In addition to wheat qu in the north, there were a large number of rice qu in the south of Jin Dynasty at the latest. Han Ji, a native of A Jin, recorded the southern grass song, that is, the rice song, in the Southern Vegetation, which is the earliest record of the southern rice song.

Xiaoqu is generally unique to the south. Since it first appeared in the literature in the Jin Dynasty, it has had many names. There are four cases in Beishan Jiujing in Song Dynasty. Its preparation method is similar, using glutinous rice or japonica rice as raw material, first soaking Polygonum hydropiper leaves or snake twist, or wringing juice. Mix juice and rice flour and knead into dough.

The production technology of traditional ditty;

Old wine, liquid medicine, rice flour and Polygonum hydropiper powder → mixing → compacting → cutting into pieces → rolling → inoculation → keeping the temperature in the tank for culture → putting the plaque for culture, changing the plaque, putting the plaque → putting it in a basket, taking it out of the basket → drying.

Traditional Xiaoqu production technology

The traditional wheat koji is completely inoculated with microorganisms naturally. The gestation of ditty was no exception before the Song Dynasty. But in the middle of>, a method of artificial inoculation is recorded, that is, "making cakes and wrapping up old songs one by one." That is to say, when the newly-made koji is rolled on the Chen Qu powder, Chen Qu powder will stick to the surface of the new koji, and there are a lot of Rhizopus spores in the old koji powder, which can propagate rapidly on the koji and form a growth advantage. Because Chen Qu with better quality can be chosen as a song artificially, and the inferior songs can be eliminated by selecting the best ones. After years of artificial propagation and natural elimination, high-quality koji (actually a microbial strain) was preserved. The source of microorganisms in natural inoculation koji-making is mainly water, raw materials themselves, or koji-making places and utensils. Strains with excellent performance cannot be passed down from generation to generation, and the quality of wine cannot remain unchanged forever.

During the Ming and Qing Dynasties, a wide variety of Chinese herbal medicines were added to Xiaoqu, which became the characteristic of this period. The Ming Dynasty's Heavenly Creations said: "Including all kinds of monarch and minister herbs. If you taste it less and taste it more, then each soil has its own method and you can't recite it. " This traditional practice has continued into modern times. There is an example in 1964 "Prescription of Medicinal Qu" collected by Mr. Zhou Henggang in Qionglai, Sichuan. There are 72 kinds of drugs in the prescription, totaling more than 50kg, which can be mixed with raw material1460kg (saccharified koji, 1964, China Finance and Economics Publishing House). However, there are also some ditties with little or no drugs. For example, only Polygonum hydropiper was added to Dongyang Daqu in Ming Dynasty. So is Ningbo Baiyao. So since the Ming Dynasty, Xiaoqu has developed in two directions: medicinal Xiaoqu and myrrh Xiaoqu.

The microorganism in Xiaoqu is mainly Rhizopus. According to the isolation and identification of relevant scientific and technological workers, among 828 strains of Mucor, Rhizopus accounted for 643 strains. Rhizopus has not only saccharification, but also alcoholase, so it has alcoholization. There are many other microorganisms in Xiaoqu, from which modern industrial microorganisms have obtained many beneficial strains and continue to make contributions to mankind.

Development of Daqu

Since the Yuan Dynasty, distilled shochu has become popular, and a large part of wheat koji has been used to brew shochu. Therefore, a kind of Daqu was differentiated from the traditional Maiqu. Although the raw materials used are basically the same as those used in yellow rice wine koji, there are certain characteristics in the production method. In modern times, Daqu and Maiqu used in yellow rice wine have become two different types of koji. During the Ming and Qing Dynasties, Henan and Huai 'an became the main production bases of China Daqu.

Daqu is differentiated from Maiqu, so the concept of Daqu is not clear in the literature of ancient wine. Generally, it refers to the large-shaped wheat koji. Daqu mentioned here refers to the wheat koji specially used for brewing distilled liquor. The main differences between Daqu for yellow rice wine and wheat koji are raw materials, koji seeds and culture temperature.

1 Daqu raw materials

The raw materials of Daqu are peas, wheat and barley. Its proportion also varies from place to place. Peas account for 30%-50% of the raw materials. Therefore, the wide use of bean raw materials is of great significance to the species and relative quantity of microorganisms in Daqu, as well as the aroma of Daqu and wine.

2 koji-making technology

Daqu has a big shape, such as> Song was made into bricks as described by Huaixian at that time, and this shape continues to this day.

The production process of Daqu;

Wheat → Moistening Wheat → Stacking → Grinding → Mixing with water → Loading into a koji mold → Treading → Cultivation between koji-making → Turnover → Stacking → Discharge → Storage → Finished koji.

