The reason is that the cork has the characteristics of softness and strong elasticity. It has many fine holes. When the bottle neck is sealed with it, the cork expands when it contacts with the wine liquid, which closes the gap of the bottle neck and prevents the wine liquid from seeping. At the same time, the wine can also contact a small amount of air through the micropores of the cork itself to achieve the purpose of breathing and development, and continue to complete its maturation process after bottling. In addition, the components of the cork soaked into the wine will also add structure to the wine. It is said that before wine was sealed with cork, there was no special wine cork. Usually, the container is first plugged with some vine grass and other materials, and then sealed with fire paint. There are many drawbacks in doing so: in the process of opening, it is inevitable that small particles of varnish and grass clippings will fall into the wine, thus affecting the hygiene of the wine; poor sealing will lead to serious oxidation of the wine, which will affect the quality of the wine; Liquid leakage is even more unavoidable, resulting in great losses.

Of course, more and more wines are now being bottled with screw caps.