°C. Suspend the washed yeast slurry in this solution at a ratio of 1:15 (g / mL) and stir at 10°C for 75 minutes.

[0052] Collect the yeast by centrifugation and wash it twice with 6℃ deionized water at a ratio of 1:8.

[0053] Suspend the yeast in sterile deionized water and adjust the concentration to 1.5 × 10⁻⁶. 8 cells / mL, stored at 2℃.

[0054] The yeast was inoculated at a standard amount (1.0 × 10⁻⁶). 7 The yeast cells / mL were inoculated into wort with a sodium ion content of 50 mg / L and primary fermentation was carried out at 20°C. After fermentation, the sodium content of the beer was measured to be 22 mg / L, which was 51% lower than that of the control group using untreated yeast (sodium content of 45 mg / L).

[0055] Example 2 The Lager yeast strain W34 / 70 was selected, cultured and collected according to the method in Example 1.

[0056] Deionized water washing conditions: ratio 1:10, temperature 5℃, wash 5 times, 15 minutes each time.

[0057] Potassium ion replacement conditions: KCl concentration 150 mmol / L, replacement temperature 6℃, treatment time 90 minutes, suspension ratio 1:12.

[0058] After two final washes, the resulting low-sodium, low-mineral brewer's yeast was stored in diluted wort at 4°C with a concentration of 1.8 × 10⁻⁶. 8 cells / mL.

[0059] When applied to wort fermentation with a sodium ion content of 60 mg / L, the sodium content of the finished beer was 28 mg / L, which was 49% lower than that of the control group (55 mg / L).

[0060] Example 3: Employing a "deep pretreatment + process optimization + flavor compensation" scheme (1) Pretreatment of malt and brewing water Select specialty malts and base malts with low protein and low mineral content; the low protein and low mineral content means that the protein content is in the range of 8-10% (dry basis) and the mineral content is in the range of 1.0-1.5% (ash content). Pre-treatment of malt by acid washing: Soak the malt in acidic water with pH 4.0-5.0 at low temperature (<30℃) for 30-60 minutes, and then drain; this operation can effectively dissolve some of the potassium, calcium, phosphate and other minerals on the surface of the malt. The contents of potassium, calcium and phosphate in malt were measured before and after pickling, and the results are shown in Table 1 below.

[0061] Table 1. Changes in mineral content before and after malt acid washing

[0062] Brewing water treatment: Use reverse osmosis water or deionized water as the base brewing water, controlling its total dissolved solids (TDS) value to <50 mg / L, preferably <20 mg / L, total ion concentration to <300 mg / L, and sodium ion concentration to <20 mg / L; then precisely add trace amounts of yeast-essential ions, including at least 5-15 μg / L Zn. 2+ 20-50 mg / L Ca 2+ 10-30 mg / L Mg 2+ ; The contents of sodium ions, calcium ions, and magnesium ions in the brewing water were measured before and after the treatment. The results are shown in Table 2 below.

[0063] Table 2 Changes in ion content before and after brewing water treatment

[0064] (2) Brewing Saccharification: Add food-grade acid (such as lactic acid) to the above brewing water to control the pH value of the saccharified mash at 5.2-5.4; this environment is conducive to enzyme activity, improves saccharification efficiency, and reduces the dissolution of undesirable substances; Boiling and sedimentation: Dynamic boiling technology is used to control the boiling intensity, which promotes the full release of thermal coagulated substances and protein-polyphenol complexes. These substances will bind some mineral ions and be removed together by vortex precipitation. The dynamic boiling technology controls the boiling intensity at a boiling temperature of 100-102℃ and a boiling time of 60-90 minutes, using intermittent stirring or a circulating pump to promote heat exchange, with the evaporation rate controlled at 8-12% per hour. The vortex sedimentation temperature is controlled at 80-90℃ and the vortex sedimentation time is 20-30 minutes. Fermentation process: Inoculate with the low-sodium, low-mineral brewer's yeast of Example 2 and ferment at 10-15℃ for 7-14 days; prioritize brewer's yeast strains with low mineral requirements, stable flavor metabolism and purity, such as brewer's yeast tolerant to low calcium and magnesium ions (such as Lager yeast strain W34 / 70); precisely control the fermentation temperature and cycle to ensure complete fermentation; (3) Flavor compensation and modification Flavor substance recovery: Collect, purify, and concentrate the volatile flavor substances in the condensate produced during the boiling process in the previous process, and add them back to the wine. Before bottling, very low doses of natural hop oils, extracts, or other natural flavor compounds (such as yeast-derived beta-glucan to enhance body) are added to precisely compensate for and modify the flavors lost due to reduced minerality, thus reshaping the body structure of the spirit.

