This eOrganic video was created by members of a project of the USDA National Institute of Food and Agriculture, Organic Agriculture Research and Extension Initiative (NIFA OREI) entitled Value Added Grains for Local and Regional Food Systems. Information was provided by Elizabeth Dyck of the Organic Growers Research and Information Sharing Network (OGRIN), Frank Kutka of the Northern Plains Sustainable Ag Society (NPSAS), and Steve Zwinger of North Dakota State University.
Watch the video clip on YouTube at https://www.youtube.com/watch?v=hA0nLfh-m0w
The ancient hulled wheats spelt, emmer, and einkorn are sought by consumers and chefs alike for their distinct flavor, nutritional properties, and the intrigue of eating a meal that has sustained humans since ancient times.
Einkorn, emmer, and spelt differ from modern wheat in that they largely do not thresh free of their hulls in the combining process. An additional step called dehulling is needed to remove hulls.
Chapter 1: Why Grow These Ancient Hulled Wheats?
Through direct marketing, farmers are able to sell wheat kernels and flours from these hulled wheats at a high price per pound to chefs, bakers, and consumers. Additionally, hulled wheat still in the hull can be marketed as animal feed, while empty hulls can be sold as animal bedding.
The hulled wheats also have characteristics that make them highly compatible with sustainable and organic production.
The hulled wheats have traditionally been grown under lower fertility conditions than modern wheat. In fact, high nitrogen fertility can cause lodging in these crops. Although more research is needed, a good rule of thumb is to plant einkorn and emmer with no more than 50%–75% of the nitrogen required for modern wheat. Winter spelt can be fertilized as winter modern wheat without the additional spring topdressing.
The hulled wheats also show tolerance to environmental stresses. Winter spelt has shown cold tolerance, and some einkorn varieties have salinity tolerance. Emmer tends to be more drought tolerant than modern wheat, and spring emmer more competitive against weeds. Emmer germplasm also contains many genes that are valuable in breeding for disease resistance.
In terms of production, spelt yields in the hull are comparable to or slightly lower than that of modern wheat. Recent research on spring emmer and einkorn suggests that yields can vary by location and management. In North Dakota, research shows that spring emmer and einkorn yields in the hull can be higher than modern spring wheat yields. In contrast, in research trials conducted in New York and Pennsylvania, yield of spring emmer and einkorn in the hull varied from 35%–93% of modern spring wheat.
Chapter 2: How to Grow Hulled Wheats
As with modern wheat, there are spring and winter varieties of spelt, emmer, and einkorn. A good starting point to grow hulled wheats is to use best management practices for modern wheat in your region, including good seedbed preparation, timely planting, and timely harvest to preserve grain quality. These hulled wheats tend to be taller and have higher rates of lodging than modern wheat. In addition to avoiding excessive nitrogen, to reduce lodging use lower planting rates for emmer and einkorn than for modern wheat.
Emmer and einkorn need to be planted in their hulls to get adequate germination. Spelt can be planted in or out of the hull. Research trials have shown a rate of 100 pounds per acre to be suitable for spring emmer and einkorn. Research is needed to determine rates for winter emmer and einkorn, although farmer experience suggests that even lower planting rates, such as 80 pounds per acre or lower, may be used. Spelt planting rate depends on whether it is planted in or out of the hull. For example, in Pennsylvania, farmers plant spelt at about 120 pounds per acre when dehulled, and about 150 pounds per acre when in the hull.
Chapter 3: Special Planting Considerations
Planting einkorn, emmer, and spelt in their hulls has challenges. The hulled seeds can clog seeding equipment, which results in skips in the field. This is due to the hairs and awns on the hulls, along with the larger size of the seed in the hull.
There are various ways to accommodate these seed characteristics in planting. Well-executed combining can remove most of the awns from the seeds. A debearder can be used to remove the hairs and awns and break up doubles before seeding. Seeding equipment may be modified to accommodate the seed characteristics, or the seed can be broadcast.
Certain varieties, such as winter emmer, have very large seeds. These larger seeds may require broadcast seeding or double planting.
Chapter 4: Dehulling Systems
A percent of the harvest of hulled wheats will dehull in the combine or thresher, but an additional dehulling and cleaning process is required to extract maximum yield and to create an edible and marketable product.
The ease of dehulling will vary depending on the species, variety, and growing conditions. For example, spelt tends to be easier to dehull than emmer or einkorn. The spelt variety Maverick is easier to dehull than others, such as Oberkulmer. Well-dried grain and low humidity are required for highest dehulling efficiency.
There are two main types of dehullers, impact and friction. In an impact dehuller, the hulled grain is thrown at high speed against a hard surface or impact ring. As the grain hits the surface, the kernel is separated from the hull. Several commercial impact dehullers are available.
In friction dehullers, the kernel is rubbed loose from the hull using one of several mechanisms. One method is to rub the grain against a rubber surface. Farmers have made very low-cost friction dehullers by replacing one or both of the metal plates in a burr mill with a rubber disk. Another farmer-built dehuller uses sections of combine rasp bars mounted on a drum to dehull grains. Yet another method of friction dehulling is to force the hulled grain through a mesh screen.
In addition to the dehuller an air column, or aspirator, is used to blow off empty hulls. A separator is used to sort dehulled kernels from those still in the hull. A commonly used separator is a gravity table. Both a separator and an aspirator are necessary to achieve a high-quality product. Some dehullers such as the Nigel Tudor model include an aspirator. The Horn friction dehuller includes both an aspirator and a gravity table.
The ancient hulled wheats, spelt, emmer, and einkorn are potentially high-value food crops that could fit well into an organic farming system. They require careful management and an extra processing step called dehulling to ready them for market.