CN111518705B

CN111518705B - Distiller's yeast and preparation method and use method thereof

Info

Publication number: CN111518705B
Application number: CN202010359262.2A
Authority: CN
Inventors: 吴再节; 孙伟; 常强; 韦孝宇; 刘翠兰; 周宏�; 王磊; 冯志成; 赵凤生
Original assignee: Anhui Wenwang Wine Co ltd
Current assignee: Anhui Wenwang Wine Co ltd
Priority date: 2020-04-29
Filing date: 2020-04-29
Publication date: 2022-08-16
Anticipated expiration: 2040-04-29
Also published as: CN111518705A

Abstract

The invention is applicable to the field of food, and provides distiller's yeast and a preparation method and a use method thereof. The preparation method comprises the steps of inoculating a koji strain obtained by selenium-enriched culture into a broken koji-making raw material, and carrying out artificial purification, screening and optimized culture on the koji strain to enrich the koji strain with elements such as selenium, so that the coordinated growth of each flora of the strain is facilitated, the survival capability of beneficial strains is improved, and the like. The culture and inoculation mode is not easy to pollute mixed bacteria, the controllability is good, the enzyme activity of the distiller's yeast prepared by adopting the distiller's yeast strain is higher, the liquefying power, the saccharifying power, the fermenting power and the esterifying power are relatively higher and the harmony is good, the ethyl ester content of the strong aromatic Daqu liquor brewed by adopting the distiller's yeast is lower, the hexyl ester content is higher, the main style of the ethyl caproate is not easy to be in a wrong lattice, the quality and the flavor of the strong aromatic Daqu liquor are stabilized, and the economic benefit of enterprises is improved.

Description

Distiller's yeast and preparation method and use method thereof

Technical Field

The invention belongs to the field of food, and particularly relates to distiller's yeast and a preparation method and a use method thereof.

Background

The distiller's yeast is a saccharifying leaven for brewing wine. The yeast is a saccharified leaven containing multiple bacteria, which is prepared by taking wheat or barley and peas as main raw materials, carrying out enrichment and expanded culture on microorganisms in the nature at a certain temperature and humidity, and then carrying out air drying.

The traditional Daqu production adopts a natural inoculation mode to artificially culture wild bacteria, the wild bacteria accumulate enzymes in the Daqu, ferment the precursor substances and ferment to provide nutrient substances, but the inoculation mode depends on the uncontrollable nature, is very easy to pollute mixed bacteria, has relatively poor controllability for culturing bacteria, and has low survival rate of beneficial bacteria, the prepared Daqu has higher acidity, lower enzyme activity, lower liquefying power, saccharifying power, relatively lower fermenting power and esterifying power and poor harmony, and the ethyl ester content of the strong aromatic Daqu liquor brewed by adopting the traditional Daqu is higher, the hexyl ester content is lower, the main body style of the liquor is easy to have mislattices, thereby the quality and the flavor of the strong aromatic Daqu liquor are seriously influenced.

Therefore, the Daqu prepared by the traditional Daqu production process has the problems of poor controllability of culture, low survival rate of beneficial strains, poor quality of the prepared Daqu, low hexyl ester content of wine brewed by the Daqu, high ethyl ester content and poor quality and flavor of the wine.

Disclosure of Invention

The embodiment of the invention provides a preparation method of yeast, aiming at solving the problems that the yeast prepared by the traditional yeast production process has poor bacteria cultivation controllability, low survival rate of beneficial bacteria, poor quality of the prepared yeast, low hexyl ester content of the brewed wine, high ethyl ester content and poor quality and flavor of the wine.

The embodiment of the invention is realized in such a way that the preparation method of the distiller's yeast comprises the following steps: inoculating a koji strain obtained by selenium-rich culture to the broken koji-making raw material, stirring and mixing to obtain a mixed material, and preparing the mixed material into a koji blank; putting the yeast blank into a pre-sterilized yeast culture room, and regulating and controlling the temperature, humidity and oxygen supply amount of the yeast culture room in stages to culture the yeast blank; and when the inter-yeast temperature, the inter-yeast humidity and the moisture content of the yeast embryo are detected to meet the requirements of the mature yeast embryo, discharging the yeast to obtain the distiller's yeast.

The embodiment of the invention also provides the distiller's yeast, and the distiller's yeast is prepared by the preparation method of the distiller's yeast.

The embodiment of the invention also provides a using method of the distiller's yeast, and particularly relates to a method for using the distiller's yeast and brewing raw materials according to the weight ratio of 21:100 is added into wine brewing raw materials for use.

According to the preparation method of the distiller's yeast provided by the embodiment of the invention, the distiller's yeast strain obtained by selenium-enriched culture is inoculated in the broken starter-making raw material, and the distiller's yeast strain is subjected to artificial purification, screening and optimized culture, so that the distiller's yeast strain is enriched with elements such as selenium, the coordinated growth of each flora of the strain is facilitated, the survival capability of beneficial strains is improved, and the like. The culture and inoculation mode is not easy to pollute mixed bacteria, the controllability is good, the enzyme activity of the distiller's yeast prepared by adopting the distiller's yeast strain is higher, the liquefying power, the saccharifying power, the fermenting power and the esterifying power are relatively higher and the harmony is good, the ethyl ester content of the strong aromatic Daqu liquor brewed by adopting the distiller's yeast is lower, the hexyl ester content is higher, the main style of the ethyl caproate is not easy to be in a wrong lattice, the quality and the flavor of the strong aromatic Daqu liquor are stabilized, and the economic benefit of enterprises is improved.

Drawings

FIG. 1 is a schematic cross-sectional view of koji produced by a conventional koji making process;

FIG. 2 is a schematic cross-sectional view of a koji produced by the koji making process provided in example 1 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment of the invention provides a preparation method of distiller's yeast, which comprises the following steps:

101, inoculating a koji strain obtained by selenium-rich culture to the broken koji making raw material, stirring and mixing to obtain a mixed material, and then making the mixed material into a koji blank.

And 102, putting the yeast blank into a pre-sterilized yeast culture room, and regulating and controlling the temperature, the humidity and the oxygen supply amount of the yeast culture room in stages to culture the yeast blank.

