Method for recovering beer from waste yeast paste

Abstract

The invention discloses a method for recovering beer from waste yeast. The method comprises the following steps: soaking waste yeast paste generated in a beer production process in deoxidized water; carrying out sedimentation treatment on the waste yeast paste obtained by soaking; collecting a supernatant and a precipitate separated from the soaked waste yeast paste after the sedimentation treatment is completed; the clear liquid flows into a fermentation tank to be subjected to post-fermentation, and first beer liquid is obtained; and performing filter pressing treatment on the precipitate by using a yeast squeezer, and enabling liquid obtained by the filter pressing treatment to flow into a fermentation tank for fermentation to obtain second beer liquid. According to the invention, the efficiency of recovering beer from waste yeast is improved.

Description

Technical Field

[0001] The present invention relates to the field of beer production, and particularly to a method for recovering beer from waste yeast mud. Background Art

[0002] In the process of beer production, waste yeast mud in the fermentation broth is an inevitable by-product. The amount of waste yeast mud produced accounts for about 2% of the total amount of the fermentation broth. This waste yeast mud not only contains a large amount of yeast components but also retains some beer liquid. In order to reduce production costs and improve economic benefits, beer production enterprises need technologies for efficiently recovering beer from waste yeast mud.

[0003] In related technologies, the beer industry mainly adopts two methods for treating waste yeast mud, as Figure 1 shown. One is to filter the waste yeast mud through a cross-flow filter to remove most of the liquor, and then add it to the post-fermentation broth for post-ripening treatment; the other is to press-filter the waste yeast mud through a yeast press, recover the beer liquid after press-filtration and mix it with the liquid in the saccharification sedimentation tank, and then carry out fermentation. Although these methods have been widely used, no matter which process is adopted, all the beer liquid in the waste yeast mud cannot be efficiently recovered, resulting in excessive beer loss. They generally have problems such as low recovery efficiency, complex operation, and large investment, and it is difficult to achieve high-efficiency recovery of beer liquid from waste yeast mud.

[0004] In summary, the beer industry urgently needs a new process technology that can improve the recovery rate of beer recovered from waste yeast mud without increasing additional equipment investment. Summary of the Invention

[0005] The present invention provides a method for recovering beer from waste yeast mud to solve the problem of relatively low efficiency in recovering beer from waste yeast mud in beer production in related technologies.

[0006] According to one aspect of the present invention, there is provided a method for recovering beer from waste yeast mud, including: placing the waste yeast mud generated in the beer production process in deoxygenated water for soaking; performing sedimentation treatment on the soaked waste yeast mud; collecting the supernatant and precipitate separated from the soaked waste yeast mud after the sedimentation treatment is completed; flowing the supernatant into a fermentation tank for post-fermentation to obtain a first beer liquid; using a yeast press to perform press-filtration treatment on the precipitate, and flowing the liquid obtained from the press-filtration treatment into the fermentation tank for fermentation to obtain a second beer liquid.

[0007] Preferably, the soaking time for placing the waste yeast mud in deoxygenated water is 12 hours to 24 hours.

[0008] Preferably, the temperature of the deoxygenated water is 7 degrees Celsius to 9 degrees Celsius.

[0009] Preferably, the mass ratio range of the deoxygenated water to the waste yeast mud is: 1:1 to 1.5:1.

[0010] Preferably, a yeast filter press is used to filter-press the precipitate, and the liquid obtained from the filter-pressing is allowed to flow into the fermentation tank for fermentation to obtain a second beer liquid, including: feeding the liquid obtained after filter-pressing the yeast filter press into a saccharification sedimentation tank and cooling it together with the boiled wort; feeding the cooled liquid into the fermentation tank for fermentation to obtain the second beer liquid.

[0011] Preferably, the filter-pressing pressure range of the yeast filter press is from 12 megapascals (Mpa) to 16 Mpa.

[0012] Preferably, the first beer liquid and the second beer liquid are subjected to microbial detection, and the detection result shows that no microorganisms are detected; the first beer liquid and the second beer liquid meet the requirements of liquor tasting.

