You bought a head of romaine and a bag of mixed greens on Sunday. By Wednesday the romaine is still perfect and the bagged greens are already slimy. Or you washed the whole head of iceberg and put it back in the fridge wet, and now it has gone limp and brown in three days. Lettuce storage is one of the most common sources of produce waste in the kitchen, and almost all of it comes from two mistakes: too much moisture and the wrong humidity setting.
The short answer: Store lettuce in paper towels inside an airtight container or zip-top bag in the crisper drawer set to high humidity. Do not store lettuce wet. Do not rewash pre-washed bagged greens. Opened bagged salad lasts only 1 to 2 days once the seal is broken. A whole head of iceberg or romaine stored correctly lasts 7 to 14 days. Delicate greens like arugula and baby spinach last 2 to 4 days regardless of method.
For a complete reference on storing over 100 foods, see our Food Storage Guide.

Key Takeaways

Crisper drawer setting: HIGH humidity for all lettuce and leafy greens
Paper towels absorb excess moisture and are the single most important storage step
Do not store lettuce wet: excess moisture is the primary cause of slimy leaves
Do not rewash pre-washed bagged greens: FDA and USDA advise against it
Opened bagged salad: 1 to 2 days only after breaking the seal
Iceberg and romaine: 7 to 14 days properly stored
Butterhead and loose-leaf: 3 to 7 days
Arugula, baby spinach, mesclun: 2 to 4 days
Wilted but not slimy: revive in an ice water bath for 15 to 30 minutes
Keep away from ethylene-producing fruits: apples, bananas, tomatoes

The Crisper Drawer Setting Almost Everyone Gets Wrong
The high humidity setting on your crisper drawer is the single most impactful change you can make for lettuce storage. Most people leave both crisper drawers on the same setting or do not adjust them at all. This is the wrong approach.
Leafy greens need high humidity to stay crisp. When the humidity is too low, lettuce loses moisture through its leaves faster than normal, causing wilting and browning. The high humidity setting restricts the vents on the drawer, trapping moisture-laden air inside. The low humidity setting is for ethylene-producing fruits like apples, pears, and avocados, which need airflow to prevent ethylene buildup. Set one drawer to high for greens and one to low for fruit. USDA and FDA guidance confirms the crisper drawer is the optimal location for all salad greens precisely because of its humidity control.
Equally important: keep lettuce in a different drawer from ethylene-producing produce. Apples, bananas, tomatoes, and pears all produce ethylene gas that wilts leafy greens significantly faster. UC Davis Postharvest Technology research confirms cucumbers and leafy greens are highly ethylene-sensitive and should be stored away from ethylene producers at all times. Keep them on separate shelves or in separate drawers.
How Long Does Lettuce Last by Type?

Type
Whole Head Unwashed
Washed 

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