How long will a bottle of open wine last unrefrigerated?

Some wines will last longer than others after opening, but generally speaking they all deteriorate, mostly because of the oxidation that occurs after exposure to air. Before a bottle is opened, there is little empty space in the bottle. After opening, however, the space obviously increases, and the wine mixes with air as the wine is poured out.

I recommend that you shouldn’t hold onto a bottle of wine for more than a day or two. The vacuum stopper will definitely help. They suck most of the air out of the bottle, which preserves the wine a bit longer.

Further, for everyday drinking you might consider buying bulk wines in boxes instead of large (3— and 4-liter) jugs. The boxes have collapsible bladders inside that prevent air contact as the wine is consumed. The quality of the wine is preserved much longer.

Whit wine should be refrigerated, and will be fine for about 3 days, longer than that , still drinkable but deteriorates more each day
red wine ,ditto, but do not refrigerate.