Gelatinization process of grains in the brewing process of Luzhou-flavor liquor

Abstract

The application discloses a grain gelatinization process in the brewing process of Luzhou-flavor liquor, and comprises the following steps: A. crushing sorghum; B. adding water to the crushed sorghum and stirring simultaneously; C. standing and keeping warm; D. spreading the crushed sorghum after being moistened and removing sundries; E. mixing the crushed sorghum with mother liquor from a pit uniformly; F. adding rice husks to the grain mash and stirring uniformly; G. putting the stirred grain mash into a steaming vat, and raising the temperature of each layer of the grain mash in the steaming vat to 88-89 DEG C; H. starting distillation and liquor extraction after the steaming vat is closed, and gradually raising the temperature in the steaming vat from 88-89 DEG C to 100-101 DEG C; I. performing high-heat steaming and grain gelatinization, controlling the surface pressure in the steaming vat to be 320-380 Pa, and controlling the temperature to be 100-101 DEG C; J. spraying water; and K. spreading and airing the grain mash after being taken out of the steaming vat. The step of keeping warm after moistening the grain improves the uniformity of water absorption of the sorghum powder, and lays a homogeneous foundation for subsequent gelatinization; and the temperature field and pressure field in the steaming vat are controlled during liquor extraction and grain steaming, so that the sorghum starch is fully gelatinized in a stable steam environment, and the uniformity of gelatinization is improved.

Description

Technical Field

[0001] This invention relates to the field of baijiu brewing technology, specifically to a grain gelatinization process in the brewing of strong-aroma baijiu. Background Technology

[0002] Strong-aroma baijiu is renowned for its unique style characterized by "rich cellar aroma, mellow sweetness, and clean finish." Its typical production process involves "solid-state fermentation in mud cellars, continuous addition of mash and ingredients, and mixed steaming and distillation." During distillation, the cooking and gelatinization of sorghum and the distillation of the liquor occur simultaneously in the same still. Gelatinization refers to the process where the starch granules in the sorghum absorb water, swell, and rupture under high temperature and humidity conditions, transforming into fermentable substances. The gelatinization effect directly affects the subsequent fermentation process and the alcohol yield.

[0003] In traditional strong-aroma baijiu production, although a wealth of experience has been accumulated, the process parameters in the gelatinization stage (such as the soaking and heat preservation time, steam flow rate, and cooking pressure) often vary depending on the worker's experience, lacking refined and standardized control. For example, insufficient soaking and heat preservation time can lead to problems such as raw and hard cores, floating water, and clumping of grain powder, resulting in poor gelatinization and affecting fermentation. During the cooking process, improper control of steam flow rate can cause pressure fluctuations inside the still, affecting the quality of the distillate and causing uneven gelatinization. Summary of the Invention

[0004] To overcome the problems of reliance on experience and unstable gelatinization effect in the existing grain gelatinization process of strong-aroma baijiu brewing, this invention provides a grain gelatinization process in the brewing process of strong-aroma baijiu.

[0005] The technical solution adopted by this invention to solve its technical problem is: The grain gelatinization process in the brewing of strong-aroma baijiu includes the following steps: A. Raw material crushing: Sorghum is selected as the raw material for crushing. B. Moistening the grain: Add water to the crushed sorghum to moisten it, and stir simultaneously; C. Insulation: After the grain is moistened and stirred, let it stand and be kept warm for a period of time; D. Spreading out and removing impurities: After the heat preservation is completed, spread out the broken sorghum that has been moistened to remove impurities. During the process, it can be turned over appropriately to promote natural cooling. E. Mixing the grain: Mix the soaked and crushed sorghum with the fermented mash; F. Mixing with chaff: Add rice husks to the mixed grain mash and mix well; G. Steaming: The well-mixed mash is steamed for 30-45 minutes, and the temperature of each layer of mash in the steamer gradually rises from room temperature to 88℃-89℃. H. Distillation: After the stills are combined, distillation begins. After the stills are combined and the liquor is collected, the gauge pressure inside the still is controlled between 110Pa and 150Pa. The time from combining the stills to the end of the liquor collection is 18 to 23 minutes. The temperature inside the still gradually rises from 88℃ to 89℃ to 100℃ to 101℃. I. Steaming the grains: After the distillation is completed, the grains are steamed over high heat to gelatinize them. The pressure inside the still is controlled between 320Pa and 380Pa, and the temperature inside the still is between 100℃ and 101℃. The steaming time is maintained at high heat for 42 to 47 minutes. J. Add water: Open the steamer lid and add water to the steamed mash. K. Spreading out of the steamer: After the fermented mash has absorbed water evenly, it is removed from the steamer and spread out to cool.

