JP2020188686A - Production method of new yeast mash - Google Patents

Abstract

To provide a production method of yeast mash, for proliferating sake yeast while suppressing the proliferation and activity of various germs by using none of lactic acid bacterium, and externally added lactic acid.SOLUTION: A saccharified liquid production method for production of yeast mash includes: mixing cooled steamed rice, rice malt, and water followed by decreasing an article temperature to 5°C or less, or further cooling steamed rice and bringing an article temperature to 5°C or less at the time of mixing; and keeping an article temperature at 5°C or less from eight hours after local warming to next local warming, until subsequent addition of sake yeast while progressing a saccharification reaction with rice malt by locally warming a plurality of times for a fixed time. It is possible to suppress the proliferation and activity of various germs by producing the saccharified liquid by progressing a saccharification reaction while keeping a low temperature, and to proliferate sake yeast before proliferation of various germs by quickly raising a temperature after the addition of sake yeast. With this, excellent yeast mash can be produced by using none of lactic acid bacterium and externally added lactic acid.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing a sake mother, which is important for sake brewing. More specifically, the present invention relates to a method for producing a liquor mother that does not use either lactic acid bacteria or externally added lactic acid.

Sake is made by saccharifying rice starch with rice jiuqu, alcoholic fermentation with yeast, and straining. Sake mother is used as this yeast in sake brewing actually performed in sake breweries. Sake mothers are grown by culturing sake yeast, and in order to be an excellent liquor mother, it is necessary that a large number of excellent yeasts of interest are cultivated and that there are no wild yeasts or bacteria that are germs.

There are two main ways to make sake mothers. One is a method of making raw liquor mothers that follows the traditional flow of "raw brewing", and the other is a method of brewing fast brewing liquor mothers that streamlines "raw yuan", which was devised in the Meiji era. The method.

In raw liquor brewing, when saccharifying rice starch in rice jiuqu, lactic acid bacteria are also grown and the acidity is increased by the lactic acid produced by the lactic acid bacteria, increasing the acidity and making it difficult for germs to grow. Then, sake yeast is added to the resulting saccharified solution and heated to grow the sake yeast. Lactic acid bacteria are supposed to grow naturally in raw sake mother brewing, but in recent years, in sake breweries in a clean environment, lactic acid bacteria do not grow naturally and it may be necessary to add lactic acid bacteria. This was a problem because it violated the definition of lactic acid brewing. Furthermore, when lactic acid bacteria that are useful in raw sake brewing are grown, there is a risk that unfavorable types of lactic acid bacteria and other miscellaneous bacteria may also grow, and it is said that these miscellaneous bacteria produce unfavorable components for sake.
In fast-brewing sake mother brewing, before saccharification, lactic acid is added directly from the outside to increase the acidity and make it difficult for germs to grow, and sake yeast is added to it without the help of lactic acid bacteria. Then, by heating, saccharification is promoted and yeast growth is also promoted. Although it is permitted to add lactic acid for brewing in fast-brewing sake mother brewing, there was a negative image of adding artificial ingredients from the outside in the present age when the organic orientation is increasing.

Various materials related to sake mother brewing. In particular, it is related to raw brewing and quick brewing.

An object of the present invention is to provide a method for producing a sake mother, which grows sake yeast while suppressing the growth and activity of various bacteria without using either lactic acid bacteria or lactic acid added from the outside.

In order to achieve the above object, as a result of various studies, the present inventor proceeds with a saccharification reaction while maintaining a low temperature to produce a saccharified solution, and subsequently, after adding sake yeast, the temperature is rapidly raised to proliferate the yeast. We have found a method for producing liquor mother that does not require the use of either lactic acid bacteria or lactic acid added from the outside, and arrived at the present invention. That is, the present invention is as follows.

