本书告诉我们中国白酒的理化分析是从20世纪50年代中期开始的，在此以前工艺操作的传授和继承全凭眼观、手摸、鼻嗅；言传身教，没有文字记载，更没有理化分析数据，所以流传着"酿酒熬糖当不了内行"的说法。当时工艺操作的主要内容是操作要领，如上甑、摊晾、冷却、合粮拌糠、人窖、封窖等手工操作和糠水配料的正确运用，由于缺乏科学知识，全靠经验掌握，而且在酿酒过程中影响发酵的因素很多，变化万千，难于控制，出酒率很低，差距很大，遇到难题就无法解决。1955年轻工业部在烟台进行了降低消耗提高出酒率的研究试验，总结了"低温发酵，定温蒸烧"的研究试验成果，并于1956年出版了《烟台酿酒操作法》一书。同年抽调当时四川省名优酒厂和糖厂的科技人员十余人，组成了研究工作组，组建了化验室，开展了试点工作。l957年四川省糖酒公司和四川省糖酒研究室（现在的四川省食品发酵工业研究院）组织实施了四川省小曲酒工艺操作的总结运用，推广了李友澄发明的"匀、透、适"工艺操作法和冉启才同志发明的"闷水"操作法，并编写了酸度、温度、水分的入桶校对表，用分析数据来确定装桶温度的查对表。（From this book we know that the physical and chemical analysis of Chinese baijiu started from 1950s. In the past the producing process depended on visual, textual and olfactory perceptions. The expertise was taught by practical and verbal instruction, without any written record, let alone physical and chemical analysis. Hence the saying that "in baijiu and sugar making experts are few". At that time the main content of producing process was some essential points of operation, like putting on the earthenware urns, spreading and airing, cooling, mixing with rice and bran, putting in the cellar and sealing off the cellar, etc and the proper application of bran and water. Due to absence of scientific knowledge, reliance on experience, and the difficulty in controlling the fermentation process subject to too many vagrant external elements, the percentage of the end product remained low; the quality of baijiu varied greatly; and many problems could not be solved. In 1955, the newly established Ministry of Light Industry conducted the research experiment to reduce loss in the process and raise end product percentage in Yantai, and drew the conclusion of "low-temperature fermentation and fixed-temperature steaming", before publishing the Yantai Baijiu Making Methods in 1956. In the same year the Ministry dispatched a dozen R&D personnel from Sichuan Mingyou Brewery and Sugar Factory and founded the research team and a laboratory for pilot work. In 1957 Sichuan Suger Liquor Company and Sichuan Sugar Liquor Laboratory (present-day Sichuan Food Fermentation Industry Research and Design Institute) organized to summarize and implement the Sichuan Province xiaoqujiu, promoted the "well-distributed, transparent and appropriate" producing process invented by Li Youcheng and the "water asphyxiating" method invented by Ran Qicai, and drafted the checking table of acidity, temperature and moisture to define the temperature in which to put baijiu in the barrel.）