Beer with good foam stability and preparation method thereof

Abstract

The present application relates to the field of beer preparation, and specifically discloses a beer with good foam stability and a preparation method thereof. A beer with good foam stability includes brewing raw materials, which include 20-25 parts of malt, 2-3 parts of glutinous rice, 0.6-0.9 parts of hops, 0.002-0.025 parts of complex enzymes and 0.02-0.25 parts of foam stabilizers by weight; the malt includes wheat malt and barley malt in a mass ratio of (4-6): 1; the foam stabilizer includes gum arabic, amino acids and zinc salts in a mass ratio of (10-15): (0.5-1): 1. A beer with good foam stability of the present application, the foam formed after being injected into the cup can last for a long time, providing consumers with a more pleasant drinking experience; in addition, the preparation method of the present application has the effect of improving the foam performance of beer and improving the drinking taste of beer.

Description

Technical Field

[0001] The present application relates to the field of beer preparation, and more specifically, to a beer with good foam stability and a preparation method thereof. Background Art

[0002] Beer is a low-concentration alcoholic beverage made from malt, hops and water through yeast fermentation. my country is now a major beer consumer and the country with the largest beer production, and the trend is increasing year by year. Beer foam is one of the important characteristics of beer and is the most intuitive characteristic for consumers to choose beer. Its quality has a great impact on the final quality of beer.

[0003] Beer foam is known as the "flower of beer" and is an important component of beer. The characteristics of beer foam mainly include beer foam stability, foaming, adhesion and foam appearance. It can not only increase the visual effect of beer and make it look more attractive, but also bring consumers a rich sense of taste. When the foam stability is poor, it is difficult for consumers to feel this rich taste during drinking, which greatly reduces the overall flavor of beer. In addition, beer foam can prevent the carbon dioxide in beer from escaping too quickly. When the beer foam stability is poor, the carbon dioxide escapes too quickly, which makes the beer taste bland and loses its vitality and bubbles.

[0004] With respect to the above-mentioned related technologies, the inventors found that in order to prolong the foam stability of beer, many existing technologies directly add iso-α-acids or other beer foam stabilizers such as propylene glycol alginate, isomerized hop extracts, etc. to the mature fermentation broth. However, if too much iso-α-acids and isomerized hop extracts are added, the bitterness of the beer will increase, and the cost of isomerized hop extracts is relatively high, which will increase the production cost of beer and thus affect its market competitiveness and the flavor of beer. Excessive addition of propylene glycol alginate may affect the taste of the beer, making it too viscous or producing an unnatural taste. Summary of the invention

[0005] In order to improve the stability of beer foam so that the foam of beer can be retained for a longer time after being poured into a cup, the present application provides a beer with good foam stability and a preparation method thereof.

[0006] In a first aspect, the present application provides a beer with good foam stability, using the following technical solution:

[0007] A beer with good foam stability comprises brewing raw materials, wherein the brewing raw materials comprise, by weight, 20-25 parts of malt, 2-3 parts of glutinous rice, 0.6-0.9 parts of hops, 0.002-0.025 parts of complex enzyme and 0.02-0.25 parts of foam stabilizer; the malt comprises wheat malt and barley malt in a mass ratio of (4-6):1; the foam stabilizer comprises gum arabic, amino acid and zinc salt in a mass ratio of (10-15):(0.5-1):1.

[0008] By adopting the above technical scheme, since wheat has a high soluble protein content, it can form protein components of different molecular weights after saccharification, and also forms a large amount of α-amino nitrogen. During the yeast fermentation process, yeast cells use a large amount of α-amino nitrogen and other nutrients to carry out early aerobic respiration and late anaerobic respiration, thereby producing a large amount of carbon dioxide and foam-type substances. Therefore, using high-content wheat as a brewing raw material can greatly enhance the foam retention of beer; wheat malt can form a large amount of hydrophobic polypeptide protein, which can be used as a surfactant to reduce the surface tension of beer foam, thereby enhancing the foam retention. In addition, the hydrophobic polypeptide protein can also interact with other beer ingredients, such as organic acids in hops, to form a two-dimensional hydrophobic network. This network structure helps to further support and stabilize the beer foam, making the foam delicate and having a strong cup-hanging property.