[0065] Example 4: Based on Example 1, an "ion exchange post-treatment" scheme is added. (1) Pretreatment of malt and brewing water Select specialty malts and base malts with low protein and low mineral content; the low protein and low mineral content means that the protein content is in the range of 8-10% (dry basis) and the mineral content is in the range of 1.0-1.5% (ash content). Pre-treatment of malt by acid washing: Soak the malt in acidic water with pH 4.0-5.0 at a low temperature (<30℃) for 30-60 minutes, and then drain; This process can effectively dissolve some of the potassium, calcium, phosphate and other minerals on the surface of the wheat bran; Brewing water treatment: Use reverse osmosis water or deionized water as the base brewing water, controlling its total dissolved solids (TDS) value to <50 mg / L, preferably <20 mg / L, total ion concentration to <300 mg / L, and sodium ion concentration to <20 mg / L; then precisely add trace amounts of yeast-essential ions, including at least 5-15 μg / L Zn. 2+ 20-50 mg / L Ca 2+ 10-30 mg / L Mg 2+ ; (2) Brewing Saccharification: Add food-grade acid (such as lactic acid) to the above brewing water to control the pH value of the saccharified mash at 5.2-5.4; this environment is conducive to enzyme activity, improves saccharification efficiency, and reduces the dissolution of undesirable substances; Boiling and sedimentation: Dynamic boiling technology is used to control the boiling intensity and promote the full release of thermal coagulated substances and protein-polyphenol complexes. These substances will bind some mineral ions and be removed together by vortex precipitation. The dynamic boiling technology controls the boiling intensity at a boiling temperature of 100-102℃ and a boiling time of 60-90 minutes, using intermittent stirring or a circulating pump to promote heat exchange, with the evaporation rate controlled at 8-12% per hour. The vortex sedimentation temperature is controlled at 80-90℃ and the vortex sedimentation time is 20-30 minutes. Fermentation process: Inoculate with the low-sodium, low-mineral beer yeast of Example 2 and ferment at 10-15℃ for 7-14 days; prioritize the selection of beer yeast strains with low mineral requirements, stable flavor metabolism and purity, such as beer yeast tolerant to low calcium and magnesium ions (such as Lager yeast strain W34 / 70); precisely control the fermentation temperature and cycle to ensure complete fermentation; (3) Post-processing After fermentation and before filtration, the wine is post-treated using ion exchange resin or selective electrodialysis. When using ion exchange resins, use those containing oxalate ions (C2O4). 2- ), phosphate ions (PO4) 3- A highly selective adsorption resin is packed into a column reactor, allowing the wine to pass through the column for targeted removal of target ions; in this embodiment, a resin specifically targeting oxalate ions (C2O4) is selected. 2- ), phosphate ions (PO4) 3- Amberlite IRA-400 is a highly selective adsorption resin. In selective electrodialysis, under the influence of an electric field, the selective permeability of the ion exchange membrane is utilized to remove ions of specific valence states (such as K+) from the wine. + Na 2+ SO4 2- The ion exchange membrane selected in this embodiment can be a combination of NeoseptaAMX (anion exchange membrane) and Neosepta CMX (cation exchange membrane); The contents of acid radicals, phosphate radicals, and potassium ions in the wine were measured before and after ion exchange resin treatment. The results are shown in Table 3 below.

[0066] Table 3. Changes in ion content of wine before and after ion exchange resin treatment.

[0067] The contents of potassium ions, sodium ions, and sulfate ions in the wine were measured before and after selective electrodialysis treatment. The results are shown in Table 4 below.

[0068] Table 4. Changes in ion content of wine before and after selective electrodialysis treatment

[0069] (4) Flavor compensation and modification Flavor substance recovery: Collect, purify, and concentrate the volatile flavor substances in the condensate produced during the boiling process in the previous process, and add them back to the wine. Before bottling, very low doses of natural hop oils, extracts, or other natural flavor compounds (such as yeast-derived beta-glucan to enhance body) are added to precisely compensate for and modify the flavors lost due to reduced minerality, thus reshaping the body structure of the spirit.

