The Effects Of Toasting Degree Of Oak Chips On Wine Aging

In recent years, oak products are widely used during wine making and wine aging, such as oak powder, oak chips, oak cubes, oak staves, oak sticks, etc. Using oak products is an economic and convenient method to improve quality of wine. This experiment studied the effect of different toasting degree of oak chips on wine’s physical and chemical index, sensory taste and aroma, and the change rule of physical and chemical index over aging time. In addition, the experimental researched the influence of alcohol degrees, acidity, and tannin content on wine aging with different toasting degree of oak chips, and the experimental results show that:(1) After adding different toasting degree of oak chips, found that the change of physical and chemical index was significant over aging time, which different baking degrees of the effects of different oak tablets in wine, which meaned different roasting degree of French oak chips had different influence on wine. After adding oak chips, total sugar, total acid, total phenol and tannin were higher than the control group, the total sugar, total acid, total phenolic and tannin increased in a certain time, and then gradually reduced over aging time. And the lower oak chip baked, the more total sugar increased. In the experiment, the total acid increased by 2.33 g/L after adding non-toasting oak chips. Besides the higher oak chip baked, the more tannin and total phenol increased. In the experiment,tannin and total phenol respectively increased by 0.308 g/L, 0.064 g/L after adding heavily toasting oak chips. After adding oak chip, total anthocyanins were lower than the control group, and decreased steadily.(2) Through the analysis of physical and chemical index and sensory taste, found alcohol degrees, acidity, tannin content and tosting degree had a significant impact on sensory taste, and the impact degree sequence decreasingly was acidity, tannin, roasting degrees,alcohol. Moreover, high acid and tannin content were conducive to wine aging with oak chips in a certain range. in the orthogonal experiments, the optimal combination were alcohol content 13%vol, acidity 5.5 g/L, tannin 1.2 g/L and moderate-toasting oak chip.(3) After adding oak chips to wine of different regions and varieties, the change of total phenol, tannin and total anthocyanins existed significant differences. There was a significant difference of sensory taste, the cabernet sauvignon, merlot from Xinjiang had hight acidity and tannin content, and sensory taste was better. However, the sensory taste of merlotfrom Ningxia with low acid and tannin content was worst. Experiments found that if the wine had a better quality, the choice of oak chips was more extensive.(4) The species of volatile components increased after adding oak chip. The species of esters, aldehydes, and phenolicsand both increased, and the species of ester was the largest increase, including oak lactone, whisky lactone, hexadecanoic acid ethyl ester, ethyl succinate,etc. The oak lactone reduced and furfural increasd with the increase of toasting degree both in cabernet sauvignon and merlot. The content of volatile components of cabernet sauvignon and cabernet sauvignon aging with oak chip from more to less were alcohols, esters, aldehydes,ketones, phenols. The content of volatile components of merlot and merlot aging with oak chips from more to less are esters, alcohols, acids, aldehydes, ketones. Inaddition the content of oak volatile components was higher in cabernet sauvignon than in merlot.