Grains of durum are amber-colored and larger than those of other types of wheat. Durum has a yellow endosperm, which gives pasta its color. When durum is milled, the endosperm is ground into a granular product called semolina. Semolina is used for premium pastas and breads.
Most durum wheat is grown in Mediterranean countries, the former Soviet Union, North America, and Argentina. US durum production is mainly in North Dakota, which produces 73% of the US crop.