The Study Of The Brewing Technology On The Quality Of The Huaxia Vineyard A Dry Red Wine

Combined with the characteristics of our own vineyards and grapes,the main topic isproducing high-grade wine products with regional characteristics-Huaxia Vineyards dry red wine Class A-by optimizing operations bothduring and post fermentation,such as cold maceration,yeast selection,and clarification of original wine.This study relies on the analysis results of several indexes,such as sugar content,alcohol content,acidity,the content of tannins and total phenols,color intensity and aromas of the wine,combining with the tasting results raised byHuaxia company'sprofessional tastinggroup,to determinesome optimal key factors in wine making.The main contents are as following:1)In the early stage of the fermentation,two key points were studied:time of macerationand the selection of pectinase.The must was tested every 24 hours after fill the tank to determine the optimal macerated time.The results showed that the best indexes of total tannins,total polyphenols and color intensitywere obtained at 96 hours of maceration,such as total tannins arrived 2.20 g/L and total polyphenolsarrived 1.82 g/L when color intensity kept stable for 4.2,after that time point,with the increase of macerated time,each individual index began to decline.Three commercial pectinases products which designed for aged wine were testedin the experiment: OR,EX and HE.The results showed that the highest content of total tannins and total polyphenols was raised with enzyme OR,but the color intensitywith enzyme OR was the lowest.Results with Enzyme EX was just the opposite with enzyme OR,while enzyme HE was in an average degree.2)5 kinds of commercial yeasts for aged wine were tested also,all of them were sampled and tested separately in the same fermentation condition(including grape variety and quantity,temperature control during fermentation,frequency of pumping-over,etc.).The results indicated that there was no significant difference among them regarding fermentation efficiency.However,the REDFRUIT yeast had the best comprehensive performance,not only considering wine indexes(total tannins,total polyphenols,color intensity,and aromas,etc.),but also the scoring from the expert tasting group(the score of the wine fermented with Red Fruit was 94 which is the peak among all the samples).3)As study in clarification of the wine,cold stabilization tests and finingexperiment were carried out to see their influence on wine quality.In the cold stabilization tests,the wine was been chilled to-4?for 6 days and sampled and tested every 24 hours.The results indicated that except for the total acidity decreased,no obvious changewas observed withincreasing of the freezing time for other indexes.In the fining experiment,6 kinds of fining agents were tested at 5 different dosages each.The result showed that bentonite BOG was the best choice of fining agent,and best performance was obtained at a dosage of 0.2 g/L.