[0009] The blend of wheat malt and barley malt helps balance the sweetness and bitterness of the beer, making the taste more harmonious.

[0010] Glutinous rice is rich in protein and polysaccharides, which help to form stable foam. Adding it as an auxiliary material helps to increase the mellowness and taste of beer.

[0011] Gum arabic in the foam stabilizer can increase the stability of beer foam, so that the beer can maintain rich foam after pouring. Zinc salts can interact with proteins and other organic substances in beer to activate enzymes and improve enzyme activation, promote the synthesis and stability of foaming proteins, and thus promote the formation and stability of foam; in the process of yeast fermentation, zinc ions can act as a catalyst to promote yeast growth, activate yeast activity, and promote yeast to produce carbon dioxide during fermentation, which promotes the production of foam. Carbon dioxide can make the size of beer foam uniform and increase the fineness; in addition, zinc ions can affect the colloidal system in beer to increase the stability and durability of foam; zinc is one of the essential elements for the human body, and the addition of zinc salts has a certain nutritional strengthening effect on beer. The addition of amino acids can form complexes with zinc ions to reduce the adverse effects of zinc ions on the taste of beer.

[0012] Optionally, the complex enzyme comprises pectinase, neutral protease and polypeptide enzyme in a mass ratio of 1:(2-3):(1-2).

[0013] By adopting the above technical solution, the neutral protease in the complex enzyme can enhance the decomposition of high molecular weight proteins and improve the non-biological stability of beer. The addition of pectinase and peptide enzyme can enhance the decomposition of pentosan during saccharification, thereby reducing the turbidity and color of beer, playing an effective clarification role, improving the filtration performance of wort, and further improving the foam performance of beer.

[0014] Optionally, the mass of the complex enzyme is 0.06-0.08% of the mass of the malt.

[0015] By adopting the above technical solution, the mass of the complex enzyme is in the optimal range of 0.06-0.08% of the mass of malt, which helps the complex enzyme to play the best role.

[0016] Optionally, the mass of the foam stabilizer is 0.5-0.7% of the mass of the malt.

[0017] By adopting the above technical solution, the mass of the foam stabilizer is in the optimal range of 0.5-0.7% of the mass of the malt, which helps the foam stabilizer to play the best role.

[0018] Optionally, the zinc salt is selected from zinc chloride or zinc sulfate.

[0019] By adopting the above technical scheme, at appropriate concentrations, both zinc chloride and zinc sulfate have excellent biocompatibility and can be used as human supplements of zinc, which is safer and harmless to the human body. The addition of zinc chloride and zinc sulfate helps to introduce zinc ions, thereby promoting the formation and stability of beer foam.

[0020] Optionally, the barley malt is Australian malt.

[0021] By adopting the above technical scheme, the use of Australian malt as a brewing raw material for barley malt can significantly improve the foam retention of beer. This is because Australian malt contains higher protein and appropriate enzyme activity. Protein is one of the main components of the foam skeleton, which can increase the stability and persistence of the foam, while the enzyme activity affects the conversion process of the wort, thereby affecting the overall taste and foam performance of the beer. Australian malt also has a higher content of anhydrous extract, which helps to increase the yield of saccharified wort and further improve the foam performance of beer. The sugar substances in the anhydrous extract, especially maltose, also play an important role in the formation and stability of the foam.

[0022] Optionally, the amino acid is any one or more of serine, threonine, lysine, arginine, aspartic acid, glutamic acid, valine, methionine, leucine, histidine, glycine, isoleucine and phenylalanine.

[0023] By adopting the above technical scheme, amino acids can have a certain effect on the taste and flavor of beer, can neutralize the effect of the addition of foam additives on the taste of beer, can remove some odors produced during the fermentation process, and can also serve as essential amino acids for the human body to increase the nutritional value of beer; in addition, the addition of amino acids can promote the growth and metabolism of yeast, can ensure that the yeast can carry out protein synthesis and other biochemical reactions during the beer brewing process, help maintain the normal function of yeast cells, promote the production of carbon dioxide, and enhance foam retention.

