A method for manufacturing glutinous rice lager beer

Abstract

A waxy rice lager beer manufacturing method, the present application relates to beer brewing technical field, by the moderate crushing of malt, soft water section control temperature saccharification high efficient decomposition of high molecular protein, improve the saccharification efficiency; then normal pressure slow filtration wort after adding wine brewing, 78 DEG C wash the chaff, make the wine brewing and wort deep integration; wort boiling and pH adjustment; boiling process in turn add waxy rice aroma leaf once, add hops twice, make the bitterness and aroma separation release, both ensure that the wine body has bitterness support, also keep the fresh hop aroma; then wort cooling after entering the sealed tank, add activated yeast, pass sterile gas, pressure fermentation 1-2 weeks; temperature gradient cooling 1 DEG C per day to 0 DEG C, low temperature storage 3-6 weeks natural clarification, avoid yeast rupture, destroy the beer refreshing taste, produce miscellaneous flavor, promote the slow and stable fusion of alcohol and flavoring material. Solve the traditional lager beer process in the single flavor, auxiliary material fusion difference, the problem of low standardization of process such as insufficient clarity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of beer brewing, in particular to a manufacturing method of waxy rice lager beer. BACKGROUND

[0002] As one of the largest beer categories in the world, lager beer is characterized by low-temperature fermentation and refreshing taste. However, traditional lager beer is mainly made of malt, and its basic flavor is formed by low-temperature fermentation of yeast. Therefore, it lacks the layered taste brought by special ingredients, and it is difficult to meet the needs of consumers for diversified flavors.

[0003] Some existing lager beer brewing methods try to add grains such as waxy rice. However, due to improper treatment of raw materials (such as poor control of soaking time and cooking temperature) or unbalanced process parameters (such as unstable saccharification temperature and fermentation pressure), the flavors of auxiliary materials may conflict with the flavors of malt and hops, resulting in uncoordinated problems such as raw rice taste and astringency.

[0004] In the traditional lager beer brewing process, high molecular proteins and yeast residues can easily cause turbidity after cold storage. Moreover, most processes use direct 0℃ rapid cooling, which can easily cause yeast to rupture when it suddenly encounters low temperature, releasing bitter nucleotides. The post-ripening period is only 2-3 weeks, and the protein-polyphenol complex does not fully settle, so additional clarifying agents are needed. Although the addition of clarifying agents can improve the clarity, it may also introduce exogenous substances that affect the purity of the flavor.

[0005] Therefore, there is an urgent need in the industry for a lager beer manufacturing method that uses waxy rice as a flavor carrier, precisely controls the whole process at low temperature, and naturally clarifies for a long period, in order to solve the problems of single flavor, poor auxiliary material integration, insufficient clarity, and low process standardization in traditional lager beer processes. SUMMARY

[0006] The purpose of the present application is to provide a manufacturing method of waxy rice lager beer, which solves the problems of single flavor, poor auxiliary material integration, insufficient clarity, and low process standardization in traditional lager beer processes.

[0007] The embodiments of the present application are implemented by the following technical solutions:

[0008] Preferably, a manufacturing method of waxy rice lager beer comprises the following steps:

[0009] Preferably, step 1. Malt is crushed, and the crushing degree is controlled to be 40-50% fine powder and 50-60% coarse powder.

[0010] Preferably, step 2. The crushed malt is added to soft water, and the temperature is controlled in stages for saccharification. The saccharification process is as follows: 50℃ protein rest for 20 min, 65℃ low-temperature saccharification for 60 min, 69℃ high-temperature saccharification for 10 min, and 78℃ gelatinization for 10 min.

[0011] Preferably, step 3. The saccharified wort is slowly filtered at normal pressure.

[0012] Preferably, step 4. After filtering the wort, the wort is mixed with wine lees, and the wort is washed at a temperature of 78℃.

[0013] Preferably, step 5. The wort in step 4 is boiled and concentrated for 90 min, and the pH of the wort is reduced to 5.2-5.4 after boiling.

[0014] Preferably, step 6. The wort is cooled to the fermentation temperature, poured into a sealed fermentation tank, activated yeast is added, and sterile gas is introduced, maintaining a pressure of 0.1-0.15 MPa, and fermented for 1-2 weeks.

[0015] Preferably, step 7. The temperature of the fermented wort is gradually reduced to 0℃, and the wort is stored at low temperature for 3-6 weeks, and naturally clarified.