And 103, when the inter-yeast temperature, the inter-yeast humidity and the moisture content of the yeast embryo are detected to meet the requirements of the mature yeast embryo, discharging the yeast to obtain the distiller's yeast.

Preferably, the koji strains comprise aspergillus niger, monascus purpureus, saccharomyces cerevisiae, pichia pastoris, caproic acid bacteria and lactic acid bacteria obtained by selenium-rich culture.

Preferably, the inoculum sizes of various bacteria in the broken starter propagation raw material are respectively as follows: 0.001-0.5% of aspergillus niger, 0.001-0.05% of aspergillus niger, 0.001-0.1% of saccharomyces cerevisiae, 0.001-0.01% of pichia pastoris, 0.0001-0.05% of caproic acid bacteria and 0.0001-0.005% of lactic acid bacteria.

A large number of experimental researches show that when the inoculation amount of the aspergillus niger is controlled to be 0.001% -0.5%, the saccharifying power of the prepared distiller's yeast is high, the taste of the brewed white spirit is good, the yield is high, the effect is not obvious when the inoculation amount is less than 0.001%, the taste harmony of the brewed white spirit is poor when the inoculation amount is more than 0.5%, and the like, so that the inoculation amount of the aspergillus niger is preferably 0.001% -0.5%. When the inoculation amount of the monascus is controlled to be 0.001-0.05%, the esterification force of the prepared distiller's yeast is high, the brewed white spirit is good in taste and high in yield, and when the inoculation amount of the monascus is higher than 0.05%, the content of ethyl ester in the brewed white spirit is increased, so that the preferred inoculation amount of the monascus is 0.001-0.05%. The caproic acid bacteria mainly affect the hexyl ester content of the wine, when the inoculation amount of the caproic acid bacteria is controlled to be 0.0001-0.05%, the brewed white wine is relatively high in hexyl ester content and relatively good in taste, the yield of the brewed white wine is highest, and when the inoculation amount is increased, the yield is reduced. When the inoculation amount of the lactic acid bacteria is 0.0001-0.005%, the contents of ethyl ester and lactofat in the brewed white spirit are relatively low, and the taste is good. The main influence of the yeast is the fermentation capacity of the wine and the like, when the inoculation amount of the saccharomyces cerevisiae is 0.001-0.1% and the inoculation amount of the pichia pastoris is 0.001-0.01%, the wine brewed by the prepared distiller's yeast has high yield, relatively low ethyl ester content and good overall taste and flavor.

In addition, through a single-factor test, strains of the yeast are changed into independent saccharomyces cerevisiae and independent pichia pastoris respectively, and the saccharomyces cerevisiae and the pichia pastoris are simultaneously inoculated, the other strains and the inoculation amount are unchanged, and the yeast preparation process is unchanged, so that various groups of distiller yeasts are prepared, the prepared groups of distiller yeasts are respectively adopted for brewing, and the brewed wine is subjected to taste test.

When the total amount of the aspergillus niger and the monascus ruber inoculated in the broken starter propagation raw material is as follows: total amount of saccharomyces cerevisiae and pichia pastoris: when the ratio of the total amount of caproic acid bacteria and lactic acid bacteria is 10:2:1, the obtained koji has high enzyme activity, high liquefying power, saccharifying power, fermenting power and esterifying power and good coordination.

In the embodiment of the invention, the distiller's yeast strain is added with selenium-containing substances, magnesium salts and vitamin B ₁ The selenium-rich culture medium is obtained by culturing, wherein the selenium-rich culture medium is added with selenium-containing substances accounting for 0.001-0.005 percent of the mass of the selenium-rich culture medium, magnesium salts accounting for 0.01-0.05 percent of the mass of the selenium-rich culture medium and vitamin B accounting for 0.001-0.005 percent of the mass of the selenium-rich culture medium ₁ 。

Preferably, the selenium-containing substance is a selenium fertilizer with the selenium content of 0.5%; the magnesium salt is food-grade anhydrous magnesium sulfate powder, and the preferred granularity is 65-150 meshes.

It should be noted that the monascus, aspergillus niger, saccharomyces cerevisiae, pichia pastoris, caproic acid bacteria and lactic acid bacteria adopted by the invention are obtained by the following separation, enrichment and culture methods respectively:

monascus: firstly, adopting a culture medium I: 50% of bran, 35-40% of water, 10-15% of vinasse and 2% of alcohol are separated and purified from high-quality distiller yeast with high esterification force to screen out multiple strains of monascus purpureus; further optimizing and screening the separated multiple strains of monascus purpureus by using a culture medium II (0.001-0.005% of selenium-containing substances are added on the basis of the culture medium I) to obtain secondarily screened monascus purpureus; then using culture medium III (adding magnesium salt 0.01-0.05% and vitamin B on the basis of culture medium II) ₁ 0.001-0.005%) to continuously screen and optimize the monascus for the second screening, and finally selecting the monascus strain with the optimal esterification efficiency.

Aspergillus niger: firstly, separating a plurality of aspergillus niger strains from high-quality distiller's yeast with high saccharification capacity by adopting a culture medium (50% of bran, 35-40% of water and 10-15% of vinasse), and then, using the culture medium (50% of bran, 35-40% of water, 10-15% of vinasse, 0.001-0.005% of selenium-containing substances, 0.01-0.05% of magnesium salts and vitamin B ₁ 0.001 to 0.005%) and purifying and culturing the isolated multiple strains of Aspergillus niger to finally select black having optimal liquefying power and saccharifying powerAn Aspergillus strain.

Saccharomyces cerevisiae, pichia pastoris: separating and purifying to screen a plurality of strains of yeast from high-quality fermented grains with relatively low ethyl ester content and high wine yield by adopting a primary yeast culture medium (the mass ratio of the primary yeast culture medium to purified water to bran to cane sugar is 100:10: 2); then adding selenium-rich yeast culture medium (based on the above-mentioned original yeast culture medium adding selenium-containing material 0.001-0.005%, magnesium salt 0.01-0.05% and vitamin B) ₁ 0.001-0.005%) and performing purification and preferential culture on the separated multiple strains of yeast, and finally selecting saccharomyces cerevisiae and pichia pastoris with relatively high distillate alcohol content and relatively low ethyl ester content.

