Craft beer using only highland barley malt as raw material and preparation method thereof

Abstract

The application belongs to the technical field of food fermentation, and particularly relates to craft beer prepared only from highland barley and a preparation method thereof. The preparation method comprises the following steps: crushing highland barley malt, adding aspergillus oryzae, adding sterile water for preheating, then performing two-stage saccharification, terminating the reaction after the two-stage saccharification is completed, filtering and collecting wort; boiling the wort, adding hops before the boiling is completed, and performing precipitation after the boiling is completed, collecting liquid, and obtaining boiled wort; adding lager yeast into the boiled wort, performing main fermentation, cooling, standing and coarse filtering, and obtaining main fermentation liquor; performing aging fermentation on the main fermentation liquor, and obtaining the craft beer. The preparation method of the craft beer prepared only from highland barley provided in the application optimizes the production process, successfully solves the problem of excessively high content of beta-glucan in highland barley malt, and thus a novel craft beer is obtained.

Description

Technical Field

[0001] This application belongs to the field of food fermentation technology, specifically relating to craft beer made solely from highland barley and its preparation method. Background Technology

[0002] Craft beer (also known as brewery beer), compared to traditional industrial beer, places greater emphasis on the quality and innovation of its ingredients, especially in the selection and blending of grains and other adjuncts, resulting in a wider variety and flavor profile. Craft beer not only organically combines traditional brewing techniques with modern technological innovation but also breaks new ground in the selection of grains, leading to a richer flavor spectrum and sensory layers, thus enabling differentiated development. Using whole grains to brew beer not only satisfies consumers' pursuit of natural ingredients but also preserves the complete nutritional components and unique flavor characteristics of the grains, bringing a more distinctive taste and health benefits to the beer.

[0003] Barley, belonging to the genus *Hordeum* of the Poaceae family, is a cereal grain primarily grown in high-altitude regions at 4000-5000 m. It is rich in nutrients, containing various amino acids and trace elements essential for the human body, and is also rich in polysaccharides with health benefits. During barley germination, changes occur in starch, protein, lipids, and polyphenols, specifically a decrease in total starch content, a significant increase in amino acid and functional peptide content, a decrease in total lipid content, and the synthesis of more phenolic compounds. While there are existing studies on developing various barley products, there is limited research on brewing craft beer solely from barley. This is because barley malt contains a high content of β-glucan; brewing beer using only barley malt can easily lead to a viscous wort, slow fermentation, a cloudy finish, and a rough flavor.

[0004] Therefore, there is a need for new types of highland barley beer and their preparation methods to overcome the current technical deficiencies. Summary of the Invention

[0005] The problem this application aims to solve is to provide a craft beer made solely from highland barley malt and its preparation method, optimize the production process, and successfully solve the problem of excessive β-glucan content in highland barley malt, thereby obtaining a new type of craft beer.

[0006] To solve the above-mentioned technical problems, this application adopts the following technical solution: On the one hand, this application provides a method for preparing craft beer using only barley malt as raw material, including the following steps: After crushing the barley malt, add Aspergillus oryzae and sterile water for preheating, then carry out two-stage saccharification. After the two-stage saccharification is completed, terminate the reaction, filter and collect the wort. The wort is boiled, hops are added before the boiling is finished, and sedimentation is carried out after the boiling is finished. The liquid is collected to obtain boiled wort. Lager yeast is added to the boiled wort for primary fermentation, followed by cooling, settling, and coarse filtration to obtain the primary fermentation liquid. The brewing liquid is aged and fermented to obtain the craft beer.

[0007] In the above technical solution, Aspergillus oryzae, which is widely used in the brewing of traditional fermented foods such as sake, miso, and soy sauce, has excellent enzyme-producing microorganisms and can effectively promote the saccharification process of barley malt. The addition of Aspergillus oryzae for two-stage saccharification can first use Aspergillus oryzae to destroy the cell walls of barley malt, reducing the content of substances such as β-glucan in the raw materials that can easily affect subsequent fermentation. Meanwhile, coarse filtration can remove relatively large suspended particles in the wine while retaining some flavor substances and yeast. Combined with subsequent aging and fermentation, it can further produce flavor substances and stabilize the flavor of the wine.

[0008] Furthermore, the Aspergillus oryzae includes Aspergillus oryzae XMS01, purchased from the China Center for Type Culture Collection, and the viable count of the Aspergillus oryzae is 1×10⁻⁶. 8 ~2×10 8 CFU / g.

[0009] Furthermore, the hops include Haraldau hops.

[0010] Furthermore, the weight ratio of the barley malt, the Aspergillus oryzae, and the sterile water is 1:(0.1~0.2):(4~5).

[0011] Furthermore, the inoculation amount of hops is 0.5~0.9 g / L.