[0016] Preferably, step 8. The wort is fermented, the temperature gradient is reduced to 0℃, and the wort is stored at low temperature for 3-6 weeks, and naturally clarified.

[0017] Preferably, the method for making wine lees in step 4 is as follows:

[0018] S4.1 The glutinous rice is soaked in water for 5-8 h, and the weight ratio of glutinous rice to water is 1:2.

[0019] S4.2 The soaked glutinous rice is filtered out and steamed in a pot for 15-20 min.

[0020] S4.3 After the glutinous rice is steamed, sterile water is added, and when the temperature is reduced to room temperature, koji is added and stirred.

[0021] S4.4 The stirred glutinous rice is placed in a fermentation tank for fermentation for 7 days, and the fermented wine lees are separated out.

[0022] Preferably, the malt in step 1 is light barley malt.

[0023] Preferably, the calcium content in the soft water in step 2 is set to 50-100 ppm, and the sulfate content is <200 ppm.

[0024] Preferably, the concentration of the wort after washing in step 4 is set to 90%-95% of the target value of beer.

[0025] Preferably, the yeast in step 7 is activated by cooling.

[0026] Preferably, the initial fermentation temperature of the wort in step 7 is set to 12℃.

[0027] Preferably, when the sugar content of the fermented wort is reduced to 3°P, the tank is sealed and the temperature is raised to 14℃ for 72 hours.

[0028] Preferably, in step 8, the temperature of the fermented wort is gradually reduced to 0℃ at a rate of 1℃ per day.

[0029] Preferably, the addition amount of malt, beer, and glutinous rice leaf is set to 250:75:2 by weight.

[0030] Preferably, during the boiling process of the wort in step 6, the ratio of the two additions of hops is 1:2.

[0031] The technical scheme of the embodiment of the present application has at least the following advantages and beneficial effects:

[0032] The manufacturing method of the glutinous rice lager beer of the present application uses light-colored malt and glutinous rice beer to form a complex flavor of "malt refreshing sweetness + glutinous rice thick rice aroma + leaf fresh herbal flavor", which is different from the single malt flavor of traditional lager beer. The addition of hops and glutinous rice leaf in stages (increasing bitterness 30-15 minutes before boiling ends, and increasing aroma 5 minutes) separates and releases the bitterness and aroma, avoids flavor conflict, and achieves the taste characteristics of "bitterness and aroma balance, refreshing and not greasy".

[0033] The manufacturing method of the glutinous rice lager beer of the present application uses segmented temperature control to efficiently decompose high molecular proteins, and cooperates with gradient cooling (1℃ per day to 0℃) and 3-6 weeks of low-temperature storage to promote the natural sedimentation of yeast and proteins, without the need for adding exogenous clarifying agents, thereby making the wine body clear and transparent, and not easy to turbidity during storage.

[0034] The manufacturing method of the glutinous rice lager beer of the present application can avoid the rupture of yeast cell membranes due to sudden temperature drop, prevent the release of bitter substances in the cells into the wine, destroy the refreshing taste of beer, inhibit the metabolic activity of residual yeast, avoid the excessive decomposition of flavor substances to produce off-flavors, slow down the oxidation reaction of alcohol and other components, make the wine flavor more pure, and slow down the molecular motion rate of alcohol, esters, and higher alcohols under long-term low-temperature storage. These substances slowly fuse and form a stable balance in the mild interaction under long-term low-temperature storage, making the wine flavor more stable, thereby avoiding the decomposition or abnormality of flavor substances under high temperature. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0037] Example: Brewing 2500L of glutinous rice lager beer

[0038] Ingredient ratio: 500kg malt; 150kg rice wine; 4kg glutinous rice leaves; 1.5kg hops.

[0039] In this embodiment, the steps for manufacturing glutinous rice lager beer are as follows:

[0040] Step 1. Crush 500 kg of malt, controlling the fineness to 40-50% fine powder, while keeping the husks intact for coarse powder.

[0041] The fineness of the malt needs to be kept moderate. If it is ground too finely, the mash produced by malt saccharification will become viscous and difficult to filter; if it is ground too coarsely, the efficiency of malt saccharification and extraction will be reduced.

[0042] In addition, light-colored barley malt is preferred, as it has the characteristics of low color intensity, high enzyme activity, and refreshing flavor.

[0043] Specifically, light-colored barley malt typically has a lower color intensity, resulting in a lighter-colored wort that ultimately gives the sticky rice lager a clear and bright appearance.

