A brewing method for perilla compound fermentation beer

Abstract

This invention discloses a brewing method for perilla-fermented beer, belonging to the field of beer brewing technology. The method includes the following steps: clarifying hot wort is heated to 50-55°C; perilla powder, acid-resistant pectinase, acid-resistant cellulase, and a co-coloring agent of citric acid and ferulic acid are added; the pH is adjusted to 3.8-4.2; enzymatic hydrolysis is performed without inactivating the enzymes; the mixture is cooled to 18-22°C and inoculated with brewing yeast for primary fermentation; when the sugar content is consistently between 3.0°P and 4.0°P for two consecutive periods, the mixture is sealed and pressurized; then cooled to 0-2°C for cold storage; the endpoint is set at a relative standard deviation of less than 5% for color values ​​over three consecutive days; and finally, the product is filtered. This invention protects perilla pigments through enzymatic hydrolysis under acidic low-temperature conditions, enhances color stability with the co-coloring agent, simplifies the process by ensuring the enzymes are not inactivated after hydrolysis, and uses color fluctuation as a dynamic indicator to control the cold storage endpoint, ensuring the product has a bright color and consistent batch-to-batch consistency.

Description

Technical Field

[0001] This invention belongs to the field of beer brewing technology, specifically a brewing method for perilla compound fermentation beer. Background Technology

[0002] Perilla (Perilla frutescens) is an annual herbaceous plant belonging to the Lamiaceae family. Its leaves are rich in anthocyanins (such as perillaldehyde and cyanidin-3-glucoside), flavonoids, and phenolic acids, possessing various physiological activities such as antioxidant and anti-inflammatory properties. Combining perilla with beer fermentation to develop perilla beer with unique flavor and functionality has become a research hotspot in the specialty beer industry.

[0003] However, existing brewing methods for perilla beer generally face a core problem: perilla pigments are easily degraded under traditional beer brewing conditions, resulting in poor and unstable product color. Specifically, the saccharification temperature of traditional beer is usually 65-72℃, and the pH is about 5.2-5.6. However, the anthocyanin pigments in perilla are sensitive to high temperatures and slightly acidic environments. Under these conditions, when perilla is added, the pigments degrade or turn brown rapidly, and the finished beer appears as a dull brownish-gray rather than a purplish-red. At the same time, the pectin, cellulose, and other components in the perilla cell walls hinder the effective dissolution of pigments and polyphenols, further reducing the utilization rate of pigments and color performance. In addition, the existing process lacks scientific basis for determining the cold storage endpoint, resulting in large color differences between batches and making it difficult to guarantee product consistency. Therefore, how to improve the pigment dissolution rate and achieve stable color control while preserving the natural color of perilla is an urgent technical problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a brewing method for perilla compound fermented beer to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a brewing method for perilla compound fermentation beer, comprising the following steps:

[0006] (1) The boiled hot wort is transferred to a vortex settling tank with a temperature control device or a heat preservation tank with a stirring device, and left to stand and clarify. The supernatant is then taken as the clarified hot wort.

[0007] (2) Collect the temperature of the clarified hot wort, and when the temperature drops to the range of 50-55°C, maintain the temperature of the clarified hot wort at 50-55°C by heating or cooling;

[0008] (3) Add perilla powder, compound enzyme preparation and co-coloring agent to the clarified hot wort after temperature control. The compound enzyme preparation includes acid-resistant pectinase and acid-resistant cellulase. The co-coloring agent is a mixture of citric acid and ferulic acid. Adjust the pH of the clarified hot wort to 3.8-4.2.

[0009] (4) Incubate at 50-55℃ for enzymatic hydrolysis, stirring intermittently during the process. Do not inactivate the enzyme after hydrolysis to obtain enzymatically hydrolyzed wort.

[0010] (5) Cool the enzymatically hydrolyzed wort to 18-22°C, adjust the pH to 3.8-4.2, and inoculate with brewing yeast for primary fermentation;

[0011] (6) During the main fermentation process, the sugar content of the fermentation broth is measured. When the sugar content is measured twice consecutively and both values ​​are within the range of 3.0°P to 4.0°P, the container is sealed and pressurized.

[0012] (7) When the sugar content of the fermentation liquid drops below 2.5°P, the main fermentation ends and the fermentation liquid is cooled to 0-2°C for cold storage. During the cold storage process, the color value of the wine is tested. When the fluctuation range of the color value is less than 5% for 3 consecutive days, the cold storage is terminated.

[0013] (8) After filtering and refrigerating the wine, collect the filtrate to obtain perilla compound fermented beer.

