How Long Does Opened Box Wine Last In The Fridge?
Wine containers have undergone a surprisingly interesting evolution over the past few decades. Whereas wine used to be found almost exclusively in thick glass bottles with enough wine to pour five different people a drink, we're now seeing wine in cans and personal-sized glass bottles. Another innovation has been boxed wine. The wine isn't held by the cardboard itself. Instead, there's a plastic bag held upright inside with a spout on the bottom from which you can pour yourself a glass or two.
When you popped the cork off your classic wine bottle in the past, you would have a day or two to drink it before you risked losing the flavor to oxidation and other effects. One useful feature of boxed wines is that they stay fresh for much longer after being opened. Boxed wine should remain drinkable for up to six weeks if you keep it in the fridge, though the quality will start to noticeably deteriorate around the three-week mark. At three weeks, it likely won't be enough to make you want to throw the wine out but if you're looking to experience the wine at its best you would do well to finish the box off beforehand.
Leaky plastic bags
You may have expected the boxed wine to last longer than six weeks. After all, the wine is still enclosed in the bag and the spout is holding the outside air at bay. While that is partly true, the answer is more complicated. The plastic bag in boxed wine is almost universally made with polyethylene. Polyethylene is very commonly used with food products because it's sturdy and doesn't leak dangerous chemicals or toxins into whatever food or liquid it's holding. That said, it's also slightly porous compared to a glass bottle.
Unlike other wines, boxed wine has an expiration date on it. That seems a little strange since many people who buy wine stick it in their wine cellar and age it for years. The difference is they're using glass bottles. Boxed wine can't be aged the way wine in glass can because it's constantly being exposed to small amounts of air due to the porous nature of the plastic, leading to oxidation.
When assessing how long your boxed wine will last after being opened, you might want to consider the age of the boxed wine itself. If you waited until the last minute to open the wine, the contents will already have undergone a good amount of oxidation which will shorten the lifespan of the wine once opened. If you buy the wine and open it the same day, you can expect it to stay fresh longer.