Cleaning and maintenance method for airing room in wine making process and application of cleaning and maintenance method

Abstract

The invention belongs to the technical field of wine making, and relates to a cleaning and maintaining method and application of an airing room in a wine making process, the wine making process sequentially comprises a sand feeding round, a sand making round, a first wine making round, a second to fourth wine making round, a fifth to sixth wine making round and a seventh wine making round, and the cleaning and maintaining method of the airing room comprises the following steps: in the sand feeding round, cleaning and maintaining the airing room; after the airing room is cleaned with boiled water, tail liquor is splashed to maintain the airing room. According to the method, firstly, boiling water is adopted for pouring, scalding and airing, non-brewing functional microorganisms are killed, then secondary metabolites such as alcohol, macromolecular organic acid and ester substances contained in tail liquor are utilized, and brewing functional microorganisms beneficial to fermentation are screened and enriched through a feedback inhibition regulation mechanism, so that the content of non-functional molds is reduced; the contents of bacillus and yeast are integrally increased, and rich enzyme systems and flavor substances are provided for subsequent fermentation.

Description

Technical Field

[0001] The invention belongs to the technical field of wine making, and relates to a cleaning and maintenance method for a drying hall in a wine making process and an application thereof. Background Art

[0002] Maotai-flavor liquor needs to be fermented in piles in the wine-making and drying hall. This process cools down the high-temperature mash in the steamer, mixes the koji, and entrains environmental microorganisms. At the same time, pile fermentation is carried out in the natural open environment of the wine-making and drying hall. The multi-bacteria solid-state fermentation process cleverly utilizes conditions such as dissolved oxygen, temperature, and inhibition of secondary metabolites to screen entrained environmental microorganisms and enrich functional microorganisms for brewing.

[0003] The winemaking drying hall is the main fermentation site for Maotai-flavor liquor. It integrates important winemaking links such as spreading and drying, spreading koji, and stacking fermentation. The interaction between koji, the environment, and the fermented mash microbial resources is the closest. Maotai-flavor liquor is extracted in seven rounds, and there is a certain period of production idleness between each round (commonly known as the "cellar period"). The mash and koji powder remaining in the drying hall provide favorable growth and reproduction conditions for the growth of complex microorganisms in the environment, thereby reducing the richness of brewing functional microorganisms. Therefore, choosing an appropriate method to clean the winemaking drying hall after the cellar period is conducive to an effective transition before the next round of production.

[0004] At present, the main methods for cleaning the drying hall are to use boiling water or to splash the tail wine. For example, the literature "Tu Huabin, Hu Feng, Yang Gangren et al. Research on the treatment method of mold spots in the drying hall during the cellar period of Maotai liquor [J]. Brewing Technology, 2019, No. 302 (08): 58-60" discloses that the drying hall is cleaned by boiling water and tail wine. The number of mold colonies on the surface of the drying hall after cleaning is statistically analyzed by culture medium dilution coating and plate counting method, and the cleaning effect of the drying hall is judged according to the increase or decrease of the number of mold colonies.

[0005] The effect of using tail wine to clean microorganisms is not ideal, and the effect of using boiling water to clean microorganisms is much greater than that of using tail wine to clean. However, the verification basis of this method only comes from the determination of the total number of mold colonies. It is believed that the smaller the total number of colonies, the better the cleaning effect. Therefore, all kinds of microorganisms in the drying hall can be disinfected indiscriminately.

[0006] But in reality, the drying hall is vacant for a long time during the cellaring stage, and the seasonal conditions in different rounds of cellaring vary greatly. Different rounds of wine making often have different distributions of brewing functional microorganisms that are beneficial to fermentation. The above method cannot maintain the drying hall while cleaning it, and play a buffering and transitional role before production, and create a drying hall environment similar to that during production in advance. Summary of the invention

[0007] The purpose of the present invention is to provide a cleaning and maintenance method and application of a drying hall in a wine-making process, by first using boiling water to scald the drying hall in the sand-making round, so as to comprehensively disinfect non-brewing functional microorganisms in the drying hall in the sand-making round, and then curing the disinfected drying hall by spraying a certain concentration of tail wine, utilizing the secondary metabolites such as alcohol, macromolecular organic acids and ester substances contained in the tail wine, and screening and enriching brewing functional microorganisms that are beneficial to fermentation through a feedback inhibition regulation mechanism, thereby reducing the content of non-functional molds, and improving the content of Bacillus and yeast as a whole, providing a rich enzyme system and flavor substances for subsequent fermentation.

[0008] In a first aspect, the present invention provides a method for cleaning and maintaining a drying hall in a wine-making process, wherein the wine-making process sequentially comprises: a sand-laying round, a sand-making round, a first wine-making round, second to fourth wine-making rounds, fifth to sixth wine-making rounds, and a seventh wine-making round, and the method for cleaning and maintaining the drying hall comprises the following steps:

[0009] In the above-mentioned sanding round, after the drying hall is cleaned with boiling water, the drying hall is maintained by spraying tail wine.

[0010] In some embodiments, the concentration of the tail wine is not less than 10% vol.

[0011] In some embodiments, the cleaning and maintenance method further comprises cleaning and maintaining the drying hall during the sand making round after the drying hall is cleaned and maintained during the sand making round.