[0044] Specifically, light-colored barley malt has a mild malty sweetness, rather than the complex flavors of caramel and nuts found in dark-colored malt. This simple basic flavor can balance the unique aroma of the glutinous rice leaves added in subsequent steps and the mellowness of the brewed beer. This ensures the beer's structural integrity without suppressing the unique flavors brought by the adjuncts, avoiding flavor clashes and highlighting the overall refreshing and harmonious feel.

[0045] Specifically, light-colored barley malt has higher enzyme activity (especially α-amylase and β-amylase), which can efficiently decompose starch into fermentable sugars during the segmented temperature-controlled saccharification process, meeting the metabolic needs of subsequent fermentation yeast in a low-temperature environment and ensuring sufficient and stable fermentation.

[0046] Step 2. Add the crushed malt into soft water, and control the temperature in stages for saccharification. The saccharification process is as follows: 50℃ protein rest for 20 min, 65℃ low-temperature stage saccharification for 60 min, 69℃ high-temperature stage saccharification for 10 min, and 78℃ temperature rising gelatinization for 10 min.

[0047] In the soft water, the calcium content is set to be within 50-100 ppm, and the sulfate content is less than 200 ppm, so as to soften the water. When the water quality is too hard (especially when the concentrations of calcium and magnesium ions are too high), the osmotic pressure balance of the subsequently added yeast cells will be destroyed, the reproduction speed of the yeast will be slowed down, the activities of various key reaction enzymes will be reduced, and thus the fermentation period is prolonged. Moreover, too high sulfate content will also affect the metabolic direction of the yeast (in a high-sulfate environment, the yeast will reduce part of the sulfate to hydrogen sulfide, producing a rotten egg smell), thereby destroying the refreshing flavor of the beer.

[0048] In the protein rest process, low temperature (lower heating temperature) is used to activate the proteases (such as endopeptidases and exopeptidases) in the malt, so as to decompose the high-molecular proteins in the malt raw material into small-molecule amino acids and polypeptides.

[0049] Preferably, high-molecular proteins are the main cause of turbidity of the beer after cold storage or long storage, and thus the decomposition can significantly improve the clarity of the beer body and increase the transparency of the beer. The amino acids produced after the decomposition are essential nutrients for yeast reproduction, and thus ensure the stable activity of the yeast in the subsequent fermentation stage.

[0050] In the low-temperature stage saccharification process, the β-amylase has the highest activity at this temperature, and can decompose the starch chains into a large amount of small-molecule fermentable sugars (such as glucose and maltose), so as to generate sufficient fermentable sugars to provide substrates for yeast metabolism, and ensure the stable generation of alcohol and CO2 in the main fermentation stage.

[0051] In the high-temperature stage saccharification process, the α-amylase activity dominates at this temperature, and can decompose starch to produce part of the non-fermentable sugars (such as dextrin). The high-temperature stage can make up for the starch that is not completely decomposed in the low-temperature stage, so as to ensure a larger starch conversion rate and improve the saccharification efficiency.

[0052] In the temperature rising gelatinization process, high temperature is used to terminate all amylase activities, and at the same time, the starch particles in the wort are completely gelatinized, the viscosity of the wort is reduced, the low-viscosity wort is easier to be filtered in the subsequent process, the filtration time and wort loss are reduced, and the risk of turbidity caused by the viscous wort is reduced.

[0053] Step 3. Slowly filter the saccharified wort at normal pressure.

[0054] Wherein, the wort after saccharification is separated from the spent grain (malt shell, undecomposed fiber, etc.) by filtration to ensure the purity of the wort entering the subsequent process; and by controlling the flow rate, the turbidity caused by the suspension of spent grain particles in the wort can be reduced, laying the foundation for the final clarity of the wine body.

[0055] Step 4. After filtering the wort, 150 kg of wine is added for mixing and washing the spent grain, with the tank water temperature controlled at 78℃ (not exceeding 78℃), and the wort concentration after washing the spent grain needs to be controlled at 90%-95% of the target value of beer.

[0056] Wherein, by washing the spent grain with 78℃ hot water, the soluble substances such as sugar and amino acids that have not been fully extracted from the spent grain can be dissolved into the wort, improving the utilization rate of raw materials, and avoiding the dissolution of bitter substances such as tannins and lignin in the malt shell caused by high temperature (> 78℃), preventing the wine body from producing off-flavors.

[0057] Preferably, adding wine before washing the spent grain can make the glutinous rice fermentation products (such as oligosaccharides, flavor substances) in the wine fully extracted by hot water during the washing process and deeply integrated with the wort; and locking the wort concentration at 90%-95% of the target value can avoid the difficulty of fermentation caused by high concentration (high metabolic pressure of yeast), and prevent the wine body from being thin.

