Soft Svevo durum wheat growing in an Idaho field.
Photo courtesy of U.S.D.A. Agricultural Research Service

WASHINGTON — Soft Svevo, a new soft durum wheat variety developed by scientists and researchers affiliated with the Agricultural Research Service of the U.S. Department of Agriculture, may expand the market for wheat.

Traditional durum wheats primarily are grown as a source of semolina — a coarse meal used to make pasta, couscous and other products. However, producing semolina requires specialized mills that can grind durum wheat’s rock-hard kernels. This, in turn, has limited the food uses for durum wheat, which comprises 3% to 5% of the total U.S. wheat crop.

Craig Morris, a chemist at the A.R.S.

Craig Morris, a chemist at the A.R.S., has a soft spot for durum, which, despite the hard nature of its kernels, is better adapted to hot, arid growing regions of the United States than the more commonly grown bread wheat varieties. Over the past 20 years, he and colleagues have delved into the genetics of wheat kernel development for clues that could broaden the number of products made from durum.

Along the way, the team determined that durum’s hard kernel texture has no relationship to pasta quality. Rather, it is durum’s yellow kernel color and high-protein content that gives pasta its desirable firmness. Additionally, these features have nothing to do with the particle size of semolina made from the kernels, Mr. Morris said.

Artisan bread made with Soft Svevo durum wheat.
Photo by Jessica Murray, U.S.D.A. Agricultural Research Service

Based on that premise, the researchers set out to create a soft durum wheat with kernels easily milled into a fine flour instead of semolina. Finding two genes that control kernel texture in soft bread wheats — Puroindoline a (Pina) and Puroindoline b (Pinb) — proved a breakthrough. The team moved these genes into an Italian durum variety to eventually produce Soft Svevo, marking the first soft durum of its kind.