Durum wheat is commercially grown and the hardest of all wheat species. It contains high amounts of protein-most with excellent gluten strength making it good for pasta and bread. Most is amber in color and invariably has a yellow endosperm, giving pasta its color. When milled, much of it is preserved as a coarse meal called semolina rather than ground into fine flour. Especially in winter, durum chapattis are relished in northern India.