If you have invested a small fortune in your cellar, and you have a tasting room to show off in, one of these is a must. You want to be able to enjoy the beauty of the wine, not have it obstructed by the decanter itself. A tight fitting stopper is nice, but since you really don't want to leave the wine in there very long, it is not essential. Preservation Systems return to top What to do with wine if you can't finish the bottle is a problem most of us have faced. The theory is that you want to be able to keep the harmful oxygen away from the remaining wine.
Vacuum pumps are common, inexpensive, and slightly better than nothing.
Disposable nitrogen systems to put your wine on tap are wonderful, but pricey and of late hard to find. A great and nearly free idea is to keep empty half bottles of wine and old corks around. Make sure the bottle and cork are clean, and then fill the bottle with wine and cork it tightly by hand. Do this with the first half of the wine, and drink what remains in the bottle, you can always go back and drink the other half of the bottle. By placing the bottle of wine on tap as soon as you open it, you ensure that every glass will be perfect, for up to a month.