[0058] Wherein, the steps for making wine are as follows:

[0059] S4.1 Soak the glutinous rice in water for 5-8h (adjust according to room temperature, the lower the room temperature, the longer the soaking time), and the weight ratio of glutinous rice to water is 1:2.

[0060] S4.2 Filter out the soaked glutinous rice and steam it for 15-20min.

[0061] S4.3 After the glutinous rice is steamed, add sterile water to make the glutinous rice absorb water to achieve the effect of rapid cooling, separation and loosening, and add wine starter when the temperature is lowered to room temperature and stir.

[0062] S4.4 Put the stirred glutinous rice into the fermentation tank for 7 days of fermentation, and separate out the fermented wine.

[0063] Step 5. Boil the wort in step 4 for 90min, and reduce the PH of the wort to 5.2-5.4 after boiling.

[0064] Wherein, by continuously boiling for 90 minutes, the protein in the wort is promoted to coagulate and form heat coagulum, improving the clarity of the wort; at the same time, part of the water is evaporated to concentrate the wort, ensuring the fullness of the wine body; and by adjusting the pH value (adding edible acid such as lactic acid to reduce the pH value) in the later stage, the yeast fermentation environment is optimized.

[0065] Step 6. Add 4 kg of glutinous rice leaves 30 minutes before the end of boiling, add 0.5 kg of hops 30-15 minutes before the end of boiling, and add 1 kg of hops again 5 minutes before the end of boiling.

[0066] The boiling time of 30 minutes before the end of boiling can make the volatile aroma substances (such as terpenes and phenols) in the glutinous rice leaves fully integrate into the wort, and avoid the destruction of flavor substances due to over-boiling, ensuring that the unique herbal aroma of glutinous rice leaves is deeply combined with the flavors of wort and hops, and together building the differentiated flavor of "glutinous rice lager".

[0067] The boiling time of 30-15 minutes before the end of boiling is sufficient to fully isomerize the a-acids in the hops, converting them into bitter substances to provide a basic bitterness to the beer body, balance the malt sweetness, and avoid a greasy taste.

[0068] The second addition of hops 5 minutes before the end of boiling can minimize the volatilization of aroma substances (such as terpenes), highlighting the unique woody and fruity flavors of hops, complementing the soft flavors of glutinous rice, and enhancing the richness of aroma levels.

[0069] Preferably, the two additions separate the bitterness and aroma, ensuring that the beer body has enough bitterness support (avoiding sweetness) and retaining the fresh hop aroma, which is consistent with the refreshing taste characteristics of glutinous rice lager beer.

[0070] Step 7. Cool the wort to the fermentation temperature (11°C) to reduce the activity of high-temperature spoilage bacteria, pour it into a sealed fermentation tank, add 1 kg of activated yeast (dry yeast activated by cold white wine), and introduce sterile air to promote yeast reproduction, maintain a pressure of 0.1-0.15 MPa, and ferment for 1-2 weeks.

[0071] Preferably, rapid cooling can significantly reduce the activity of spoilage bacteria, providing a low-temperature fermentation environment to create a "sterile window" for subsequent yeast inoculation, and the sterile air after cooling can provide initial oxygen for yeast to proliferate in the aerobic respiration stage, reserving enough bacteria for subsequent anaerobic fermentation.

[0072] A large number of yeast can quickly start fermentation, avoiding a long fermentation period due to insufficient yeast (which is prone to spoilage bacteria). 6 However, a high inoculation amount (such as more than 15 x 10

[0073] The initial fermentation temperature of the wort is set to 12°C, and when the wort fermentation sugar degree drops to 3°P, the tank is sealed and the temperature is raised to 14°C to start diacetyl reduction, which is maintained for 72 hours; the total fermentation time is 1-2 weeks, and the fermentation process ends when the wort sugar degree reaches 3-5°P.

[0074] Preferably, the initial temperature of 12℃ can reduce the ester production (such as ethyl acetate) of yeast, avoid the banana taste and other flavors to destroy the refreshing feeling of beer; the diacetyl reduction at 14℃ can decompose the green taste substances into non-odorous components, and inhibit the generation of miscellaneous flavors; and the pressure of 0.1-0.15 MPa can retain an appropriate amount of CO2, giving the wine a moderate killing feeling, and balancing the mild flavor of glutinous rice.