[0013] Preferably, the concentration range of the waste yeast mud is 50% to 70%.

[0014] The method for recovering beer from waste yeast mud provided by the present invention involves soaking the waste yeast mud generated during the beer production process in deoxygenated water; performing sedimentation treatment on the soaked waste yeast mud; allowing the supernatant obtained from the sedimentation to flow into the fermentation tank for post-fermentation to obtain a first beer liquid; using a yeast filter press to filter-press the precipitate and flowing it into the fermentation tank for fermentation to obtain a second beer liquid, maximizing the recovery of the liquor in the waste yeast mud, improving the liquor recovery rate of the waste yeast mud, maximizing the recovery of the beer liquor in the waste yeast mud, significantly increasing the liquor recovery rate, reducing the waste of beer, and thus effectively reducing the production cost. Description of the Drawings

[0015] The drawings described herein are used to provide a further understanding of the present invention, form a part of this application, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0016] Figure 1 is a schematic diagram of recovering beer from waste yeast mud in the related art;

[0017] Figure 2 is a flowchart of the method for recovering beer from waste yeast mud according to an embodiment of the present invention;

[0018] Figure 3 is a schematic diagram of the method for recovering beer from waste yeast mud according to an embodiment of the present invention. Detailed Embodiments

[0019] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] This embodiment provides a method for recovering beer from waste yeast sludge. Figure 2 is a flowchart of the method for recovering beer from waste yeast sludge according to an embodiment of the present invention, as Figure 2 shown, the method includes the following steps S102 to step S108.

[0021] Step S202, placing the waste yeast sludge generated during the beer production process in deoxygenated water for soaking.

[0022] Step S204, performing sedimentation treatment on the soaked waste yeast sludge.

[0023] Step S206, collecting the supernatant and sediment separated from the soaked waste yeast sludge after the sedimentation treatment is completed.

[0024] Step S208, flowing the supernatant into a fermentation tank for post-fermentation to obtain a first beer liquid.

[0025] Step S210, using a yeast press to perform pressure filtration on the sediment, and flowing the liquid obtained from the pressure filtration into the fermentation tank for fermentation to obtain a second beer liquid.

[0026] In the related art, a part of the recovered yeast sludge is reused in the beer production process, and the treatment of the remaining waste yeast sludge is divided into two types. One is that it is filtered and deoxygenated by a cross-flow filter by the brewery and then added to the post-fermentation liquid for post-ripening treatment (the yeast sludge is entrusted by the contractor to be used as other materials); the other is that it is pressure-filtered by a yeast press, and the filtered beer is sent to a saccharification sedimentation tank and cooled and oxygenated together with the boiling wort and then sent to a fermentation tank for re-fermentation (the yeast sludge is entrusted by the contractor to be used as other materials). However, no matter which process method is used, the beer recovery rate in the waste yeast sludge is low. Therefore, a process that can ensure quality and improve the beer recovery rate from the waste yeast sludge at a relatively low cost is needed.

[0027] Through the above embodiments, the waste yeast sludge is washed, soaked, and sedimented, and then the methods of pressure filtration and washing combined with pressure filtration are used to obtain the first beer liquid and the second beer liquid, maximizing the recovery of the liquor in the waste yeast sludge, improving the recovery rate of the liquor in the waste yeast sludge, significantly increasing the recovery rate of the liquor, reducing the waste of beer, and thus effectively reducing the production cost. Compared with the related art, the technical solution of this embodiment is simple to implement, has a low cost, and does not require additional large-scale equipment investment, and has significant economic and social benefits.

[0028] It should be noted that in beer production, post-fermentation (also known as secondary fermentation or aging stage) is a crucial step after primary fermentation, directly affecting the taste, clarity, and stability of beer. Post-fermentation is a continuation stage after primary fermentation and is usually carried out in a closed container (such as a storage tank, fermentation tank, or wine bottle). The yeast activity slows down, but still undergoes slow metabolism, promoting the maturation and flavor optimization of beer.

