To choose the best red leaf lettuce, look for a clear color and no rusty or soggy sections. The vertical ridges in the center of each leaf should be crisp rather than soft and not too wide or the lettuce may be too tough or chewy. It's best to buy red leaf lettuce for immediate use, as it tends to loose its crispness and flavor after three days. Look for heads with tighter packed lettuce leaves rather than loose ones.
Even tightly packed leaves can usually be examined quickly for bugs and brown spots by grasping the top of each leaf and gently pulling it away from the lettuce head. While a few insects or bug-chewed sections aren't going to ruin red leaf lettuce for your table, don't choose heads that have a large number of them. Ruffle-edged red or green leaf lettuce can be difficult to wash because of the small crevices in which bugs or dirt can hide, but you could soak separated leaves in a tub or bowl of water to help remove debris.
Purchasing the red lettuce from a farmer's market or produce shop, in which fresh fruits and vegetables are delivered daily rather than a supermarket in which these items are typically brought in less often, can be a good idea. As a general rule, you should only buy as many heads of red leaf lettuce as you can use up within three days to avoid a loss of freshness and flavor. You may want to consider buying organic lettuce, as it's grown without pesticides and is usually easier to clean. If you choose the pre-packaged washed and torn red leaf lettuce, make sure to check the "best before" date. Keep in mind that the date mainly concerns the freshness of the lettuce before the package is opened rather than after.
If you are at least partly interested in buying the red version of leaf lettuce for its color, such as to create a colorful salad for a dinner party, you'd be best to choose a vibrant variety such as oak leaf. This type of red leaf lettuce is bold in its redness unlike some varieties in which the color is rather faded looking. While several red lettuce types feature dark, almost black ruffly edges, don't choose a head that has any brown, limp edges, as this may indicate a lack of freshness.