[0075] Step 8. The temperature of the fermented wort is gradually reduced at a rate of 1℃ per day to 0℃, and the low-temperature storage is performed for 3-6 weeks to perform natural clarification.

[0076] In the process, the slow gradient cooling can avoid the rupture of the cell membrane of the yeast cells due to sudden temperature drop (such as directly from 14℃ to 0℃), prevent the release of bitter substances (such as nucleotides) in the cells into the wine, destroy the refreshing taste of beer, and inhibit the metabolic activity of residual yeast to avoid the decomposition of flavor substances to produce miscellaneous flavors. At the same time, low temperature slows down the oxidation reaction of alcohol and other components, making the wine flavor more pure. Under the condition of long-term low-temperature storage, the molecular motion rate of alcohol, esters, higher alcohols and other flavor substances is slowed down. These substances slowly integrate and form a stable balance in the mild interaction under long-term low-temperature, so that the beer flavor is more stable (the longer the time, the purer the beer flavor), thereby avoiding the decomposition or abnormality of flavor substances under high temperature.

[0077] In the process, the slow gradient cooling can avoid the rupture of the cell membrane of the yeast cells due to sudden temperature drop (such as directly from 14℃ to 0℃), prevent the release of bitter substances (such as nucleotides) in the cells into the wine, destroy the refreshing taste of beer, and inhibit the metabolic activity of residual yeast to avoid the decomposition of flavor substances to produce miscellaneous flavors. At the same time, low temperature slows down the oxidation reaction of alcohol and other components, making the wine flavor more pure. Under the condition of long-term low-temperature storage, the molecular motion rate of alcohol, esters, higher alcohols and other flavor substances is slowed down. These substances slowly integrate and form a stable balance in the mild interaction under long-term low-temperature, so that the beer flavor is more stable (the longer the time, the purer the beer flavor), thereby avoiding the decomposition or abnormality of flavor substances under high temperature.

[0078] Further, in order to ensure the stability of the process in the brewing of the glutinous rice lager beer and maintain the stability of the flavor, the sources of the brewing raw materials are fixed.

[0079] In the process, the slow gradient cooling can avoid the rupture of the cell membrane of the yeast cells due to sudden temperature drop (such as directly from 14℃ to 0℃), prevent the release of bitter substances (such as nucleotides) in the cells into the wine, destroy the refreshing taste of beer, and inhibit the metabolic activity of residual yeast to avoid the decomposition of flavor substances to produce miscellaneous flavors. At the same time, low temperature slows down the oxidation reaction of alcohol and other components, making the wine flavor more pure. Under the condition of long-term low-temperature storage, the molecular motion rate of alcohol, esters, higher alcohols and other flavor substances is slowed down. These substances slowly integrate and form a stable balance in the mild interaction under long-term low-temperature, so that the beer flavor is more stable (the longer the time, the purer the beer flavor), thereby avoiding the decomposition or abnormality of flavor substances under high temperature.

[0080] Raw material category Raw material source Pale malt Pilsen malt, Australian malt, Canadian malt Sake lees Northeast Wufang Xueliang Glutinous Rice Glutinous rice leaf Yunnan glutinous rice leaf Hops Czech saaz Yeast Fermantids S23 dry yeast

[0081] Pilsen malt is preferred as a classic pale malt, with stable enzyme activity and high saccharification efficiency, and is a traditional choice for lager beer, which can lay the foundation for pure basic flavor. Australian malt and Canadian malt have moderate protein content, and the fermented beer is more mellow, which is suitable for the thick and mellow feeling of glutinous rice.

[0082] Preferably, the Northeast Wufang Xuerong glutinous rice is selected to make the wine, which has full particles, high starch content and high amylopectin content, and can produce unique glutinous rice aroma and slight rice aroma after fermentation. After soaking for 5-6 hours in summer and 8 hours in winter, the flavor of the wine can be kept pure after 7 days of fermentation without raw rice taste or rancid taste.

[0083] Preferably, Yunnan glutinous rice has a fresh herbal aroma and a weak woody tone, and a small amount of addition can highlight the characteristics without overstealing the flavor.

[0084] Preferably, Czech saaz is a classic aroma hop in Europe, characterized by soft woody aroma and citrus aroma, low and delicate bitterness, suitable for the demand of "refreshing and not bitter" of lager beer.

[0085] Preferably, Fermanidis s23 yeast belongs to the following fermentation yeast, which is low temperature resistant and has low ester production, and its activity is relatively stable, and its inoculation amount is highly suitable for the low temperature fermentation environment of glutinous rice lager.

