Barley was one of the earliest cultivated grains, possibly dating back to 8000 BC. After harvest, barley is processed to remove two outer hulls which are inedible. The remaining grain is coated in a layer called the aleurone which is rich in fiber, B vitamins and protein. In this state, it is called whole barley. Oftentimes, the aleurone is removed leaving a less nutritious core called pearl barley. When the whole barley grain is toasted and cracked, the result is called barley grits. Barley can also be ground to flour, but has a very low gluten content meaning it is usually combined with wheat flours when used for baking. Sprouted barley is often used in salads. Barley has been a primary food source in the Middle East for centuries. Prior to wheat, it was a principle grain in parts of Europe. Barley was initially introduced to the United States as a component for brewing beer, and is still widely used for that purpose.