Study On Major Wine-making Technology Of Red Wine

Cabernet Sauvignon and Cabernet Gernischt (main and characteristic varieties in Yantai of China) are the primary varieties to product quality dry red wine in domestic at present and they were used as material in this study. The effects of major process of grape harvesting time, maceration, alcohol fermentation, malo-lactic fermentation on wine quality were studied to evaluate conventional dry red wine technology, these results will provide a theoretic base for the improvement and application of technology to dry red wine.The results showed:The sugar content of Cabernet Sauvignon in Yantai reached 200g/L on Oct.14th (year of 2004) and kept this level after that time, however, tannins and total phenols of skins were increased obviously after Oct.14th.When grapes were harvested at the end of October, the sugar content was 200mg/L, the total phenols was 250 mg/L, tannins was 270 mg/L, colour intensity of skins was 2.0, the grapes were fit for producing aged wine, from Oct.14th to end of Oct, for middle aged wine. If the grape were used to product fresh wine, they should be harvested from Oct.9th to Oct.14th. During alcohol fermentation,the increments of total phenols, tannins and colour intensity were greater than the quantity before/after alcohol fermentation. The increments of phenols was 122.8 to 470.2%, colour intensity was 110.2% to 192%, the variation trend of colour intensity increased firstly, then fall, when the alcohol fermentation carries through 60%, the colour intensity reach maximum, from now on, the rate of dissolving of phenols dropped obviously. Therefore, in bloomy fermentation, to control temperature and rate were benefits to dissolving of phenols and increasing of colour intensity, the fine colour and the high quality tannins were achieved. The mineral elements increased evidently in must during fermentation, the mineral elements of wine come from grape skins, the new organic acid (lactic acid, succinic acid) were created synchronously, tartaric acid concentration dropped prominently, the decreasing range of malic acid was relation to degree of MLF, to add VVR to wine during alcohol fermentation was good to colour intensity, phenols and sense.The results on maceration before alcohol fermentation of Cabernet Sauvignon and Cabernet Gernischt were found that maceration before alcohol fermentation can increase colour intensity and concentration of phenols and tannins, at one time, wine quality can be improved to a certain degree, however, measures of controlling temperature should be used in this technology, moreover, some circulation should be cooperated.Running off residue was put off and maceration time was prolonged after alcohol fermentation, the results discovered:Prolonging maceration time after alcoholic fermentation had no effect on alcohol content, sugar content, total acid and pH, but this treatment makes the solids increase in some extent.Total phenols and tannins increased continuously during time of prolonging maceration and the rate of...