Study Of The Key Technology On Conservation Mud Pit And Production Daqu In Luzhou-flavor Liquor

Pit mud and Daqu were the most important conditions for Luzhou liquor production process. In this paper, an experiment was studied for the mud pit conservation and the Daqu making process in the winter. Firstly, pit mud crystallization had been purified, analyzed. The Mud pit’s liquid conservation was made by using Caproic acid bacteria, esterifying fluid, after-run, yellow water. Besides, refer to the Daqu production experience in summer. Daqu process parameters were optimized in the winter. The main research results were as follows:(1)The physical and chemical indicators of pit mid were detected and the crystallization in pit mid was analyzed.In seriously degradated pit mud, the moisture 33%, the p H 4.01. The ammonia nitrogen, potassium, phosphorus were generally lower 2 to 3 times than the normal mud pit. Through the study of pit mud crystallization, the results showed that crystallization slightly soluble in water at room temperature, soluble in hot water and acid, insoluble in ethanol and alkali. The pit mud crystallization was analyzed by using electron microscope scanning and infrared spectroscopy technology, the results showed that the main components of the pit mud crystallization were ferrous lactate, magnesium lactate and lactic acid copper.(2) The mud pit conservation liquid was studied and applied.Caproic acid bacteria and esterifying fluid were prepared in the laboratory. The acid-producing ability of the caproic Acid bacteria was about 432mg/100 m L. The esterifying liquid was composed of yellow water50%, ending liquor25%, spot-bottom water10%, compound caproic acid solution4%, esterifying enzyme2%, Daqu2%, pit mud1%. The optimal esterifying liquid culture conditions were temperature 35℃, alcohol12%(v/v), initial p H3.5, the amount of enzyme 4%, fermentation time 28 d ~ 35 d. The Mud pit conservation liquid was made by using caproic acid bacteria20%, esterifying fluid30%, yellow water20%, ending liquor20%, Daqu5%, pit mud5%, 32~35 ℃ sealed fermentation 5 days. The mud pit conservation liquid was applied to degraded and severely degraded pits. Through the wine quality analysis, it showed that the quality of wine was improved, the ethyl caproate, total acid, total esters of the degraded pits promotion rates were 42.7%, 16.2%, 37.5%. The the quality of wine produced by severely degraded pits ethyl caproate, total acid, total esters promotion rates were 24.2%, 16.0%, 19.3%.(3)The koji-making technology of Daqu in winter was studied.The moisture, comminution degree and the amount of old Daqu in winter Koji-making was Optimization with reference the Growth law in Summer Koji-making. The resulted showed that the moisture was kept about 37%, not more than 38%, because the molding problem of Daqu;The comminution degree must be controlled about 34%, and the old Daqu was added approximately 5% during the production in the winter. In a word, all the changes of Production parameters in order to make the temperature follow the rule that “slowly up in front, hold on in the middle, slowly down in the end.