Q: I heard that boxed wine is loaded with sugar to preserve it. Is that true? Is there less sugar in a bottle of red wine than a box of red wine? -Daniel, Winnipeg, Canada
A: The sugar content in wine varies due to myriad factors (the winemaker, grape, region, weather and when it's harvested, to name a few). Remember to take into account that some of the most coveted (and most expensive) wines in the world are sweet wines, like Sauternes and Port. Sweet doesn't necessarily mean cheap or bad.
While there are some boxed wines that are on the sweeter end of the table-wine spectrum, sweetness is not a prerequisite. In fact, the boxed-wine category isn't only growing rapidly, but it's becoming more diverse. Boxed wines are now competitive both in quality and value to their bottled counterparts.
You can't really judge a box by its cover-some boxed wines are following trends for wines with a touch of residual sugar to emphasize smooth textures and amplify flavors. Others aren't. There's no need to make a boxed wine sweeter for preservation. Keep in mind that most boxed wines are meant to be drunk within a year or so (the plastic bag inside can be permeable to oxygen, and the wine will start to fade after a year or so).
If you're concerned about sugar in your diet, consult your physician.