[0029] In implementation, when adopting this embodiment, the set value range of the temperature of the deoxygenated water for washing and soaking the spent yeast sludge, the set value of the addition amount of the deoxygenated water for washing and soaking the spent yeast sludge, and the set value of the sedimentation time after washing and soaking the spent yeast are the core technical means. If the parameter settings are unreasonable, the ideal value cannot be obtained.

[0030] Preferably, the time for soaking the spent yeast sludge in deoxygenated water is 12 hours to 24 hours. This technical feature is a key technical parameter for controlling the soaking of the spent yeast sludge. The setting of this soaking time directly affects the soaking effect of the spent yeast sludge and the efficiency of beer recovery.

[0031] The spent yeast sludge usually contains a large amount of organic matter, especially yeast cell walls, proteins, and polysaccharides, etc. Soaking the spent yeast sludge in deoxygenated water, the deoxygenated environment helps to promote the growth of anaerobic microorganisms, thus accelerating the degradation of organic matter in the spent yeast sludge. This process can effectively reduce the volume and weight of the spent yeast sludge, facilitating subsequent treatment (such as anaerobic digestion). Sometimes the spent yeast sludge contains some heavy metals or toxic substances, and soaking in deoxygenated water can help reduce the dissolution or further reaction of these harmful substances by reducing the oxidation reaction rate. In addition, the use of deoxygenated water can prevent the generation of harmful by-products of certain harmful substances in the presence of oxygen.

[0032] The time range of 12 to 24 hours of soaking helps the spent yeast sludge to fully contact with the deoxygenated water, ensuring the dissolution and destruction of substances, making it easier to achieve better effects in subsequent treatment processes.

[0033] By soaking the spent yeast sludge in deoxygenated water for 12 hours to 24 hours, effects such as the degradation of organic matter, cell wall breaking, release of nutrients, and reduction of harmful substances can be achieved, thereby improving the subsequent treatment efficiency of the spent yeast sludge and reducing the treatment difficulty.

[0034] Preferably, the temperature of the deoxygenated water is 7 degrees Celsius to 9 degrees Celsius. When the temperature of the deoxygenated water is maintained at 7°C to 9°C, it is a key technical parameter for controlling the soaking of the waste yeast sludge. This temperature setting directly affects the soaking effect of the waste yeast sludge and the efficiency of beer recovery. It can reduce the rate of microbial activity, help control the reaction speed, and avoid excessive degradation. It gently destroys the yeast cell wall and effectively releases nutrients without excessive oxidation or damage. It extends the duration of the deoxygenation effect and maintains a stable anaerobic environment. It inhibits the excessive dissolution of harmful substances, which is helpful for environmental protection. It reduces the generation of by-products and maintains the treatment effect of the waste yeast sludge. Therefore, this technology can improve the efficiency of waste yeast sludge treatment, reduce the difficulty of treatment, and facilitate beer recovery through lower temperature control.

[0035] Preferably, the mass ratio of deoxygenated water to waste yeast sludge is in the range of 1:1 to 1.5:1.

[0036] Setting the mass ratio of deoxygenated water to spent yeast sludge within the range of 1:1 to 1.5:1 is a key technical parameter for controlling spent yeast sludge soaking. This mass ratio directly affects the soaking effect of spent yeast sludge and the efficiency of beer recovery.

[0037] Spent yeast sludge contains a large amount of organic matter, such as proteins, sugars, and lipids. By setting an appropriate mass ratio of deoxygenated water to spent yeast sludge, the beer components in the spent yeast sludge can be effectively dissolved and released into solution. In practice, a mass ratio between 1:1 and 1.5:1 achieves the following: Improved solubility: A sufficient amount of deoxygenated water allows for wider penetration of the spent yeast sludge, promoting the extraction and dissolution of organic matter. Ensured sufficient water: Sufficient water provides a sufficient medium for the decomposition of soluble substances.

[0038] This mass ratio is not only effective in extracting the substance, but also reduces costs by using the appropriate amount of water. Too little water may require longer soaking times, making processing more difficult; while too much water increases the cost of processing and subsequent separation and concentration.

