How To Select And Store Romaine Lettuce
Choose bright, crisp heads of romaine lettuce. Avoid bunches that have rust, holes or that are limp, wilted or yellowing. It is common to find romaine that has slight browning along the very edges of the outer leaves. This is okay as long as the rest of the head looks fresh and green. I just trim the brown edges off the outer leaves.
Romaine is highly perishable. I store it in the fridge in a large plastic tub with a piece of paper towel to absorb excess moisture and condensation. My lettuce will keep for up to 5 days this way. If you store wet lettuce in a produce bag, it will likely only last a couple days.
Whenever possible, choose organic romaine (sames goes for any leafy green) as greens are often high in pesticide residue.