[0014] Further, the perilla powder has a particle size of 20-40 mesh; based on the total mass of the clarified hot wort, the amount of the compound enzyme preparation added is 0.05%-0.15%, and the mass ratio of pectinase to cellulase in the compound enzyme preparation is 1:1-2:1; the amount of the colorant added is 0.02%-0.08%, and the mass ratio of citric acid to ferulic acid in the colorant is 2-5:1.

[0015] Furthermore, after incubation at pH 3.8–4.2 and 50–55°C for 30 minutes, the enzyme activity retention rate of the acid-resistant pectinase and acid-resistant cellulase is not less than 60%.

[0016] Furthermore, the incubation and enzymatic hydrolysis time is 30-60 minutes; the intermittent stirring method is: stirring once every 10 minutes, stirring speed is 50-100 rpm, and the duration of each stirring is 1-2 minutes.

[0017] Furthermore, the inoculation amount of the brewing yeast is 0.5% to 0.8% of the volume of the clarified hot wort, and the main fermentation temperature is 18 to 22°C; the time interval between the two sugar content tests is 12 hours, and the absolute value of the difference between the two test values ​​is ≤0.2°P.

[0018] Furthermore, the cold storage period is 7 to 14 days; the fluctuation range of the chromaticity value is characterized by the relative standard deviation of the chromaticity values ​​over 3 consecutive days.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. In this invention, enzymatic hydrolysis is performed at 50-55℃ and pH 3.8-4.2, avoiding the problem of rapid anthocyanin degradation at the high temperature of 65-72℃ and the relatively high pH of 5.2-5.6 in traditional saccharification. Combined with the color-co-coloring effect of citric acid and ferulic acid, the finished beer presents a bright purplish-red color, overcoming the defects of dull color and severe browning.

[0021] 2. In this invention, acid-resistant pectinase and cellulase are used to efficiently decompose the cell wall of perilla under acidic conditions and promote pigment release. The enzyme is not inactivated after enzymatic hydrolysis, and the residual enzyme activity is naturally inhibited after cooling, thus avoiding the destruction of pigment and aroma by high-temperature enzyme inactivation and saving energy.

[0022] 3. In this invention, the relative standard deviation of the color value for three consecutive days during the cold storage process is less than 5% as the dynamic criterion for terminating the cold storage, replacing the fixed duration mode and ensuring color consistency between batches. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1

[0025] Wort: Prepare 12°P hot wort according to conventional beer brewing process, boil it and then transfer it to a vortex settling tank with a temperature control device or an insulated tank with a stirring device, let it stand and clarify, and take the supernatant as the clarified hot wort, with a volume of 1000L.

[0026] Perilla powder: Perilla leaves are dried and then pulverized through a 30-mesh sieve.

[0027] Compound enzyme preparation: acid-resistant pectinase (purchased from a certain company, food grade, pH 3.8-4.5 activity > 80%) and acid-resistant cellulase (purchased from a certain company, food grade, pH 3.8-4.5 activity > 75%), with a mass ratio of 1.5:1.

[0028] Co-coloring agent: Citric acid to ferulic acid in a mass ratio of 3:1.

[0029] Brewing yeast: Commercial dry brewer's yeast (SafAle™ S-04), used after activation.

[0030] step:

[0031] Clarified hot wort: The boiled hot wort is transferred to a vortex settling tank with a temperature control device or an insulated tank with a stirring device, and left to stand for 30 minutes. The supernatant is then taken as the clarified hot wort.

[0032] Temperature control: When the online temperature probe shows that the temperature of the clarified hot wort has dropped to 53°C, the jacketed circulating water heating / cooling system of the heat preservation tank is activated to stabilize the temperature at 50-55°C (53±2°C in this embodiment).

[0033] Adding ingredients and adjusting pH: Add perilla powder (0.5% of the weight of clarified hot wort), compound enzyme preparation (0.1% of the weight of clarified hot wort), colorant (0.05% of the weight of clarified hot wort), and adjust the pH to 4.0 with food-grade citric acid.

[0034] Enzymatic hydrolysis: Incubate at 53±2℃ for 45 min, stirring at 80 rpm for 1.5 min every 10 min during the hydrolysis. After the hydrolysis is completed, do not heat up to inactivate the enzyme, and directly obtain the hydrolyzed wort.

[0035] Cooling and inoculation: Cool the enzymatically hydrolyzed wort to 20°C using a plate heat exchanger, adjust the pH to 4.0 with citric acid, inoculate with activated brewing yeast at a rate of 0.6% of the volume of the clarified hot wort, and transfer to a fermentation tank.

