Barley has a nutlike flavour and is high in carbohydrates, with moderate quantities of protein, calcium, and phosphorus and small amounts of the B vitamins. Because it contains little gluten, an elastic protein substance, Barley flour is used to make an unleavened type, or flatbread, and to make porridge, it is a staple food grain. Pearl barley, the most popular form in many parts of the world, consists of whole kernels from which the outer husk and part of the bran layer have been removed by a polishing process. It is added to soups. Barley has a soft straw, used mostly as bedding for livestock and as a feed providing bulk roughage.