When evaluating iceberg lettuce, also known as crisphead lettuce, at the produce stand, you should look for lettuce heads that are light or medium green in color. The leaves should show no sign of browning or wilting, and the lettuce head should be compact and firm. The main concern when shopping for iceberg lettuce is its freshness. Cooks typically choose this lettuce for use in recipes because of its crispness. If the lettuce is no longer fresh, it won't have this quality and can spoil the sandwich or salad in which it is included.
Iceberg lettuce is a commonly used salad green in the United States. It is often the basis for green salads and is a common addition to sandwiches. This type of lettuce is often used as a garnish for other types of salads, such as tuna and chicken salads. Unlike other types of salad greens, this lettuce does not have a great deal of flavor. Instead, it provides crispy texture to recipes that use other, more flavorful ingredients, such as salad dressings, seasoned meats, and blanched vegetables. Those who wish to incorporate more complex flavors into salads and sandwiches, however, may decide to use a lettuce other than iceberg.
After choosing a fresh head of iceberg, you can prepare it so that it can remain fresh for up to two weeks in the vegetable drawer of your refrigerator. This process typically involves running the lettuce under cold water, removing its core with a knife, and allowing it to dry upside down over paper towels. Once the lettuce is cleaned and cored, place it in a sealed container before refrigeration. It is always wise to carefully examine lettuce before using it in recipes. If you find brown leaves, peel them off and use the fresher leaves in your cooking.
Some critics of iceberg lettuce have noted that it is relatively low in many nutrients, though others point out that a cup of the lettuce provides 22 percent of a person's daily requirement of vitamin K as well as small amounts of folate and vitamins A and C. The lettuce is also very low in calories, making it a staple in many weight-loss diets. Dieters will typically add a significant amount of iceberg lettuce to a salad or sandwich to experience the satisfaction of eating a large quantity of food while actually consuming very few calories.