Brick Daqu is made by specialized Daqu makers. Treading is a hard and interesting job. Quite special. First of all, its strict organizational form and cooperative working method often have a supervisor, who is the owner or experienced person of Qufang. Starting workers have a strict division of labor. Some people specialize in measuring raw materials and water, some people specialize in mixing materials, and some people specialize in handling. The curved surface is put into the wooden mold, and the pedal is practical. There are a dozen or even dozens of treadmills. Ask everyone to step on a few feet. For example, the first person steps on three feet in a row, the second person takes it, and at the same time, he turns over, steps on three feet again, and the third person takes it again. A piece of music needs up to 60 people to step on. Then someone will take out the wooden model, and someone will step on the corners of the block, and someone will be responsible for repairing the block to make it smooth. Several people moved to the music room. The purpose of such a strict tread structure system is to make high-quality tread blocks. The most important thing is to make the song compact. On the one hand, it is to reduce the damage of koji during transportation. More importantly, the compactness of sake koji directly or indirectly affects the microorganisms that propagate in sake koji. It is probably hundreds of years' experience to make a block with a brick-shaped bending die, which is considered to be the best geometric shape. As mentioned above, the original bending modulus is smaller, including round and flat square, and the brick shape of cuboid is the best geometric shape determined by comprehensive factors. These factors include, roughly, the viscosity of curved surface, the need of moisture evaporation, the need of heat dissipation, the strength when stepping on it, the need of accumulation of curved pieces and the need of handling.

3 culture temperature

After koji is made, it is sent to the koji room, and microbial cells are naturally inoculated through various channels. In the closed winding chamber, microorganisms begin to multiply and release heat, and the increase of temperature accelerates the evaporation of water, which makes the temperature and humidity in the whole winding chamber rise. There is no obvious difference between Daqu and yellow rice wine wheat starter in the operation of bacterial culture, and turning over, ventilation and accumulation are still necessary operation steps. But the key difference is the incubation temperature. Daqu becomes high temperature qu.

Daqu culture temperature can reach 50-60℃. Different places have different practices. For example, during the Republic of China, the culture temperature in Tangshan was 52℃, and the culture temperature of Maotai liquor koji could reach 60℃. The workers who turn the song often go into the song room naked to operate, and they are sweating.

One of the objective reasons for the development of Daqu in the direction of high temperature Daqu may be that the number of blocks piled up in the curved chamber increased, which led to the rapid and large temperature rise of the curved chamber (as mentioned above, this was caused by zigzag stacking). During the Ming and Qing Dynasties, koji-making became a handicraft industry, and Qufang specialized in producing liquor koji. In order to make full use of the space, the number of curved chambers can be increased as much as possible. Another important reason is that people realize that the wine brewed by high-temperature koji has a good aroma. Although its mechanism has not been fully clarified, one thing is certain, that is, the ratio of thermophilic bacteria to thermophilic bacteria growing on koji changes with the change of culture temperature, and the metabolites of thermophilic bacteria have certain influence on the aroma components of wine.

The highest temperature of different types of Daqu is different during culture.

There are roughly three kinds: medium temperature koji, high temperature koji and ultra-high temperature koji.

Medium-temperature Daqu is represented by Fenjiu Daqu of Fen-flavor liquor, and its highest temperature is below 50℃.

The characteristics of its cultivation technology are: the emphasis of koji making is to arrange koji, the windows of the koji room are sealed and opened day and night, and the temperature rises and falls suddenly. The temperature of hot koji and cold koji is strictly controlled, and the fluctuation range of hot koji is large, which is suitable for the growth of most mesophilic microorganisms, especially white koji.

Medium-temperature koji has the highest saccharifying power, liquefaction power and fermentation power.

High-temperature Daqu is represented by Luzhou-flavor liquor Daqu. The highest temperature during koji-making was higher than 50℃. During koji-making period, stacking koji was the main method, and tight covering and moisture preservation were the main methods. The temperature control during culture mainly depends on warping. Only when the highest temperature exceeds the limit of process requirements, warping is carried out, and humidity is released to cool down.

This process is characterized by more heat and less cold.

The saccharifying power, liquefaction power and fermentation power of starter are not as good as those of medium temperature starter.

Ultra-high temperature Daqu is represented by Daqu for Maotai-flavor liquor. For example, the Daqu used in Moutai liquor focuses on Daqu accumulation and is tightly covered, mainly for heat preservation and moisture retention. When the temperature of Daqu rose to 60-65℃, it began to turn over.

The saccharifying power, liquefaction power and fermentation power of ultra-high temperature koji are the lowest. Therefore, the amount of koji is the largest, and the ratio of koji to grain is as high as 1: 1.

Modern liquor production, high-quality liquor and national famous liquor all adopt Daqu brewed by traditional methods. In order to reduce the labor intensity of koji-making workers, mechanized koji-making has been applied.