Hulled barley just has the outer husk removed (which is the inedible part). It's chewier, nuttier in flavor and darker in color than pearl barley. It also takes a little longer to cook. Pearl barley has its hull removed as well as the outer husk, and it's polished a bit. You can use whichever type you want. Just adjust the cooking time if you need to. Personally, I like pearl barley best.