[0070] Comparative Example: Beer Brewed Using Traditional Methods This comparative example uses conventional beer brewing processes and ingredients, without any special treatments to reduce mineral content, in order to simulate common traditional beers available on the market.

[0071] (1) Malt selection and treatment: Use ordinary base malt (such as Australian two-row barley malt), with a protein content of 10.5%-11.5% (dry basis) and a mineral content (ash) of 2.0%-2.3%.

[0072] No pickling pretreatment was performed.

[0073] Brewing water treatment: Used simply filtered municipal drinking water. Total dissolved solids (TDS): Approximately 350 mg / L. No reverse osmosis or deionization treatment was performed, and yeast-essential ions were not precisely added.

[0074] (2) Brewing Saccharification process: No food-grade acid was added to adjust the pH of the saccharification mash; the natural pH of the saccharification mash is 5.6-5.8.

[0075] Boiling and sedimentation: Conventional boiling is used for 60 minutes, with a boiling intensity (evaporation rate) of approximately 6-8% per hour; after boiling, the mixture is allowed to settle for 15 minutes at a temperature of approximately 95°C.

[0076] Fermentation process: Inoculate with ordinary lager brewer's yeast (such as S-189), fermentation temperature 12℃, fermentation time: 10 days.

[0077] (3) Post-processing: After fermentation, the product is directly filtered through conventional diatomaceous earth and then bottled. Targeted ion removal technologies such as ion exchange resins and selective electrodialysis are not used.

[0078] Flavor compounds from the boiling condensate were not recovered. No additional flavor-compensating substances (such as hop oil or beta-glucan) were added.

[0079] The results of the detection of key mineral ion content in the beer products obtained in this comparative example are shown in Table 5 below.

[0080] Table 5

[0081] Therefore, compared with traditional processes, the low-mineral beer brewed by the method of the present invention has significantly reduced total mineral content and the content of specific ions (such as potassium, sodium, and phosphate) that have potential health effects, achieving the expected low-mineral level.

[0082] A panel of trained evaluators conducted blind sampling and scoring (out of 10) of the product of Example 1 of the present invention and the comparative product. The results are shown in Table 6 below.

[0083] Table 6

[0084] Sensory evaluation results show that, despite the significant reduction in mineral content, the product of this invention is significantly superior to beer brewed using conventional methods in terms of body, bitterness quality, and overall flavor harmony. This demonstrates that this invention successfully resolves the contradiction between "mineral reduction" and "flavor preservation" by targeting mineral removal and combining it with flavor compensation. It not only avoids flavor loss but also enhances the purity and drinking experience of the beer.

[0085] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for brewing low-mineral beer, characterized in that, Includes the following steps: (1) Pretreatment of malt and brewing water Select a specialty malt with low mineral content as the base malt; First, a special type of malt with low mineral content is selected as the base malt. At the same time, the malt undergoes further acid washing pretreatment: the malt is soaked in acidic water with pH 4.0-5.0 at a low temperature (<30℃) for 30-60 minutes, and then drained. This operation can further and effectively dissolve some of the potassium, calcium, phosphate and other minerals on the surface of the malt husk. Brewing water treatment: Reverse osmosis water or deionized water is used as the base brewing water, with its total dissolved solids (TDS) value controlled at < 50 mg / L, total ion concentration below 300 mg / L, and sodium ion concentration below 20 mg / L; then, trace amounts of yeast-essential ions are precisely added, including at least 5-15 μg / L Zn. 2+ 20-50 mg / L Ca 2+ 10-30 mg / L Mg 2+ ; (2) Brewing Saccharification: Food-grade acid is added to the brewing water to control the pH of the saccharified mash at 5.2-5.4; this environment is conducive to enzyme activity, improves saccharification efficiency, and reduces the dissolution of undesirable substances. Boiling and sedimentation: Dynamic boiling technology is used to control the boiling intensity and promote the full release of thermal coagulated material and protein-polyphenol complex. During this process, thermal coagulated material and protein-polyphenol complex will bind some mineral ions, which are then removed by vortex precipitation. Fermentation process: Inoculate with brewer's yeast and ferment at 10-15℃ for 7-14 days; (3) Post-processing After fermentation and before filtration, the wine is post-treated using ion exchange resin or selective electrodialysis. (4) Flavor compensation and modification Flavor substance recovery: Collect, purify, and concentrate the flavor substances that volatilize from the boiling condensate in the previous process, and add them back to the wine. Before bottling, very low doses of natural hop oil, extracts, or other natural flavor compounds are added to precisely compensate for and modify the flavor lost due to reduced mineral content, thus reshaping the body structure of the spirit. These other natural flavor compounds include β-glucan derived from yeast.