Caproic acid bacteria: separating and screening polycaproic acid bacteria from the bottom cellar mud of a high-quality cellar with relatively high content of hexyl ester by adopting an original caproic acid bacteria culture medium (95-96% of purified water, 2-3% of ethanol, 0.5% of yeast powder, 0.5% of potassium hydrogen phosphate, 0.5% of sodium acetate, 0.1% of sodium carbonate, 0.025% of calcium carbonate, 0.025% of ammonium sulfate, 0.025% of ammonium phosphate, 0.025% of sodium sulfide and 0.025% of magnesium sulfate); then using caproic acid bacteria selenium-rich culture medium (adding selenium-containing substance 0.001-0.005% and vitamin B on the basis of the above-mentioned procaproic acid bacteria culture medium) ₁ 0.001-0.005% and magnesium salt is kept at 0.01-0.05%), further purifying and optimally culturing the separated multiple caproic acid bacteria, and finally obtaining the caproic acid bacteria strain with relatively high caproic acid content.

Lactic acid bacteria: separating and purifying to screen out a plurality of strains of lactic acid bacteria from high-quality fermented grains with relatively low ethyl ester content by adopting an original lactic acid bacteria culture medium (95-96% of purified water, 1.5-2.5% of glucose, 1% of peptone, 0.5% of yeast powder, 0.5% of sodium acetate, 0.2% of potassium hydrogen phosphate, 0.2% of ammonium citrate, 0.1% of calcium carbonate, 0.01% of tween and 0.01% of magnesium sulfate); then adopting a lactobacillus selenium-rich culture medium (0.001-0.005% of selenium-containing substance and vitamin B are added on the basis of the original lactobacillus culture medium) ₁ 0.001-0.005% and 0.01-0.05% magnesium salt), and finally selecting the lactobacillus strain with relatively good distillate taste and relatively low ethyl ester content.

The aspergillus niger, monascus purpureus, saccharomyces cerevisiae, pichia pastoris, caproic acid bacteria and lactic acid bacteria obtained by separation are enriched, optimized and purified and cultured through the selenium-rich culture medium of the various bacteria, the survival capability of the various bacteria can be improved, the growth coordination among the bacteria populations is favorably improved, the beneficial bacteria populations are promoted to generate more liquefying enzymes, saccharifying enzymes, esterifying enzymes and the like, the coordinated biochemical capability of the distiller's yeast containing the distiller's yeast bacteria in wine brewing is further improved, the content of hexyl ester in wine is increased, the content of ethyl ester in the wine is reduced, the flavor and the quality of the wine are further improved, and the production efficiency and the economic benefit of a wine enterprise are comprehensively improved.

In step 101, the raw materials for making the yeast are wheat, barley and pea, and the raw materials are required to be full and clean, have no soil, impurities, mildew, pesticide pollution and worm-eating, and the dust carried by the raw materials must be removed by a vibrating screen when the raw materials are put in storage. Preferably, the ratio of wheat, barley and peas in the starter propagation raw material is 92.5: 5: 2.5 weight ratio.

In order to allow the koji mold inoculated into the koji-making raw material to sufficiently culture and utilize various nutritional components therein, it is preferable to crush the koji-making raw material and treat the crushed koji-making raw material with a 40-mesh sieve to obtain a crushed koji-making raw material having a predetermined crushed particle size.

The adjustment and setting of the preset crushing granularity are related to the ambient temperature during the starter propagation, and in the actual production, the starter propagation raw materials can be crushed into different granularities according to the ambient temperature during the starter propagation so as to meet the culture requirements. For example, when the ambient temperature is below 20 ℃, the crushing particle size is 35-37%; when the ambient temperature is 20-25 ℃, the crushing granularity is 37.1-39%; the crushing granularity is 39.1-41% when the ambient temperature is 25-30 ℃; when the ambient temperature is 30-35 ℃, the crushing granularity is 41.1-43%; when the ambient temperature is more than 35 ℃, the crushing granularity is 43.1-45%.

In the preferred embodiment of the invention, the starter propagation raw materials and the selenium-rich yeast seeds can be fed into the hopper in a plurality of times according to the relevant requirements so as to be uniformly mixed. In the embodiment of the invention, after the raw materials are mixed, a crusher can be started to crush the mixed materials, and the crushing grain size standard is as follows: when the crushed mixed material passes through a 40-mesh sieve, the fine powder accounts for the following proportion: the crushing granularity is 35-37% when the temperature is below 20 ℃; the crushing granularity is 37.1-39% at the temperature of 20-25 ℃; the crushing granularity is 39.1-41% at the temperature of 25-30 ℃; the crushing granularity is 41.1-43% at the temperature of 30-35 ℃; the crushing granularity is 43.1-45% at the temperature of over 35 ℃. The difference of the crushing particle sizes of the two groups of grinding rollers cannot exceed 1 percent. The particle size of the crushed particles is checked every half hour. If the process requirements cannot be met, timely adjustment is carried out. And (4) if an abnormal condition occurs (for example, the requirement cannot be met after the crushing granularity is adjusted for 5 minutes), stopping the machine immediately and reporting to a workshop attendant for treatment.

Further, the mixed materials are sent into a pre-sterilized yeast making room to be made into yeast blanks, and the specific operation is as follows: the mixed materials are sent into a feed inlet of a koji making machine in a koji making room which is sterilized in advance, the moisture of the fabric is roughly measured by hands, and the feed amount is observed. When the moisture of the fabric is roughly measured by hands, the fabric is generally held into a mass by hands, and the fabric is not sticky or loose and reaches the standard. When the adhesive is stuck to the hands, the moisture is large; the water content is small when the product is loose. The mixed material is added with water and stirred uniformly, and is formed by mechanical pressing, the water content of the formed bent blank is checked on line, the average water content of the formed bent blank is required to be 36-39%, the bent blank has no pimples, is consistent in size and thickness, and has smooth and flat surface, clear edges and corners and no phenomena of edge deletion and corner falling. The method for testing the moisture of the yeast blank comprises the following steps: taking a sample of a yeast blank on a yeast conveying belt of a yeast making machine, taking a 10 g yeast blank sample at the section, placing the yeast blank sample on an aluminum dryer with known weight, flattening, drying to constant weight, cooling and weighing; calculating the formula: moisture (10-weight of dried material)/10 × 100%; the water content testing frequency of the yeast blank is twice in one house, and the recorded data is the average value of the two times.

