For more than 5,000 years, farmers in the Andes have cultivated quinoa, which is the goosefoot plant's seed. Many vegetarians prepare quinoa soup because quinoa is a complete protein and a good source of calcium, iron, and many vitamins, including vitamin B and E. As a soup additive, it acts as a thickener, and some people describe the flavor as nutty, like wild rice. Quinoa is gaining in popularity, and there are cookbooks devoted to cooking with the seed.
Traditional quinoa soups of the Andes region usually vary depending on what is in season. A basic soup often has a combination of potatoes, cabbage, and onions. The soup is flavored with annatto butter, oregano, and other herbs that may be available. Normally, the cook stirs in some flavorings, such as cilantro, just before serving the soup. In Ecuadorian market soup stands, vendors offer diced avocadoes, ground or crushed roasted peanuts, and crumbled fresh cheeses as stir-in ingredients.
When using quinoa, a cook needs to remember to rinse the grain well before preparing it. Most experienced cooks suggest rinsing it even if the packaging says it is pre-washed. The seeds have a bitter substance called saponins that may give the soup an off flavor. Some cooks rub the seeds together as they wash them because it helps to knock off more of the coating. Most recipes advise cooks to rinse the quinoa, but some neglect to remind people to do so.
Although some people soak quinoa before cooking it, it is not necessary. Generally, to make quinoa soup, a cook may replace the rice in a soup recipe with the same amount of quinoa. Cooks normally use a two parts liquid to one part quinoa. For a broth-style soup, they increase the liquid, and for a thicker stew-style soup, they use the two-to-one formula. Most recipes suggest simmering the quinoa for 20 to 30 minutes or until tender.
The liquids that a cook uses will determine some of the soup's flavor. Many recipes suggest using a combination of broth, such as chicken broth, and water. Other recipes list only plain water. The quinoa is a natural thickener, and therefore a cook should watch the liquid levels to prevent scorching.
A quick way to make quinoa soup is to add cooked quinoa to a basic vegetable or other soup, including canned soups. A cook can toast well-rinsed quinoa over medium-low heat in a dry skillet. It is imperative to stir the seeds constantly to prevent scorching. The roasting brings out the sweet nutty flavor and adds a new flavor dimension to a soup. Some cook the quinoa separately if the vegetables or meat needs to cook longer than 15 to 20 minutes.
The farmers who raise quinoa eat the leaves like collard greens or spinach. Sometimes they add the leaves to the soup, and a cook can prepare a similar soup by using spinach or greens in place of the quinoa leaves. Typically, quinoa soup has a good balance of amino acids, and adding ingredients like spinach, tomatoes, and other nutrient-rich vegetables makes it a very nutritional dish.
Even though quinoa is a seed, people often call it a grain. Generally, the most common seeds are beige, but they may also be red, black, and other colors. Some cooks seek out the more colorful seeds to give their quinoa soup a touch of charm.