2. The brewing method according to claim 1, characterized in that... Low mineral content means that the mineral content, calculated as ash, is in the range of 1.0-1.5%.

3. The brewing method according to claim 1, characterized in that, In brewing water treatment, the total dissolved solids (TDS) value of basic brewing water is controlled at < 20 mg / L.

4. The brewing method according to claim 1, characterized in that, The dynamic boiling technology controls the boiling intensity by maintaining the boiling temperature at 100-102℃ and the boiling time at 60-90 minutes, using intermittent stirring or circulating pumps to promote heat exchange, and controlling the evaporation rate at 8-12% per hour.

5. The brewing method according to claim 1, characterized in that, The temperature of the cyclone precipitation is 80-90℃, and the time is 20-30 minutes.

6. The brewing method according to claim 1, characterized in that, The brewer's yeast is a low-sodium, low-mineral brewer's yeast, and the preparation method of the low-sodium, low-mineral brewer's yeast includes the following steps: S1, the activated brewing yeast is inoculated into a culture system containing sterilized wort, cultured to the late logarithmic growth stage, and the pretreated yeast sludge is collected by centrifugation; S2, the pretreated yeast sludge in S1 is washed by centrifugation with deionized water multiple times to obtain washed yeast sludge; S3, the washing yeast sludge in S2 is placed in a potassium-rich washing solution for ion exchange, and centrifuged to obtain the exchanged yeast sludge. S4. The replacement yeast sludge from S3 is washed again by centrifugation with deionized water to obtain low-sodium, low-mineral brewer's yeast.

7. The brewing method according to claim 6, characterized in that, In S2, the pretreated yeast slurry is suspended in sterile deionized water at a mass-to-volume ratio of 1:5 to 1:10 (g / mL) and gently stirred for 10 to 15 minutes. The centrifugation parameters are as follows: 3000-5000 rpm, 5-10 minutes. The washing process is repeated 3-5 times. Potassium-rich washing solution is prepared by using deionized water to prepare a solution containing 50-200 mmol / L potassium chloride, and the solution temperature is controlled at 4-10℃. In S3, the washing yeast sludge is suspended in the above potassium-rich washing solution at a mass-to-volume ratio of 1:5 to 1:20 (g / mL); and then gently stirred at 4-15℃ for 30-120 minutes. In step S4, the replacement yeast slurry is washed 1-2 times by centrifugation with sterile deionized water at 4-10℃ at a mass-to-volume ratio of 1:5~1:10 (g / mL); the final low-sodium yeast slurry is then suspended in sterile deionized water or diluted wort to achieve a concentration of (1.0~2.0) × 10⁻⁶. 8 1 live cells / mL, stored at 0-4℃; The brewing yeast is either Ale yeast WLP001 or Lager yeast W34 / 70.

8. The brewing method according to claim 1, characterized in that, When selective electrodialysis is used, under the influence of an electric field, and when using ion exchange resins, the oxalate ions (C2O4) are used. 2- ), phosphate ions (PO4) 3- A highly selective adsorption resin is packed into a column reactor, allowing the wine to pass through the column for targeted removal of target ions; the resin is effective against oxalate ions (C2O4). 2- ), phosphate ions (PO4) 3- Highly selective adsorption resins include strong base anion exchange resins such as Amberlite IRA-400, Lewatit MP-500, and Dowex 1x2; By utilizing the selective permeability of ion exchange membranes, specific valence ions in the wine can be separated. The ion exchange membrane is an anion exchange membrane, a cation exchange membrane, or a selective membrane. The anion exchange membrane includes Neosepta AMX, the cation exchange membrane Neosepta includes CMX, and the selective membrane includes Fumasep FAB.

9. A beer brewed using the brewing method for low-mineral beer according to any one of claims 1 to 8, characterized in that, Total dissolved solids content ≤ 600 mg / L, potassium ion content ≤ 300 mg / L, sodium ion content ≤ 50 mg / L, sulfate ion content ≤ 150 mg / L, phosphate ion content ≤ 300 mg / L.

10. The application of the method according to any one of claims 1 to 9 in the field of brewing.

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