In actual production, different temperature conditions have different requirements for making a curved blank, specifically: moisture content of the yeast blank: when the temperature is lower than 25 ℃, the moisture of the yeast is 36-38%, and when the temperature is higher than 25 ℃, the moisture of the yeast is 37-39%. In addition, the appearance of the bent blank is required to be free of edges and corners, flat in appearance, smooth in six surfaces and consistent in thickness (7.5 +/-0.5) cm. The compact degree of the yeast is not tight. The compactness of the yeast blank refers to the tightness of the yeast making raw material after the yeast blank is formed, and can be realized by adjusting the length of a connecting rod of a yeast making machine, and the optimal length of the connecting rod is 92 cm.

In the embodiment of the invention, the curved house is cleaned, 4 (2mX2m)4 steel plates with holes are paved on the terrace in the middle of the curved house from the door opening to the inside in a linkage manner, the middle steam pipeline is movably connected, the relevant pipeline valve is debugged and checked, the ventilation window door is closed, and the like. And (4) unloading and stacking the cleaned bent frames on two sides of the wall-near access door respectively by using an electric forklift fork, and stacking the bent frames inwards in sequence for sterilization. Preparing a plurality of dry reed mats one day before entering a room, spraying the reed mats by a water cleaning machine, and placing the reed mats on a stainless steel bent frame beside a door for sterilization when the reed mats are required to be wet without water spraying. The door and window are closed, the lower valve outside the house is opened to open steam, hot steam is introduced to open the bent frame and the reed mat in the house for sterilization, and the problems that fumigation is not in place and not thorough, residual stains are difficult to clean, and time and labor are wasted during traditional sulfur fumigation sterilization are well solved. The steam sterilization and disinfection can be adopted to sterilize the roof, the inner wall, the terrace, the mat, the bent frame and other corners of the bent house. And if necessary, opening an upper valve outside the room to open steam, introducing hot steam into the heating pipeline to heat the room to raise the temperature, and ensuring that the temperature in the room reaches more than 60 ℃ and is maintained for more than 30 minutes so as to ensure the sterilization effect.

In the embodiment of the invention, the starter propagation process further comprises processes of residue beating, starter picking and starter transporting. The slag removing process specifically comprises the following steps: and (4) placing leftover materials and unqualified bent blanks collected in the bending process to a specified position. And adding leftover materials into a residue removing machine by a shovel, breaking unqualified bent blanks into quarter pieces, and adding the broken pieces into the residue removing machine by hands. The raw materials for making the yeast after being subjected to slag beating are evenly added into a yeast making stirrer through a conveyer belt. Unqualified bent and leftover materials need to be subjected to slag removal in time in the production process for adding. The residue beating needs to be uniform, and the yeast making raw materials after residue beating do not have dry flour and pimples. The raw materials after being subjected to slag removal are added into a starter propagation stirrer at a constant speed, can not be neglected, and are strictly forbidden to be directly added onto a conveying belt.

And in the process of picking up the yeast, the yeast picking up personnel visually inspect whether the thickness of the yeast blocks reaches the standard or not, whether the edges and corners of the yeast blank are lacking or not, lightly press the yeast blank by fingers, estimate whether the moisture content of the yeast blank reaches the standard or not, and pick up unqualified yeast blanks to carry out slag removal and rework.

And the yeast conveying step is to use a forklift to stack qualified yeast blanks to form a stainless steel yeast blank frame stack, stably convey and place the stainless steel yeast blank frame stack at the corresponding ordered position inside the specified yeast house of the whole house personnel.

In step 102, the yeast blank is placed into a pre-sterilized yeast culture room, the temperature, humidity and oxygen supply amount of the yeast culture room are regulated and controlled in stages, the yeast room temperature of the yeast blank is 28-50 ℃, the yeast room humidity is 50% -99.9%, and the yeast blank is cultured.

In the embodiment of the invention, before the koji culture, the whole house is firstly carried out, namely the koji culture house is arranged. When the whole house is finished, all indoor anti-explosion fans are well fixed according to specific positions and inclination angles for indoor relatively uniform. Closing the valve before the intermediate steam pipeline is articulated, and removing the intermediate steam pipeline, etc. The stainless steel curved blank frame is piled up and put down at a proper position, and then a sterilized wet reed mat is covered on the stainless steel curved blank frame. After the stainless steel bent blank frame stacks are stacked according to the requirements of the whole bent house and the sterilized damp reed mats are covered on the stainless steel bent blank frame stacks, the three temperature sensors and the three humidity sensors are placed among bent blanks of the stainless steel bent blank frame stacks at three positions in the middle to test the temperature and the humidity of the bent blanks. 5-15 kg of bacterial powder water is sprayed on the bent blocks stacked on the stainless steel bent blank frame by using spraying equipment indoors before closing the door. After the sanitary cleaning is done, a wind-proof curtain is hung on the inner side of the doorway, and then the door is closed. Entering a room when the temperature is lower than 30 ℃, and closing a window; when the temperature is higher than 30 ℃, the temperature of the koji room is reduced by using an air conditioner 1 hour in advance; meanwhile, the stainless steel bent blank frame is piled while spraying cold water on the ground or on the wall to protect moisture and reduce the temperature. The stainless steel bent blank frame stacks and the like are required to be arranged orderly and not to be inclined, and the line spacing is 20-50 cm. When the temperature is higher than 25 ℃ (tidal steam is low), 5-15 kg of clean water is sprayed indoors by high-pressure spraying equipment in advance before entering a room. When the temperature is over 30 ℃, spraying a little of mist water on the surface of the bent blank of the stainless steel bent blank rack stack by using spraying equipment. And (4) finding out unqualified (lacking edges and falling corners, thickness, water content and crushing granularity are not accordant and the like) koji blanks, and taking out the koji culture room in time.