[0012] Furthermore, the inoculum size of the lager yeast is 1×10⁻⁶. 7 ~2×10 7 CFU / mL.

[0013] Furthermore, the malt extract has a sugar content of 12-14 °P.

[0014] Furthermore, the sugar content of the main fermentation liquid for brewing is 2.5~3.2 °P.

[0015] Furthermore, the two-stage saccharification includes a first-stage saccharification at a temperature of 25-28°C for 10-20 minutes and a second-stage saccharification at a temperature of 65-70°C for 20-30 minutes.

[0016] Furthermore, the preheating temperature is 20~25℃, and the preheating time is 15~20 min.

[0017] Furthermore, the temperature for terminating the reaction is 75~80℃, and the time for terminating the reaction is 10~15 min.

[0018] Furthermore, the boiling time is 50-60 minutes.

[0019] Furthermore, the hops are added 10-15 minutes before the end of the gelatinization process.

[0020] Furthermore, the temperature of the primary fermentation for brewing is 18~22℃, and the fermentation time is 8~10 days.

[0021] Furthermore, the cooling temperature is 1~3℃.

[0022] Furthermore, the coarse filtration is performed using a 300-400 mesh filter.

[0023] Furthermore, the aging and fermentation temperature is 20~25℃, and the aging and fermentation time is 5~7 months.

[0024] On the other hand, this application provides craft beer prepared by the above method.

[0025] Furthermore, the craft beer has an alcohol content of 6.5-7.6% vol and a residual sugar concentration of 1.5-2.1 °P.

[0026] This application has the following beneficial effects: 1. The craft beer preparation method provided in this application uses only barley malt as raw material, which not only preserves the unique flavor of barley malt, but also successfully breaks the prejudice that whole barley malt raw material is not suitable for making high-quality craft beer, and successfully obtains a grain beer with high nutritional value and stability and unique flavor.

[0027] 2. Adding Aspergillus oryzae during the saccharification of highland barley malt can effectively solve the problem of excessive β-glucan content in highland barley malt, avoiding slow fermentation and poor filtration in the later stages, and successfully achieving efficient production of all-highland barley malt craft beer. Detailed Implementation

[0028] The technical solutions in some embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments provided in this application, all other embodiments obtained by those skilled in the art are within the scope of protection of this application.

[0029] Hereinafter, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0030] In describing some embodiments, the expression "A and / or B" may be used. It is readily understood that "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0031] In describing some embodiments, the expressions "at least one of A, B and C" and "at least one of A, B or C" may be used, both of which have the same meaning and include the following combinations of A, B and C: only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, and a combination of A, B and C.

[0032] Example 1

[0033] Prepare all-barley malt craft beer using the following method: S1. Crush 5 kg of highland barley malt and pass it through a 60-mesh sieve, then add 0.5 kg of live bacteria with a count of 2×10⁻⁶. 8 CFU / g of Aspergillus oryzae XMS01 was added to sterile water at 20°C and stirred for 20 min for preheating. Then, a first-stage saccharification was carried out at 25°C for 20 min to allow Aspergillus oryzae to fully utilize the barley malt for pre-fermentation, thereby reducing the β-glucan content in the raw material while increasing the content of flavor substances. Then, the temperature was raised to 70°C for 20 min for a second-stage saccharification. After saccharification, the temperature was raised to 75°C and held for 15 min to terminate the reaction. After filtration, wort with a sugar content of 12.1°P was collected. S2. Boil the wort for 60 min, and add Haraldau hops at an inoculation rate of 0.9 g / L 10 min before the end of boiling, collect the liquid, and obtain boiled wort; S3 with 1×10 7 The lager yeast was inoculated into the boiled wort at an inoculation rate of CFU / mL. After 8 days of primary fermentation at 22°C, the temperature was lowered to 3°C and then allowed to stand for 2 hours. The mixture was then coarsely filtered through a 400-mesh filter to obtain a primary fermentation liquid with a sugar content of 2.5 °P. S4. Transfer the brewing main fermentation liquid to a stainless steel tank and age and ferment at 25°C for 5 months to obtain the all-barley malt craft beer.