[0012] In some embodiments, the cleaning and maintenance method further includes maintaining the drying hall during the wine-making round after the sand-making round, and the method of maintaining the drying hall during the wine-making round is: spreading Daqu on the drying hall to maintain the drying hall.

[0013] In some embodiments, the cleaning and maintenance method further includes cleaning the airing hall after the first round of wine making and during the second to fourth rounds of wine making, and the method of cleaning the airing hall during the second to fourth rounds of wine making is: by scalding the airing hall with boiling water.

[0014] In some embodiments, the cleaning and curing method further includes cleaning and curing the drying hall after the second to fourth rounds of wine making and during the fifth to sixth rounds of wine making. The method of cleaning and curing the drying hall during the fifth to sixth rounds of wine making is: first scalding the drying hall with boiling water, and then curing it by successively spraying tail wine and Daqu; the concentration of the tail wine is not less than 10% vol.

[0015] In some embodiments, the cleaning and maintenance method also includes cleaning and maintaining the drying hall in the seventh round of wine making after the fifth to sixth rounds of wine making, and the manner of cleaning and maintaining the drying hall in the seventh round of wine making is: using boiling water and cellar-keeping dregs to clean the drying hall in turn, and then curing the drying hall by splashing tail wine; or using boiling water and cellar-keeping dregs to clean the drying hall in turn, and then curing the drying hall by spreading Daqu; the concentration of the tail wine is not less than 10% vol.

[0016] In some embodiments, the method of spreading and ironing the cellar-keeping dregs to clean the air-drying hall is as follows: steam the cellar-keeping dregs with a steam pressure of not less than 0.12 MPa for 20-40 minutes, and then evenly spread the cellar-keeping dregs on the floor of the air-drying hall. The amount of cellar-keeping dregs used is sufficient to fully cover the air-drying hall, with a thickness of not less than 2 cm. When the cellar-keeping dregs cool to about 40°C, the ironing is stopped.

[0017] In some embodiments, the cleaning and maintenance method also includes analyzing the microbial diversity and its succession patterns of the drying hall before and after the sand-laying round, sand-making round, first round of wine-making, second to fourth rounds of wine-making, fifth to sixth rounds of wine-making, and seventh round of wine-making.

[0018] In a second aspect, the present invention provides an application of any one of the above-mentioned cleaning and maintenance methods in the brewing of Maotai-flavor liquor.

[0019] In summary, the present application includes at least one of the following beneficial technical effects:

[0020] By first using boiling water to scald the drying hall in the Xiasha round, the non-brewing functional microorganisms in the drying hall in the Xiasha round are disinfected more comprehensively, and then a certain concentration of tail wine is sprayed on the drying hall for maintenance. The tail wine contains secondary metabolites such as alcohol, large molecular organic acids and ester substances, and the brewing functional microorganisms that are beneficial to fermentation are screened and enriched through the feedback inhibition regulation mechanism, thereby reducing the content of non-functional molds, and overall increasing the content of Bacillus and yeast, providing rich enzyme systems and flavor substances for subsequent fermentation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a result diagram of the diversity of dominant microorganisms before and after cleaning and curing of the drying hall in the wine-making sanding round in Example 1 of the present invention;

[0022] Figure 2 This is a result diagram of the dominant microbial diversity before and after the air-drying hall cleaning and curing in a round of wine making in Example 1 of the present invention;

[0023] Figure 3 This is a result diagram of the dominant microbial diversity before and after the air-drying hall cleaning and curing in the second to fourth rounds of wine making in Example 1 of the present invention;

[0024] Figure 4 This is a result diagram of the diversity of dominant microorganisms before and after the air-drying hall cleaning and curing in the fifth to sixth rounds of wine making in Example 1 of the present invention;

[0025] Figure 5 This is a result diagram of the dominant microbial diversity before and after the air-drying hall cleaning and curing of seven rounds of wine making in Example 1 of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below by specific embodiments, which do not limit the protection scope of the present invention. Some non-essential modifications and adjustments made by others based on the concept of the present invention still fall within the protection scope of the present invention.

[0027] At present, the main cleaning methods for the air drying hall are to use boiling water or splashing tail wine to clean. The effect of tail wine cleaning microorganisms is not ideal. The effect of boiling water cleaning microorganisms is much greater than that of tail wine cleaning. However, the verification basis of this method is only derived from the determination of the total number of mold colonies, and there is no selective disinfection of various microorganisms in the air drying hall. In fact, the air drying hall cleaning process cannot simply disinfect microorganisms. Due to the long vacancy time of the winemaking air drying hall during the cellar period, and the long fermentation cycle of sauce-flavored liquor, each round is in a different season, and the seasonal conditions of different rounds of cellar period are quite different. Often, different winemaking rounds have different distributions of brewing functional microorganisms that are beneficial to fermentation. For these microorganisms, if they are retained, it will be beneficial to the brewing of liquor. Therefore, taking appropriate air drying hall cleaning and maintenance measures can play a buffering and transitional role before production, creating an air drying hall environment similar to that during production in advance, and can effectively stimulate brewing functional microorganisms.

[0028] If we can analyze the changing patterns of brewing functional microorganisms on the surface of the drying hall before and after cleaning, and clarify the cleaning and maintenance methods required for the drying hall cleaning process in different rounds of cellaring, it will be of great significance to promote the improvement of the quality of the fermentation of mash in the drying hall of Maotai-flavor liquor.

