The common sense of Wine-making--about the wine yield rate.
Regarding the wine yield: There are many factors that affect the wine yield. If you don’t know where the problem is, it is difficult to start. Most of your friends are doing wine and selling wine. If the wine yield is very low, it will greatly increase the production cost and cause Loss of profits and even losses, bad wine quality will also affect the sales of liquor, because abnormal fermentation will produce many impurities that affect the quality of wine.
The first factor: control the initial starch concentration in a proper range
Why do I put this factor in the first place? This is because very few people carry out fine control of starch concentration, or make corresponding adjustments and don't know why they do this. Only when they understand can they adjust flexibly in the process of making wine.
First, let me talk about the basic principles of liquor fermentation: the process of liquor fermentation is to convert starch into glucose through a saccharification process, and then yeast converts glucose into ethanol under anaerobic conditions.
Note: Saccharomyces cerevisiae cannot directly use starch, it must first turn into sugar and then into wine.
All the operation and control conditions of liquor fermentation are carried out around this basic principle.
Starch in grain is the effective ingredient for wine production. The concept of starch concentration is the ratio of starch to the entire material. For example, the starch content of rice is 70%, so 100 catties of rice contains 70 catties of starch, which is 70 catties of starch. The key to wine production.
The initial starch concentration of wine is generally controlled at 20~30%. The starch content of the grain we make wine is generally between 60~70%. The starch content of different grains is also different. For example, the starch content of grain: about 70% of rice, Corn 65%, wheat 65%, sorghum 70%
There are generally two commonly used methods to control the initial starch concentration:
The first type is liquid fermentation, usually 100 kg of grain plus 200 to 300 kg of water.
The second type is solid-state fermentation, adding mixed grains. The mixed grains are the distiller's grains after steaming the wine. After cooling to a suitable temperature, the ratio of adding the mixed grains is generally 100 catties of grain plus 300 to 500 kilograms of mixed grains.
According to the season and the residual starch content of the mixed grains, the temperature in summer is high, and the starch concentration generally needs to be controlled at a relatively low level. Therefore, the mixed grains must be larger. If the temperature rises slowly in winter, the starch concentration needs to be controlled at a higher level. Level.
What happens if the initial starch concentration is not controlled at 20~30%?
The first is the high concentration of starch. For example, after steaming the grain and adding the koji medicine, it will be fermented directly in the barrel. In this case, whatever koji medicine we use, the grain will not be completely fermented. In this case, wine can be produced, but the grain yield rate Very low.
In the second case, if the starch concentration is very low, such as adding 500 kg of water to 100 kg of grain in liquid fermentation, the fermentation broth is very dilute. In this case, the fermentation intensity is low, the fermentation is slow, and it is easy to be infected, and it will often occur. The problem of low wine yield.
After we understand this principle, we can flexibly adjust it in the actual operation process. This is the effect of the initial starch concentration on the wine yield.
The second major factor: proper dissolved oxygen
Appropriate dissolved oxygen is generally speaking that there needs to be an appropriate amount of air in the process of making wine.
First of all, let’s talk about the principle: in the early stage of liquor fermentation, microorganisms such as yeast and Rhizopus use oxygen in the air to carry out aerobic fermentation. The number of cells increases, and some enzymes such as metabolic glucoamylase and amylase help to decompose food. In the middle and late stages, when the oxygen is consumed, the yeast will begin anaerobic fermentation to produce ethanol. If it is not well controlled, abnormal fermentation will occur.
In the first case, there is too little dissolved oxygen. If you find that there is less bubbling in liquid fermentation, the fermentation is not moving, and solid-state fermentation finds that the temperature rises slowly, then you must consider whether it is insufficient dissolved oxygen;
In the second case, there is too much dissolved oxygen, and the most prone case with too much dissolved oxygen is rancidity, because most of the bacteria are aerobic bacteria. If the number of bacteria is up in the early stage, the fermentation will directly fail.