[0006] In this application, an additional heat preservation step is added after the grain soaking to improve the uniformity of water absorption of sorghum flour, laying a homogeneous foundation for subsequent gelatinization; during the distillation and steaming stages, the temperature and pressure fields inside the still are controlled to ensure that the sorghum starch is fully gelatinized in a stable steam environment, thereby improving the uniformity of gelatinization.

[0007] In some embodiments, the sorghum breakage requirement in step A is that 6% to 10% of the sorghum passes through a 20-mesh sieve, and the sorghum breakage rate is ≥99%.

[0008] In some embodiments, the synchronous stirring time in step B is 12-15 minutes; the heat preservation time in step C is 30-50 minutes.

[0009] In some embodiments, in step E, the sorghum that has been moistened is mixed with the mother lees from the cellar at a mass ratio of 1:3 to 5, and the moisture content of the mother lees from the cellar is between 59% and 63%.

[0010] In some embodiments, in step F, the amount of rice husks used is 18% to 25% of the sorghum mass, the rice husks are mixed 20 minutes before steaming, and the moisture content of the mash after mixing is between 51% and 53%.

[0011] In some embodiments, in step G, the steam flow rate of the upper steamer is controlled between 120 kg / h and 200 kg / h.

[0012] In some embodiments, the moisture content of the mash after adding water in step J is controlled between 57% and 61%.

[0013] In some embodiments, the moisture content after spreading out to dry in step K is controlled at 52%~58%.

[0014] In some embodiments, in steps H and I, temperature sensors are set for different mash layers, pressure sensors are set inside the steamer, and steam inlet valves are adjusted to maintain the set temperature and pressure range.

[0015] In some embodiments, the steam flow rate during the distillation stage in step H is controlled between 250 kg / h and 300 kg / h; after the distillation is completed in step I, the steam flow rate is controlled between 350 kg / h and 450 kg / h for high-heat steaming and gelatinization of the grain.

[0016] The beneficial effects of this invention are: After soaking the grains, an additional heat preservation step is added to improve the uniformity of water absorption of sorghum flour, laying a homogeneous foundation for subsequent gelatinization. During the distillation and steaming stages, the temperature and pressure fields inside the still are controlled to ensure that the sorghum starch is fully gelatinized in a stable steam environment, thereby improving the uniformity of gelatinization. Attached Figure Description

[0017] Figure 1 A flowchart of the grain gelatinization process in the brewing of strong-aroma baijiu provided by the present invention; Figure 2 The curves showing the changes in steam flow rate, temperature inside the steamer, and pressure in Example 1 are shown. Detailed Implementation

[0018] The invention will be further described below with reference to the accompanying drawings.

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] like Figure 1 As shown, this invention provides a grain gelatinization process in the brewing of strong-aroma baijiu. The aim is to achieve the following objectives by systematically optimizing key parameters such as raw material crushing degree, grain soaking and heat preservation time, steam flow rate and internal pressure during the steaming and distillation processes, and by combining real-time feedback control from temperature and pressure sensors: (1) Improve the water absorption uniformity of sorghum flour during the grain soaking stage to avoid undesirable phenomena such as gray lumps, raw and hard centers, and clumping; (2) To achieve stable control of the temperature and pressure fields inside the still during the distillation process, and to ensure uniform gelatinization of starch; (3) Overcome the shortcomings of traditional processes that rely on experience and have large parameter fluctuations, and improve the quantitative control level and process stability of the gelatinization process; (4) Improves starch utilization and alcohol yield, reduces raw material waste, and is suitable for large-scale production of strong-aroma baijiu made from sorghum.