[0029] Based on this, the inventors used high-throughput sequencing technology to detect the microbial metagenome in the drying hall, and analyzed the microbial diversity and its succession rules before and after the cleaning of the drying hall from the shavings of Maotai-flavor liquor to the seventh round of cellaring. The seven rounds of Maotai-flavor liquor each play different roles in the blending, and together affect the final flavor and quality of the liquor. Therefore, the inventors combined the brewing functional microorganisms required in different rounds, and designed the cleaning and maintenance methods and applications of the drying hall in different rounds of winemaking processes.

[0030] First is the round of sand-laying. In this round, since the air-drying hall may be vacant for a longer time, the air-drying hall has accumulated more microorganisms that are not related to the brewing function. It is necessary to clean and maintain the air-drying hall in advance to create an air-drying hall environment similar to that during production in advance. In order to remove non-brewing microorganisms as much as possible, boiling water or cellar dregs are used to scald the air-drying hall. However, scalding the cellar dregs is more likely to increase the content of Mucor than cleaning the air-drying hall with boiling water, and it becomes the main dominant fungus. The cleaning effect is not as good as boiling water. Therefore, boiling water is preferred to clean the air-drying hall in the round of sand-laying. However, since the brewing functional microorganisms are also affected to a certain extent, it is necessary to screen and enrich the brewing functional microorganisms in the air-drying hall as much as possible. Therefore, the brewing functional microorganisms are inoculated into the air-drying hall by spreading koji. However, since the cellar period of the round of sand-laying is usually in mid-to-late October, the average temperature of Maotai is below 20℃, and the microorganisms cultivated by the high-temperature koji-making process of Maotai-flavor liquor are mainly thermophilic microorganisms. Under medium and low temperature conditions, Mucor has a significant growth advantage, which inhibits the growth of thermophilic microorganisms to a certain extent, and finally the enrichment effect of brewing functional microorganisms is not significantly improved. Taking into account that the tail wine of Maotai-flavor liquor contains secondary metabolites such as alcohol, macromolecular organic acids and ester substances, the microorganisms that are beneficial to fermentation were screened through feedback inhibition regulation mechanism. Then, they tried to sprinkle the tail wine on the drying hall. The result was better than that of inoculating microorganisms. It reduced the content of non-functional molds and increased the content of Bacillus and yeast overall, providing rich enzyme systems and flavor substances for subsequent fermentation.

[0031] During the sand-making round, the drying hall had a short vacancy period and its status did not change much, so no deep cleaning and maintenance was carried out in this round.

[0032] The first round of winemaking is the first round of base wine production. A good air-drying hall production environment is beneficial to the subsequent multiple rounds of fermentation. Therefore, the air-drying hall was first scalded with boiling water to explore the effect on the microorganisms in the air-drying hall. The result was not significant. Although the relative content of Bacillus increased slightly, it had no significant effect on the overall dominant microbial composition. So we tried to sprinkle the tail wine on the air-drying hall. The results showed that the relative content of Lactobacillus and thermophilic fungi increased slightly, and the dominant microbial composition was not significantly different from that of boiling water cleaning. So we tried to inoculate brewing functional microorganisms into the air-drying hall by sprinkling Daqu. It was found that the relative content of Bacillus increased, and the relative content of thermophilic fungi and film-coated yeast was greatly increased, providing power for subsequent fermentation, as well as providing a variety of flavor substances and their precursors.

[0033] The second to fourth rounds of winemaking are further fermented on the basis of the first round of winemaking. After the drying hall is cleaned with boiling water, the richness of foreign bacteria in the drying hall is effectively reduced, the types of foreign bacteria are reduced by more than 60%, the relative content of Candida and Lactobacillus is reduced, and the relative content of Issatchengen, Pichia trichosporon, Staphylococcus, Lactococcus, etc. is increased. In order to further increase the content of Bacillus and yeast, the tail wine is tried to continue to be used for drying hall maintenance. As a result, the relative content of Staphylococcus was reduced before production, but the relative content of acid-producing bacteria such as Lactobacillus, Lactococcus, Coxsackie, and Acinetobacter was also increased, resulting in an increase in the acidity of the base wine. Therefore, the tail wine is not suitable for treatment here. Therefore, they switched to using Daqu, and found that the dominant bacteria in Daqu were no longer Bacillus, and the proportion of enzyme-producing and acid-producing bacteria such as Staphylococcus, Klebsiella, and Pantoea increased significantly. The use of Daqu for maintenance could not reduce the content of acid-producing microorganisms in the drying hall. In addition, yeast became the main dominant fungus in Daqu, but in the second to fourth rounds of drying hall, yeast had a greater advantage, and the use of Daqu for maintenance also could not affect the composition structure of the dominant fungi in the drying hall.

[0034] In summary, it is recommended to use boiling water to scald the drying hall, pay attention to the amount and clean it in time to prevent water accumulation. It is not recommended to use tail wine or Daqu for maintenance. The temperature gradually warms up during the second to fourth rounds of winemaking, and bacteria are easy to breed in the drying hall during the cellar stage. Using boiling water to clean the drying hall can effectively inhibit bacteria and ensure the quality of fermentation in the later rounds. Using tail wine or Daqu for drying hall maintenance cannot change the original dominant microbial structure of the drying hall, and it is difficult to achieve the expected effect of maintenance.