In order to prevent the problems that the quality of the yeast blank is affected by the cracking of the yeast blank, the uneven growth of strains and the like caused by the sudden rise and fall of the temperature and the humidity of the yeast culture room in the culture process of the yeast blank, the temperature, the humidity and the oxygen supply amount of the yeast culture room are regulated and controlled in nine stages, so that the temperature between the yeasts of the yeast blank is 28-50 ℃, and the humidity between the yeasts is 50-99.9%, so as to culture the yeast blank.

And (3) preserving heat and moisture for 0-1 day, and mainly adjusting by using high-pressure spraying equipment and a moisture valve or spraying facilities and an indoor fan, so that the temperature and the humidity of the koji are 28-35 ℃ and 96.0-99.9% respectively.

And (3) controlling the temperature and keeping the moisture for 1-2 days, and mainly adjusting the temperature and the moisture of the koji by using a spraying facility or high-pressure spraying equipment or a moisture valve, an indoor fan, an air conditioner and the like so that the temperature and the humidity of the koji are 30-42 ℃ and 90.0-99.9% respectively.

The temperature of the koji room is raised to about 40 ℃ after 2-3 days (when the koji mold is fully covered by 90-100 percent of koji skin), the humidity control and the temperature control are carried out (namely, the water on the surface of the koji blank is slowly evaporated, the koji skin is dried and is not sticky, the speed is high, the koji blank is preliminarily fixed and formed, the speed is high, the thickness and the drying and cracking of the koji block skin and the like caused by the remarkable change of the koji blank are prevented), the adjustment is mainly carried out by a fan or a window or a warm air valve and the like for 1-3 hours, the temperature of the koji room is 30-39 ℃, the humidity of the koji room is 85-98 percent, and the humidity control and the temperature control and the humidity control can be carried out for 3-6 days after the temperature and the humidity are adjusted and simultaneously in accordance with the later period.

And controlling humidity, controlling temperature and ventilating for 3-6 days, mainly adjusting by using a fan or a window and a wet and warm steam valve or an air conditioner and the like, and performing stable work in the white space by referring to a key focus table of yeast culture so that the temperature of the yeast space is 30-40 ℃ and the humidity of the yeast space is 90-99.9%.

And (3) supplying oxygen, controlling humidity and controlling temperature for 6-10 days, mainly adjusting by using a fan or a window, an air conditioner or a steam heating valve and the like, and making stable work at night in a white room with reference to a key focus list of yeast culture so that the temperature of the yeast room is 32-44 ℃ and the humidity of the yeast room is 80-99.9%.

And (3) controlling the temperature, humidity and oxygen for 10-15 days, mainly adjusting by using a fan or a window, an air conditioner and the like, and performing stable work in the white space by referring to a key concern list of yeast culture so that the temperature and the humidity in the yeast space are 35-50 ℃ and 70-99.9 percent respectively.

Temperature control, humidity reduction and oxygen supply are carried out for 15-20 days, intermittent adjustment is mainly carried out by a warm air valve or a fan or a window, stable work is carried out in the white space and at night by referring to a key concern list of yeast culture, the temperature in the yeast space is 35-50 ℃, and the humidity in the yeast space is 60-93%.

And (3) after 20-25 days, heating and dehumidifying, and mainly adjusting by using a steam heating valve or a fan or a window or an air conditioner and the like, wherein the temperature and the humidity between the two is 32-42 ℃ and 60-90%.

And (3) preserving heat and reducing humidity for 25-35 days, and mainly adjusting by using a steam heating valve or a fan or a window or an air conditioner and the like to ensure that the temperature and the humidity between the koji are 32-40 ℃ and 50-85%.

In the yeast culture process, when the temperature difference of three temperature and humidity sensors in a yeast culture room is more than 5 ℃ or the humidity difference is more than 10%, the switch of a fan in the room is adjusted, and the temperature difference between the yeast of the three temperature and humidity sensors in the room is adjusted to be within 2 ℃ or within 5%. The bent piece temperature result of the temperature sensor test in every bent room is kept watch on at any time to carry out bent piece growth progress judgement, the bent piece growth progress condition is looked over through looking the glass to the condition in good time, carries out humiture etc. in the regulation bent room such as high pressure spraying equipment or wet steam valve or air conditioner or warm steam valve or fan or window.

In order to produce high-quality and stable yeast, the traditional yeast making process adopts yeast turning to increase the oxygen content and consistency of yeast blanks so as to promote the growth of microorganisms in the yeast blanks and produce enzymes. In the whole yeast culture process, 3-7 times of yeast turning operation is often required, yeast blanks in each room must be turned and piled in each yeast turning operation, the labor cost is high, the labor intensity is high, the consumed time is long, and the like, and the yeast blanks are easily infected with mixed bacteria due to various reasons in the yeast turning process, so that the quality and the stability of the yeast blanks are difficult to ensure, the yeast blanks seriously polluted can be directly scrapped, resources are wasted, and the cost input of a factory is increased. Moreover, the temperature difference of the surface of the yeast blank is large (the temperature difference of the yeast surface reaches more than 10 ℃ during yeast turning) in the artificial yeast turning culture mode, and the culture quality of the yeast blank can be seriously influenced by the sudden rise and fall of the temperature.

In the embodiment of the invention, the intelligent koji culture room is adopted to culture koji blanks instead of the traditional artificial koji turning culture. Specifically, temperature and humidity information in a collection room is monitored in real time through a temperature and humidity sensor arranged in a koji culture room and uploaded to a server; the server judges whether the temperature and the humidity in the koji culture room are within a preset temperature and humidity range of each stage according to the received temperature and humidity information, and if not, sends a control instruction of spraying, humidifying, ventilating, heating and cooling to a high-pressure spraying device, a wet steam valve, an air conditioner, a warm steam valve or a fan which are arranged in the koji culture room; after receiving the control instruction, the high-pressure spraying device or the wet steam valve or the air conditioner or the warm steam valve or the fan sprays/humidifies/ventilates/leads to cold wind and the like to the koji culture room, thereby leading the koji culture room to keep a stable temperature and humidity environment, leading the temperature difference change of the koji culture table to be not more than +/-2 ℃ every day and night, leading the culture of the koji blank to be relatively stable and having good quality.