[0024] Optionally, the hops include any one or more of Warrior hops, Magnum hops, Centennial hops and Citral hops.

[0025] By adopting the above technical scheme, bitter hops have a higher content of α-acid, and can be more fully isomerized during the beer brewing process, thereby enhancing the stability and fineness of the foam and making the foam last longer in the cup; bitter hops have excellent antiseptic properties and are a natural preservative, which can not only increase the aroma of beer, but also extend the shelf life of beer.

[0026] In a second aspect, the present application provides a method for preparing beer with good foam stability, comprising the following steps:

[0027] The malt is crushed and sieved, soaked in water and then mixed evenly with glutinous rice, saccharified at a feeding temperature of 51-55°C for 28-32 minutes, then cooled to 42-48°C, complex enzyme is added, and saccharification is continued for 25-30 minutes to obtain saccharified mash;

[0028] The saccharified mash is filtered and washed to obtain the first wort;

[0029] The first wort is boiled, and a foam stabilizer is added 20-25 minutes before the end of boiling; hops are crushed, and the hops are added to the boiled first wort twice, the first addition is 15-20 minutes before the end, and the second addition is 5-10 minutes before the end;

[0030] The first wort after boiling is cooled, vortexed and precipitated for 15-20 minutes, and then filtered twice to obtain the second wort;

[0031] Yeast is added to the second wort, and the mixture is sealed and fermented at 10-12°C for 7-18 days to obtain beer fermentation liquid. The inoculation amount of the yeast is 8-10×10 6 Pieces / mL;

[0032] The beer fermentation liquid is centrifuged and then filled, sterilized and packaged as a finished product.

[0033] By adopting the above technical scheme, the feeding temperature and insulation time in the present application are conducive to the development of enzyme activity and the rest of protein, conducive to the formation of α-amino nitrogen and medium-molecular peptide substances, and conducive to enhancing the stability of foam; adding hops twice helps to improve the utilization rate of hops, the first addition is mainly used for boiling and extraction of bitterness, and the second addition helps to extract aroma, which can better improve the aroma of beer and enrich the taste of beer.

[0034] Optionally, during the boiling process, the mass ratio of the amount of hops added for the first time to the amount of hops added for the second time is (3-4):1.

[0035] By adopting the above technical solution, the amount of hops added in the first addition is greater than that added in the second addition, which helps to control the bitterness and aroma of the beer and helps to make fuller use of the hops.

[0036] Optionally, the specific method of soaking the malt in water after crushing and sieving is as follows: soak the crushed malt in water at 10-12°C for 10-12h, then heat the water to 20-22°C and continue soaking for 10-12h, and then mix with glutinous rice for saccharification after natural cooling.

[0037] By adopting the above technical scheme, the malt is soaked in a combination of low and high temperatures. The early low-temperature soaking stage is helpful to fully dissolve and retain more free active enzymes, and the dissolution rate of colloidal substances such as proteins and polysaccharides in the malt can be slowed down under the low temperature environment, so that the colloidal substances can gradually play a role under the action of enzymes; the later high-temperature treatment helps to further promote the dissolution and conversion of substances such as proteins and polysaccharides in the malt, improve the soaking effect, and lay a good foundation for the subsequent saccharification and fermentation processes, thereby enhancing the foam stability of the beer.

[0038] Optionally, the first added hops are pretreated as follows before being added to the boiling first wort: crushed hops and zinc oxide are added to 84-86° C. hot water and stirred, and kept warm for 8-12 minutes; then kept warm at a pressure of 50-60 kPa for 8-12 minutes.