[0035] The fifth to sixth rounds of winemaking are the later rounds of the production of Maotai-flavor liquor. It is necessary to increase the relative content of Bacillus, yeast, and functional molds, while controlling the relative content of acid-producing bacteria and non-brewery functional bacteria such as Mucor and Penicillium. Therefore, after boiling water blanching and air-drying, the effects of tail wine and Daqu treatment on the structure of dominant microbial flora were tested. The results showed that the combination of tail wine and Daqu treatment significantly increased the relative content of Bacillus, which increased by about 30 percentage points compared with before cleaning, and reduced the proportion of acid-producing bacteria. At the same time, it significantly increased the relative content of Rhizopus, Aspergillus, Candida, Pichia pastoris, etc., and inhibited the growth of non-brewery functional molds such as Mucor and Penicillium. However, after testing, it was found that the effect of using the two alone was not as good as that of combined use.

[0036] The temperature during the seventh round of winemaking is relatively high. There are many foreign bacteria and mold in the drying hall during the idle period of production. Using only boiling water for cleaning can easily lead to the rebound of low-level foreign bacteria after cleaning. The structure of dominant bacteria in the drying hall before production is basically the same as before cleaning. At the same time, boiling water can effectively reduce the content of mold, but the inhibition time is short, which can easily lead to a surge in the content of mold before production. Using only the scalding of the cellar dregs for cleaning can effectively clean low-level foreign bacteria and reduce the content of mold, but it is also easy to rebound before production and increase the relative content of acid-producing bacteria. Using both boiling water and scalding of the cellar dregs for cleaning can effectively clean low-level foreign bacteria, but it also increases the relative content of acid-producing bacteria, reduces the content of mold, and weakens the rebound effect, which greatly increases the proportion of yeast. After the drying hall was cleaned, the tail wine was used for maintenance, which significantly increased the relative content of Bacillus before production, reduced and inhibited the content of Mucor, increased the content of Aspergillus, and ensured the coordinated ratio of functional mold and yeast; after the drying hall was cleaned, Daqu was used for maintenance, which significantly increased the relative content of Bacillus and Aspergillus before production, reduced and inhibited the content of Mucor, and ensured the coordinated ratio of functional mold and yeast; after the drying hall was cleaned, the tail wine combined with Daqu was used for maintenance, which compressed the relative content of Bacillus and functional mold, and significantly increased the relative content of non-brewery functional bacteria such as Balloon Fungus and Deku Fungus. The overall maintenance effect was lower than that of using tail wine or Daqu alone.

[0037] Therefore, it is recommended to use boiling water combined with spreading and scalding the cellar dregs to clean the drying hall during the seventh round of winemaking, and to use tail wine or Daqu to maintain the drying hall. The effects of the two when used alone are the same.

[0038] Example 1

[0039] A method for cleaning and maintaining a drying hall in a wine-making process and its application, comprising the following steps:

[0040] Step 1: Microbiological analysis

[0041] High-throughput sequencing technology was used to detect the microbial metagenome in the drying hall, and the microbial diversity and its succession rules were analyzed before and after the cleaning of the drying hall from the shaving stage to the seventh round of cellaring of Maotai-flavor liquor. Figure 1-5 The specific analysis method is as follows:

[0042] 1.2.1 Total DNA extraction from samples

[0043] Sterile cotton and physiological saline were used to wipe and collect the dust on the airing hall floor. Genomic DNA was extracted according to the instructions of the DNA extraction kit, and NanoDrop One was used to detect the integrity, concentration and purity of the DNA.

[0044] 1.2.2 PCR amplification and product electrophoresis detection

[0045] Using genomic DNA as template, according to the selection of sequencing area, use specific primers with barcode and TaKaRa Premix PCR amplification was performed using the PCR primers of version 2.0. For identification of bacterial diversity: primers of 16S V4 region (515F and 806R); for identification of fungal diversity: primers of ITS1 region (ITS5-1737 F and ITS2-2043 R).

[0046] Amplification program: 94℃ pre-denaturation for 5min, 30 cycles (94℃ denaturation for 30s, 52℃ annealing for 30s, 72℃ extension for 30s), and finally 72℃ extension for 10min. The amplification system includes 25μL 2x Premix Taq, 1μL Primer-F (10μM) buffer, 1μL Primer-R (10μM) buffer, 50ng DNA template and Nuclease-free water added to 50μL. Each sample was repeated 3 times, and the PCR products of the same sample were mixed.

[0047] 1.2.3 PCR product electrophoresis detection

[0048] The fragment length and concentration of PCR products were detected by 1% agarose gel electrophoresis, and samples with main band length within the normal range could be used for further experiments.

[0049] 1.2.4 Pooling and gel cutting and purification

[0050] After comparing the concentrations of PCR products using GeneTools Analysis Software (Version 4.03.05.0, SynGene), the required volume of each sample was calculated according to the equal mass principle, and the PCR products were mixed. The PCR mixed product was recovered by Gel Extraction Kit (Omega, USA), and the target DNA fragment was recovered by elution with TE buffer.

