Beer brewing process adopting two-time sequential fermentation

Abstract

The invention relates to the technical field of beer, and discloses a two-time sequence fermentation beer brewing process, which comprises the steps of saccharification and fermentation, the fermentation step comprises a first round of upper fermentation and a second round of lower fermentation, according to different strain characteristics, upper strain fermentation is firstly carried out, then lower strain fermentation is carried out, and after the upper strain fermentation is finished, the lower strain fermentation is carried out. Yeast is removed through a centrifugal sequence, and then wort and the yeast below are added for fermentation, so that each fermentation is guaranteed to be pure fermentation, and the product is controllable in flavor, good in consistency and good in stability. According to the invention, the novel and unique-flavor beer with Aire flavor and Lager flavor can be produced by compounding the flavor differences of the two yeasts.

Description

Technical Field

[0001] The invention relates to the technical field of beer processing, and in particular to a secondary sequential fermentation beer brewing process. Background Art

[0002] Beer is one of the oldest alcoholic beverages in human history and the third most consumed beverage in the world after water and tea. It can replenish nutrients in the body, maintain the balance of electrolytes in the body, and has a certain effect on preventing hypertension and gastritis.

[0003] Beer is a low-alcohol beverage rich in carbon dioxide and made from barley malt, hops and water through yeast fermentation. It is called "liquid bread" and is a low-concentration alcoholic beverage.

[0004] Secondary fermentation is a process for producing beer, which can improve the aroma and taste of beer and produce beer with unique flavor. However, most of the existing secondary fermentation methods are to mix yeasts together for fermentation. During fermentation, various yeasts compete with each other, and the fermentation consistency is difficult to control, resulting in poor stability of the final product. Summary of the invention

[0005] The present invention is proposed to solve the problem that various yeasts compete with each other during fermentation, fermentation consistency is difficult to control, and the stability of the final product is poor.

[0006] The present invention provides a secondary sequential fermentation beer brewing process, comprising the following steps:

[0007] 1) Saccharification: Saccharification is the process in which the malt contents continue to dissolve and decompose under the action of enzymes. After the malt and auxiliary material crushed materials are mixed with water, they are kept at different temperature ranges for a certain period of time, so that the enzymes in the malt can fully act on the corresponding substrates under the most suitable conditions, decompose them and dissolve them in water. The mixed liquid after the raw materials and auxiliary material crushed materials are mixed with water is called "mash" (liquid), and the mash after saccharification is called saccharification liquid. Various dry substances (solutes) dissolved in water are called "extracts". The extracts are composed of fermentable and non-fermentable substances. The saccharification process should extract as much malt dry matter as possible and decompose them appropriately under the action of enzymes. The specific steps are as follows;

[0008] 1.1 According to the formula table, weigh the malt raw materials by weight: 350 parts of added wheat, 500 parts of low-value wheat malt, 75 parts of 25EBC Munich malt, 25 parts of 40EBC caramel malt, and 25 parts of oat rice;

[0009] Auxiliary materials: CaSO4 1.5 parts, ZnSO4·7H2O 0.005 parts;

[0010] Hops: 0.5 parts of Qingdao hops, 1 part of imported Hallertau traditional hops, 2 parts of imported Cascade hops;

[0011] 1.2 The wet grinding feeding process is adopted, and the feeding temperature is 37.0±0.5℃. The weighed malt raw materials are ground while adding water. The ground materials are put into the saccharification pot and stirred evenly. After the saccharification feeding is completed, CaSO4 is added to the saccharification pot. The low temperature of 37.0±0.5℃ is adopted to facilitate the leaching of enzymes and ferulic acid in malt and produce more 4-VG (4-vinylguaiacol);

[0012] 1.3 Heating and heating up, follow the following process in sequence:

[0013] Heat the saccharification pot to 45.0±0.5℃ at a heating rate of 1℃ / min and keep warm for 20min;

[0014] Continue to heat the saccharification pot to 72.0±0.5℃ at a heating rate of 1℃ / min, and keep it warm for 30min until the iodine test is complete;

[0015] Continue to heat the saccharification pot at a heating rate of 1°C / min until the temperature reaches 77.0±0.5°C and then stop heating;

[0016] 1.4 Filter the saccharification liquid in the saccharification pot to obtain the first wort with a concentration of 17.0-18.0°P;

[0017] 1.5 Boil the filtered first wort and add different hops in turn:

[0018] Add Qingdao dahua when boiling for 10 minutes;

[0019] When boiling for 30 minutes, add the imported Hallertau traditional hops, which are produced in Germany and are a typical aromatic hop variety. They are characterized by a strong aroma and a slightly bitter taste, providing a unique taste and aroma.

