Bring to a boil, then reduce the heat and simmer 25 to 30 minutes for pearl barley and 45 to 1 hour for hulled barley (for hulled barley, you can add more water if the pan becomes dry).
Drain any excess water. Season with additional salt, butter or olive oil, and herbs if serving as a side dish. Or, place it in a single layer on a baking sheet and allow to cool for a few minutes (pop it in the freezer to speed up cooling) before using in salad recipes.