[0051] 1.2.5 Library construction and sequencing

[0052] according to Ultra TM IIDNA Library Prep Kit for The library was constructed using the standard procedure, and the constructed amplicon library was sequenced using the Illumina Nova 6000 platform.

[0053] 1.2.6 Sequencing data processing

[0054] (1) Paired-end Raw Reads data filtering: Use fastp to perform sliding window quality trimming (-W 4-M 20) on the paired-end Raw Reads data. At the same time, use cutadapt software to remove primers based on the primer information at both ends of the sequence to obtain paired-end Clean Reads after quality control; (2) Paired-end Clean Reads splicing: For paired-end sequencing data, usesearch-fastq mergepairs is used to filter out non-compliant tags based on the overlap relationship between PEreads to obtain the original spliced ​​sequence (Raw Tags); (3) Raw Tags sequence quality filtering: Use fastp to perform sliding window quality trimming (-W4-M 20) on the Raw Tags data to obtain valid spliced ​​fragments (Clean Tags).

[0055] 1.2.7 OTU species annotation

[0056] (1) Use usearch-sintax to compare the representative sequence of each OTU with the SILVA (16S), RDP (16S), Greengenes (16S), SILVA (18S), and Unite (ITS) databases to obtain species annotation information (the confidence threshold is set to 0.8 by default, and the default databases are SILVA (16S), SILVA (18S), and Unite (ITS)), so as to understand the species origin of all sequences; (2) Removal of contaminating OTUs: Remove OTUs and their tags that are annotated as chloroplasts or mitochondria (16S amplicons) and cannot be annotated to the kingdom level, and obtain the number of valid tag sequences and OTU taxonomy comprehensive information table for each sample used for analysis.

[0057] Step 2: Different rounds of airing hall cleaning and maintenance

[0058] (1) Sand wheel

[0059] Before the start of the sanding round, use boiling water to clean the drying hall, and then evenly sprinkle the tail wine on the drying hall for maintenance.

[0060] The temperature of the boiling water is greater than 90°C. Sprinkle an appropriate amount of boiling water evenly on the wine-making drying hall. The amount of boiling water should be enough to fully cover the drying hall without any accumulation of water. Clean the drying hall immediately after the boiling water is finished.

[0061] In the process of pouring the tail wine, the tail wine with a concentration of not less than 10% vol is placed in a watering pot. The amount of pouring is to fully cover the airing hall. The total amount is preferably not more than 120kg. There is no need to clean the airing hall after pouring the tail wine. In this embodiment, the area of ​​the airing hall is about 230m 2 .

[0062] The second cellaring period of Xiasha is usually in mid-to-late October, when the average temperature of Moutai is below 20℃. The microorganisms cultivated in the high-temperature koji-making process of Maotai-flavor liquor are mainly thermophilic microorganisms. Mucor has a significant growth advantage under medium and low temperature conditions, which inhibits the growth of thermophilic microorganisms to a certain extent. Therefore, the use of Daqu curing and drying hall does not significantly improve the enrichment effect of brewing functional microorganisms.

[0063] (2) Sand making wheel

[0064] The sand-making round is usually only one day apart from the wine-making round. It only requires cleaning the drying hall, and no additional cleaning and maintenance are required.

[0065] (3) One round of wine making

[0066] Use 50kg of Daqu to maintain the drying hall. Just clean the drying hall before production. Additional cleaning or use of tail wine for maintenance is not recommended.

[0067] In the process of spreading the koji, the koji powder used in wine production is placed in the koji basket. The height of the basket mouth should not be higher than 50cm from the ground when spreading the koji. The amount of koji spread should be enough to fully cover the drying hall, and the total amount should not exceed 50kg. Before production the next day, the koji powder on the surface of the drying hall can be swept clean.

[0068] The first round of cellaring for winemaking is usually between late January and early February, when the average temperature in Maotai is below 10°C. Due to the low temperature, the growth of microorganisms is inhibited, and the relative content of lactobacilli among bacteria is as high as over 90%, and the relative content of yeasts such as Pichia pastoris and Saccharomyces cerevisiae is as high as over 70%. The use of boiling water cleaning and tail wine maintenance has little effect on the composition and abundance of dominant microorganisms in the drying hall. The use of Daqu maintenance in the drying hall increases the relative content of high-temperature resistant functional molds and promotes the production and accumulation of sauce-flavored substances and their precursors.

[0069] (4) Second to fourth rounds of winemaking

[0070] Use boiling water to scald the drying hall, pay attention to the amount and clean it in time to prevent water accumulation. It is not recommended to use tail wine or Daqu for maintenance. Among them, the method of scalding the drying hall with boiling water is the same as the sand round.

[0071] The temperature is comfortable during the second to fourth rounds of winemaking, and bacteria are easy to breed in the drying hall during the cellar period. Although they cannot form an advantage in the core area of ​​liquor brewing, there are many types. Using boiling water to clean the drying hall can effectively inhibit bacteria and ensure the fermentation quality. However, using tail wine or Daqu for drying hall maintenance cannot change the original advantageous microbial structure of the drying hall, and it is difficult to achieve the expected effect of maintenance.