[0020] When boiling for 60 minutes, add imported Cascade fragrant flowers, which are produced in the United States and are characterized by medium to high intensity floral fragrance and unique smell, with extremely significant grapefruit and citrus aroma and taste;

[0021] 1.6 Swirl precipitation for 20 minutes, add ZnSO4·7H2O during the swirling process, and put into the fermentation tank after cooling;

[0022] 2) Fermentation and wine storage

[0023] 2.1 First fermentation

[0024] 2.1.1 For the first fermentation, three batches of wort were added, each batch was 5 kL, a total of 15 kL of wort, wort temperature: 18.0 ± 0.5 ℃;

[0025] 2.1.2 Wort oxygenation: Oxygenation for each batch, sterile air flow control: 0.18~0.22m 3 / h;

[0026] 2.1.3 Yeast addition: Add into the tank along with the wort flow. In the first round, add JLQ3# yeast for fermentation. JLQ3# yeast is also called ale yeast. Yeast has poor coagulation and precipitation properties and is not easy to coagulate and precipitate. During the fermentation process, the yeast will move to the liquid surface. The fermentation temperature is high, generally between 15 and 25°C. The fermentation is vigorous and the fermentation time is short. The fermentation produces more flavor substances, rich foam, full and mellow taste, prominent aroma of the wine, and can form a good nutty and fruity taste.

[0027] 2.1.4 Condensate discharge: Condensate is discharged once every 24 hours and 48 hours when the tank is full;

[0028] 2.1.5 Main fermentation and reduction temperature: freely raise the temperature to 20.0±0.5℃ for main fermentation and diacetyl reduction;

[0029] 2.1.6 Diacetyl reduction: Test the apparent sugar content (AE value) every day. When the apparent sugar content reaches the limit AE value measured when the fermentation liquid is full + 1.5-1.7°P, seal the can for reduction. The can is sealed and the pressure is maintained at 0.10-0.12MPa.

[0030] 2.1.7 Yeast recovery: After the main fermentation is completed, the yeast shall be recovered and reused within 72 hours, and the unused yeast or excess yeast shall be discharged;

[0031] 2.1.8 Diacetyl treatment control: Start measuring diacetyl after 7 days of full tank, if diacetyl is ≤60ppb, start centrifugation to another clean fermentation tank, control the yeast count within 0.003 billion / ml, and cool to 13℃, ready to receive wort and yeast for the second fermentation.

[0032] 2.2 Second fermentation

[0033] 2.2.1 The second fermentation is carried out in 5 kl of the fermentation liquid from the above fermentation, and the wort temperature is 12.5 ± 0.5 ℃;

[0034] 2.2.2 Wort oxygenation: Sterile air flow control: 0.18~0.22m 3 / h;

[0035] 2.2.3 Yeast addition: Add into the tank with the wort flow, add strain JLQ8# bottom fermentation yeast, JLQ8# yeast is also called lager yeast, yeast has good cohesion, after fermentation, yeast settles at the bottom of the wine, fermentation temperature is low, generally 4 ~ 12 ℃, fermentation time is long, the wine needs to be stored at low temperature in the later stage, lager beer has rich foam, delicate, soft and clean taste, obvious hop aroma, and prominent ester aroma;

[0036] According to the design requirements, the flavor of the strains above or below can be achieved. The preference for different flavors can be achieved by adjusting the ratio of the wort fermented above and below.

[0037] 2.2.4 Condensate discharge: Condensate is discharged once every 24 hours and 48 hours when the tank is full;

[0038] 2.2.5 Main fermentation and reduction temperature: freely raise the temperature to 13.0±0.5℃ for main fermentation and diacetyl reduction;

[0039] 2.2.6 Diacetyl reduction: test the apparent sugar content (AE value) every day, seal the cans for reduction when the AE value is +1.5~1.7°P, and keep the cans at a pressure of 0.10~0.12MPa;

[0040] 2.2.7 Yeast recovery: The yeast is not recycled and is directly discharged into the waste yeast pool.

[0041] 2.2.8 Diacetyl treatment control: Start measuring diacetyl after the tank is full for 9 days. If diacetyl is ≤40ppb, cool the wine to -1℃~-2℃ for storage;

[0042] 2.2.9 Waste yeast discharge: Discharge once a day during canning, during the reduction period, and when the temperature drops to 0°C. Discharge once every 2 to 3 days during the post-storage period until there is no obvious yeast precipitation.