1. 1. A method for producing a saccharified solution for producing a liquor mother, which promotes a saccharification reaction before adding yeast under conditions in which lactic acid is substantially absent.
2. 2. After mixing the cooled steamed rice, rice jiuqu, and water, the product temperature is lowered to 5 ° C or less, or the steamed rice is further cooled to bring the product temperature to 5 ° C or less at the time of mixing, and then multiple times, locally for a certain period of time. For the production of sake mothers, the product temperature from 8 hours after local heating to the next local heating remains 5 ° C or less until the subsequent addition of sake yeast, while advancing the saccharification reaction with rice jiuqu. Method for producing saccharified liquid.
3. 3. The method for producing a saccharified solution for producing a liquor mother according to the above 2, wherein the local heating temperature is 80 to 98 ° C.
4. A saccharified solution is produced by the method of any one of 1 to 3 above, and sake yeast is added to the saccharified solution at 5 ° C. or lower so as to form an interface between the solution containing sake yeast and the saccharified solution, and after the addition. Is a method for producing sake mother, wherein the target temperature zone having a range of 1 ° C. before and after the target temperature is reached within 2 to 6 days from the start of temperature rise, and the target temperature is between 15 and 25 ° C.
5. In a method of growing sake yeast with a saccharified solution, sake yeast is added to the saccharified solution so that an interface is formed between the solution containing sake yeast and the saccharified solution, and the sake yeast is grown in the supernatant portion above this interface. A method of growing sake yeast.
6. A saccharified solution for producing sake mothers immediately before the addition of sake yeast, which has an acidity of 1 or less.
7. A saccharified solution for producing sake mothers immediately before the addition of sake yeast, which is a saccharified solution for producing sake mothers that does not substantially contain lactic acid.

According to the present invention, a large number of excellent sake yeasts of interest can be cultivated without using either lactic acid bacteria or lactic acid added from the outside, and an excellent liquor mother free of wild yeasts and bacteria which are various germs can be produced. In addition, compared to the conventional raw sake mother brewing, by not growing lactic acid bacteria, it is possible to suppress the growth and activity of unfavorable types of lactic acid bacteria and other miscellaneous bacteria, which reduces the flavor of sake. It is possible to suppress the generation of unfavorable components.
In addition, from the Meiji era when microbiology came from the West to the present, sake mother production uses lactic acid bacteria and / or externally added lactic acid to suppress the growth of germs and grow good sake yeast. It is common knowledge to let them (Reference: Takeyuki Kurosu, "Yeast (1)", Jyokyo, 1998, l93, No. 5, 334, 4th and 3rd lines from the lower left, Nada's sake glossary. The page of "Sake Mother / Moto" (http://www.nada-ken.com/main/jp/index_shi/220.html). In other words, it can be said that it is epoch-making to find a method for producing sake mothers that does not use either lactic acid bacteria or lactic acid added from the outside.
In the first place, in recent sake breweries where a clean environment is being prepared, various microorganisms such as brewed yeast and lactic acid bacteria are less likely to be mixed. The inventor of the present invention can utilize this clean environment to promote saccharification while maintaining the product temperature of the saccharified solution at a low temperature by controlling the temperature, and if it is possible to grow excellent yeast while suppressing the active growth of microorganisms, lactic acid bacteria. I started my research thinking that it might be possible to realize a method for producing sake mothers that suppresses the growth and activity of germs without using any of the lactic acid added from the outside. This idea itself can be said to be truly epoch-making in the world of sake production, which tends to stick to traditional methods.

The state of the temperature change when the long-term low-temperature saccharified liquor mother was produced was shown. The changes in the number of bacteria and the number of yeasts in the production of long-term low-temperature saccharified liquor mothers are shown. The state of the temperature change when the sake mother was manufactured by the mountain abandoned brewing of the raw system was shown. The temperature was raised from the middle of the saccharification reaction, and the state of the temperature change when the raw sake mother was produced was shown. The temperature was raised from the middle of the saccharification reaction, and the changes in the number of bacteria and the number of yeasts when the raw sake mother was produced were shown. The state of the temperature change when the long-term low-temperature saccharified liquor mother used by grinding steamed rice was produced was shown. The changes in the number of bacteria and the number of yeasts when producing a long-term low-temperature saccharified liquor mother used by grinding steamed rice are shown. The state of the temperature change when the short-term low-temperature saccharified liquor mother was produced was shown. The changes in the number of bacteria and the number of yeasts in the production of short-term low-temperature saccharified liquor mothers are shown. A photograph showing how yeast is growing by placing a bottle in an incubator.

The method for producing the sake mother of the present invention will be described below. The basis of the manufacturing method is the brewing of raw liquor mothers represented by mountain abandonment, and the parts that are different from that are mainly described.

