Hard Red Spring Wheat
Hard red spring wheat -- grown mostly in North Dakota, Montana, South Dakota and Minnesota -- stands out as the aristocrat of wheat for baking bread. Hard red spring has the highest protein content of all U.S. wheats (usually 13 to 16 percent) which, in turn, corresponds with greater gluten content. For this reason, flour mills in the United States and in many export markets blend hard red spring wheat with lower protein wheats to increase the gluten content in the resulting batch of flour. The addition of hard red spring improves dough handling and mixing characteristics, and water absorption.
Durum is the hardest of all wheats. Its density, combined with its high protein content and gluten strength, make durum the wheat of choice for producing premium pasta products. Pasta made from durum is firm with consistent cooking quality. Durum kernels are amber-colored and larger than those of other wheat classes. Also unique to durum is its yellow endosperm, which gives pasta its golden hue.
When durum is milled, the endosperm is ground into a granular product called semolina. A mixture of water and semolina forms a stiff dough. Pasta dough is then forced through dies, or metal discs with holes, to create hundreds of different shapes.
Durum production is geographically concentrated to North Dakota and the surrounding area because it demands a special agronomic environment. North Dakota produces 73 percent of the U.S. durum crop. Many international and domestic millers prefer North Dakota durum for its color and strong gluten characteristics.