The temperature and the humidity of the koji culture room are intelligently adjusted through the nine stages to culture the koji blanks, compared with the traditional manual regular koji turning culture process, the regulation and control of the koji blank culture condition are more intelligent, the 6-time koji turning process is omitted, the koji turning operators do not need to operate in the high-temperature koji culture room for a long time, the risks of sweating, dehydration, difficult breathing and the like generated when the operators operate at high temperature are avoided, the labor intensity and the labor cost of repeatedly loading and unloading the koji blanks are reduced, and the life safety of the operators is favorably ensured; but also avoids the problems that the temperature of the yeast blank product drops sharply due to the requirements of turning yeast and ventilating for cooling in the yeast culture process, and the temperature is difficult to reach the expected temperature in the later period; and the phenomenon that the bent blank hangs and mildews due to alternate cold and hot can be prevented when the bent blank product is turned over. Meanwhile, the phenomena that the temperature of the product does not rise in the early period of the yeast culture, the temperature of the product does not rise in summer and is too high, and the temperature of the product does not remain in the middle and later periods can be avoided. In addition, the method does not need to move, fold and combine the house in the yeast culturing process, and solves the problems that the 'water nest' and the 'core generation' are easily caused because the temperature is difficult to come because the heat preservation is too late when the house is moved, folded and combined in the traditional process; or the problem that the bent blank is too early in a moving and gathering room, the moisture in the bent blank is more, the bent blank is easy to burn, and the like. The method can also realize the culture of yeast blank in four seasons, the controllability is strong, and the prepared yeast for making hard liquor has good quality and stability.

In step 103, after the yeast culturing time reaches 28 days, whether the yeast is mature or not can be judged according to the yeast temperature, the yeast humidity and the variation of the yeast in the yeast room.

The embodiment of the invention also provides a using method of the distiller's yeast, and the distiller's yeast and brewing raw materials can be specifically mixed according to the weight ratio of 21:100 is added into wine brewing raw materials for use. The distiller's yeast is added according to the proportion for brewing wine, so that the quality and the yield of the raw wine are improved, and the raw wine has good taste and flavor.

The technical solution and the technical effect of the present invention will be further described by specific examples.

Example 1

The koji of example 1 was prepared by the following steps:

and (3) crushing the starter propagation raw material, and screening the crushed starter propagation raw material by a 40-mesh sieve to obtain a crushed starter propagation raw material with the crushing strength of 35.6%. Inoculating aspergillus niger (the inoculum size is 0.3 percent of the weight of the starter propagation raw material), monascus (the inoculum size is 0.02 percent of the weight of the starter propagation raw material), saccharomyces cerevisiae (the inoculum size is 0.06 percent of the weight of the starter propagation raw material), pichia pastoris (the inoculum size is 0.004 percent of the weight of the starter propagation raw material), caproic acid bacteria (the inoculum size is 0.03 percent of the weight of the starter propagation raw material) and lactic acid bacteria (the inoculum size is 0.002 percent of the weight of the starter propagation raw material) which are cultured by a selenium-rich culture medium into the crushed starter propagation raw material respectively, stirring and mixing to obtain a mixed material. And (3) feeding the mixed material into a starter propagation room which is sterilized in advance for starter propagation to obtain a starter blank with the moisture content and the shape meeting the preset requirements. And putting the yeast blank into a pre-sterilized yeast culture room, and regulating and controlling the temperature, the humidity and the oxygen supply amount of the yeast culture room in stages to culture the yeast blank. And when the yeast blank is detected to be continuous for at least one day, and the temperature, humidity and humidity change value among the yeast of the yeast blank meet the requirement of the mature yeast blank, discharging the yeast to obtain the distiller's yeast.

Example 2

Compared with the embodiment 1, the difference is only that: inoculating aspergillus niger with an inoculum size of 0.45 percent of the weight of the starter propagation raw material, aspergillus niger with an inoculum size of 0.05 percent of the weight of the starter propagation raw material, saccharomyces cerevisiae with an inoculum size of 0.09 percent of the weight of the starter propagation raw material, pichia pastoris with an inoculum size of 0.01 percent of the weight of the starter propagation raw material, caproic acid bacteria with an inoculum size of 0.01 percent of the weight of the starter propagation raw material and lactobacillus with an inoculum size of 0.004 percent of the weight of the starter propagation raw material into the crushed starter propagation raw material respectively, stirring and mixing to obtain a mixed material. The same procedure as in example 1 was repeated except that koji was prepared.

Example 3

Compared with the embodiment 1, the difference is only that: inoculating aspergillus niger (the inoculum size is 0.15 percent of the weight of the starter propagation raw material), aspergillus oryzae (the inoculum size is 0.02 percent of the weight of the starter propagation raw material), saccharomyces cerevisiae (the inoculum size is 0.03 percent of the weight of the starter propagation raw material), pichia pastoris (the inoculum size is 0.005 percent of the weight of the starter propagation raw material), caproic acid bacteria (the inoculum size is 0.015 percent of the weight of the starter propagation raw material) and lactic acid bacteria (the inoculum size is 0.002 percent of the weight of the starter propagation raw material) which are cultured by a selenium-rich culture medium into the crushed starter propagation raw material respectively, stirring and mixing to obtain a mixed material. The other conditions were the same as in example 1, and a koji was obtained.

Example 4

Compared with example 1, the difference is that: inoculating aspergillus niger (the inoculum size is 0.13 percent of the weight of the starter propagation raw material), monascus (the inoculum size is 0.02 percent of the weight of the starter propagation raw material), saccharomyces cerevisiae (the inoculum size is 0.025 percent of the weight of the starter propagation raw material), pichia pastoris (the inoculum size is 0.005 percent of the weight of the starter propagation raw material), caproic acid bacteria (the inoculum size is 0.013 percent of the weight of the starter propagation raw material) and lactic acid bacteria (the inoculum size is 0.002 percent of the weight of the starter propagation raw material) which are cultured by a selenium-rich culture medium into the crushed starter propagation raw material respectively, stirring and mixing to obtain a mixed material. Koji was prepared under the same conditions as in example 1.

