Classification of distiller's yeast Throughout the history of brewing wine with grain raw materials in the world, we can find that there are two categories. One is to saccharify the raw materials themselves into sugar by using enzymes produced during grain germination, and then convert the sugar into alcohol by yeast; The other is to make koji with moldy grain, and saccharify and ferment grain raw materials into wine with enzyme preparation contained in koji. Since written records, the vast majority of China's wine is brewed with distiller's yeast, and China's distiller's yeast method has a great influence on neighboring countries, such as Japan, Vietnam and Thailand. Therefore, before describing the varieties and characteristics of China wine, it is necessary to have a more detailed understanding of China's distiller's yeast. Although the people of China have been dealing with Qu Tile for thousands of years, they know that wine must be added with koji, but they have never known the essence of Qu Tile. Modern science has solved the mystery. Daqu is made because a large number of microorganisms and enzymes secreted by microorganisms (amylase, glucoamylase, protease, etc.) grow on it. ). Enzymes have biocatalysis, which can accelerate the conversion of starch and protein in cereals into sugars and amino acids. Sugar is decomposed into ethanol under the action of yeast enzyme, which is alcohol. Tillers also contain many such enzymes, which have saccharifying effect. The starch of tiller itself can be converted into sugar, and then converted into ethanol under the action of yeast. At the same time, koji itself contains starch and protein, which are also raw materials for brewing. Liquor-making with distiller's yeast is the essence of China's liquor-making. The microorganisms growing in koji are mainly molds. The use of molds is a great invention of China people. Professor Kenichiro Sakaguchi, a famous Japanese microbiologist, thinks that this is even comparable to four great inventions of ancient china, which is obviously inferred from the important position of bioengineering technology in today's science and technology. With the development of the times, the methods created by the ancients in China will show its important role more and more. The origin of distiller's yeast can't be verified. The earliest text about distiller's yeast may be Zhou Chaozuo's "If you are distiller's yeast, you will only be a tiller" in the Book of Classics and Numerology. From the analysis of scientific principles, koji actually evolved from moldy grain. The production technology of distiller's yeast was comprehensively summarized for the first time in Qi Yao Min Shu in the Northern Wei Dynasty, and reached a high level in the Song Dynasty. Mainly manifested in the following aspects: the variety of distiller's yeast is complete, the technology is perfect, and the saccharification and fermentation ability of distiller's yeast, especially southern Xiaoqu, is very high. Modern distiller's yeast is still widely used in the brewing of yellow rice wine and liquor. In terms of production technology, due to the mastery of microorganism and brewing theory, the development of koji has leapt to a new level. The original koji was moldy or germinated grain, and people improved it to make it suitable for wine making. Because of the different raw materials and production methods, the natural conditions in the producing areas are different, and the varieties of Qu are rich and colorful. Roughly in the Song Dynasty, the types and production techniques of China distiller's yeast were basically finalized. Later generations made some improvements on this basis. The following are the types of koji-making in China: The classification system of koji-making Edit This paragraph is divided into wheat and rice according to the raw materials of koji-making. Therefore, they are called wheat koji and rice koji respectively. There are many kinds of rice-based koji, such as rice-based Xiaoqu, steamed rice-based red koji or black-coated red koji, and rice koji (Aspergillus oryzae). According to whether the raw materials are ripe or not, they can be divided into raw wheat koji and cooked wheat koji. According to the additives in koji, there are many kinds, including Chinese herbal medicine koji and bean koji with bean raw materials (peas, mung beans, etc.). ). According to the shape of qu, it can be divided into Daqu (straw bag qu, brick qu, hanging qu), Xiaoqu (cake qu) and Sanqu. According to the source of microorganisms in koji, it can be divided into traditional koji (naturally inoculated by microorganisms) and pure koji (such as koji inoculated by Aspergillus oryzae, koji inoculated by Rhizopus, koji inoculated by Aspergillus Niger). Classification and editing of koji In this paragraph, koji can be roughly divided into five categories, which are used for different wines. They are: wheat koji, which is mainly used for brewing yellow wine; Xiaoqu, mainly used for brewing yellow rice wine and Xiaoqu wine; Monascus is mainly used for brewing red koji wine (red koji wine is a variety of yellow rice wine); Daqu is used to brew distilled liquor. Bran koji was developed in modern times, and the culture with bran as raw material was inoculated with pure mold. Can be used to replace some big songs or small songs. At present, bran koji method is one of the main methods of liquor production in China. Its liquor production accounts for more than 70% of the total output. The first song, the second song, the third song and so on. It is the name of different fractions of wine produced by different time of receiving wine during distillation. That is to say, the naming of fermentation and storage time, such as Tequ, Chen Qu, Touqu and Erqu, is also called quality grading. Among them, it is stipulated that the special songs should be kept for three years, one year for the first time and half a year for the second time. Daqu is the general name of liquor with Daqu as saccharifying starter, that is, Daqu liquor; Tequ refers to super Daqu liquor, which is also a particularly good Daqu liquor.