Lettuce, regardless of variety, is susceptible to heat and can wilt easily if not properly stored, even when kept in the fridge. Condensation that builds up during storage can lead to rotted, wet, slimy leaves. Too little humidity, however, can also lead to wilted lettuce. To prolong your lettuce's shelf life, store it properly in the refrigerator, packaged correctly, for lettuce that can last between 1 to 3 weeks.
Lettuce is best stored as a head, and cleaned and cut when needed. However, in some cases, this is not possible, such as with baby lettuce, or if you don't normally have time throughout the week. If cleaning lettuce prior to storing, washing and drying the leaves is crucial. Water droplets on the leaves can speed up rotting and encourage the leaves to become slimy.
To clean heads of lettuce, remove the lettuce leaves by hand, tearing the whole leaf off at the base. Submerge the leaves in a bowl of cold water. Brush away any visible dirt. Dry the lettuce in a lettuce spinner, removing as much excess water as possible. Pat the leaves dry with paper towel or a clean dishcloth before storing.
Lettuce that is stored outside of a sealed plastic container needs to be stored in the vegetable crisper. These drawers regulate the humidity level, prolonging the shelf life of lettuce. The drawers are also insulated, so that the lettuce does not accidentally freeze.
In the case of lettuce stored in a sealed container, keep the lettuce on a shelf, outside of the crisper drawer. Do not place the lettuce near the back of the fridge, as the cooler temperatures may accidentally freeze the delicate greens.