Example 5

Compared with the embodiment 1, the difference is that: inoculating aspergillus niger (the inoculation amount is 0.001 percent of the weight of the starter propagation raw material), monascus (the inoculation amount is 0.001 percent of the weight of the starter propagation raw material), saccharomyces cerevisiae (the inoculation amount is 0.1 percent of the weight of the starter propagation raw material), pichia pastoris (the inoculation amount is 0.001 percent of the weight of the starter propagation raw material), caproic acid bacteria (the inoculation amount is 0.0001 percent of the weight of the starter propagation raw material) and lactic acid bacteria (the inoculation amount is 0.005 percent of the weight of the starter propagation raw material) which are cultured by a selenium-rich culture medium into the crushed starter propagation raw material respectively, stirring and mixing to obtain a mixed material. Koji was prepared under the same conditions as in example 1.

Example 6

Compared with example 1, the difference is that: inoculating aspergillus niger (the inoculum size is 0.2 percent of the weight of the starter propagation raw material), monascus (the inoculum size is 0.04 percent of the weight of the starter propagation raw material), saccharomyces cerevisiae (the inoculum size is 0.04 percent of the weight of the starter propagation raw material), pichia pastoris (the inoculum size is 0.008 percent of the weight of the starter propagation raw material), caproic acid bacteria (the inoculum size is 0.02 percent of the weight of the starter propagation raw material) and lactic acid bacteria (the inoculum size is 0.004 percent of the weight of the starter propagation raw material) which are cultured by a selenium-rich culture medium into the crushed starter propagation raw material respectively, stirring and mixing to obtain a mixed material. The other conditions were the same as in the above examples, and koji was obtained.

Comparative example 1

The only difference from example 1 is that the inoculated species of aspergillus niger, aspergillus rubrus, saccharomyces cerevisiae, pichia pastoris, caproic acid bacterium and lactic acid bacterium were all various species cultured using their corresponding original media, and the other conditions were the same as example 1 to obtain koji. That is, comparative example 1 is different from example 1 only in that the koji mold is one cultured in a selenium-rich medium or one cultured in the original medium.

In order to further illustrate the technical effects of the present invention, the following detailed description is further provided in combination with specific test examples:

test I,

FIG. 1 is a sectional view showing a koji prepared by a conventional koji making process (natural inoculation), and FIG. 2 is a sectional view showing a koji prepared by the koji preparation process of example 1 of the present invention. As can be seen from FIGS. 1 and 2, the whole appearance of the koji made by the conventional koji making process is brown and relatively uniform in color, while the koji made by the koji making process of the present invention has brown water circles (as indicated by the circles marked by 2 in the figure) interspersed with yellow red water circles (as indicated by the circles marked by 1 and 3 in the figure) within the white circles.

The distiller's yeast prepared by the traditional distiller's yeast preparation process, the distiller's yeast prepared by the distiller's yeast preparation process of the embodiments 1-6 of the invention and the distiller's yeast prepared by the comparative example 1 are respectively adopted for brewing white spirit, and except that the adopted distiller's yeast are different, other raw materials adopted for brewing the wine and other conditions in the brewing process are controlled to be consistent. In the brewing process, the liquification power, the saccharification power, the fermentation power and the esterification power of the distiller's yeast are respectively tested according to the ' strong fragrance Daqu detection operating procedure ' DB34/T3085-2018 of local standard of Anhui province, and the test results are recorded, which is detailed in the following table 1. The taste, ethyl ester content (calculated as ethyl acetate) and hexyl ester content of the brewed wine mixture are tested according to the GB/T10345, and the test results are shown in the following table 2.

TABLE 1

As can be seen from table 1 above, the results of the biochemical tests performed on the koji prepared by the koji preparation processes of examples 1 to 6 of the present invention and the koji prepared by the conventional koji preparation process and the koji preparation process of comparative example 1 show that the liquification power, the saccharification power, the fermentation power and the esterification power of the koji prepared by examples 1 to 6 of the present invention are significantly improved compared to the koji prepared by comparative example 1 and the conventional koji preparation process, which indicates that the liquification power, the saccharification power, the fermentation power and the esterification power of the koji prepared by the culture in the selenium-rich medium can be comprehensively improved by preparing the koji strain.

TABLE 2

As can be seen from the above table 2, when the distiller's yeast prepared in the embodiments 1-6 of the invention is used for brewing Luzhou-flavor liquor, compared with the distiller's yeast prepared in the comparative example 1 and the traditional distiller's yeast preparation process, the Luzhou-flavor liquor has the advantages of strong aroma, mellow, sweet, refreshing, full and harmonious taste and long flavor; the latter two have prominent ethyl ester fragrance and lack of purity. The content of ethyl ester in the former is obviously reduced to 157.75-186.56 mg/100mL from 311.38mg/100mL, while the content of hexyl ester is greatly improved to 170.15-208.21 mg/100mL from 88.16mg/100 mL. Namely, the ethyl caproate for brewing the Luzhou-flavor liquor by adopting the distiller's yeast prepared in the embodiments 1 to 6 of the invention has the advantages of prominent main body style, no deviation and mislattices, high quality of the liquor and good taste and flavor.

From the comparison result between the comparative example 1 and the example 1, the strong aromatic white spirit brewed by the distiller's yeast strain obtained by adopting the original culture medium has higher ethyl ester content, inharmonious mouthfeel and wrong lattices, so the flavor quality of the white spirit is relatively poor; adding selenium-containing substance, magnesium salt and vitamin B ₁ The strong aromatic white spirit is brewed by the distiller's yeast prepared from the distiller's yeast strain cultured by the selenium-rich culture medium, the content of hexyl ester in the white spirit is high, the content of ethyl ester is low, the main style of ethyl caproate in the white spirit is outstanding, the quality is high, and the taste and flavor are good. This indicates that the addition of selenium-containing substances, magnesium salts and vitamin B ₁ The selenium-rich culture medium is used for culturing the distiller's yeast strains in a selenium-rich way, so that the survival capability of each beneficial strain is improved, the growth coordination among strains is improved, the beneficial strains are promoted to produce more liquefying enzymes, saccharifying enzymes, esterifying enzymes and the like, the coordinated biochemical capability of the distiller's yeast containing the distiller's yeast strains in the wine brewing process is improved, the hexyl ester content in the wine is improved, the ethyl ester content in the wine is reduced, the flavor and the quality of the wine are improved, and the production efficiency and the economic benefit of wine enterprises are comprehensively improved.