Roughly speaking, in the production of liquor mother, steamed rice is saccharified with rice jiuqu and yeast is grown in this saccharified solution. It is done below. The fact that lactic acid is substantially absent means that the saccharified solution does not contain enough lactic acid to suppress the growth of various bacteria, and a small amount of lactic acid derived from various bacteria such as wild yeast and bacteria may be present. Absent. In other words, it means that the saccharified solution is produced under the condition that neither lactic acid produced by growing lactic acid bacteria nor lactic acid added from the outside, for example, lactic acid for brewing, is present.
The saccharification reaction is a saccharification reaction before the addition of yeast. Since the enzyme of Jiuqu is not inactivated even after the addition of yeast, saccharification proceeds, but after the addition of yeast, lactic acid derived from yeast is produced, so the lactic acid concentration is expected to increase.

The production of liquor mother will be described in detail.
First, prepare the raw materials, steamed rice, rice jiuqu, and water. The steamed rice is cooled as it is because it is hot as it is, but the steamed rice after cooling is more preferably 0 to 17 ° C., further preferably 11 to 16 ° C., and particularly preferably 5 to 10 ° C.

Next, steamed rice, rice jiuqu, and water are mixed. For mixing, steamed rice may be added after mixing the jiuqu and water in advance and eluting the enzyme of the jiuqu into water to make the jiuqu.

Immediately after mixing, the product temperature is lowered to 5 ° C. or lower, or the steamed rice is pre-cooled to a lower temperature to bring the product temperature to 5 ° C. or lower at the time of mixing. When lowering the product temperature, it is more preferably 3 to 18 hours, more preferably 3 to 12 hours, and the product temperature is lowered to the target temperature of 5 ° C. or lower. The temperature after the decrease, or when it is 5 ° C. or lower at the time of mixing, the temperature at that time is more preferably 0 to 5 ° C., further preferably 1 to 4 ° C., and particularly preferably 2 to 3 ° C. When mixed, the steamed rice absorbs moisture and swells, but it is more preferable to stir this slowly. By stirring, not only saccharification can be promoted, but also the product temperature can be lowered, and the temperature can be made uniform. Since the temperature is lowered to 6 to 7 ° C. in the generally practiced raw liquor brewing, the present invention is characterized in that the temperature is lower than that of the raw liquor brewing.
After the product temperature reaches the target value, it is more preferable to provide a non-heating period (Utase). The period is more preferably 0.5 days to 3 days, still more preferably 1 to 2 days. During the Utase period, stirring may be performed about once a day to prevent the surface from drying out. It is believed that nitrate-reducing bacteria proliferate during this Utase period to produce nitrite from nitrates in water, which acts as one of the suppressors of the growth of germs. In raw liquor brewing, after the temperature reaches 6 to 7 ° C, it is left at that temperature for 2 to 3 days to make Utase, so the temperature of Utase is lower than in raw liquor brewing.

