The Influence Of Automatic Circulation And Manual Capping Process On The Quality Of Young-aged Merlot Red Wine

In order to develop and maximize the potential of Merlot in the sub wine region,two distinct techniques-manual capping and automatic circulation were adopted for the vinification process.Meanwhile,two other key points(grape sorting,cold maceration)of the production technology were controlled during winemaking process.In this paper,two different techniques(manual capping and automatic circulation)were compared and the physicochemical indexes,phenolic compounds,sensory evaluation were also analyzed to improve the quality of Merlot wine.It can provide theoretical foundations for the vinification process,thus promoting the development of variety regionalization at the eastern foot of Helan Mountain.The main research results are as follows:1)At the end of the cold maceration,the relative content of the total phenolic compounds in grape juice was 57(D280nm),and the extraction rate of the anthocyanin and the maturity of grape seeds were 56% and 40%,respectively.2)Compared with capping process,the alcoholic fermentation(AF)speed for the automatic circulation could be faster,2 days in advance to finish the AF.And it showed that the alcoholic content(15.09%)and total phenolic compounds content of the wine with manual capping treatment were higher,0.35 g/L of volatile acid content with 0.06 g/L higher than automatic circulatory process.3)It displayed that the anthocyanin content for the wine with automatic circulatory treatment could be higher and the extraction rate was faster and more severe.During the AF,the content of anthocyanin increased dramatically,and then dropped to around 750mg/L after AF.During the transferring operation,it obtained more tannins of capping treatment,0.3% higher than automatic circulation.4)With these two treatments(manual capping and automatic circulation),it showed the intensity and tone of the red wine color were 2.5 and 0.5,respectively,making no significant difference.5)It found that after capping treatment,the complexity of wine tasting rose obviously such as the bitterness,raw grassy taste,astringency,with higher tannins and poor structure,while the wine after automatic circulatory treatment seemed to be more balanced,darker and more abundant for aromas.