[0034] Example 2

[0035] Prepare all-barley malt craft beer using the following method: S1. Crush 5 kg of highland barley malt and pass it through a 60-mesh sieve, then add 0.7 kg of bacteria with a viable count of 1.5 × 10⁻⁶. 8 CFU / g of Aspergillus oryzae XMS01 was added to sterile water at 22°C and stirred for 18 min for preheating. Then, a first-stage saccharification was carried out at 27°C for 15 min to allow Aspergillus oryzae to fully utilize the barley malt for pre-fermentation, thereby reducing the β-glucan content in the raw material while increasing the content of flavor substances. Then, the temperature was raised to 67°C for 25 min for a second-stage saccharification. After saccharification, the temperature was raised to 78°C and held for 13 min to terminate the reaction. After filtration, wort with a sugar content of 12.8°P was collected. S2. Boil the wort for 55 minutes, and add Haraldau hops at an inoculum rate of 0.7 g / L 12 minutes before the end of boiling, collect the liquid, and obtain boiled wort. S3 with 1.5×10 7 Lager yeast was inoculated into the boiled wort at an inoculation rate of CFU / mL. After 9 days of primary fermentation at 20°C, the temperature was lowered to 2°C and then allowed to stand for 2 hours. The mixture was then coarsely filtered through a 350-mesh filter to obtain a primary fermentation liquid with a sugar content of 2.8 °P. S4. The brewing main fermentation liquid is transferred to a stainless steel tank and aged at 23°C for 6 months to obtain the all-barley malt craft beer.

[0036] Example 3

[0037] Prepare all-barley malt craft beer using the following method: S1. Crush 5 kg of highland barley malt and pass it through a 60-mesh sieve, then add 1 kg of live bacteria with a count of 1×10⁻⁶. 8 CFU / g of Aspergillus oryzae XMS01 was added to sterile water at 25°C and stirred for 15 min for preheating. Then, a first-stage saccharification was carried out at 28°C for 10 min to allow Aspergillus oryzae to fully utilize the barley malt for pre-fermentation, thereby reducing the β-glucan content in the raw material while increasing the content of flavor substances. Then, the temperature was raised to 65°C for 30 min for a second-stage saccharification. After saccharification, the temperature was raised to 80°C and held for 10 min to terminate the reaction. After filtration, wort with a sugar content of 13.8°P was collected. S2. Boil the wort for 50 minutes, and add Haraldau hops at an inoculation rate of 0.5 g / L 15 minutes before the end of boiling, collect the liquid, and obtain boiled wort. S3 with 2×10 7The lager yeast was inoculated into the boiled wort at an inoculation rate of CFU / mL. After 10 days of primary fermentation at 18°C, the temperature was lowered to 1°C and then allowed to stand for 2 hours. The mixture was then coarsely filtered through a 300-mesh filter to obtain a primary fermentation liquid with a sugar content of 3.2 °P. S4. Transfer the brewing main fermentation liquid to a stainless steel tank and age it at 20°C for 7 months to obtain the all-barley malt craft beer.

[0038] Comparative Example 1 To verify the beneficial effects of adding Aspergillus oryzae, the method for preparing all-barley malt craft beer in this comparative example is the same as in Example 1; the only difference between Comparative Example 1 and Example 1 is that: In S1, 0.5 kg of bacteria with a viable count of 2 × 10⁻⁶ were used. 8 Replace CFU / g of Aspergillus oryzae XMS01 with 0.5 kg of sterile water.

[0039] Comparative Example 2 To verify the beneficial effects of the timing of Aspergillus oryzae addition, whole barley malt craft beer was prepared according to the following method: S1. Crush 5 kg of highland barley malt and pass it through a 60-mesh sieve. Add sterile water at 20°C and stir for 20 minutes to preheat. Raise the temperature to 70°C and perform a first-stage saccharification for 20 minutes. Then, cool the temperature to 25°C and add 0.5 kg of live bacteria with a count of 2×10⁻⁶. 8 The two-stage saccharification of Aspergillus oryzae XMS01 (CFU / g) was carried out for 20 min. After saccharification, the temperature was raised to 75℃ and held for 15 min to terminate the reaction. The wort was collected after filtration. S2. Boil the wort for 60 min, and add Haraldau hops at an inoculation rate of 0.9 g / L 10 min before the end of boiling, collect the liquid, and obtain boiled wort; S3 with 1×10 7 The lager yeast was inoculated into the boiled wort at an inoculation rate of CFU / mL. After 8 days of primary fermentation at 22°C, the temperature was lowered to 3°C and then allowed to stand for 2 hours. The mixture was then coarsely filtered through a 400-mesh filter to obtain the primary fermentation liquid. S4. Transfer the brewing main fermentation liquid to a stainless steel tank and age and ferment at 25°C for 5 months to obtain the all-barley malt craft beer.

