‘DNS’ is a common term when referring to the production of hard red spring wheat. Around the coffee shop you may hear your neighbor say, “I’m growing DNS.”
What is DNS? DNS is short for ‘Dark Northern Spring’ –and what is that?
Under the Official United States Standards for Grain, the market class ‘Hard Red Spring wheat’ is divided into three subclasses: Dark Northern Spring wheat, Northern Spring wheat, and Red Spring wheat.
What differentiates the sub-classes? It is the percentage of “dark, hard, and vitreous kernels”. To be classed as Dark Northern Spring wheat, the sample must have 75 percent or more dark, hard, and vitreous kernels. The limits for Northern Spring wheat are more than 25% but less than 75% dark, hard, and vitreous kernels; and Red Spring wheat has less than 25%.
Beyond the official market classification, the grain trade may impose any number of additional criteria. For example, to receive top prices, ‘DNS’ often must have a minimum of 14% protein. Some elevators may discount grain below this threshold with a sliding scale and may reward higher protein levels with premiums.
The Standards harken back to a time when analyzing protein was slow and laborious. In a very general sense, the percentage of vitreous kernels is correlated with protein content. And so at one time, a quick visual assessment of the percentage of vitreous kernels was a reasonable proxy for protein content. Why protein so important? Generally speaking, protein content has a direct relationship to gluten content, and as you may know, gluten is the visco-elastic (rubbery) material that allows us to make light airy yeast-leavened bread. I often refer to gluten as the ‘horsepower’ of wheat and so from bakers to millers to the elevator to the producer, higher protein is usually rewarded with premium prices because of its greater performance and value.
For more information contact Dr. Craig F. Morris, Director USDA-ARS Western Wheat Quality Laboratory, at firstname.lastname@example.org or 509-335-4062.