[0021] The grain gelatinization process in the brewing of strong-aroma baijiu includes the following steps: A. Raw material crushing: Sorghum is selected as the raw material for crushing. The crushing degree requirement is that 6%~10% of the sorghum passes through a 20-mesh sieve, and the sorghum crushing rate is ≥99%.

[0022] B. Moistening the grain: Add water to the crushed sorghum to moisten the grain, and stir (mix) it simultaneously for 12-15 minutes.

[0023] C. Insulation: After the grain is moistened and turned (stirred), it is left to stand and insulate to promote the full absorption of water by the broken sorghum. The insulation time is controlled to be 30-50 minutes.

[0024] D. Spreading out and removing impurities: After the heat preservation is completed, spread out the broken sorghum after it has been soaked to remove impurities. During the process, you can turn it over appropriately to promote natural cooling and ensure that the sorghum after soaking absorbs water evenly, has no gray lumps, no hard or raw center when touched, no clumping, no off-flavors, and the moisture content is controlled between 39% and 42%.

[0025] E. Mixing the Grains: Mix the soaked crushed sorghum with the fermented mash at a mass ratio of 1:3 to 5. The moisture content of the fermented mash should be between 59% and 63%. The fermented mash contains abundant moisture, acidity, and residual starch. After mixing with the crushed sorghum, the moisture and acidity in the mash can further regulate the physicochemical properties of the mash, which is beneficial for subsequent gelatinization and fermentation.

[0026] F. Mixing with rice husks: Add rice husks to the mixed grain mash and mix thoroughly. The amount of rice husks should be 18% to 25% of the sorghum weight. The mixing with rice husks should be done 20 minutes before steaming to prevent the rice husks from absorbing too much moisture and affecting the steam penetration efficiency. After mixing thoroughly, the moisture content of the mash should be between 51% and 53%.

[0027] G. Steaming: The mixed mash is steamed into the steamer. During the steaming stage, steam is introduced and the mash is spread evenly. The steam flow rate is controlled between 120 kg / h and 200 kg / h to ensure that the steam rises evenly. The steaming time is controlled between 30 and 45 minutes. The temperature of each layer of mash in the steamer gradually rises from room temperature to 88℃ to 89℃.

[0028] H. Distillation: After the still is combined, distillation begins. During the distillation process, the steam flow rate is controlled between 250 kg / h and 300 kg / h. After the still is combined and the distillation begins, the gauge pressure inside the still is controlled between 110 Pa and 150 Pa. The time from the combination of the still to the end of the distillation process is 18 to 23 minutes. The temperature inside the still gradually rises from 88℃ to 89℃ to 100℃ to 101℃.

[0029] I. Steaming the grains: After the distillation is completed, the steam flow rate is controlled between 350 kg / h and 450 kg / h for high-heat steaming and gelatinization of the grains. The gauge pressure inside the still is controlled between 320 Pa and 380 Pa, and the temperature inside the still is controlled between 100℃ and 101℃. The high-heat steaming time is maintained for 42 to 47 minutes.

[0030] In the above-mentioned sorghum gelatinization process steps H and I, the temperature of the mash and the pressure inside the still are monitored in real time by temperature sensors of different mash layers and pressure sensors of the still lid. The steam inlet valve is adjusted in response to maintain the set temperature and pressure range, ensuring uniform and stable gelatinization. The time from distillation to the end of steaming is 60 to 70 minutes.

[0031] J. Adding water: Open the steamer lid and pour hot water into the cooked mash to allow the starch to further absorb water, expand, and gelatinize, while simultaneously adjusting the moisture content of the mash before it enters the pit. Water can be added once or multiple times to ensure even distribution, full absorption and expansion of the grains, uniform gelatinization of the starch, and no floating water. After adding water, the moisture content of the mash should be controlled between 57% and 61%.

[0032] K. Spreading and Cooling: After the mash has absorbed water evenly, it is spread out of the steamer and cooled. After cooling, the mash will be tender, firm, large, elastic, and have good suspension viscosity. The moisture content is controlled at 52%~58%.

[0033] The grain gelatinization process in the brewing of strong-aroma baijiu disclosed in this invention has at least the following advantages over existing technologies: (1) By optimizing the grain moistening process and specific operating steps, this invention improves the water absorption uniformity of sorghum flour, effectively avoiding phenomena such as gray lumps, raw and hard core, floating water, and clumping in the grain moistening process, laying a homogeneous foundation for subsequent gelatinization.