[0040] Comparative Example 3 To verify the beneficial effects of using only barley malt as a raw material in this application, craft beer was prepared according to the following method: S1. Crush 5 kg of wheat germ and pass it through a 60-mesh sieve, then add 0.5 kg of live bacteria with a count of 2×10⁻⁶. 8CFU / g of Aspergillus oryzae XMS01 was added to sterile water at 20°C and stirred for 20 min for preheating. Then, a first-stage saccharification was carried out at 25°C for 20 min to allow Aspergillus oryzae to fully utilize the barley malt for pre-fermentation, thereby reducing the β-glucan content in the raw material while increasing the content of flavor substances. Then, the temperature was raised to 70°C for 20 min for a second-stage saccharification. After saccharification, the temperature was raised to 75°C and held for 15 min to terminate the reaction. The wort was then collected after filtration. S2. Boil the wort for 60 min, and add Haraldau hops at an inoculation rate of 0.9 g / L 10 min before the end of boiling, collect the liquid, and obtain boiled wort; S3 with 1×10 7 The lager yeast was inoculated into the boiled wort at an inoculation rate of CFU / mL. After 8 days of primary fermentation at 22°C, the temperature was lowered to 3°C and then allowed to stand for 2 hours. The mixture was then coarsely filtered through a 400-mesh filter to obtain the primary fermentation liquid. S4. Transfer the brewing main fermentation liquid to a stainless steel tank and age and ferment at 25°C for 5 months to obtain the all-barley malt craft beer.

[0041] Experimental Example 1: Determination of Physicochemical Indices The physicochemical properties of the craft beers prepared in Examples 1-3 and Comparative Examples 1-3 were measured, and the results are shown in Table 1.

[0042] Table 1 Physicochemical Indicators

[0043] Experiment Example 2: Sensory Analysis Scoring Five tasters were invited to score the craft beers prepared in Examples 1-3 and Comparative Examples 1-3 according to the sensory analysis method in GB / T 4928-2008 "Beer Analysis Methods" (average value was taken). The scoring results are shown in Table 2.

[0044] Table 2 Sensory Evaluation

[0045] As can be seen from the table above, the craft beer and its preparation method made from barley malt described in this application, by dividing saccharification into two stages and adding Aspergillus oryzae in the first stage for auxiliary saccharification, can ensure that the β-glucan in the barley malt is effectively consumed, so that the subsequent brewing main fermentation process can have a better fermentation environment, and the final beer has a rich aroma and flavor.

[0046] The above description is merely a preferred embodiment of this application. It should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this application should be within the protection scope of the appended claims.

Claims

1. A method for preparing craft beer using only barley malt as raw material, characterized in that, Includes the following steps: After crushing the barley malt, add Aspergillus oryzae and sterile water for preheating, then carry out two-stage saccharification. After the two-stage saccharification is completed, terminate the reaction, filter and collect the wort. The wort is boiled, hops are added before the boiling is finished, and sedimentation is carried out after the boiling is finished. The liquid is collected to obtain boiled wort. Lager yeast is added to the boiled wort for primary fermentation, followed by cooling, settling, and coarse filtration to obtain the primary fermentation liquid. The brewing liquid is aged and fermented to obtain the craft beer.

2. The method according to claim 1, characterized in that, The Aspergillus oryzae includes Aspergillus oryzae XMS01, and the viable count of the Aspergillus oryzae is 1×10⁻⁶. 8 ~2×10 8 CFU / g; And / or, the hops include Haraldau hops.

3. The method according to claim 2, characterized in that, The weight ratio of the barley malt, the Aspergillus oryzae, and the sterile water is 1:(0.1~0.2):(4~5). And / or, the inoculation amount of the hops is 0.5~0.9 g / L; And / or, the inoculum size of the lager yeast is 1 × 10⁻⁶. 7 ~2×10 7 CFU / mL.

4. The method according to claim 1, characterized in that, The wort has a sugar content of 12-14 °P; And / or, the sugar content of the main fermentation liquid for brewing is 2.5~3.2 °P.

5. The method according to claim 1, characterized in that, The two-stage saccharification includes a first-stage saccharification at a temperature of 25-28°C for 10-20 minutes and a second-stage saccharification at a temperature of 65-70°C for 20-30 minutes.

6. The method according to claim 1, characterized in that, The preheating temperature is 20~25℃, and the preheating time is 15~20 min; And / or, the temperature for terminating the reaction is 75~80℃, and the time for terminating the reaction is 10~15 min; And / or, the boiling time is 50-60 min; And / or, the hops are added 10-15 minutes before the end of gelatinization; And / or, the temperature of the primary fermentation of the wine is 18~22℃, and the time of the primary fermentation of the wine is 8~10 days; And / or, the cooling temperature is 1~3℃; And / or, the coarse filtration is performed using a 300-400 mesh filter; And / or, the aging and fermentation temperature is 20~25℃, and the aging and fermentation time is 5~7 months.

7. Craft beer prepared by the method according to any one of claims 1 to 6.

8. The craft beer according to claim 7, characterized in that, The craft beer has an alcohol content of 6.5-7.6% vol and a residual sugar concentration of 1.5-2.1 °P.

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