[0086] Example 1

[0087] In this embodiment, in order to improve the saccharification degree of malt and maintain the clarity of wort after saccharification, segmented temperature control saccharification is adopted. Please refer to Tables 1, 2, 3 and 4. In order to determine whether different saccharification stages have an effect on malt saccharification, multiple control groups with different saccharification processes are set up for comparison experiments.

[0088] The experimental conditions of Experiment 1 are as follows:

[0089] The malt is crushed and added to soft water. The experimental group is protein rest + low temperature saccharification + high temperature saccharification + temperature rise gelatinization, and the control group is low temperature saccharification + high temperature saccharification + temperature rise gelatinization. Each group of different saccharification stages is repeated 4 times, and the detection time is based on 4 parallel determination values.

[0090] Table 1: Segmented temperature control saccharification

[0091] Experimental group Control group 1 Control group 2 Control group 3 High molecular protein residual amount 0.31g / L 0.97g / L 1.11g / L 1.03g / L Amino acid content 200mg / L 137mg / L 132mg / L 136mg / L Wort clarity Clear Turbid Turbid Turbid

[0092] From Table 1, the control group without protein rest is because the protease in the malt is not activated by low temperature, so that the decomposition efficiency of high molecular protein in the malt raw material is reduced, and it is difficult to decompose into amino acids, resulting in too much residue, so that the wort after saccharification is relatively turbid, thereby indicating that high molecular protein will affect the clarity of the wort after saccharification, and the protein rest stage needs to be set to improve the decomposition rate of high molecular protein in the malt raw material.

[0093] The configuration conditions of Experiment 2 are as follows:

[0094] The malt is crushed and soft water is added, the experimental group is protein rest + low-temperature saccharification + high-temperature saccharification + temperature rising gelatinization, and the control group is protein rest + high-temperature saccharification + temperature rising gelatinization, and each group of different saccharification stages is repeated 4 times, and the detection time is based on 4 parallel determination values.

[0095] Table 2: Temperature control saccharification by stages

[0096] Experimental group Control group 1 Control group 2 Control group 3 Fermentable sugar amount 7.0°P 6.4°P 6.2°P 6.4°P

[0097] From Table 2, the control group without low-temperature saccharification is because the activity of α-amylase is always low, so the decomposition efficiency of starch is reduced, and it is difficult to generate small molecule fermentable sugar, so that the amount of fermentable sugar is reduced, and then the reproduction of yeast is affected, so the low-temperature saccharification stage needs to be set to improve the decomposition rate of starch decomposition into small molecule fermentable sugar.

[0098] The configuration conditions of Experiment 3 are as follows:

[0099] The malt is crushed and soft water is added, the experimental group is protein rest + low-temperature saccharification + high-temperature saccharification + temperature rising gelatinization, and the control group is protein rest + low-temperature saccharification + temperature rising gelatinization, and each group of different saccharification stages is repeated 4 times, and the detection time is based on 4 parallel determination values.

[0100] Table 3: Temperature control saccharification by stages

[0101] Experimental group Control group 1 Control group 2 Control group 3 Starch conversion rate 97.1% 90.3% 90.8% 89.4%

[0102] From Table 3, the control group without high-temperature saccharification is because the activity of β-amylase is always low, so the decomposition efficiency of starch is reduced, and it is difficult to completely decompose the starch that is not completely decomposed in the low-temperature stage, so that the starch conversion rate is reduced, so the high-temperature saccharification stage needs to be set to promote the complete decomposition of starch.

[0103] The configuration conditions of Experiment 4 are as follows:

[0104] Malt was crushed and added to soft water. The experimental group was subjected to protein rest + low-temperature saccharification + high-temperature saccharification + temperature increase gelatinization, and the control group was subjected to protein rest + low-temperature saccharification + high-temperature saccharification. Each group was repeated 4 times in different saccharification stages, and the detection time was based on 4 parallel measurements.

[0105] Table 4: Temperature-controlled saccharification in stages

[0106] Experimental group Control group 1 Control group 2 Control group 3 Mash viscosity 15cP 21cP 22cP 19cP Wort turbidity 5NTU 13NTU 14NTU 13NTU

[0107] As shown in Table 1, the control group without temperature increase gelatinization has some enzymes in the wort continuing to work (such as protease), causing large molecular substances such as high molecular proteins in the malt raw materials to continue to remain in the wort, making the saccharified wort more turbid, thereby affecting the clarity of the saccharified wort. Therefore, a temperature increase gelatinization stage is needed to improve the clarity of the malt raw materials and inactivate various enzymes.