Test II, optimization of addition ratio of koji

By adopting a yeast difference comparison test, except that the weight ratio of the distiller's yeast to the brewing raw material provided by the embodiment 1 of the invention is changed, other brewing raw materials and brewing process conditions are regulated and controlled to be consistent, the taste, the ethyl ester content, the hexyl ester content and the wine yield of the brewed mixed wine sample are tested, and the test results are shown in the following table 3. Wherein, the method for testing the mouthfeel, the ethyl ester content and the hexyl ester content refers to the first test. The yield is measured by converting 65 degrees of average value measured by land pounds for acceptance and warehousing of the wine depot.

TABLE 3

As can be seen from the above Table 3, when the addition ratio of the distiller's yeast to the brewing raw materials is 21:100, the brewed white spirit has the best taste, and the lowest ethyl ester content and the highest hexyl ester content.

In addition, the distiller's yeast prepared by the traditional distiller's yeast making process is used for brewing, the adding proportion of the distiller's yeast is 27:100, the taste test scoring result of the brewed white spirit is 81.8, the ethyl ester content is 306.6mg/100mL, the hexyl ester content is 89.0mg/100mL, and the yield is 296.3 kg. Therefore, compared with the distiller's yeast prepared by the traditional distiller's yeast making process, the distiller's yeast provided by the embodiment of the invention has the advantages that the ethyl ester content of the wine is obviously reduced, the hexyl ester content is obviously increased, the taste and flavor are good, the quality of the strong-aroma white spirit is ensured, the production cost is reduced, and the performance of enterprises is greatly improved.

In summary, the embodiment of the invention adopts the selenium-rich culture medium for culturing the koji fermentation strains to perform artificial enrichment, separation, purification, screening and optimization culture on the separated koji fermentation strains, so that the koji fermentation strains are enriched with elements such as selenium, the coordinated growth of each strain flora is facilitated, and the survival capability of beneficial strains is improved. The culture and inoculation mode is not easy to pollute mixed bacteria, the controllability is good, the enzyme activity of the distiller's yeast prepared by adopting the distiller's yeast fermentation bacteria is higher, the liquefying power, the saccharifying power, the fermenting power and the esterifying power are relatively higher and the harmony is good, the ethyl ester content of the strong aromatic Daqu liquor brewed by adopting the distiller's yeast is lower, the hexyl ester content is higher, the main style of the ethyl caproate is not easy to be staggered, the quality and the flavor of the strong aromatic Daqu liquor are stabilized, and the economic benefit of enterprises is improved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. The preparation method of the distiller's yeast is characterized by comprising the following steps:

inoculating a koji strain obtained by selenium-rich culture to the broken koji-making raw material, stirring and mixing to obtain a mixed material, and preparing the mixed material into a koji blank;

putting the yeast blank into a pre-sterilized yeast culture room, and regulating and controlling the temperature, humidity and oxygen supply amount of the yeast culture room in stages to culture the yeast blank;

when the inter-yeast temperature, the inter-yeast humidity and the moisture content of the yeast blank are detected to meet the requirements of the mature yeast blank, discharging the yeast to obtain the distiller's yeast;

the distiller's yeast strain comprises Aspergillus niger, Monascus ruber, Saccharomyces cerevisiae, Pichia pastoris, caproic acid bacteria and lactobacillus which are obtained by selenium-rich culture;

the inoculation amounts of various bacteria in the broken starter propagation raw materials are respectively as follows: aspergillus niger 0.001-0.5%, Aspergillus niger 0.001-0.05%, Saccharomyces cerevisiae 0.001-0.1%, Pichia pastoris 0.001-0.01%, caproic acid bacteria 0.0001-0.05%, lactic acid bacteria 0.0001-0.005%.

2. The method for preparing koji according to claim 1, wherein the total amount of Aspergillus niger and Aspergillus kawachii inoculated in the koji-making raw material after the crushing treatment is: total amount of saccharomyces cerevisiae and pichia pastoris: the ratio of the total amount of caproic acid bacteria and lactic acid bacteria is 10:2: 1.

3. The method for producing koji according to claim 1, wherein the koji species is cultured in a selenium-rich medium supplemented with selenium-containing substances, magnesium salts and vitamin B1.

4. The method for producing koji according to claim 3, wherein the selenium-rich medium contains 0.001 to 0.005% by mass of a selenium-containing substance, 0.01 to 0.05% by mass of a magnesium salt and 0.001 to 0.005% by mass of vitamin B1.

5. The method for preparing koji according to claim 1, wherein the step of culturing the koji blank by placing the koji blank in a previously sterilized koji culture chamber and controlling the temperature, humidity and oxygen supply amount of the koji culture chamber in stages comprises:

and putting the yeast blank into a pre-sterilized yeast culture room, and regulating the temperature, humidity and oxygen supply amount of the yeast culture room in stages to ensure that the yeast room temperature of the yeast blank is 28-50 ℃, the yeast room humidity is 50% -99.9%, and culturing the yeast blank.

6. The method for preparing koji according to claim 1, wherein said step of obtaining said koji by discharging koji when it is detected that the inter-koji temperature, inter-koji humidity and moisture content of said koji blank all meet the requirements for koji blank ripening comprises:

and when the yeast blank is detected to be continuous for at least one day, the temperature between the yeasts is 35-40 ℃, the humidity between the yeasts is 50-80% and the humidity change value is less than 5%, discharging the yeasts to obtain the distiller's yeast.

7. A koji according to any one of claims 1 to 6, which is produced by the method for producing a koji.

8. The method for using the koji according to claim 7, wherein the ratio by weight of the koji to the brewing raw materials is 21:100 is added into wine brewing raw materials for use.