[0043] 2.3 Beer centrifugation and packaging

[0044] 2.3.1 Remove the yeast and see the wine, then start centrifugation, the yeast count should be controlled within 0.001 billion / ml;

[0045] 2.3.2 Delivery to the packaging workshop for filling and packaging into finished wine.

[0046] Furthermore, in step 2.1.3, during the first round of yeast addition, the yeast count in the full tank is controlled at 70-130 million / ml.

[0047] Furthermore, in step 2.2.3, during the second round of yeast addition, the yeast count in the full tank is controlled at 0.07 to 0.13 billion / ml.

[0048] Furthermore, the amount of wort introduced into the first fermentation step 2.1.1 is 5 kL, and the amount of wort introduced into the fermentation liquid at the end of the above fermentation in the second fermentation step 2.2.1 is 15 kL.

[0049] Furthermore, after step 1.4, the method further includes a step of washing the remaining sorghum grains after filtering the saccharification liquid, wherein the residual sugar in the washed grains is 2.0-2.5°P and the water temperature for washing the grains is 76.5-77.5°C.

[0050] Compared with the prior art, the advantages of the present invention are:

[0051] 1. According to the characteristics of different strains, the present invention first performs fermentation of the upper strain and then performs fermentation of the lower strain. After the fermentation of the upper strain is completed, the yeast is removed by centrifugation, and then wort and the lower yeast are added for fermentation, thereby ensuring that each fermentation is pure strain fermentation, and the flavor of the product is controllable, and the consistency and stability are good.

[0052] 2. Utilize the flavor differences of the two yeasts to produce a new type of unique beer with both ale and lager flavors.

[0053] 3. By controlling the ratio of the wort fermented above and below, the flavors produced by different styles of yeast can be highlighted. Both ale-flavored beer and lager-flavored beer can be produced.

[0054] 4. The method of fermenting above first and then below solves the problem that the fermentation tank can only be cooled but not heated, and the problem of high-temperature fermentation temperature control of yeast strains above. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 is a process flow chart of the saccharification process of Example 1,

[0057] Figure 2 The fermentation process flow chart of Example 1 is shown in FIG. DETAILED DESCRIPTION

[0058] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below in conjunction with embodiments. The description in this section is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention.

[0059] Example 1

[0060] 1)Reference Figure 1 ,according to Figure 1 The process flow for saccharification:

[0061] 1.1 According to the raw material formula table 1 (concentration: 13.0°P; output 5k1), weigh the materials:

[0062] Table 1

[0063]

[0064] 1.2 Add 3kL of water to the saccharification pot, with a material-water ratio of 1:3.25, and heat it to 37.0±0.5℃. Use the wet grinding feeding process to grind the weighed malt raw materials. Wet grinding is the process of grinding solid materials with water or its solution as the medium. That is to say, when the raw materials are ground, add water while grinding. Put the ground materials into the saccharification pot and stir them evenly. After the saccharification feeding is completed, add 1.5kg of CASO4 to the saccharification pot;

[0065] 1.3 Heating and heating up, follow the following process in sequence:

[0066] Heat the saccharification pot to 45.0±0.5℃ at a heating rate of 1℃ / min and keep it warm for 20min;

[0067] Continue to heat the saccharification pot to 72.0±0.5℃ at a heating rate of 1℃ / min, and keep it warm for 30min until the iodine test is complete;

[0068] Continue to heat the saccharification pot at a heating rate of 1°C / min until the temperature reaches 77.0±0.5°C and then stop heating;

[0069] 1.4 Filter the saccharification liquid in the saccharification pot to obtain the first wort with a concentration of 17.0-18.0°P. After filtering, the remaining slag after filtering the saccharification liquid needs to be washed. The residual sugar in the washed slag is 2.0-2.5°P, and the water temperature for washing slag is 76.5-77.5℃;

[0070] 1.5 Boil the filtered first wort and add different hops in turn:

[0071] When boiling for 10 minutes, add 0.5 kg of Qingdao Dahua;

[0072] Add 1kg of imported Hallertau traditional hops when boiling for 30 minutes;

[0073] Add 2kg of imported Cascade fragrant flowers when boiling for 60 minutes;

[0074] During the initial boiling, the wort can be circulated to avoid overflowing. The initial boiling wort yield of 5kL / batch is 5.4-5.6kL, and the initial boiling wort concentration is 12.8-13.3°P.

