Oxygen Valve in Home Wine Making

"Welcome to the Gundel Winery. I am here behalf of Expert Village. I am Joel Tama, representing Gundel Winery since 1998. This is a very important apparatus during fermentation. This is actually a valve, a stopping valve. This stopper will, if it is really filled with water, it is a water stop valve which is very important, because if you let the gases out of the barrel that are forming due to fermentation, but since it is filled with water, it does not let the oxygen, the fresh air, get into the barrel. So this way, you can terminate oxidation. And this is a very important factor to eliminate oxidation if you want to keep the wine real fruity, fresh, crispy, you always have to eliminate oxidation. And this way, you can solve this problem."