Next, the saccharification reaction by rice jiuqu is promoted by locally heating for a certain period of time. Immediately reduce the temperature to 5 ° C or lower after local heating. After the temperature is lowered to 5 ° C or lower, the product temperature is maintained at 5 ° C or lower until the next local heating. Then, it is locally heated again. This is repeated a plurality of times until the subsequent yeast addition. That is, the product temperature may temporarily exceed 5 ° C. after local heating, but in principle, the product temperature is maintained at 5 ° C. or lower until the subsequent yeast addition.
The local heating for a certain period of time is more preferably 0.5 to 6 minutes per local location, further preferably 1 to 4 minutes, and particularly preferably 1 to 2 minutes. The number of local parts to be heated is more preferably 1 in 28 to 40 L, and more preferably about 5 to 7 in the case of a 200 L tank. The local heating temperature (hereinafter, local heating temperature) is more preferably 80 ° C. to 98 ° C., further preferably 90 to 95 ° C. The local ambient temperature is set to 50-60 ° C., which is a temperature suitable for the aspergillus enzyme to proceed with the saccharification reaction.
After the local heating, the product temperature is immediately lowered to 5 ° C. or lower. Specifically, it is more preferably 5 ° C. or lower within 8 hours after the local heating, further preferably within 5 hours, and within 3 hours. Is particularly preferable. However, if the elapsed time from local heating is short, the temperature difference due to local heating may not be eliminated, so the product temperature after the temperature difference is eliminated or agitation estimated from temperature measurements at multiple locations. After eliminating the temperature difference, the product temperature is set to 5 ° C. or less. The temperature of the product is lowered and maintained by setting the temperature around the tank to the target temperature or lower by placing it in a room where the temperature can be adjusted.
The frequency of local heating is more preferably once every 1 to 2 days. The product temperature from 5 ° C or lower to the next local heating shall be maintained at 5 ° C or lower. That is, "local heating ⇒ keep 5 ° C or less ⇒ maintain 5 ° C or less ⇒ local heating" is repeated. The product temperature may temporarily exceed 5 ° C after local heating, but as a general rule, the product temperature should be maintained at 5 ° C or lower until the subsequent yeast addition.
In principle, the temperature of 5 ° C. or lower is maintained until the addition of sake yeast, which is a later step, but since sake yeast is added after the glucose concentration reaches 20 g / 100 mL or more, more preferably 25 g / 100 mL or more, the sugar content is higher than that. In principle, the temperature will be maintained at 5 ° C or lower until the temperature reaches. The glucose concentration is a value measured by Gluco Jr. (manufactured by Biot Co., Ltd.), which measures the generated current using a biosensor using glucooxidase and converts it into a glucose concentration.
For example, when locally heating a barrel containing hot water called a warm air barrel, the temperature of the surface of the warm air barrel, which is the local heating temperature, that is, the warm skin is set to 80 ° C to 98 ° C. More preferably, 90 to 95 ° C. is even more preferable. At this time, the temperature of the hot water put in the warm air barrel is between 80 and 100 ° C., and the temperature around the warm air barrel is 50 to 60 ° C., which is a temperature suitable for the koji enzyme to proceed with the saccharification reaction. It is more preferable that the warm-up barrel charging time per local location is 1 to 2 minutes, and in the case of a 200L tank, the charging time is 10 to 15 minutes in total at 5 to 7 locations. The temperature around the tank is set to 3 ° C. or lower, and the product temperature is maintained at 5 ° C. or lower after the product temperature reaches 5 ° C. until the next local heating. In other words, although there is a possibility that the temperature will temporarily exceed 5 ° C after local heating, in principle, the temperature should be kept below 5 ° C until the addition of sake yeast.
At 5 ° C. or lower, even low-temperature lactic acid bacteria can hardly grow or act. Therefore, in the production method of the present invention, lactic acid bacteria are almost absent when yeast is added later. Furthermore, the growth and activity of other germs can be suppressed. In addition, warm skin has a high temperature of 80 to 98 ° C, and the ambient temperature is relatively high, 50 to 60 ° C, so that it has a bactericidal effect locally and around it. Occurs. In the case of normal raw skin, warm skin is about 60 to 70 ° C, and the temperature around the warm (warm barrel) is also about 40 ° C. Therefore, the method of the present invention is to increase the bactericidal effect by setting the local temperature to a higher temperature. Is also one of the features. That is, by maintaining the temperature at a low temperature, both the growth of lactic acid bacteria and the growth / activity of various germs are suppressed, and the germs are sterilized at a high temperature locally during local heating.

Here, it is usually about 12 to 15 days to keep the product temperature below 5 ° C. from after Utase to the addition of yeast, but if you want to produce sake mother in a shorter period of time, for example 1-3 In this case, in order to accelerate the saccharification reaction, high-potency Jiuqu, that is, Jiuqu with α-amylase activity of 500 U / g or more and glucoamylase activity of 250 U / g or more, is used. It is more preferable to use. The steamed rice is preferably softer, that is, the water absorption rate of the steamed rice varies depending on the rice production year and the production rate, but is preferably 40% to 45%. The water absorption rate of steamed rice (%) = ((weight of steamed rice-weight of white rice) / weight of white rice) x 100.
Furthermore, when liquor is produced in a short period of time, as will be described later, the production of nitrite and sugar is insufficient, and the suppression of the growth of various germs may be insufficient. for, it is preferable to use viable microorganisms number 10 ³ CFU / g or less of koji.