[0039] In practice, step S210 can be performed in the following manner: the beer liquid after the yeast press is filtered is sent to the saccharification sedimentation tank and cooled together with the boiled wort; the cooled liquid is sent to the fermentation tank for fermentation to obtain the second beer liquid.

[0040] In beer production, the beer after yeast press filtration often contains a high level of yeast residue, impurities, and unfermented substances. Filter pressing can effectively remove yeast precipitates and other solid impurities from the beer, thereby improving its clarity, reducing unnecessary interference, and enhancing its purity.

[0041] In addition, the taste of the liquor can be improved: The filtered liquor is clear and transparent, reducing the astringency or bitterness in the taste and making the flavor of the beer softer and rounder.

[0042] In implementation, the pressure filtration treatment can improve the subsequent fermentation efficiency: Removing excess solid substances helps the normal growth and reproduction of yeast during the fermentation process, avoiding the inhibitory effect of impurities on yeast, thereby improving the fermentation efficiency.

[0043] The cooling process of the liquor and wort is very important in beer production. It can avoid the influence of too high temperature on yeast: The yeast in beer will be inhibited or die at too high temperatures, while the cooled liquid temperature will help maintain the activity of yeast and provide a suitable environment for fermentation. The ideal fermentation temperature is usually between 15°C and 25°C, so cooling the liquid to the appropriate fermentation temperature is crucial for ensuring the fermentation process.

[0044] In addition, it can promote a good fermentation environment: When the cooled liquor and wort are mixed, the lower temperature helps to stabilize the fermentation environment and prevent evaporation or loss of volatile substances that may occur when overheated. At the same time, cooling also reduces the loss of some volatile components (such as aroma substances) in the beer, enhancing the flavor of the beer.

[0045] In beer production, feeding the cooled liquid into the fermentation tank for fermentation is a key step in beer production. The fermentation tank provides a well-controlled environment for yeast to ensure the smooth progress of the fermentation process. The fermentation tank provides appropriate oxygen and nutrients: In the initial stage of fermentation, yeast requires a small amount of oxygen to initiate its metabolic activities. The cooled liquid can better contact with yeast in the fermentation tank and provide the nutrients required by yeast. Ensure temperature control and gas exchange: The fermentation tank is usually equipped with a temperature control system to maintain a stable temperature during the fermentation process and avoid the influence of temperature fluctuations on yeast activity. At the same time, the fermentation tank helps with gas exchange and emission, ensuring the normal emission of carbon dioxide and avoiding inhibition of the fermentation process.

[0046] This preferred embodiment can improve the fermentation efficiency and the quality of the liquor. By using the liquor after pressure filtration treatment, the generation of adverse by-products (such as off-flavors, strange smells, etc.) during the fermentation process can be reduced, improving the quality of the final beer. After the liquid in the fermentation tank is properly cooled, the fermentation process of yeast is also more stable, and the final product more meets the quality standards.

[0047] As a preferred implementation method, the pressure filtration pressure range of the yeast filter press can be 12 Mpa to 16 Mpa. In this preferred implementation method, the separation efficiency is significantly improved under a relatively high pressure filtration pressure.

[0048] Secondly, improve the clarity of the beer. Impurities can be removed: The high-pressure operation of the yeast filter press can effectively remove residual yeast, microorganisms and other solid impurities in the beer, making the appearance of the beer clearer and more transparent. This has a positive impact on both the taste and stability of the beer, especially in the production of beers with high clarity requirements (such as craft beers).

[0049] In addition, rapid filtration can be carried out. Since the higher filter press pressure can accelerate the speed of the liquid passing through the filter cloth, the time required for the overall filtration process is greatly shortened. This is particularly important for the production lines of large breweries, which can improve the working efficiency of the production line and ensure the stability of the production rhythm.

[0050] As another preferred implementation, after step S210, a microbial detection step can also be carried out. For example: perform microbial detection on the first beer liquid and the second beer liquid, and the detection result shows that no microorganisms are detected; the first beer liquid and the second beer liquid meet the requirements for liquor tasting.

[0051] As a preferred implementation, the concentration range of the waste yeast sludge is 50% to 70%. This preferred embodiment ensures the efficiency of waste yeast sludge recovery.

