As lettuce loses its moisture while sitting in the refrigerator, it becomes limp and will eventually brown and wilt, though you can sometimes bring back some crispness and color by plunging it into cold water. A better option is to stop the wilting in the first place by using aluminum foil in a trick that works for most types of lettuce.

You may toss your head of lettuce into the fridge with the plastic bag you bought it with, but you should wrap it in foil instead. Foil works better than plastic (or no covering at all) to keep moisture inside the lettuce leaves, helping them last much longer, and very fresh lettuce can last as long as a month when tightly wrapped in foil.

Another benefit is that you can wipe off the aluminum foil and use it again on a new head of lettuce, keeping plastic out of a landfill while also reducing the amount of food waste in your home. This move is good for the health of the environment and your own health, since you'll get to eat way more salad when your lettuce stays fresh.