Quinoa is a species of goosefoot (Chenopodium) grown as a crop primarily for its edible seeds. It is a pseudocereal rather than a true cereal as it is not a grass. Its leaves are also eaten as a leaf vegetable, much like amaranth, but the commercial availability of quinoa greens is currently limited.
Similar Chenopodium species, such as Pitseed Goosefoot (Chenopodium berlandieri) and Fat hen (Chenopodium album), were grown and domesticated in North America as part of the Eastern Agricultural Complex before maize agriculture became popular. Fat hen, which has a widespread distribution in the Northern Hemisphere, produces edible seeds and greens much like quinoa but in lower quantities. When grown in heavily fertilised fields, it can accumulate dangerously high concentrations of nitrates.
Quinoa in its natural state has a coating of bitter-tasting saponins, making it unpalatable. Most quinoa sold commercially in North America has been processed to remove this coating. Some have speculated this bitter coating may have caused the Europeans who first encountered quinoa to reject it as a food source, since they adopted other indigenous food plants of the Americas like maize and potatoes. This bitterness has beneficial effects during cultivation as the plant is unpopular with birds and thus requires minimal protection. There have been attempts to lower the saponin content of quinoa through selective breeding to produce sweeter, more palatable varieties. When new varieties were introduced by agronomists to native growers in the high plateau, however, the native growers rejected the new varieties despite their 'magnificent' yields. Because the seeds no longer had a bitter coating, birds had consumed the entire crop after just one season.
The saponins in quinoa can be mildly toxic, as can be the oxalic acid in the leaves of all the chenopodium family. The risks associated with quinoa are minimal, provided it is properly prepared and leaves are not eaten to excess.
The first step in preparing quinoa is to remove the saponins, a process that requires soaking the grain in water for a few hours, then changing the water and resoaking again, or rinsing it in ample running water either in a fine sieve or in cheesecloth. Boxed quinoa typically has been pre-rinsed for convenience.
A common cooking method is to treat quinoa much like rice, bringing two cups of water to a boil with one cup of grain, covering at a low simmer and cooking for 14–18 minutes or until the germ separates from the seed. The cooked germ looks like a tiny curl and should have a slight bite to it (like al dente pasta). Alternatively, one can use a rice cooker to prepare quinoa. To that end, one volume of quinoa should be combined with two volumes of water.
Vegetables and seasonings can also be added to make a wide range of dishes. Chicken or vegetable stock can be substituted for water during cooking, adding flavour. It is also suited to vegetable pilafs, complementing bitter greens like kale.
Quinoa flour can be used in wheat-based and gluten-free baking. For the latter, it can be combined with sorghum flour, tapioca, and potato starch to create a nutritious gluten-free baking mix. A suggested mix is three parts quinoa flour, three parts sorghum flour, two parts potato starch, and one part tapioca starch.
Lastly, quinoa may be germinated in its raw form to boost its nutritional value. Germination activates its natural enzymes and multiplies its vitamin content. In fact, quinoa has a notably short germination period: only 2-4 hours resting in a glass of clean water is enough to make it sprout and release gases, as opposed to, e.g., 12 hours overnight with wheat. This process, besides its nutritional enhancements, softens the grains, making them suitable to be added to salads and other cold foods.