The actual operation of controlling dissolved oxygen:
The first type is liquid fermentation. In the first 3 days of fermentation, the fermentation broth is stirred 1 to 2 times a day. After stirring, it is sealed immediately. The stirring process is to break up the settled grains to prevent clumping, and the other is very The important factor is to dissolve part of the oxygen into it.
The second type is solid-state fermentation. Solid-state fermentation will cause the grains to compact and agglomerate. In this case, the use of bran husks should be increased. The main purpose of bran husks is to loosen them. Only the mash is loose enough. When it enters the tank for fermentation, there will be proper dissolved oxygen, and the fermentation will be normal. The main component of bran shell is cellulose, which does not produce wine by itself. The palatability of distillers grains containing bran shell by livestock is a little less palatable. In addition, the bran husk is also very helpful for steaming wine. The fermented glutinous rice is more compacted, and it is not easy to steam the wine. At this time, adding a part of the bran husk can make the wine easier to steam.
The third factor: controlling the fermentation temperature
First of all, let’s first understand the basic principles: the most suitable growth and reproduction temperature for yeast is 20~30℃, and the most suitable fermentation temperature is 38~40℃. According to this basic principle, we know that the initial temperature is 20~30℃. It can grow up, and the maximum temperature of fermentation should not exceed 40 degrees.
The actual operation is as follows:
The first is to use the exposed fermentation container to make wine. In this way, the temperature of the wine making environment and fluctuations will have a greater impact on the temperature of the fermentation container.
At this time, we need to intervene in external conditions to create a suitable fermentation environment. For example, in summer, we need to take cooling measures and a low initial temperature to make wine. In winter, we need to heat the fermentation container to prevent rapid heat dissipation. The fermentation temperature is too low. .
The second method adopts pit or terrarium fermentation. Relatively speaking, the environmental temperature change of this operation method does not have a great impact on the temperature of the fermentation system, and it is also difficult to change the temperature of the fermentation system through the intervention of ambient temperature. Later, it will be difficult for us to make adjustments.
At this time, it is necessary to set a reasonable entering pool temperature and adjust the appropriate starch concentration into the pool. For example, the starch concentration into the pool is 22, and the temperature in the pool is generally controlled at about 24~26℃. It is higher in winter and lower in summer. Consider the influence of the ambient temperature on the temperature of the fermentation system before the cellar is sealed. All in all, the temperature in the early stage of fermentation should be controlled below 30°C, and the top temperature in the middle and late stages of fermentation should not exceed 40°C. This is the basic principle of fermentation temperature control.
The fourth factor: inhibit the growth and reproduction of miscellaneous bacteria
Inhibiting bacteria mainly includes two aspects: one is sterilization, which is to do a good job of disinfection and environmental sanitation; the other is to inhibit the growth of miscellaneous bacteria and prevent them from growing rapidly.
The first point is well understood. The simpler aspect is to use hot water to sterilize the fermentation container, fermentation water, cooling bed, and operating tools. If the bacteria is more serious, you can use quicklime, hydrogen peroxide and other chemicals to sterilize.
The second point of inhibiting the growth of bacteria is to use the growth characteristics of the bacteria. The main types of bacteria in the production of liquor include acetic acid bacteria, lactic acid bacteria, etc. Most of them require oxygen to grow, and the optimum growth temperature is above 30°C. , We can set a lower initial temperature to achieve the purpose of inhibiting the growth of miscellaneous bacteria. When the number of yeasts grows up, the growth of miscellaneous bacteria will be inhibited to achieve the purpose of antibacterial bacteria.
The fifth factor: the application of saccharification and fermentation production technology in liquor production
Generally speaking, from the beginning to the end of liquor fermentation, the process of saccharification of starch and conversion of glucose into ethanol is always coordinated. If the conversion rate of starch into glucose is slower than the rate that yeast converts glucose into ethanol, the yeast is likely to decay prematurely. If the rate is too fast, high glucose concentration will inhibit the yeast's ethanol production, so we have to choose the relative matching of saccharification and fermentation. Only by using distiller’s yeast can the yield rate be higher. If you have friends who are using the production process of glucoamylase plus dry yeast, you can try the saccharification and fermentation process.