[0034] (2) This invention combines real-time monitoring and feedback adjustment of temperature and pressure sensors in the distillation and steaming stages to achieve segmented and precise control of steam flow and pressure inside the still, ensuring uniform and stable temperature and pressure fields inside the still. This allows sorghum starch to fully gelatinize under a stable steam environment, improving gelatinization uniformity. At the same time, the specific operation steps of adding water allow the mash after steaming to further complete the starch absorption, expansion, and gelatinization before exiting the still, precisely controlling the moisture content upon entering the fermentation pit, which is beneficial to the stable growth and metabolism of microorganisms during subsequent fermentation.

[0035] (3) By precisely controlling key parameters such as sorghum breakage, grain soaking and heat preservation time, steam flow rate and pressure during the steaming process, this invention overcomes the problems of traditional processes relying on experience and large parameter fluctuations, realizes quantitative control of the gelatinization process, and improves the stability of the process.

[0036] (4) The method of the present invention reduces the waste of raw materials caused by uneven gelatinization by precisely controlling the parameters of each process, and the alcohol yield can be increased by 6.1 to 7.9 percentage points. It is suitable for the large-scale production of strong-aroma baijiu made from sorghum and has broad industrial application prospects.

[0037] Example 1 A. Raw material crushing: Qualified sorghum was selected as raw material, and the original moisture content was measured to be 10.3%. The sorghum was crushed until 8.47% passed through a 20-mesh sieve, with a crushing rate of 99.3%.

[0038] B. Moistening the grain: Add water to the crushed sorghum and stir simultaneously to moisten the grain. The stirring time should be controlled within 13 minutes.

[0039] C. Keep warm: After stirring, let stand and keep warm for 35 minutes.

[0040] D. Spreading and removing impurities: After the insulation is completed, the sorghum is transferred to the spreading area and spread out to remove impurities, turning it over twice during the process. After completion, check that the sorghum flour has absorbed water evenly, has no lumps or gray residue, has no hard or raw center when rubbed between the fingers, has no clumping, and has no off-odors. The moisture content of the sorghum flour after soaking is tested to be 39.4%, which meets the requirements.

[0041] E. Mixing the grain: Mix the moistened sorghum flour with the mother mash from the pit at a mass ratio of 1:4. The actual moisture content of the mother mash was 62.1%.

[0042] F. Mixing with rice husks: Add rice husks at 23% of the weight of sorghum flour to the mixed grain mash 20 minutes before steaming, stir well, and test the moisture content of the mash before steaming to be 51.9%.

[0043] G. Steaming: The mixed mash is steamed. During the steaming stage, the steam flow rate is controlled at 150kg / h~170kg / h, and the steaming time is 37 minutes. The steaming requirements are followed: steaming and light spreading. The temperature of each layer of mash in the steamer gradually rises from room temperature to 88℃~89℃.

[0044] H. Distillation: During the distillation process, temperature sensors in the upper, middle, and lower layers of the still and pressure sensors on the still lid are used to monitor the process in real time, and the steam inlet valve is adjusted accordingly. In the distillation stage after the still is closed, a slow-fire distillation is used, with the steam flow rate controlled at 280 kg / h to 300 kg / h and the gauge pressure inside the still controlled between 110 Pa and 130 Pa. The entire process from closing the still to the end of distillation takes 20 minutes, during which the temperature inside the still gradually rises from 88℃ to 89℃ to 100℃ to 101℃.

[0045] I. Steaming the grains: After the distillation process is completed, increase the steam flow rate to steam the grains over high heat. The steam flow rate is 380 kg / h to 400 kg / h. The gauge pressure inside the still is controlled at 320 Pa to 340 Pa. The temperature of each layer of mash inside the still is between 100℃ and 101℃. The high-heat steaming stage takes 45 minutes (65 minutes from the time the still is closed to the time it is removed, and 105 minutes from the time it is placed on the still to the time it is removed).

[0046] J. Water addition: A large amount of water is evenly sprinkled into the cooked mash at one time to ensure that the grains absorb water fully and the starch expands and gelatinizes. The moisture content of the mash is measured to be 57.7%.

