The packaging helps it stay fresh longer
“We are talking zero light penetration (one of the potent killers of great grape juice) in a box,” says Lipp. Light is the enemy of good wine, and that’s just not a problem when the wine comes in a box rather than a bottle.
In fact, on average, boxed wine that’s just been opened will stay fresh in a refrigerator for two to four weeks. That’s 21-28 times longer than bottled stuff, for those of you keeping track. (You should keep track.)