[0072] (5) Five to six rounds of winemaking

[0073] The drying hall is scalded by boiling water, and 10% vol tail liquor is combined with 50 kg of Daqu for curing. The method of scalding the drying hall with boiling water and curing the drying hall with tail liquor is the same as that of the round of sand making, and the method of curing the drying hall with Daqu is the same as that of curing the drying hall with Daqu in the first round of wine making. In other embodiments, the concentration of tail liquor can also be other concentrations greater than 10% vol, such as 11% vol, 12% vol, 14% vol, 15% vol, etc., which mainly plays a role in disinfecting microorganisms.

[0074] During the fifth and sixth rounds of winemaking, the temperature in Maotai Town is high and the rainfall is heavy. Boiling water is more effective in cleaning the bacteria in the drying hall. Using tail wine combined with Daqu to maintain the drying hall is more effective in reducing acid-producing bacteria and increasing the proportion of Bacillus. At the same time, it increases the content of functional molds, which promotes the improvement of the quality of stacking fermentation.

[0075] (6) Seven rounds of wine making

[0076] It is recommended to use two methods to clean and maintain the drying hall: one is to use boiling water combined with scalding the cellar dregs for cleaning, and then use 10% vol of tail wine for maintenance; the other is to use boiling water combined with scalding the cellar dregs for cleaning, and then use 50kg of Daqu for maintenance. Among them, the method of scalding the drying hall with boiling water and maintaining the drying hall with tail wine is the same as the round of adding sand, and the method of maintaining the drying hall with Daqu is the same as the method of maintaining the drying hall with Daqu in the first round of wine making. The specific method of scalding the cellar dregs to clean the drying hall is: steam the cellar dregs with a steam pressure of not less than 0.12MPa for 30 minutes, and evenly spread the cellar dregs on the floor of the drying hall after steaming. The amount of cellar dregs should be enough to fully cover the drying hall, and the thickness should not be less than 2cm. When the cellar dregs cool to about 40℃, stop scalding and clean the drying hall.

[0077] The above two cleaning methods have similar effects, and are significantly effective in reducing and inhibiting the content of Mucor, ensuring the coordinated ratio of acid-producing bacteria and Bacillus, and also ensuring the coordinated ratio of functional mold and yeast.

[0078] Comparative Example 1

[0079] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0080] During the next sanding, the drying hall is cleaned with boiling water in the same way, and no maintenance is performed on the drying hall.

[0081] The drying hall after the sand cleaning was subjected to microbial detection and analysis. The microbial analysis method was the same as in Example 1. The results were as follows:

[0082] The fungal richness decreased significantly, and the bacterial richness did not change significantly, but the Weissella content decreased and the Staphylococcus content increased, indicating that the boiling water cleaning had a significant inhibitory effect on some fungi. Staphylococcus is a common bacterium in the air. After boiling water cleaning, the humidity in the air-drying hall is high and the relative content of this bacterium increases. Since there are basically no nutrients in boiling water, mold cannot have an advantage over yeast, but since the brewing functional microorganisms are also affected to a certain extent, it is necessary to screen and enrich the brewing functional microorganisms in the air-drying hall by maintaining the air-drying hall after cleaning.

[0083] Comparative Example 2

[0084] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0085] The next sanding wheel is only used in the same way as in Example 1 to clean the airing hall by spreading and scalding the cellar dregs, and no airing hall maintenance is performed.

[0086] The same method was used to test the microorganisms in the drying hall after the lower sand wheel was cleaned. The results are as follows:

[0087] The increase in Mucor content has made it the main dominant fungus, indicating that the dregs will remain in the drying hall after being cleaned, providing nutrients for the production of mold.

[0088] Comparative Example 3

[0089] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0090] The same method is used for cleaning the drying hall in each round of sand removal, using boiling water and scalding the cellar dregs, and no maintenance is performed on the drying hall.

[0091] The same method was used to test the microorganisms in the drying hall after the lower sand wheel was cleaned. The results are as follows:

[0092] The result is close to that of comparative example 2, but the increase of Mucor content is more obvious, becoming the main dominant fungus, indicating that the residue will remain in the drying hall after cleaning, providing nutrients for the production of mold.

[0093] Comparative Example 4

[0094] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0095] The same method is used to clean the drying hall by boiling water during the next sanding round, and the same method is used to maintain the drying hall by spreading Daqu.

[0096] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0097] There was no significant change in the composition of dominant bacteria before and after cleaning, but the content of Bacillus decreased, and the content of Mucor and Fusarium in fungi increased. The experiment simultaneously detected the microorganisms of the Xiasha round koji, and the core bacteria were Bacillus, and the core fungi were Rhizopus, Aspergillus, and thermophilic fungi, indicating that the Xiasha round koji curing and drying hall could not inoculate the dominant microorganisms into the drying hall. This is mainly due to the fact that the Xiasha round koji period is usually in mid-to-late October, and the average temperature of Maotai is below 20℃. The microorganisms cultivated by the high-temperature koji making process of Maotai-style liquor are mainly thermophilic microorganisms, and the effect of thermophilic microorganisms cannot be exerted when the temperature is low.

[0098] Comparative Example 5

[0099] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0100] The same method is used to clean the drying hall with boiling water during the next round of sanding, and the same method is used to maintain it by combining the spraying of tail wine and spreading of Daqu.