[0039] By adopting the above technical scheme, the utilization rate of α-acid of hops in the traditional beer brewing process is only 30-40%. Through pretreatment isomerization, the modified hops can be added to the saccharification pot for further isomerization, and the α-acid in the hops can be more efficiently converted into iso-α-acid. The iso-α-acid and the foaming protein in the wort form foam through physical and chemical reactions, thereby improving the ability to generate beer foam; in addition, since the isomerized α-acid and the foaming protein are adsorbed on the surface of carbon dioxide together, an iso-α-acid complex can be formed. This complex is formed by the combination of the amino group in the protein lysine and the hydroxyl group in the iso-α-acid, and has both hydrophilicity and hydrophobicity. The hydrophilic part is adsorbed in the foam wall, and the hydrophobic part is adsorbed outside the foam wall, which makes the foam more durable and delicate. The formed foam layer isolates the air, avoids direct contact between the air and the liquid surface, and prevents carbon dioxide from emitting from the beer into the air, thereby enhancing the stability of the foam; zinc oxide can act as a catalyst for the isomerization reaction to promote the occurrence of the reaction. Improving the isomerization efficiency through pretreatment can save raw materials and reduce production costs.

[0040] Optionally, the glutinous rice is pretreated as follows before saccharification: glutinous rice is mixed with water and then soaked for 1-2 hours, and washed 2-3 times, wherein the mass ratio of glutinous rice to water is 1:(2-3).

[0041] By adopting the technical scheme, the glutinous rice is pre-treated and cleaned to remove the rice bran in the glutinous rice, thereby preventing the fat content of the rice bran from being unfavorable to the generation of foam.

[0042] In summary, this application has the following beneficial effects:

[0043] 1. Since the present application adopts a foam stabilizer, gum arabic and zinc salt are added to the boiling wort. Both gum arabic and zinc salt can promote the stability of foaming protein by interacting with proteins and other organic substances in beer or forming a stable combination. The two can synergistically effectively enhance the generation and stability of beer foam and increase the fineness of the foam.

[0044] 2. This application uses wheat malt as the main component of malt. Wheat is rich in soluble protein. After saccharification, it can produce a large number of protein components with different molecular weights, which can effectively enhance the production and stability of beer foam. The addition of complex enzymes can effectively improve the non-biological stability of beer, thereby promoting the stability of beer foam.

[0045] 3. In the beer preparation method of the present application, hops are pretreated under high temperature and high pressure, which can effectively improve the utilization rate of hops, produce more iso-α-acids, increase the production of beer foam, and at the same time improve the utilization rate of raw materials and reduce production costs. DETAILED DESCRIPTION

[0046] The following examples further illustrate the present application in detail. Example

[0047] Embodiment 1: A beer with good foam stability comprises brewing raw materials, and the components and amounts of the brewing raw materials are shown in Table 1. The malt in the brewing raw materials comprises wheat malt and barley malt in a mass ratio of 5:1, the chroma of the wheat malt is 2.5-3.5 EBC, and the leaching rate is greater than 60%; the barley malt is Australian malt, the chroma is 4-6 EBC, and the Kulbach value is greater than 40%; the hops are Citrus hop particles; the yeast is English ale yeast (Angel CY115); the complex enzyme comprises pectinase, neutral protease and polypeptide enzyme in a mass ratio of 1:2:1, and the pectinase is selected from Shanghai Yuanye Biotechnology Co., Ltd. Company, S10007; neutral protease is selected from Shanghai Yuanye Biotechnology Co., Ltd., S10051; polypeptide enzyme is selected from Shanghai Yuanye Biotechnology Co., Ltd., S10205; foam stabilizer includes gum arabic, zinc sulfate and amino acid in a mass ratio of 10:1:0.5, gum arabic is selected from Qinuo Hebei Qianju Biological Official Store, 7858; zinc sulfate is selected from Shanghai Yuanye Biotechnology Co., Ltd., S22124; zinc oxide is selected from Shanghai Yuanye Biotechnology Co., Ltd., S27346; amino acid is glycine, selected from Shanghai Yuanye Biotechnology Co., Ltd., B21915.