The saccharified solution immediately before the addition of sake yeast has an acidity of 1 or less, more preferably 0.5 or less, and particularly preferably 0.2 or less. The lower the acidity, the more the growth and activity of germs are suppressed. The acidity is measured by the acidity titration method according to the analysis method prescribed by the National Tax Agency. In normal raw sake mother brewing, the acidity produced by lactic acid bacteria, which is mainly lactic acid, suppresses the growth of various bacteria, so the acidity immediately before the addition of sake yeast cannot be 1 or less.
In addition, the saccharified solution at this time does not substantially contain lactic acid, which means that it does not contain enough lactic acid to be effective in suppressing the growth of various bacteria, and a small amount of lactic acid derived from various bacteria such as wild yeast and bacteria. May exist.

In raw liquor brewing, the temperature is raised to about 20 ° C by about 1 ° C per day after leaving it at 6 to 7 ° C for 2 to 3 days. It is said that by raising the temperature little by little, lactic acid bacteria are grown, the growth of various bacteria such as bacteria and wild yeast is suppressed, and an environment suitable for the growth of sake yeast is created.
The present invention is characterized in that the product temperature is not gradually raised in the saccharification process before the addition of sake yeast and is kept at 5 ° C or lower in principle, and lactic acid bacteria can hardly grow at 5 ° C or lower. , It can be said that it is an unusual production method from the traditional production method of raw material that requires the growth of lactic acid bacteria. Furthermore, since lactic acid bacteria are not grown, sugar consumption is reduced by that amount, and a saccharified solution having a high sugar concentration that is a nutrient for sake yeast can be produced. The higher the sugar concentration, the more effective the concentrated sugar compression can be. The sugar consumption can be measured by reducing the Baume scale.

In raw liquor brewing, low temperature, nitrite produced by nitrate-reducing bacteria, lactic acid produced by lactic acid bacteria, and concentrated sugar transition in a well-balanced manner to prevent the growth of germs and create an environment suitable for the growth of sake yeast. It is considered. The present invention does not rely on lactic acid bacteria, but uses low temperature, nitrite, and concentrated sugar below the raw liquor mother in a well-balanced manner to prevent the growth of germs and create an environment suitable for the growth of sake yeast. It is thought that there is.

Next, sake yeast is added to the saccharified solution. Sake yeast is a yeast used for sake brewing, and typical sake yeasts include various types of yeast. In the present invention, sake yeast is added after the sugar content has increased so that the growth of various germs can be suppressed by compression of concentrated sugar during yeast growth. However, when the sugar content is high, not only the germs but also the sake yeast itself grows. It becomes difficult to proceed. Therefore, the yeast solution is added so that an interface is formed between the yeast solution and the saccharified solution, and more preferably water is further added. Then, yeast is grown in the supernatant above this interface. As the water to be added, for example, water obtained by co-washing the container containing yeast is used. Although sugar permeates into the supernatant from the saccharified solution, the sugar concentration is still low, so that concentrated sugar compression does not occur. Furthermore, in sake mother brewing, sake yeast is usually added after the nitrite reaction disappears, but in the present invention, lactic acid may not be used and the nitrite reaction does not completely disappear, but in the present invention, the nitrite reaction occurs. Sake yeast may be added before it disappears. This is also because yeast grows in the supernatant, making it less susceptible to nitrite.
By growing the yeast in the supernatant in this way, the yeast is not affected by the concentrated sugar compression or nitrite while applying concentrated sugar compression to the germs in the saccharified solution, so that the sake yeast can be grown. Proceed. The interface is naturally formed without adding the yeast solution to the saccharified solution and stirring, but it is more preferable to add it gently and gently.
After that, if the sake yeast growth progresses to some extent, it may be stirred, for example, it may be stirred 2-3 days after the addition of sake yeast.

