A common tip is to look for salad bags that are deflated. The theory goes that bagged lettuce and salad greens are initially sold with the air sucked out of them, and that as they decompose, the greens emit gas (true, they do emit carbon dioxide), puffing up the bag. While this might have been true once, modern salad bags are breathable thanks to modified atmospheric packaging (MAP), so that method won’t work to spot older bagged greens. The key issues with bagged salad greens are freshness and water. The easiest way to keep your bagged lettuce fresh is to simply buy the freshest salad bag, and use it within a day or two (easier said than done, we know). Check the sell-by date, and grab the latest date you can find. Water is the enemy of salad longevity. It can host the bacteria that will eventually decompose your greens. So your first task, if you’re not planning on making a salad recipe from your bagged salad greens within two days, is to get it out of that bag and get it dried. Your best tool for drying greens is, the most popular tool designed for drying greens: a salad spinner. Once you’ve thoroughly spun your greens, leave them in the spinner for a minute. Take a paper towel (or cloth, if you want) and line a container of some sort. This could be an airtight plastic container, a glass Pyrex type, or even a reusable plastic bag (aka Ziploc bag). The most important thing is that you pick a container that seals completely. Once you’ve got your towel in your container, toss in your greens and store the whole thing in the crisper drawer of your refrigerator. If you want to keep the greens for more than five days or so, you’ll have to replace the towel. Another option, especially in the winter months, is to skip the bagged salad greens. Whole heads of lettuce will last for a couple of weeks in the refrigerator, as will other hearty or bitter greens like cabbage, endive, radicchio, and kale. (You may have to discard the outer layer of leaves, but don’t worry, the inner ones are still good!) To store whole heads of greens like lettuce, opt for the same method: wrap in a paper towel, stick in a resealable bag or container, and pop in the fridge. The upside is that whole heads will last much, much longer than bagged greens—and taste better, too.