[0075] 5kl / batch wort yield: 5.0~5.2kL, wort concentration: 13.15~13.55°P;

[0076] The boiling evaporation rate is controlled at: 6-8% at normal pressure;

[0077] 1.6 Swirl precipitation for 20 minutes, add ZnSO4·7H2O during the swirling process, cool and put into the fermentation tank, swirling time ≤20 minutes, precipitation time: 20 minutes, rapid cooling temperature: 20.0℃, rapid cooling time ≤60 minutes, ice water temperature: 3~5℃, wort oxygenation: oxygenation for each batch, sterile air flow control: 0.18~0.22m 3 / h.

[0078] 2)Reference Figure 2 ,according to Figure 2 Fermentation process:

[0079] 2.1 First fermentation

[0080] 2.1.1 For the first fermentation, three batches of wort were added, each batch was 5 kL, a total of 15 kL of wort, wort temperature: 18.0 ± 0.5 ℃;

[0081] 2.1.2 Wort oxygenation: Oxygenation for each batch, sterile air flow control: 0.18~0.22m 3 / h;

[0082] 2.1.3 Yeast addition: Add into the tank along with the wort flow. In the first round, add strain JLQ3# yeast for fermentation. The number of yeast in the full tank is controlled at 700-1300 million / ml. JLQ3# yeast is also called ale yeast. Yeast has poor coagulation and precipitation properties and is not easy to coagulate and precipitate. During the fermentation process, the yeast will move to the liquid surface. The fermentation temperature is high, generally 15-25°C. The fermentation is vigorous and the fermentation time is short. The fermentation produces more flavor substances, rich foam, full and mellow taste, prominent wine aroma, and can form a good nutty and fruity taste. The formula of fermentation raw materials and auxiliary materials is shown in Table 2:

[0083] Table 2

[0084]

[0085] 2.1.4 Condensate discharge: Condensate is discharged once every 24 hours and 48 hours when the tank is full;

[0086] 2.1.5 Main fermentation and reduction temperature: freely raise the temperature to 20.0±0.5℃ for main fermentation and diacetyl reduction;

[0087] 2.1.6 Diacetyl reduction: Test the apparent sugar content (AE value) every day. When the apparent sugar content reaches the limit AE value measured when the fermentation liquid is full + 1.5-1.7°P, seal the can for reduction. The can is sealed and the pressure is maintained at 0.10-0.12MPa.

[0088] 2.1.7 Yeast recovery: After the main fermentation is completed, the yeast shall be recovered and reused within 72 hours, and the unused yeast or excess yeast shall be discharged;

[0089] 2.1.8 Diacetyl treatment control: Start measuring diacetyl after the tank is full for 7 days. If diacetyl is ≤60ppb, start centrifugation to another clean fermentation tank. The yeast count is controlled within 0.003 billion / ml and cooled to 13℃ to prepare for the second fermentation of wort and yeast.

[0090] 2.2 Second fermentation

[0091] 2.2.1 The second fermentation is carried out in 5 kL of the fermentation liquid from the above fermentation, and the wort temperature is 12.5 ± 0.5 ℃;

[0092] 2.2.2 Wort oxygenation: Sterile air flow control: 0.18~0.22m 3 / h;

[0093] 2.2.3 Yeast addition: Add into the tank along with the wort flow, add JLQ8# yeast for bottom fermentation, and control the yeast count in the tank to 700-1300 million / ml; JLQ8# yeast is also called lager yeast, which has good cohesiveness. After fermentation, the yeast settles to the bottom of the beer. The fermentation temperature is low, generally 4-12°C, and the fermentation time is long. The beer needs to be stored at low temperature in the later stage. Lager beer has rich foam, delicate, soft and clean taste, obvious hop aroma and prominent ester aroma;

[0094] According to the design requirements, the flavor of the strains above or below can be achieved. The preference for different flavors can be achieved by adjusting the ratio of the wort fermented above and below.

[0095] 2.2.4 Condensate discharge: Condensate is discharged once every 24 hours and 48 hours when the tank is full;

[0096] 2.2.5 Main fermentation and reduction temperature: freely raise the temperature to 13.0±0.5℃ for main fermentation and diacetyl reduction;

[0097] 2.2.6 Diacetyl reduction: Test the apparent sugar content (AE value) every day. When the apparent sugar content reaches the limit AE value measured when the fermentation liquid is full + 1.5-1.7°P, seal the can for reduction. The can is sealed and the pressure is maintained at 0.10-0.12MPa.

