Health chef's comments: 1. Oxidation of wine: After wine is put into oak barrel, there will be some oxygen in the barrel, which will oxidize oak barrel and wine. In the process of oxidation, wine will produce different aromatic substances, soften tannins, promote the precipitation of insoluble substances, make wine soft and balanced, and enhance the color and stability of wine. Moreover, the oak barrel is breathable, and oxygen will come in little by little to promote the oxidation.

2. Wine alcoholization: The most important components in oak lignin are vanillin, eugenol, guaiacol and their derivatives; Although these components are rare, they are important components of all phenolic compounds derived from grape phenols in wine. Secondly, yeast can absorb oak exudate and transform oak aroma into wine aroma components through biochemical transformation.

3. Old and new oak barrels and their sizes: the size of oak barrels will affect the effect of moderate oxidation, because the larger the volume, the smaller the oxidation effect per unit of wine. In addition, the influence of old and new oak barrels on wine is also different. The newer the barrel, the better the sealing, and the stronger the wood texture brought to the wine.

4. Disadvantages of oak barrels: oak barrels not only bring benefits to wine. For example, if the oak barrel is not cleaned or is too old, it will not only bring bad smell to the wine, such as musty smell and rotten wood smell, but even cause excessive oxidation to deteriorate the wine. In addition, poor quality oak will bring poor quality tannins to wine, making it dry and unpalatable.