[0048] Table 1 Components and dosage of brewing raw materials in Examples 1-4

[0049]

[0050] The method for preparing the beer with good foam stability comprises the following steps:

[0051] S1, put glutinous rice in a container, add 5.6Kg of water into the container and stir to mix, soak for 1h, pour out the dirty water containing rice bran and add clean water again, repeat washing 2 times;

[0052] S2, crushing and sieving the malt and placing it in an impregnation container, adding 94 kg of water at a temperature of 10° C. into the impregnation container to impregnate the crushed malt for 10 hours, then heating the water in the container to 20° C. and continuing to impregnate for 12 hours, adding glutinous rice into the container, and stirring evenly with the malt;

[0053] S3, adding the malt and glutinous rice stirred evenly in the container to the saccharification pot, heating the saccharification pot to 51°C at a rate of 2°C / min for saccharification, keeping the temperature for 28 minutes, then cooling to 42°C, adding complex enzyme, and continuing saccharification for 25 minutes to obtain saccharified mash;

[0054] S4, subjecting the saccharified mash obtained in S3 to an iodine test, heating the mash to 75° C. after the iodine test is qualified, filtering the mash once, washing the dregs, and obtaining the first wort;

[0055] S5, add 2.5 kg of water at a temperature of 84° C. into the pressure vessel, crush the hops, take 0.6 kg of hops and zinc oxide, add them into the pressure vessel, stir and heat for 8 minutes, then pressurize to 50 kPa and keep warm for 12 minutes, and filter after decompression to obtain the pretreated hops;

[0056] S6, pour the first wort into a boiling pot, boil for 60 minutes, add the foam stabilizer into the boiling pot 20 minutes before the end of boiling; add hops into the boiling first wort twice, add the pretreated hops prepared in S5 into the boiling pot 15 minutes before the end, and take 0.2 kg of crushed hops into the boiling pot 5 minutes before the end;

[0057] S7, cooling the first wort after boiling, vortexing and settling for 15 minutes, and then filtering twice to obtain the second wort;

[0058] S8, adding the second wort to the fermentation tank and aerating it, the aeration flow rate is 10mL / min, adding yeast, and sealing and fermenting at 12°C for 7 days to obtain beer fermentation liquid, the yeast inoculation amount of the full tank is 8×10 6 Pieces / mL;

[0059] S9. Cool the beer fermentation liquid to 2°C and store it in cold storage. After centrifugation, fill and sterilize it, and finally package it.

[0060] Example 2: A beer with good foam stability. The difference from Example 1 is that the components and amounts of the brewing raw materials are as shown in Table 1, the malt includes wheat malt and barley malt in a mass ratio of 6:1; the complex enzyme includes pectinase, neutral protease and polypeptide enzyme in a mass ratio of 1:3:2; the foam stabilizer includes gum arabic, zinc chloride and amino acid in a mass ratio of 12:1:0.8, and the zinc chloride is selected from Shanghai Yuanye Biotechnology Co., Ltd., T49483.

[0061] The method for preparing the beer with good foam stability comprises the following steps:

[0062] S1. Put glutinous rice in a container, add 7.2 kg of water into the container, stir and mix, soak for 2 hours, pour out the dirty water containing rice bran and add clean water again, and repeat washing 3 times.

[0063] S2, crush the malt, sieve it and place it in an impregnation container, add 94 kg of water at a temperature of 12 ° C into the impregnation container to impregnate the crushed malt for 12 hours, then heat the water in the container to 22 ° C and continue to impregnate for 10 hours, add glutinous rice into the container, and stir evenly with the malt;

[0064] S3, adding the malt and glutinous rice stirred evenly in the container to the saccharification pot, heating the saccharification pot to 55°C at a rate of 2°C / min for saccharification, keeping the temperature for 32 minutes, then cooling to 48°C, adding complex enzyme, and continuing saccharification for 30 minutes to obtain saccharified mash;

[0065] S4, subjecting the saccharified mash obtained in S1 to an iodine test, heating the mash to 75°C after the iodine test is qualified, filtering the mash once, washing the dregs, and obtaining the first wort;