[0036] Primary fermentation: Control the fermentation temperature at 20℃. Starting from the 3rd day of fermentation, monitor the sugar content of the fermentation broth every 12 hours. When the sugar content is 3.4°P and 3.3°P respectively (the difference is 0.1°P, both within the range of 3.0 to 4.0°P), seal the tank and increase the pressure to 0.12 to 0.15 MPa.

[0037] Cold storage and color monitoring: After the main fermentation is completed (total fermentation time is about 7 days, sugar content drops to 2.2°P), the fermentation broth is cooled to 1°C for cold storage. The color is measured daily (using the EBC colorimetric method). The color values ​​for 3 consecutive days are 8.5, 8.4, and 8.4 EBC, respectively. The relative standard deviation is calculated to be about 0.7%, which is less than 5%, meeting the termination condition. At this time, the cold storage time is 10 days.

[0038] Filtration: The beer is filtered using a diatomaceous earth filter, the filtrate is collected, and then bottled to obtain perilla compound fermented beer.

[0039] Product specifications: Alcohol content 4.2% vol, original wort concentration 11.8°P, color 8.4 EBC, clear and transparent purplish-red, with a unique aroma of perilla and a light fruit ester fragrance, and fine and long-lasting foam.

[0040] Example 2

[0041] The basic steps are the same as in Example 1, the difference being:

[0042] The perilla powder has a particle size of 20 mesh, and the amount of compound enzyme added is 0.05% (pectinase: cellulase = 1:1), and the amount of co-coloring agent added is 0.02% (citric acid: ferulic acid = 2:1).

[0043] Enzymatic hydrolysis temperature 50℃, time 60min, stirring at 50rpm for 2min every 10min;

[0044] The main fermentation temperature was 18℃, the inoculum size was 0.5%, and the jar was sealed when the sugar content was 3.0°P and 3.1°P for two consecutive times.

[0045] The cold storage temperature was 0℃. The relative standard deviation of the color value was 4.8% for 3 consecutive days after the 7th day of cold storage, and the cold storage was terminated.

[0046] The resulting beer has a slightly lighter color (7.2 EBC), a refreshing flavor, and good color stability.

[0047] Example 3

[0048] The basic steps are the same as in Example 1, the difference being:

[0049] The perilla powder has a particle size of 40 mesh, and the amount of compound enzyme added is 0.15% (pectinase: cellulase = 2:1), and the amount of co-coloring agent added is 0.08% (citric acid: ferulic acid = 5:1).

[0050] Enzymatic hydrolysis temperature 55℃, time 30min, stirring at 100rpm for 1min every 10min;

[0051] The fermentation was carried out at a primary fermentation temperature of 22°C, with an inoculum size of 0.8%, and the jars were sealed when the sugar content was 4.0°P and 3.9°P for two consecutive times.

[0052] The cold storage temperature is 2℃. The relative standard deviation of the color value is 3.5% for 3 consecutive days after the 14th day of cold storage, and the cold storage is terminated.

[0053] The resulting beer had the deepest color (9.6 EBC) and a strong perilla characteristic.

[0054] Comparative examples (not employing key features of this invention)

[0055] Perilla powder was added at the traditional beer saccharification temperature (65℃, pH 5.4), without pH adjustment or the addition of a colorant. After enzymatic hydrolysis, the temperature was raised to 85℃ to inactivate the enzymes, and the rest was the same as in Example 1. Results: The finished beer was grayish-brown (color intensity only 3.5 EBC), and the color intensity decreased by 30% after one week of storage, indicating poor stability and a weak perilla aroma.

[0056] Key Parameter Description

[0057] Temperature control and color protection: Anthocyanins degrade at extremely low rates below 50℃ and under acidic conditions (pH < 4). This invention selects a temperature of 50–55℃ to ensure the optimal activity range of acid-resistant enzymes while avoiding thermal degradation of the pigment.

[0058] Selection of acid-resistant enzymes: The acid-resistant pectinase and cellulase used in this invention have an enzyme activity retention rate of no less than 60% after incubation at pH 3.8–4.2 and 50–55°C for 30 min. This performance can be verified by the following method: Take an appropriate amount of enzyme preparation, incubate it under the above conditions for 30 min, and use the DNS method to determine the residual enzyme activity. Calculate the retention rate by comparing it with the initial untreated enzyme activity.