[0098] 2.2.7 Yeast recovery: The yeast is not recycled and is directly discharged into the waste yeast pool;

[0099] 2.2.8 Diacetyl treatment control: Start measuring diacetyl after the tank is full for 9 days. If diacetyl is ≤40ppb, cool the wine to -1℃~-2℃ for storage;

[0100] 2.2.9 Waste yeast discharge: Discharge once a day during canning, during the reduction period, and when the temperature drops to 0°C. Discharge once every 2 to 3 days during the post-storage period until there is no obvious yeast precipitation.

[0101] 2.3 Beer centrifugation and packaging

[0102] 2.3.1 Remove the yeast and see the wine, then start centrifugation, the yeast count should be controlled within 0.001 billion / ml;

[0103] 2.3.2 Delivery to the packaging workshop for filling and packaging into finished wine.

[0104] Example 2

[0105] Compared with Example 1, the difference is that the amount of wort in the first upper fermentation is adjusted from 15kL to 5kL, and the amount of wort in the second lower fermentation is adjusted from 5kL to 15kL; the other processes are the same.

[0106] Comparative Example 1

[0107] Compared with Example 1, the difference is that only JLQ3# above strain is used for fermentation, the wort volume is 15kL, and after the diacetyl reduction of the above strain is completed, the temperature is directly cooled to -1°C ~ -2°C for storage; other processes are the same, and the prepared ale wheat beer is used as Comparative Example 1.

[0108] Comparative Example 2

[0109] Compared with Example 1, the difference is that only JLQ3# bottom strain is used for fermentation, the wort volume is 15kL, and after the diacetyl reduction of the bottom strain fermentation is completed, the temperature is directly cooled to -1°C ~ -2°C for storage; other processes are the same, and the prepared lager wheat beer is used as Comparative Example 2.

[0110] The final wine quality of this embodiment is shown in Table 3.

[0111] Table 2

[0112]

[0113] It can be seen from Table 3 that in two examples and two comparative examples:

[0114] ① The test results of original wort concentration, alcohol content, diacetyl and other indicators are similar;

[0115] ②The acidity index of JLQ3# upper yeast is slightly higher than that of JLQ8# lower yeast;

[0116] ③ Among the flavor substance indicators, the ester aroma, mellow aroma, and 4-VG aroma produced by the yeast of JLQ3# are all prominent, which are much higher than those of the yeast of JLQ3#. The flavor indicators of the two yeasts are quite different;

[0117] ④ In Example 1, the fermentation ratio of the above yeast accounts for 75%, and the product style is more like ale flavor, but the aroma is relatively softer than that of single ale, with richer layers and longer lasting;

[0118] In Example 2, the fermentation ratio of the above yeast is 25%, and the product style is lager-flavored, and has the clove flavor unique to ale wheat beer. The aroma is more prominent than that of single lager beer, and the layers are richer and more persistent. The taste of the two comparative examples is relatively single and does not have the characteristics of rich layers.

[0119] ⑤ The present invention can utilize the flavor differences of the two yeasts to compositely produce a new type of beer with unique flavor that has both ale flavor and lager flavor.