[0066] S5, add 2.5 kg of water at a temperature of 86° C. into the pressure vessel, crush the hops, take 0.72 kg of hops and zinc oxide, add them into the pressure vessel together, stir and heat for 12 min, then pressurize to 60 kPa and keep warm for 8 min, and filter after decompression to obtain the primary pretreated hops;

[0067] S6, pour the first wort into a boiling pot, boil for 60 minutes, add the foam stabilizer into the boiling pot 25 minutes before the end of boiling; add hops into the boiling first wort twice, add the pretreated hops prepared in S5 into the boiling pot 20 minutes before the end, and take 0.18 kg of crushed hops into the boiling pot 10 minutes before the end;

[0068] S7, cooling the first wort after boiling, swirling and settling for 20 minutes, and then filtering twice to obtain the second wort;

[0069] S8, adding the second wort to the fermentation tank and aerating it, the aeration flow rate is 10mL / min, adding yeast, and sealing and fermenting at 10°C for 18 days to obtain beer fermentation liquid, the yeast inoculation amount of the full tank is 10×10 6 Pieces / mL;

[0070] S9. Cool the beer fermentation liquid to 2°C and store it in cold storage. After centrifugation, fill and sterilize it, and finally package it.

[0071] Example 3: A beer with good foam stability. The difference from Example 1 is that the components and amounts of the brewing raw materials are as shown in Table 1, the malt includes wheat malt and barley malt in a mass ratio of 4:1; the hops are century hop particles; the foam stabilizer includes gum arabic, zinc sulfate and amino acids in a mass ratio of 15:1:1, and the other steps are the same as in Example 1.

[0072] Example 4: A beer with good foam stability. The difference from Example 1 is that the components and amounts of the brewing raw materials are as shown in Table 1, and the other steps are the same as those in Example 1.

[0073] Example 5: A beer with good foam stability. The difference from Example 1 is that the added amount of the complex enzyme is 0.0144 kg, and the other steps are the same as Example 1.

[0074] Example 6: A beer with good foam stability. The difference from Example 1 is that the added amount of the complex enzyme is 0.0192 kg, and the other steps are the same as Example 1.

[0075] Example 7: A beer with good foam stability. The difference from Example 1 is that pectinase and polypeptide enzyme are not added, and the other steps are the same as those of Example 1.

[0076] Example 8: A beer with good foam stability. The difference from Example 1 is that no neutral protease is added, and the other steps are the same as Example 1.

[0077] Example 9: A beer with good foam stability. The difference from Example 1 is that the amount of foam stabilizer added is 0.12 kg, and the other steps are the same as Example 1.

[0078] Example 10: A beer with good foam stability. The difference from Example 1 is that the amount of foam stabilizer added is 0.168 kg, and the other steps are the same as Example 1.

[0079] Example 11: A beer with good foam stability. The difference from Example 1 is that step S2 is: crush the malt and place it in an impregnation container, add 94 kg of water with a temperature of 10°C to the impregnation solution, and impregnate for 22 hours, add glutinous rice to the container, and stir evenly with the malt. The other steps are the same as in Example 1.

[0080] Example 12: A beer with good foam stability. The difference from Example 1 is that step S2 is: crush the malt and place it in an impregnation container, add 94 kg of water with a temperature of 20°C to the impregnation solution, impregnate for 22 hours, add glutinous rice to the container, and stir evenly with the malt. The other steps are the same as in Example 1.

[0081] Example 13: A beer with good foam stability. The difference from Example 1 is that the hops added for the first time are not pretreated, and the other steps are the same as those in Example 1. Comparative Example

[0082] Comparative Example 1: A beer with good foam stability, which is different from Example 1 in that wheat malt is replaced by barley malt of equal mass, and other steps are the same as Example 1.

[0083] Comparative Example 2: A beer with good foam stability, which is different from Example 1 in that no complex enzyme is added, and other steps are the same as Example 1.