After the yeast is added, the temperature is raised rapidly to grow the yeast. In the present invention, the saccharified solution kept at 5 ° C. or lower is raised to a target temperature range having a range of 1 ° C. before and after the target temperature over 2 to 6 days, more preferably 2.5 to 4.5 days. Warm up. The target temperature is a temperature suitable for yeast growth, and is a temperature between 15 ° C. and 25 ° C., although it varies depending on the yeast and brewery environment. The average rate of temperature rise from the start of temperature rise to reaching the target temperature range is about 2 ° C./day to 12.5 ° C./day.
The temperature rise is performed, for example, by placing a container containing a saccharified solution containing yeast in a space set to a target temperature. In this way, the target temperature range is reached in about 36 to 108 hours, depending on the production scale. It is also more preferable in that the supernatant that comes into direct contact with the space is warmed first and the yeast grows. Since the mixture is not stirred for a while after the yeast is added, the temperature may be slightly uneven, but the temperature is measured not on the surface but near the center.
It is considered that the added sake yeast is grown before various germs such as unuseful lactic acid bacteria grow by rapidly raising the temperature from a temperature of 5 ° C. or lower to a target temperature range.
Since the production of sake is parallel double fermentation, the saccharification fermentation continues even if yeast is added, that is, the production process of the saccharified liquid and the growth process of sake yeast overlap with each other on the time axis.

When the target temperature range is reached, the yeast is grown at the same temperature for about 0.5 to 4 days, more preferably about 2 to 3 days, and then the product temperature is lowered. Although it depends on the characteristics of yeast, the Baume degree is 12 or less and the alcohol content is 5 or more, so the product temperature is lowered (cooling) and the product is left to rest at a low temperature of 10 ° C or less (withering). This cooling and withering are the same as those for raw brewing and quick brewing.

The liquor mother produced in this way contains almost no lactic acid produced by lactic acid bacteria and does not contain lactic acid added from the outside.

Hereinafter, the present invention will be described with reference to Examples. The method for producing a liquor mother of the present invention is broadly divided into those having a long low temperature time (hereinafter, a method for producing a long-term low temperature saccharified liquor mother) and those having a short temperature (hereinafter, short-term low temperature saccharified liquor mother). Manufacturing method), but each is shown below.

Example 1
<Long-term low-temperature saccharified liquor mother>

<Experimental example 1 Production of long-term low-temperature saccharified liquor mother>
30 kg of rice jiuqu and 95 L of water were mixed and left for 1 to 2 hours to elute the enzyme of the jiuqu into water to make water jiuqu. Next, 60 kg of cooled steamed rice was put into this water jiuqu. At this time, the charging temperature was 15.4 ° C. (See FIG. 1, the same applies to Experimental Example 1 below). The day of preparation was set to day1. After the preparation, the water jiuqu and steamed rice were mixed well. After a few hours, the steamed rice absorbed water and swelled. After swelling, I slowly put a paddle so that the steamed rice would not be crushed, and performed a rough paddle. In addition to promoting saccharification by spreading the koji enzyme throughout the steamed rice, the rough paddle lowered the product temperature and made the temperature uniform. The tank containing these was moved to a room set to a room temperature of 2.0 to 2.5 ° C., and the product temperature was lowered from the afternoon of day 1 to 3.2 ° C. by the morning of day 2.
After that, a paddle was put in once a day to prevent the surface from drying, and the temperature was maintained at around 3 ° C., and local heating was performed from the morning of day4. Local heating was performed by putting a warm air barrel (hereinafter referred to as warm air). The warm air barrel was filled with hot water at 100 ° C. For warming up, one warming barrel was used for one tank. The warm air barrels were placed in the tank, and after 1 to 2 minutes had passed in one place, the warm air barrels were moved to the next place in the tank, and warm air was put in a total of 5 to 7 places in the tank. The warm barrels remained in the tank for a total of 10 to 15 minutes. After putting in the warm barrel, the warm skin on the surface was 90 ° C, the temperature in the immediate vicinity of the barrel was 70 ° C, and the temperature around the barrel was 50 to 60 ° C. When the product temperature was measured 5 to 8 hours after the completion of warming up, it was a value of 5 ° C. or less.
After the first warming in the morning of day4, warming was performed every two days for day5, day7, day9, and after day5 to proceed with saccharification. The last warm air was added to day15 and yeast was added to day18. During this period, the product temperature was maintained at 5 ° C. or lower during the period from the temperature drop after mixing to the addition of yeast, the elapse of a certain period of time from the warming, and the next warming.
Sake yeast uses the association yeast 901 No. yeast, addition of yeast, two liquid culture yeast ^{500mL (2.0~3.0 × 10 8 cells /} mL, yeast same number of following liquid culture in yeast) , A total of 1 L was added. The liquid-cultured yeast was added gently so that an interface was formed between the yeast and the saccharified solution. Further, the container containing the liquid-cultured yeast was co-washed and the water was added. After the addition, the supernatant liquid covered the surface of the saccharified liquid.
After the addition of yeast, the mixture was moved to a liquor chamber set at 20 ° C., and the temperature was raised from 3 ° C. to 19.6 ° C. in 4 days from day 18 to day 21 while warming the whole. Since the amount of sake yeast increased steadily, the inside of the container was stirred on day 20.
The product temperature was maintained at around 20 ° C. from day 21, and cooling was started from day 24. After that, through the process of withering, the sake mother was completed on day31.
The number of bacteria and the number of yeasts were counted by days 1, 18, 21, and 31, and the transition of each number per 1 mL of liquor mother was examined (Fig. 2). As a result, it was found that the bacteria did not grow, the yeast increased vigorously after the addition, and a large number of excellent yeasts were cultivated, and an excellent liquor mother without various germs could be produced.