[0059] The rationale for the non-enzyme-inactivation process: After enzymatic hydrolysis, the wort is immediately cooled to 18–22°C. At this temperature, the activity of acid-resistant enzymes is significantly reduced (retention rate <20%), and the pH further decreases to 3.5–3.8 during primary fermentation. The acidic environment further inhibits enzyme activity, therefore, no special enzyme inactivation treatment is necessary. The small amount of residual enzyme activity can slightly degrade pectin, which is beneficial for beer clarification and will not cause abnormal product viscosity.

[0060] Calculation of chromaticity fluctuation range: The relative standard deviation (coefficient of variation) is calculated using the following formula:

[0061]

[0062] In the formula, The standard deviation of chromaticity values ​​over three consecutive days. This is the average of the color values ​​over three consecutive days. When RSD < 5%, it indicates that the color of the wine has basically stabilized, and cold storage can be discontinued.

[0063] Equipment adaptability notes: If using a conventional vortex sedimentation tank (usually without active heating / cooling function), the tank needs to be equipped with a jacket or coil temperature control device, or the heated wort can be pumped into an insulated tank with a stirring device for subsequent temperature-controlled enzymatic hydrolysis after clarification. The insulated tank with a stirring device has a built-in temperature control system and can be used directly.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A brewing method for perilla-infused compound fermented beer, characterized in that, Includes the following steps: The boiled hot wort is transferred to a vortex settling tank or an insulated tank with a stirring device, allowed to stand and clarify, and the supernatant is taken to obtain the clarified hot wort. The temperature of the hot wort is collected, and when the temperature drops to the range of 50-55°C, the temperature of the hot wort is maintained at 50-55°C by heating or cooling. Perilla powder, a compound enzyme preparation, and a co-coloring agent are added to the heated wort after temperature control. The compound enzyme preparation includes acid-resistant pectinase and acid-resistant cellulase, and the co-coloring agent is a mixture of citric acid and ferulic acid. The pH of the heated wort is then adjusted to 3.8–4.

2. Enzymatic hydrolysis is carried out at 50-55℃ with intermittent stirring during the process. No enzyme inactivation treatment is performed after the hydrolysis is completed to obtain enzymatically hydrolyzed wort. The enzymatically hydrolyzed wort is cooled to 18–22°C, the pH is adjusted to 3.8–4.2, and brewer's yeast is inoculated for primary fermentation. During the primary fermentation process, the sugar content of the fermentation broth is monitored. When the sugar content is measured twice consecutively within the range of 3.0°P to 4.0°P, the container is sealed and pressurized. When the sugar content of the fermentation liquid drops below 2.5°P, the primary fermentation ends, and the fermentation liquid is cooled to 0-2°C for cold storage. During the cold storage process, the color value of the wine is monitored, and the cold storage is terminated when the fluctuation range of the color value is less than 5% for three consecutive days. After filtering and refrigerating the beer, the filtrate is collected to produce perilla compound fermented beer.

2. The brewing method for perilla compound fermented beer according to claim 1, characterized in that: The perilla powder has a particle size of 20-40 mesh; based on the total mass of the clarified hot wort, the amount of the compound enzyme preparation added is 0.05%-0.15%, and the mass ratio of pectinase to cellulase in the compound enzyme preparation is 1:1-2:1; the amount of the co-coloring agent added is 0.02%-0.08%, and the mass ratio of citric acid to ferulic acid in the co-coloring agent is 2-5:

1.

3. The brewing method for a perilla-infused compound fermented beer according to claim 1, characterized in that: The acid-resistant pectinase and acid-resistant cellulase retained at an activity of no less than 60% after being incubated at pH 3.8–4.2 and 50–55°C for 30 minutes.

4. The brewing method for perilla compound fermented beer according to claim 1, characterized in that: The incubation and enzymatic hydrolysis time is 30-60 minutes; the intermittent stirring method is: stirring once every 10 minutes, stirring speed is 50-100 rpm, and the duration of each stirring is 1-2 minutes.

5. The brewing method for a perilla-infused compound fermented beer according to claim 1, characterized in that: The inoculation amount of the brewing yeast is 0.5% to 0.8% of the volume of the clarified hot wort, and the main fermentation temperature is 18 to 22°C; the time interval between the two sugar content tests is 12 hours, and the absolute value of the difference between the two test values ​​is ≤0.2°P.

6. The brewing method for a perilla-infused compound fermented beer according to claim 1, characterized in that: The cold storage period is 7 to 14 days; the fluctuation range of the chromaticity value is characterized by the relative standard deviation of the chromaticity values ​​over 3 consecutive days.

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