[0120] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A secondary sequential fermentation beer brewing process, characterized in that it comprises the following steps: 1) Saccharification 1.1 According to the formula table, weigh the malt raw materials by weight: 350 parts of added wheat, 500 parts of low-value wheat malt, 75 parts of 25EBC Munich malt, 25 parts of 40EBC caramel malt, and 25 parts of oat rice; Auxiliary materials: CaSO4 1.5 parts, ZnSO4·7H2O 0.005 parts; Hops: 0.5 parts of Qingdao hops, 1 part of imported Hallertau traditional hops, 2 parts of imported Cascade hops; 1.2 Use wet grinding and feeding technology, with a feeding temperature of 37.0±0.5℃, grind the weighed malt raw materials, add water while grinding, put the ground materials into the saccharification pot and stir evenly, and add CaSO4 to the saccharification pot after saccharification and feeding; 1.3 Heating temperature, follow the following process in sequence: Heat the saccharification pot to 45.0±0.5℃ at a heating rate of 1℃ / min and keep it warm for 20min; Continue to heat the saccharification pot to 72.0±0.5℃ at a heating rate of 1℃ / min, and keep it warm for 30min until the iodine test is complete; Continue to heat the saccharification pot at a heating rate of 1°C / min until the temperature reaches 77.0±0.5°C and then stop heating; 1.4 Filter the saccharification liquid in the saccharification pot to obtain the first wort with a concentration of 17.0-18.0°P; 1.5 Boil the filtered first wort and add different hops in turn: Add Qingdao dahua when boiling for 10 minutes; Add imported Hallertau traditional hops when boiling for 30 minutes; Add imported Cascade fragrant flowers when boiling for 60 minutes; 1.6 Swirl and precipitate for 20 minutes, add ZnSO4·7H2O during the swirling process, and put into the fermentation tank after cooling; 2) Fermentation and wine storage 2.1 First fermentation 2.1.1 Three batches of wort were fermented for the first time, 5 kL each, a total of 15 kL wort, wort temperature: 18.0 ± 0.5 ℃; 2.1.2 Wort oxygenation: Oxygenation for each batch, sterile air flow control: 0.18~0.22m 3 / h; 2.1.3 Yeast addition: Add into the tank along with the wort flow, add strain JLQ3# for top fermentation yeast in the first round; 2.1.4 Condensate discharge: Condensate is discharged once every 24 hours and 48 hours when the tank is full; 2.1.5 Main fermentation and reduction temperature: freely raise the temperature to 20.0±0.5℃ for main fermentation and diacetyl reduction; 2.1.6 Diacetyl reduction: Test the apparent sugar content (AE value) every day. When the apparent sugar content reaches the limit AE value measured when the fermentation liquid is full + 1.5-1.7°P, seal the can for reduction. The can is sealed and the pressure is maintained at 0.10-0.12MPa. 2.1.7 Yeast recovery: After the main fermentation is completed, the yeast shall be recovered and reused within 72 hours, and the unused yeast or excess yeast shall be discharged; 2.1.8 Diacetyl treatment control: Start measuring diacetyl after 7 days of full tank, if diacetyl is ≤60ppb, start centrifugation to another clean fermentation tank, control the yeast count within 0.003 billion / ml, and cool to 13℃, ready to receive wort and yeast for the second fermentation; 2.2 Second fermentation 2.2.1 The second fermentation is carried out in 5 kL of the fermentation liquid from the above fermentation, and the wort temperature is 12.5 ± 0.5 ℃; 2.2.2 Wort oxygenation: Sterile air flow control: 0.18~0.22m 3 / h; 2.2.3 Yeast addition: Add into the tank along with the wort flow, add strain JLQ8# yeast for bottom fermentation; 2.2.4 Condensate discharge: Condensate is discharged once every 24 hours and 48 hours when the tank is full; 2.2.5 Main fermentation and reduction temperature: freely raise the temperature to 13.0±0.5℃ for main fermentation and diacetyl reduction; 2.2.6 Diacetyl reduction: test the apparent sugar content (AE value) every day, seal the cans for reduction when the AE value is +1.5~1.7°P, and keep the cans at a pressure of 0.10~0.12MPa; 2.2.7 Yeast recovery: The yeast is not recycled and is directly discharged into the waste yeast pool; 2.2.8 Diacetyl treatment control: Start measuring diacetyl after the tank is full for 9 days. If diacetyl is ≤40ppb, cool the wine to -1℃~-2℃ for storage; 2.2.9 Waste yeast discharge: Discharge once a day during canning, during the reduction period, and when the temperature drops to 0°C. Discharge once every 2 to 3 days during the post-storage period until there is no obvious yeast precipitation; 2.3 Beer centrifugation and packaging 2.3.1 Remove the yeast and see the wine, then start centrifugation, the yeast count should be controlled within 0.001 billion / ml; 2.3.2 Delivery to the packaging workshop for filling and packaging into finished wine.

2. A secondary sequential fermentation beer brewing process according to claim 1, characterized in that: Step 2.1.3: When adding yeast for the first time, the yeast count in the full tank is controlled at 700 million to 130 million per ml.

3. A secondary sequential fermentation beer brewing process according to claim 1, characterized in that: Step 2.2.3 During the second round of yeast addition, the yeast count in the full tank is controlled at 700 million to 130 million per ml.

4. A secondary sequential fermentation beer brewing process according to claim 1, characterized in that: The amount of wort introduced in the first fermentation step 2.1.1 is 5 kL, and the amount of wort introduced in the fermentation liquid at the end of the second fermentation step 2.2.1 is 15 kL.

5. A secondary sequential fermentation beer brewing process according to claim 1, characterized in that: After step 1.4, the method also includes a step of washing the remaining sorghum grains after filtering the saccharification liquid. The residual sugar in the washed sorghum grains is 2.0-2.5°P, and the water temperature for washing the sorghum grains is 76.5-77.5°C.

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