[0084] Comparative Example 3: A beer with good foam stability, which is different from Example 1 in that no foam stabilizer is added, and other steps are the same as Example 1.

[0085] Comparative Example 4: A beer with good foam stability, which is different from Example 1 in that gum arabic is not added, and other steps are the same as Example 1.

[0086] Comparative Example 5: A beer with good foam stability, which is different from Example 1 in that no zinc salt is added, and the other steps are the same as Example 1.

[0087] Comparative Example 6: A beer with good foam stability, which is different from Example 1 in that no amino acid is added, and the other steps are the same as Example 1.

[0088] Comparative Example 7: A beer with good foam stability, which is different from Example 1 in that all hops and zinc oxide are pretreated and added to the boiling pot at one time 15 minutes before the end of boiling, and the other steps are the same as Example 1.

[0089] Comparative Example 8: A method for preparing beer with good foam stability, comprising the following steps:

[0090] S1. Grinding and enzymolysis of malt: Grind the mixed malt (containing 10 kg of barley malt and 0.7 kg of wheat malt), take 10 kg of the mixed malt crumbs and put them in a saccharification pot, add 40 kg of 37°C hot water, add 300 U / g of neutral protease, and keep warm for 40 minutes for enzymolysis;

[0091] S2, saccharification and filtration: heat the saccharification pot and slowly raise the temperature to 65°C and stop heating. After saccharification for 60 minutes, filter to obtain wort;

[0092] S3, boiling fermentation: after boiling the wort for 5 minutes, bitter hops and 0.09 kg of propylene glycol alginate are added, after boiling for 60 minutes, aromatic hops are added and boiled for another 10 minutes, vortexed to precipitate, cooled and oxygenated, poured into a sterilized fermentation tank, inoculated with yeast, sealed and fermented for 10 days, in the late fermentation stage, i.e. 48 hours before the end of fermentation, brewing tannins are added at an amount of 35 mg / L, filtered after the fermentation is completed, and finished beer is obtained.

[0093] Performance testing

[0094] Foam stability performance test: According to the second method of foam retention test in "GB / T4928-2008 Beer Analysis Method": stopwatch method, the foam duration of the finished beer prepared in the examples and comparative examples was tested. Each group of beer was tested 3 times, and the average value was filled in Table 3.

[0095] Sensory evaluation: The sensory evaluation panel consisted of 10 sensory evaluation members (aged 20-55 years old, 5 males and 5 females). The evaluators had no obvious likes or dislikes for beer. The panel members evaluated the appearance, aroma, foam and taste attributes of the beer samples served in transparent glasses three times, and finally took the average value as the final sensory evaluation score of each group. The specific evaluation criteria are shown in Table 2, and the sensory evaluation results are shown in Table 3.

[0096] Table 2 Sensory evaluation standards

[0097]

[0098] Table 3 Beer foam stability performance test and sensory evaluation score data table

[0099]

[0100] According to the performance test data of Examples 1-13 and Comparative Examples 1-8, it can be seen that the beer prepared by the beer preparation method with good foam stability of the present application has a foam retention of more than 290s, and the foam is rich, white and delicate, and can last for a long time in the cup, with good foam performance.

[0101] It can be seen from the performance test data of Examples 1-4 and Comparative Example 1 that wheat malt as the main brewing raw material can effectively enhance the generation of beer foam and the stability of foam compared to barley malt as the main brewing raw material.

[0102] It can be seen from the performance test data of Examples 1-4, Examples 5-8 and Comparative Example 2 that the addition of the complex enzyme can significantly improve the non-biological stability of beer, pectinase and peptide enzyme play an effective role in clarifying beer, and the effect is most significant when the addition amount of the complex enzyme accounts for 0.006-0.008% of the added mass of malt.

[0103] It can be seen from the performance test data of Examples 1-4, Examples 9-10 and Comparative Examples 3-6 that the addition of foam stabilizer significantly increases the foam duration and enhances the stability of beer foam, and the best effect can be achieved when the foam additive is added in an amount of 0.5-0.7% of the malt added mass. Both gum arabic and zinc salt are beneficial to enhancing the stability of beer foam, and the synergistic effect of the two is better. The addition of amino acids can balance the taste impact of beer caused by the addition of zinc salt.

