Native peoples of both North and South America once considered amaranth a staple food crop. First cultivated several thousand years ago, the plant peaked in agricultural importance during the 1400s when it became a mainstay of the Aztecs in central Mexico. In the 1970s, American researchers rediscovered amaranth's potential. Commercial production of amaranth remains small, but several varieties are now available to the home gardener.
Harvest amaranth leaves and stems when young and tender. Cook the plant as a boiled vegetable like beet greens or spinach. Cut the plants off near the ground with a utility knife when between 1 and 1 1/2 feet tall. For the best crop of edible foliage choose Asian varieties grown especially for their succulent leaves. Young leaves may be eaten raw. Vigorous plants regrow and provide several harvests in one season.
Harvest amaranth seeds in fall after the first frosts kill the plant's leaves. Seedheads remain on the stalk and should shed seeds easily if rubbed between the hands. Since the tiny seed scatters easily, cut the seedheads carefully with a knife and collect them for threshing. Place a window screen over a clean wheelbarrow and rub the drying seedheads over the screen. As amaranth seed dislodges it falls through into the wheelbarrow.
Winnow by gradually pouring the amaranth seed into a mesh kitchen strainer, through the airflow from a box fan, and into a clean plastic bucket. Process small amounts of seed, rubbing them against the mesh first to loosen hulls. Some seed may fall through the mesh, so work over the bucket. As the seed falls, the chaff blows away and falls outside the bucket, while the bucket catches the seed. Winnow amaranth more than once to ensure a clean product. Start with the lowest fan speed to be sure the seed doesn't blow away with the chaff. Some practice is necessary.
Cook amaranth as a boiled grain by washing thoroughly and adding equal amounts of amaranth seed and water to a pot. Bring the pot to a boil. Reduce to simmer, cover and cook for about 12 minutes or until the amaranth absorbs the water. Add salt as needed. Eat cooked amaranth like rice, or combine amaranth with brown rice for a tasty mixed grain dish.
Pop amaranth like popcorn when the grain properly dries. Test by dropping a pinch of the seed into oil, in a covered pan. If most of the grain pops into fluffy kernels, pop a larger amount in oil like popping corn. If the experiment yields small popped kernels with a chewy consistency, the seed needs further drying. Make popped amaranth treats by mixing popped amaranth with honey or molasses and forming the nutritious blend into bars.
Use a stone or bur mill to grind amaranth seed into a wholesome flour. Add nutritional value to wheat flour recipes by substituting small portions of amaranth for wheat. Since amaranth is not a cereal grain, most people with allergies to cereal grains do not react to amaranth. Add amaranth flour to gluten-free bread recipes for a boost of flavor and texture. Amaranth flour mixes well at one part amaranth flour to four parts flours from other grains and seeds.