[0047] K. Unloading and Cooling: After the mash has absorbed water evenly, it is unloaded from the steamer and cooled. After cooling, the mash is put into the pit and becomes tender, firm, large, elastic, and has good suspension viscosity. The moisture content is tested to be 55.1%.

[0048] Figure 2 This is a monitoring data curve chart for the entire process of Example 1, from loading to unloading, fully covering the three process stages: loading (0-37 min), distillation (37-57 min), and steaming (57-105 min). Real-time monitoring data of steam flow, internal pressure of the still, and the temperature of the upper, middle, and lower layers of mash in the still were recorded simultaneously throughout the process. The monitoring data fully demonstrates that Example 1 was implemented strictly according to the preset process control parameters, and the operating conditions were stable at each stage.

[0049] Comparative Example 1 Step C‵ is used, and the remaining conditions are the same as in Example 1.

[0050] C‵. Insulation: The insulation time was changed to 5 minutes. The results showed that the insulation time was insufficient, the sorghum flour did not absorb water sufficiently, and water floated on the surface. Some sorghum flour had a raw or hard core, which affected the subsequent grain gelatinization effect, resulting in loose mash, poor suspension viscosity, and undercooked grain (with raw core).

[0051] Comparative Example 2 The procedure G‵ is followed, and the remaining conditions are the same as in Example 1.

[0052] G‵. Steaming: During the steaming stage, the steam inlet valves were controlled based on experience, without monitoring specific steam flow data. Results showed that the steam rose unevenly during steaming, resulting in slow steam inflow and smoke penetration, requiring repeated adjustments to the steam valves. This led to a "stuttering" phenomenon during the subsequent distillation process, with prolonged distillation time, affecting the subsequent high-heat steaming time for the grains. Consequently, the mash entering the fermentation pit was loose, had poor suspension viscosity, and poor grain gelatinization.

[0053] Comparative Example 3 Step I is followed, and the remaining conditions are the same as in Example 1.

[0054] I. Steaming the grain: During the high-heat steaming stage, the steam flow rate was controlled at 300 kg / h to 320 kg / h, and the pressure and temperature inside the steamer were not monitored. The results showed that when steaming the grain over high heat, the steam flow rate was low, resulting in loose mash, small grains, insufficient expansion of the grains, poor gelatinization, and poor suspension viscosity.

[0055] The gelatinization effect of Example 1 and Comparative Examples 1-3 was evaluated, and the results are shown in the table below.

[0056] Note: The sensory scores of the sorghum after soaking and the lees after entering the cellar are comprehensively evaluated by 5 first-level winemakers (out of 100 points).

[0057] The results are analyzed as follows.

[0058] (1) Grain moistening effect: Example 1, Comparative Example 2, and Comparative Example 3 all adopted the grain moistening process parameters of the present invention. After moistening, the moisture content of sorghum flour was between 39.2% and 39.5%, which met the target control range. Comparative Example 1 did not adopt the grain moistening and heat preservation time process parameters of the present invention. After moistening, the grain moisture content (38.7%) was lower than the target control range. Based on the sensory scores of sorghum flour after moistening, Example 1, Comparative Example 2, and Comparative Example 3 were all higher than Comparative Example 1. At the same time, comparing the alcohol yield of Example 1 and Comparative Example 1, Example 1 was 7.9 percentage points higher, indicating that the process of the present invention can significantly improve the grain moistening effect of sorghum.

[0059] (2) Steaming effect: Example 1 used the precise steam flow control parameters of the present invention during the distillation stage, Comparative Example 2 controlled the steam in the still based on experience, and Comparative Example 3 did not use the steam control parameters of the present invention during the steaming stage. The sensory score of the mash entering the fermentation pit in Example 1 was higher than that in Comparative Examples 2 and 3. At the same time, comparing the alcohol yield of Example 1 with that of Comparative Examples 2 and 3, Example 1 increased by 6.1 to 7.3 percentage points. This shows that the present invention effectively improves the gelatinization effect of starch by precisely controlling the steam flow, still pressure and temperature during the stilling and distillation stages.