[0104] It can be seen from the performance test data of Examples 1-4 and Examples 11-12 that the combination of low and high temperatures is more conducive to the foam stability of beer than simply using high or low temperatures to soak the malt. The combination of low and high temperatures helps the malt to dissolve more protein during the soaking process, thereby laying a good foundation for the subsequent saccharification and fermentation processes, and at the same time makes the beer taste more mellow and comfortable.

[0105] It can be seen from the performance test data of Examples 1-4, Example 13 and Comparative Example 7 that pre-treatment of hops allows the hops to be isomerized in advance under the catalysis of zinc oxide, effectively improving the utilization rate of α-acids in hops, allowing the hops to produce more iso-α-acids, effectively improving the foam generation and foam stability of beer, and adding hops twice is more conducive to the extraction of bitterness and aroma of hops than adding hops all at once, and the combination of bitterness and aroma is appropriate, making the beer rich in aroma, harmonious in aroma, and mellow and comfortable in taste.

[0106] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A beer with good foam stability, comprising brewing raw materials, characterized in that: In parts by weight, the brewing raw materials include 20-25 parts of malt, 2-3 parts of glutinous rice, 0.6-0.9 parts of hops, 0.002-0.025 parts of complex enzymes and 0.02-0.25 parts of foam stabilizers; the malt includes wheat malt and barley malt in a mass ratio of (4-6):1; the foam stabilizer includes gum arabic, amino acids and zinc salt in a mass ratio of (10-15):(0.5-1):1; the complex enzyme includes pectinase, neutral protease and polypeptide enzyme in a mass ratio of 1:(2-3):(1-2); The method for preparing the beer with good foam stability comprises the following steps: The malt is crushed and sieved, and the crushed malt is soaked in water at 10-12°C for 10-12h, and then the water is heated to 20-22°C and soaked for 10-12h, and then the water is naturally cooled and mixed with glutinous rice, and saccharified at a feeding temperature of 51-55°C for 28-32min, and then the temperature is cooled to 42-48°C, and a complex enzyme is added, and the saccharification is continued for 25-30min to obtain a saccharified mash; The saccharified mash is filtered and washed to obtain the first wort; The first wort is boiled, and a foam stabilizer is added 20-25 minutes before the end of boiling; hops are crushed, and the hops are added to the boiled first wort twice, the first addition is 15-20 minutes before the end, and the second addition is 5-10 minutes before the end, and the mass ratio of the first addition amount of hops to the second addition amount of hops is (3-4):1; The first added hops are pretreated as follows before being added to the first boiling wort: crushed hops and zinc oxide are added to hot water at 84-86°C and stirred, kept warm for 8-12 minutes, and then kept warm at a pressure of 50-60 kPa for 8-12 minutes; The first wort after boiling is cooled, vortexed and precipitated for 15-20 minutes, and then filtered twice to obtain the second wort; Yeast was added to the second wort and fermented in a sealed state at 10-12°C for 7-18 days to obtain beer fermentation liquid. The inoculation amount of the yeast was 8×10 6 --10×10 6 Pieces / mL; The beer fermentation liquid is centrifuged and then filled, sterilized and packaged as a finished product.

2. The beer with good foam stability according to claim 1, characterized in that: The mass of the complex enzyme is 0.06-0.08% of the mass of the malt.

3. The beer with good foam stability according to claim 1, characterized in that: The mass of the foam stabilizer is 0.5-0.7% of the mass of the malt.

4. The beer with good foam stability according to claim 1, characterized in that: The zinc salt is selected from zinc chloride or zinc sulfate.

5. The beer with good foam stability according to claim 1, characterized in that: The glutinous rice is pretreated as follows before saccharification: the glutinous rice is mixed with water and then soaked for 1-2 hours, and washed 2-3 times, and the mass ratio of the glutinous rice to water is 1:(2-3).

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