[0108] Experimental Example Two

[0109] In this embodiment, in order to ensure that the wine body has sufficient bitterness support (avoiding sweetness) and retains fresh hop aroma, in line with the taste characteristics of the waxy rice lager beer, two-time addition of hops is adopted. In order to determine whether the addition time and addition times have an effect on the flavor of the wine body, multiple control groups with different addition times are set up for comparative experiments.

[0110] The experimental group configuration conditions are as follows:

[0111] The wort was boiled, and a certain amount of waxy rice leaf was added 30 minutes before the end of boiling. A certain amount of hops was added at a time before the end of boiling. Each group of experiments with different hop addition times was repeated 4 times, and the detection time was based on 4 parallel measurements.

[0112] Table 5: Waxy rice leaf boiling single hop addition time

[0113] Addition time (end of boiling time) 0min 5min 10min 15min 20min 25min 30min 60min 90min Alpha-acid isomerization rate 7% 28% 49% 63% 68% 72% 75% 91% 93% Aroma substance content (μg / L) 0.2 15.2 13.2 10.6 8.8 6.4 3.1 1.7 1.1

[0114] As shown in Table 5, during the waxy rice leaf boiling process, the earlier the hops are added before the end of boiling, the longer the hops are cooked, the higher the isomerization rate of α-acid in the hops, the more bitter substances are converted, and the bitterness is heavier. The later the hops are added before the end of boiling, the shorter the hops are cooked, the lower the degree of volatilization of aroma substances in the hops, the more aroma substances are contained, and the hop aroma is more fragrant. (Among them, the hops need to be cooked before the aroma substances can be dissolved into the wort. Therefore, adding hops 5 minutes before the end of boiling will produce more aroma substances.)

[0115] Therefore, in order to realize the bitter taste support and the hop aroma reservation of the rag beer, the hops are added twice, the first time for increasing the bitterness of the beer body and the second time for increasing the aroma of the beer body.

[0116] Experimental Example Three

[0117] In this embodiment, in order to ensure the fusion of flavor molecules during fermentation and storage, maintain the flavor of the beer body, and avoid the influence of chemical clarifying agents on the flavor of the beer body, a long-time gradient slow cooling fermentation and storage method is adopted. In order to determine whether the gradient cooling has an influence on the flavor and clarity of the beer body, a plurality of control groups with different cooling rates and storage times are set up for comparison experiments.

[0118] The configuration conditions of this experimental group a are as follows:

[0119] After the wort is fermented by the yeast for 1-2 weeks, the gradient cooling is performed, the experiments of each group with different storage times are repeated 4 times, and the detection time is based on the 4 parallel measurement values.

[0120] Table 6: Fermentation and storage time of wort

[0121] Storage time 0 days 5 days 10 days 15 days 20 days 25 days 30 days 35 days 40 days Turbidity 7.1NTU 6.1NTU 4.9NTU 3.7NTU 3.1NTU 2.7NTU 2.4NTU 2.2NTU 2.1NTU Body TBA value (mg / kg) 0.64 0.53 0.44 0.36 0.30 0.25 0.21 0.17 0.14

[0122] As shown in Table 6, during the wort cooling and storage process, with the increase of the storage days, the turbidity of the beer body gradually decreases, and the TBA value (thiobarbituric acid value) of the beer body also gradually decreases. The decrease rate of the turbidity of the beer body presents a power function curve distribution (the power function index is a negative number). When the beer body is stored for more than 15 days, the decrease rate of the turbidity begins to significantly decrease. Until 40 days, the turbidity of the beer body gradually stabilizes at about 2 NTU. Therefore, the optimal storage time of the rag beer should be 2 weeks-6 weeks.

[0123] The TBA value of the beer body is a key index for measuring the aging degree and flavor stability of the beer. The gradual decrease of the TBA value indicates that the flavor substances in the beer body begin to fuse and form a balance, the oxidation and decomposition of the flavor substances gradually decrease, and the flavor of the beer gradually tends to be stable. When the TBA value of the beer body is lower than 0.4 mg / kg, the oxidation taste of the beer body is not obvious, and the flavor begins to be stable.

[0124] The configuration conditions of this experimental group b are as follows:

[0125] After the wort is fermented by the yeast for 1-2 weeks, the gradient cooling is performed, the experiments of each group with different storage times are repeated 4 times, and the detection time is based on the 4 parallel measurement values.