[0101] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0102] The relative content of Bacillus was slightly increased. Although the contents of Rhizopus, thermophilic fungi and Monascus were increased after cleaning, the content of Mucor surged before production, which compressed the content of yeast and other fungi. The cleaning effect was not as good as just spraying the tail wine to maintain the drying hall.

[0103] To sum up, during the second cellaring period of Xiashalun, it is recommended to use boiling water to clean the drying room and then evenly sprinkle the tail wine on the drying room for maintenance.

[0104] Comparative Example 6

[0105] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0106] After one round of wine making, the drying room is only cleaned by pouring boiling water in the same way, and no maintenance is performed on the drying room.

[0107] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0108] The relative content of Bacillus in the drying hall increased slightly, but had no significant effect on the overall dominant microbial composition.

[0109] Comparative Example 7

[0110] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0111] After one round of wine making, the drying hall is cleaned by pouring boiling water in the same way, and 10% vol of tail wine is poured for maintenance.

[0112] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0113] The relative contents of lactobacilli and thermophilic fungi in the drying hall increased slightly, and the composition of dominant microorganisms had no significant difference from that in the boiling water cleaning.

[0114] Comparative Example 8

[0115] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0116] After one round of wine making, the drying hall is cleaned by pouring boiling water in the same way, and the same method is used to maintain it by combining 10% vol of tail wine with 50 kg of Daqu.

[0117] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0118] Compared with before cleaning and maintenance, the relative content of Bacillus in the drying hall decreased, the relative content of Lactobacillus increased, and the changes in the dominant fungal composition were not obvious.

[0119] In summary, it is recommended to use 50kg of Daqu to maintain the drying hall during the cellar period of the first round of winemaking. The drying hall can be cleaned before production. Additional cleaning or use of tail wine for maintenance is not recommended.

[0120] Comparative Example 9

[0121] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0122] For the second to fourth rounds of wine making, the drying hall is cleaned by pouring boiling water in the same way, and the drying hall is cured by adding 10% vol of tail wine in the same way.

[0123] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0124] Compared with before cleaning and maintenance, although the relative content of Staphylococcus was reduced, the relative content of other acid-producing bacteria was increased, which may lead to an increase in the acidity of the base wine.

[0125] Comparative Example 10

[0126] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0127] For the second to fourth rounds of wine making, the drying hall is cleaned by pouring boiling water, and the wine is cured by using 50kg of Daqu in the same way.

[0128] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0129] The content of Bacillus in Daqu decreased, and the proportion of enzyme-producing and acid-producing bacteria such as Staphylococcus, Klebsiella, and Pantoea increased. The use of Daqu to maintain the drying hall has little effect on the dominant microbial structure of the drying hall. In addition, the content of Pichia in Daqu accounts for about 50%, and Candida accounts for about 10%. Yeast is the dominant fungus in Daqu from the second to fourth rounds. However, yeast has an absolute advantage in the fourth round of drying hall, which reduces the curing effect of Daqu.

[0130] Comparative Example 11

[0131] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0132] For the second to fourth rounds of wine making, the drying hall is cleaned by pouring boiling water in the same way, and the same method is used to maintain it by combining 10% vol of tail wine with 50 kg of Daqu.

[0133] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0134] Compared with before cleaning and maintenance, the dominant microbial structure of the drying hall, which is mainly composed of acid-producing bacteria and yeast, cannot be affected.

[0135] In summary, it is recommended to use boiling water to scald the drying hall during the fourth round of winemaking. Pay attention to the amount and clean it up in time to prevent water accumulation. It is not recommended to use tail wine or Daqu for maintenance.

[0136] Comparative Example 12

[0137] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0138] After five to six rounds of wine making, the drying room is cleaned by pouring boiling water in the same way, and no drying room maintenance is performed.

[0139] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0140] Compared with before cleaning and maintenance, the richness of bacteria in the airing hall was effectively reduced, the number of bacteria species was reduced by 30%, and the relative content of Bacillus, Kropenschyma (high temperature resistant functional bacteria) and Rhizopus in the airing hall was significantly increased, but the effect was not as good as that in Example 1.

[0141] Comparative Example 13

[0142] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0143] After five to six rounds of wine making, the drying hall is cleaned by pouring boiling water in the same way, and the 10% vol tail wine is used for maintenance in the same way.

[0144] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0145] Compared with before cleaning and curing, the relative contents of lactobacillus and yeast increased significantly, and the relative contents of Bacillus, Kropyrnia and Aspergillus were compressed, which may have a negative impact on fermentation and base wine flavor.

[0146] Comparative Example 14

[0147] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0148] After five to six rounds of wine making, the wine is cleaned and dried in the same way by pouring boiling water, and cured by using 50kg of Daqu in the same way.

[0149] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0150] Compared with before cleaning and maintenance, the relative contents of Bacillus, Kropensella and Aspergillus in the drying hall were significantly improved, but the effect was not as good as that in Example 1.

[0151] In summary, it is recommended to use boiling water to scald and air the wine in the fifth round of winemaking, and use 10% vol of tail wine + 50kg of Daqu for maintenance.

[0152] Comparative Example 15

[0153] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0154] After seven rounds of wine making, the drying room is cleaned by pouring boiling water in the same way, and no drying room maintenance is performed.