<Comparative Experiment Example 1 Manufacture of sake mother by abandoned mountain brewing
In order to compare the state of the temperature change, the state of the temperature change when the sake mother was manufactured from the mountain abandoned brewing of the raw system was shown (Fig. 3). A sake mother was produced on a scale of 60 kg of steamed rice, 30 kg of rice jiuqu, and 95 L of water. The temperature was gradually increased from day6, and yeast was added on day22 when the acidity was sufficiently increased. From this figure, it can be seen that the saccharification reaction of the present invention is carried out at a low temperature and the temperature is raised promptly after the addition of yeast, as compared with the brewing of raw liquor.

Example 2

<Comparative Experiment Example 2 Production of raw liquor mother whose temperature has been raised from the middle of the saccharification reaction>
40 kg of steamed rice, 20 kg of rice jiuqu, and 63 L of water were prepared, and the liquor mother was produced up to day 10 in the same manner as in Experimental Example 1. However, after the preparation, a paddle was added to grind the steamed rice.
A 1/3 amount was separated into a sample of Experimental Example 2 on day 10, and the remaining 2/3 amount was gradually heated to advance Comparative Experimental Example 2. If the temperature is gradually increased from day 4 after Utase, it is expected that the number of germs will increase, which may affect the actual sake brewing. Therefore, the temperature was decided to increase from the middle of saccharification. The state of the temperature change is shown in FIG.
The number of bacteria and the number of yeasts were counted by days 10, 18, 23, 25, and 32, and the transition of each number per 1 mL of liquor mother was examined (Fig. 5).

<Experimental Example 2 Production of long-term low-temperature saccharified liquor mother used by grinding steamed rice>
Using a part of the sample of Comparative Experimental Example 2, the liquor mother was produced according to Experimental Example 1 after day 10.
One-third of the amount was separated by day 10 of Comparative Experimental Example 2 to prepare a sample of Experimental Example 2, and the production of liquor mother was continued according to Experimental Example 1. The state of the temperature change at this time is shown in FIG.
The number of bacteria and the number of yeasts were counted by days 10, 18, 23, 25, and 32, and the transition of each number per 1 mL of liquor mother was examined (Fig. 7).
From the results of Comparative Example 2 and Experimental Example 2, Experimental Example 2, Comparative experimental example without the bacteria would once grown as 2, the number of yeast in day23 8 × 10 ⁷ next Comparative Example 2 because of 7.1 × greater than 10 ⁷ it is could see that the yeast is increasing vigorously, good yeast are many cultures, it was found that was able to produce within excellent shubo of bacteria.

Example 3
<Experimental example 3 Production of short-term low-temperature saccharified liquor mother>