[0052] This embodiment provides a method for recovering beer from waste yeast sludge. Refer to Figure 3 and the following will be a detailed description.

[0053] In this embodiment, first use deoxygenated ice water (about 9°C) to wash, soak and settle the waste yeast sludge. The supernatant liquor is recovered into a fermentation tank where the main fermentation has ended within 72 hours and the yeast has been recovered, and then undergoes post-fermentation and maturation before direct filtration. The settled yeast sludge is then filter-pressed by a yeast filter press, and the liquor after filter-pressing is sent to a saccharification sedimentation tank, cooled and oxygenated together with the boiling wort, and then sent to a fermentation tank for further fermentation.

[0054] By combining the two methods of washing and pressure filtration, the liquor in the waste yeast sludge can be maximally recovered, improving the recovery rate of the liquor in the waste yeast sludge.

[0055] During the implementation of the liquor recovery process, the combination of ice water washing and soaking and yeast filter pressing can maximally recover the beer in the waste yeast sludge. However, factors such as the temperature of the deoxygenated water, the addition amount of deoxygenated water, and the soaking time during washing will affect the amount of clarified liquor. Therefore, the setting of these parameters has a great impact on the effect of the project.

[0056] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer and more understandable, in combination with Table 1 and Table 2 below, the present invention will be further described in detail. When the temperature of deoxygenated water is 9 °C (degrees Celsius), there are four cases of adding deoxygenated water amounts of 1:1, 1:1.2, 1:1.5, and 1:1.7 respectively, and the soaking time is compared in three time periods, with a total of 12 schemes. Judging from the experimental results, the optimal scheme for the implementation of this process is Scheme 9. Therefore, Scheme 9 was repeated twice to verify the research results. After repeated tests, when the temperature of deoxygenated water is 8 °C, the highest beer recovery rate of the recycled waste yeast mud is obtained when the added amount of deoxygenated water is 1.5 times the amount of yeast mud and the sedimentation time is between 12 and 24 hours. The recovery rate can be doubled on the basis of the original direct pressing after recovery. According to this scheme, the deoxygenated water temperature was changed to 8 °C and 7 °C for testing, and the results were similar to those of Scheme 9 at 9 °C. Tests were also conducted on deoxygenated water temperatures less than 7 °C and greater than 9 °C respectively. When the temperature is less than 7 °C, if the temperature is too low, it will affect the power energy consumption for producing deoxygenated water, and at the same time, the clarified wine liquid added to the fermentation tank will lower the temperature of the fermentation tank due to the low temperature. When the temperature is greater than 9 °C, due to the high temperature, the yeast sedimentation effect is poor and the yeast wine recovery rate is low.

[0057] In addition, microbial sampling and testing were carried out on the washed and clarified beer and the fermentation broth in the fermentation tank after the implementation of this technical solution. The test results showed that no microorganisms were detected; a sensory evaluation comparison and verification of the flavor matching were carried out between the finished products produced by filtering the fermentation broth of the recycled washed and clarified beer and the finished products produced without using this scheme. In the sensory evaluation results, the average sensory evaluation score of the finished products of this scheme was 7.72 points, and the control samples are shown in Table 2.

[0058] As can be seen from Table 1 and Table 2 below, the extraction efficiency is relatively high when the temperature is between 7 and 9 degrees Celsius.

[0059] The soaking time of the waste yeast mud in deoxygenated water is 12 hours to 24 hours.

[0060] Preferably, the mass ratio range of deoxygenated water to the waste yeast mud is: 1:1 to 1.5:1. Table 1 below shows that when the temperature of deoxygenated water is 9 °C, there are four cases of adding deoxygenated water amounts of 1:1, 1:1.2, 1:1.5, and 1:1.7 respectively, and the soaking time is compared in three time periods, with a total of 12 schemes. The waste yeast mud in Table 1 is 50 hl (hectolitre, HektoLitre), and the concentration is 60%.