[0155] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0156] Compared with before cleaning and maintenance, it is easy to cause the growth of low-level foreign bacteria after cleaning. Although Staphylococcus becomes the absolute dominant bacteria before production, the relative content of Bacillus is compressed. At the same time, boiling water for drying the clothes can effectively reduce the content of Mucor, but the inhibition time is short, which can easily lead to a surge in the content of Mucor before production.

[0157] Comparative Example 16

[0158] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0159] After seven rounds of wine making, the same method is used to clean the drying room by spreading and scalding the cellar dregs, and no drying room maintenance is performed.

[0160] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0161] Compared with before cleaning and maintenance, it can effectively clean low-content foreign bacteria and reduce the content of Mucor, but it is also prone to rebound before production and increases the relative content of acid-producing bacteria.

[0162] Comparative Example 17

[0163] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0164] After seven rounds of wine making, the same method is used to clean the drying hall by using boiling water and cellar dregs, and no drying hall maintenance is performed.

[0165] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0166] Compared with before cleaning and maintenance, low levels of foreign bacteria can be effectively cleaned, but the relative content of acid-producing bacteria is increased, the content of Mucor is reduced, and the rebound effect is weakened.

[0167] Comparative Example 18

[0168] A method for cleaning and maintaining a drying hall in a wine-making process and its application, which differs from Example 1 in that:

[0169] After seven rounds of wine making, the same method was used to clean and dry the drying hall by using boiling water and cellar dregs, and the same method was used to maintain the wine by combining 10% vol of tail wine with 50 kg of Daqu.

[0170] The same method was used to test the drying hall for microorganisms, and the results were as follows:

[0171] Compared with before cleaning and maintenance, the relative content of Bacillus and functional molds was compressed, and the relative content of non-brewing functional bacteria was significantly increased. The overall maintenance effect was lower than using tail wine or Daqu alone.

[0172] In summary, the following two methods can be used to clean the airing hall during the seventh round of winemaking: one is to use the cellar-keeping dregs to spread and scald for cleaning, and 10% vol of tail wine is used for curing; the other is to use the cellar-keeping dregs to spread and scald for cleaning, and 50 kg of Daqu is used for curing. The two cleaning methods have similar effects.

[0173] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A method for cleaning and maintaining a drying hall in a wine-making process and its application, the wine-making process comprising: The sand-laying round, the sand-making round, the first wine-making round, the second to fourth wine-making rounds, the fifth to sixth wine-making rounds and the seventh wine-making round are characterized in that the cleaning and maintenance method of the air-drying hall comprises the following steps: In the above-mentioned sanding round, after the drying hall is cleaned with boiling water, the drying hall is maintained by spraying tail wine.

2. The cleaning and maintenance method according to claim 1, characterized in that: The concentration of the tail wine is not less than 10% vol.

3. The cleaning and maintenance method according to claim 1, characterized in that: It also includes cleaning and maintaining the drying hall during the sand making round after the sanding round.

4. The cleaning and maintenance method according to claim 1, characterized in that: It also includes curing the drying hall during a round of wine making after the sand making round. The curing method of the drying hall during the wine making round is to spread Daqu on the drying hall to maintain the drying hall.

5. The cleaning and maintenance method according to claim 1, characterized in that: It also includes cleaning the airing hall after one round of wine making and during the second to fourth rounds of wine making. The method of cleaning the airing hall during the second to fourth rounds of wine making is to scald the airing hall with boiling water.

6. The cleaning and maintenance method according to claim 1, characterized in that: It also includes cleaning and maintaining the air-drying hall after the second to fourth rounds of wine making and during the fifth to sixth rounds of wine making. The method of cleaning and maintaining the air-drying hall during the fifth to sixth rounds of wine making is: first scalding the air-drying hall with boiling water, and then maintaining the air-drying hall by successively spraying tail wine and Daqu; the concentration of the tail wine is not less than 10% vol.

7. The cleaning and maintenance method according to any one of claims 1 to 6, characterized in that: It also includes cleaning and curing the drying hall in the seventh round of wine making after the fifth to sixth rounds of wine making, and the method of cleaning and curing the drying hall in the seventh round of wine making is: using boiling water and cellar-keeping dregs to clean the drying hall in turn, and then curing the drying hall by splashing tail wine; or using boiling water and cellar-keeping dregs to clean the drying hall in turn, and then curing the drying hall by spreading Daqu; the concentration of the tail wine is not less than 10% vol.

8. The cleaning and maintenance method according to claim 7, characterized in that: The method of spreading and scalding the cellar-keeping dregs to clean the air-drying hall is specifically as follows: steaming the cellar-keeping dregs with a steam pressure of not less than 0.12 MPa for 20-40 minutes, and then evenly spreading the cellar-keeping dregs on the floor of the air-drying hall. The amount of cellar-keeping dregs used is sufficient to fully cover the air-drying hall, with a thickness of not less than 2 cm. When the cellar-keeping dregs cool to about 40° C., the scalding is stopped.

9. The cleaning and maintenance method according to claim 7, characterized in that: It also includes analyzing the microbial diversity and its succession patterns of the drying hall before and after the sand-laying round, sand-making round, first round of wine-making, second to fourth rounds of wine-making, fifth to sixth rounds of wine-making, and seventh round of wine-making.

10. Application of the cleaning and maintenance method according to any one of claims 1 to 8 in the brewing of Maotai-flavor liquor.

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