Most recipes recommend using the whole leaves as they are easy to remove before serving the dish they flavored. Stews and soups are commonly seasoned with bay leaf, as are bean and lentil dishes. Pickled vegetables frequently contain a bay leaf in the brine.
Whole dried bay leaf has a strong flavor that slowly flavors foods as they cook or age. When crushed or ground, the flavor may become overpowering and, when cooked for long periods, can become bitter and harsh. The latter usually overpowers the other spices in the dish and may even make it unpalatable.
If the strong flavor of crushed bay leaf is preferred, tying roughly crushed leaves in a fine cheesecloth or placing the pieces in a metal tea-straining ball imparts the flavors and can be easily removed at the end of the cooking process.