[0126] Table 7: Fermentation and storage time of wort

[0127] Cooling amplitude (℃ / day) 0 1 2 4 6 8 10 12 14 Yeast rupture rate 1% 3% 7% 15% 22% 27% 30% 31% 33% Body bitterness value 34BU 15BU 18BU 21BU 23BU 26BU 30BU 30BU 32BU

[0128] As shown in Table 7, during the wort cooling and storage process, the greater the cooling range, the more severe the temperature change that the yeast in the wine body will bear, which will increase the yeast rupture rate, thus producing off-flavors, making the wine body bitter, and the wine body bitterness value increasing. Therefore, the lower the cooling range, the lower the yeast rupture rate in the whole wine body, so by cooling at a gradient of 1℃ per day, the flavor of the wine body can be maintained and the production of off-flavors can be reduced.

[0129] It is worth noting that, as shown in Table 6, the fermentation and storage period of the whole waxy rice lager beer is controlled at 2-6 weeks, so by cooling at a gradient of 1℃ per day, the initial fermentation temperature can be brought to 0℃ before the two-week storage period, maintaining low-temperature storage conditions.

[0130] It is worth noting that in Table 7, when the cooling range is 0 (i.e. always maintained at 14℃), the wine body will become bitter after fermentation and storage, because the fermentation and storage temperature is relatively high, and in a high-temperature environment, the yeast metabolism rate will increase, which will produce off-flavors, and various flavor substances will also be more prone to oxidation reactions at high temperatures, thus increasing the TBA value and turbidity of the wine body, and further producing off-flavors and bitterness, affecting the flavor of the wine body.

[0131] The above is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for manufacturing glutinous rice lager beer, characterized by, Includes the following steps: Step 1. Grind the malt, controlling the grinding degree to 40-50% fine powder, while retaining the integrity of the malt husk in the coarse powder; Step 2. Add the crushed malt to soft water and saccharify in stages with controlled temperature. The saccharification process is as follows: protein rest at 50℃ for 20 minutes, saccharification at a low temperature of 65℃ for 60 minutes, saccharification at a high temperature of 69℃ for 10 minutes, and gelatinization at 78℃ for 10 minutes. Step 3. Slowly filter the saccharified wort under normal pressure; Step 4. After filtering the wort, add the fermented rice and mix. Wash the lees, keeping the water temperature at 78℃. Step 5. Boil and concentrate the wort from Step 4 for 90 minutes. After boiling, lower the pH of the wort to 5.2-5.

4. Step 6. Add glutinous rice and bay leaves 30 minutes before the end of boiling, add hops 30-15 minutes before the end of boiling, and add hops a second time 5 minutes before the end of boiling. Step 7. Cool the wort to the fermentation temperature, pour it into a sealed fermentation tank, add activated yeast, and purge with sterile gas, maintaining a pressure of 0.1-0.15 MPa, and ferment for 1-2 weeks; Step 8. Reduce the temperature gradient of the fermented wort to 0°C and store it at low temperature for 3-6 weeks until it clarifies naturally; The method for making fermented rice in step 4 is as follows: S4.1 Soak glutinous rice in water for 5-8 hours, with a weight ratio of glutinous rice to water of 1:2; S4.2 After soaking, filter out the glutinous rice and steam it for 15-20 minutes. S4.3 After the glutinous rice is steamed, add sterile water and cool it to room temperature before adding yeast and stirring. S4.4 The stirred glutinous rice is put into a fermentation tank and fermented for 7 days, and the fermented rice wine is separated. In step 7, the initial temperature for wort fermentation is set to 12°C. When the wort fermentation sugar content drops to 3°P, seal the container and raise the temperature to 14°C, maintaining this temperature for 72 hours. In step 8, the temperature of the fermented wort is gradually reduced to 0°C at a rate of 1°C per day. The weight ratio of added malt, rice wine, glutinous rice leaves, and hops is set to 250:75:2:0.

75. In step 6, during the wort boiling process, the ratio of hops added in the two stages is 1:

2. The malt used in step 1 is light-colored barley malt.

2. The method of claim 1, wherein the waxy rice Lager beer is characterized by, In step 2, the calcium content in the soft water is set between 50-100 ppm, and the sulfate content is <200 ppm.

3. The method of claim 1, wherein the waxy rice Lager beer is characterized by, In step 4, the wort concentration after rinsing is set to 90%-95% of the target beer value.

4. The method of claim 1, wherein the waxy rice Lager beer is characterized by, In step 7, the yeast is activated by cooled boiled water.