[0061] Table 1

[0062]

[0063] Table 2

[0064]

[0065] In the related art, effectively improving the beer recovery rate in waste yeast sludge is a difficult problem. Usually, it requires high equipment investment and complex operation processes, and it is impossible to achieve simple and efficient recovery. Through the above-mentioned embodiments and their preferred implementation manners, the problem in the related art of how to optimize the processes of washing, soaking, sedimentation, and pressure filtration of waste yeast sludge to improve the recovery rate of beer liquid in waste yeast sludge while reducing production costs is solved on the premise of ensuring beer quality. Moreover, in the preferred implementation manner, the parameter settings (such as the temperature of deoxygenated water, the addition amount, and the soaking time) in the processes of washing and sedimentation of waste yeast sludge are provided, which improves the beer recovery rate and provides a new, cost-controllable, and excellent-effect technical solution for the beer production industry.

[0066] In summary, the global beer and beverage industry is in a period of technological innovation and upgrading, and is transforming towards low-carbon and intelligent development. Maximizing the recovery of beer from beer waste yeast sludge can reduce energy consumption, thereby promoting beer production enterprises to achieve carbon neutrality projects.

[0067] In addition, the technical solution of this application does not require additional investment in equipment. The new process further promotes the beer industry to adapt to the new era, achieve sustainable development, and resource allocation.

[0068] This technical solution can bring relatively good economic benefits. For example: With the development of the beer brewing industry, reducing production costs is an important measure for enterprises to improve market competitiveness and achieve sustainable development. This project is committed to using new process technologies to improve the recovery rate of beer in waste yeast sludge, achieving the reduction of beer losses and the saving of energy fluids and labor costs. Secondly, the technical solution of this application can help achieve the maximization of economic benefits, help enterprises enhance their competitiveness in the industry, and then improve the company's performance, with great commercial value.

[0069] It should be noted that the technical solution of this application can help beer manufacturing companies reduce beer losses, improve production efficiency, save labor hours, and production energy consumption, thereby reducing production costs. Assuming that the annual output is 600,000 hl, the recovered beer liquid from yeast sludge can be increased by 2,520 hl, and 100,800 yuan can be saved.

[0070] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for recovering beer from waste yeast sludge, characterized in that, Including: Placing the waste yeast sludge generated during the beer production process in deoxygenated water for soaking; Performing sedimentation treatment on the waste yeast sludge obtained from the soaking; Collecting the supernatant and precipitate separated from the soaked waste yeast sludge after the sedimentation treatment is completed; Flowing the supernatant into a fermentation tank for post-fermentation to obtain a first beer liquid; Using a yeast filter press to perform pressure filtration on the precipitate, and flowing the liquid obtained from the pressure filtration into the fermentation tank for fermentation to obtain a second beer liquid.

2. The method according to claim 1, wherein The time for placing the waste yeast sludge in the deoxygenated water for soaking is 12 hours to 24 hours.

3. The method according to claim 1, characterized in that, The temperature of the deoxygenated water is 7 degrees Celsius to 9 degrees Celsius.

4. The method according to claim 1, wherein Wherein, The mass ratio range of the deoxygenated water to the waste yeast sludge is: 1:1 to 1.5:

1.

5. The method according to claim 1, characterized in that, Using a yeast filter press to perform pressure filtration on the precipitate, and flowing the liquid obtained from the pressure filtration into the fermentation tank for fermentation to obtain a second beer liquid includes: Sending the liquor after pressure filtration by the yeast filter press into a saccharification sedimentation tank to be cooled together with the boiled wort; Sending the cooled liquid into the fermentation tank for fermentation to obtain the second beer liquid.

6. According to the method described in claim 1 or 5, characterized in that, The pressure filtration pressure range of the yeast filter press is 12 MPa to 16 MPa.

7. The method according to any one of claims 1 to 5, characterized in that, Also including: Performing microbial detection on the first beer liquid and the second beer liquid, and the detection result shows that no microorganisms are detected; The first beer liquid and the second beer liquid meet the requirements for liquor tasting.

8. The method according to any one of claims 1 to 5, characterized in that, Also including: The concentration range of the waste yeast sludge is 50% to 70%.

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