30 kg of steamed rice, 15 kg of rice jiuqu, and 50 L of water were prepared. Koji, alpha-amylase activity 500 U / g dry koji above, glucoamylase activity 250 U / g dry koji above, were used following viable microorganisms number 10 ³ CFU / g. The "Kikkoman enzyme activity measurement kit" was used for the activity measurement. The steamed rice used had a water absorption rate of 40 to 45%. The water absorption rate of steamed rice (%) = ((weight of steamed rice-weight of white rice) / weight of white rice) x 100. The state of the temperature change is shown in FIG. After the preparation, the product temperature was lowered immediately. At this time, a paddle was added so that the steamed rice would not be crushed. Warm air was added to day3 and day4, and the mixture was moved to a liquor chamber at 19 ° C. on day5, and yeast was added. As the sake yeast, Kyokai yeast No. 1801 was used. The target temperature zone was reached on day 8, cooling was performed from day 10, and the liquor mother was completed on day 16.
The number of bacteria and the number of yeasts were counted by days 1, 5, 9 and 14, and the transition of each number per 1 mL of liquor mother was examined (Fig. 9). As a result, it was found that the bacteria did not grow, the yeast increased vigorously after the addition, and a large number of excellent yeasts were cultivated, and an excellent liquor mother without various germs could be produced.

Example 4
<Examination of yeast addition method on a small scale>
Using the saccharified solution having a high sugar concentration produced in Experimental Example 2, the relationship between the yeast addition method and the yeast growth rate was examined.
First, four 4L plum wine bottles containing 2L of the saccharified solution were prepared. The properties of the saccharified solution are shown in Table 1. Next, 5.5 mL of liquid-cultured yeast was added to each of the four bottles, and 2.7 mL of water obtained by co-washing the container containing the yeast solution was added. As the yeast, yeast No. 901 of Kyokai yeast was used. The yeast solution was added so as to form an interface (A-1, A-2), or was added and then stirred (B-1, B-2).

The four bottles were placed in an incubator set at 18 ° C. The incubator used was divided into two stages, but A-1 and B-1 were arranged in the upper stage, and A-2 and B-2 were arranged in the lower stage (Fig. 10). Then, 48 hours after being placed in the incubator, the contents of all four bottles were stirred and placed in the incubator for another 24 hours. The target temperature range was reached in about 6 hours.
After 24 hours, the bottle was taken out, moved to a liquor chamber at 3 ° C., the number of yeasts in 1 mL of liquor was counted, and the results are shown in Table 2. It seems that there was a difference in the heating rate between the upper and lower stages of the incubator, so when comparing A-1 and B-1 and A-2 and B-2 in the same stage, A-1 is 1. It was found that the yeast proliferated 5 times and A-2 was 1.8 times that of B-2, and the yeast added so as to form an interface grew more vigorously than the one stirred immediately after the preparation.

By producing a liquor mother by the method for producing a liquor mother of the present invention, it is possible to produce an excellent liquor mother in which a large number of excellent yeasts are cultivated without using either lactic acid bacteria or lactic acid and the contamination with various germs is small. By using this sake mother, it is possible to produce good-tasting sake with less miscellaneous taste, which is useful for the sake industry.

Claims (7)

A method for producing a saccharified solution for producing a liquor mother, which promotes a saccharification reaction before adding yeast under conditions in which lactic acid is substantially absent. After mixing the cooled steamed rice, rice jiuqu, and water, the product temperature is lowered to 5 ° C or less, or the steamed rice is further cooled to bring the product temperature to 5 ° C or less at the time of mixing, and then multiple times, locally for a certain period of time. For the production of sake mothers, the product temperature from 8 hours after local heating to the next local heating remains 5 ° C or less until the subsequent addition of sake yeast, while advancing the saccharification reaction with rice jiuqu. Method for producing saccharified liquid. The method for producing a saccharified solution for producing a liquor mother according to claim 2, wherein the local heating temperature is 80 to 98 ° C. A saccharified solution is produced by the method of any one of claims 1 to 3, and sake yeast is added to the saccharified solution at 5 ° C. or lower so as to form an interface between the solution containing sake yeast and the saccharified solution. After that, a method for producing sake mother, in which the target temperature zone having a range of 1 ° C. before and after the target temperature is reached within 2 to 6 days from the start of temperature rise, and the target temperature is between 15 and 25 ° C. In a method of growing sake yeast with a saccharified solution, sake yeast is added to the saccharified solution so that an interface is formed between the solution containing sake yeast and the saccharified solution, and the sake yeast is grown in the supernatant portion above this interface. A method of growing sake yeast. A saccharified solution for producing sake mothers immediately before the addition of sake yeast, which has an acidity of 1 or less. A saccharified solution for producing sake mothers immediately before the addition of sake yeast, which is a saccharified solution for producing sake mothers that does not substantially contain lactic acid.