[0060] In summary, the process of this invention effectively solves the problems of parameter control relying on experience, unstable gelatinization effect, and uneven water absorption in traditional gelatinization processes by systematically optimizing the parameters of each process, thereby improving the gelatinization effect and utilization rate of starch and enhancing process stability.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The grain gelatinization process in the brewing of strong-aroma baijiu is characterized by: Includes the following steps: A. Raw material crushing: Sorghum is selected as the raw material for crushing. B. Moistening the grain: Add water to the crushed sorghum to moisten it, and stir simultaneously; C. Insulation: After the grain is moistened and stirred, let it stand and be kept warm for a period of time; D. Spreading out and removing impurities: After the heat preservation is completed, spread out the broken sorghum that has been moistened to remove impurities. During the process, you can stir it appropriately to promote natural cooling. E. Mixing the grain: Mix the soaked and crushed sorghum with the fermented mash evenly; F. Mixing with chaff: Add rice husks to the mixed grain mash and mix well; G. Steaming: The well-mixed mash is steamed for 30-45 minutes, and the temperature of each layer of mash in the steamer gradually rises from room temperature to 88℃-89℃. H. Distillation: After the stills are combined, distillation begins. After the stills are combined and the liquor is collected, the gauge pressure inside the still is controlled between 110Pa and 150Pa. The time from combining the stills to the end of the liquor collection is 18 to 23 minutes. The temperature inside the still gradually rises from 88℃ to 89℃ to 100℃ to 101℃. I. Steaming the grains: After the distillation is completed, the grains are steamed over high heat to gelatinize them. The pressure inside the still is controlled between 320Pa and 380Pa, and the temperature inside the still is between 100℃ and 101℃. The steaming time is maintained at high heat for 42 to 47 minutes. J. Add water: Open the steamer lid and add water to the steamed mash. K. Spreading out of the steamer: After the fermented mash has absorbed water evenly, it is removed from the steamer and spread out to cool.

2. The grain gelatinization process in the brewing of strong-aroma baijiu as described in claim 1, characterized in that, In step A, the required sorghum breakage is that 6% to 10% of the sorghum passes through a 20-mesh sieve, and the sorghum breakage rate is ≥99%.

3. The grain gelatinization process in the brewing of strong-aroma baijiu as described in claim 1, characterized in that, The synchronous stirring time in step B is 12-15 minutes; the heat preservation time in step C is 30-50 minutes.

4. The grain gelatinization process in the brewing of strong-aroma baijiu as described in claim 1, characterized in that, In step E, the crushed sorghum after being moistened is mixed with the mother mash from the cellar at a mass ratio of 1:3 to 5, and the moisture content of the mother mash from the cellar is between 59% and 63%.

5. The grain gelatinization process in the brewing of strong-aroma baijiu as described in claim 1, characterized in that, In step F, the amount of rice husks used is 18% to 25% of the sorghum mass. The rice husks are mixed 20 minutes before steaming. After mixing evenly, the moisture content of the fermented mash in the steamer is between 51% and 53%.

6. The grain gelatinization process in the brewing of strong-aroma baijiu as described in claim 1, characterized in that, In step G, the steam flow rate of the upper steamer is controlled between 120 kg / h and 200 kg / h.

7. The grain gelatinization process in the brewing of strong-aroma baijiu as described in claim 1, characterized in that, In step J, the moisture content of the mash after adding water should be controlled between 57% and 61%.

8. The grain gelatinization process in the brewing of strong-aroma baijiu as described in claim 1, characterized in that, In step K, the moisture content after spreading out to dry should be controlled at 52%~58%.

9. The grain gelatinization process in the brewing of strong-aroma baijiu as described in any one of claims 1-8, characterized in that, In steps H and I, temperature sensors are set for different mash layers, pressure sensors are set inside the steamer, and steam inlet valves are adjusted to maintain the set temperature and pressure range.

10. The grain gelatinization process in the brewing of strong-aroma baijiu as described in claim 9, characterized in that, In step H, the steam flow rate during the distillation stage is controlled between 250 kg / h and 300 kg / h; after the distillation is completed in step I, the steam flow rate is controlled between 350 kg / h and 450 kg / h for high-heat steaming and gelatinization of the grain.

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