Barley and other grains are the seeds of grasses.
Grains can add protein as well as fiber and stick-to-the-ribs bulk to both meat-based and meatless vegetable soups. "Grains" are technically limited to varieties of grasses, and many are available in more- and less-processed forms, according to whether the outside layer, the bran, has been polished off. The more bran, the more fiber and vitamins, but the longer the grain will take to cook.
Barley
Barley is probably most closely associated with hearty Scottish beef soups, but it goes equally well with turkey and a variety of vegetables. Its nutty flavor may overpower lighter meats such as chicken, but its soft texture can give a soup a nearly creamy feeling without milk. Barley without its bran is often called "pearled"; "quick" barley is presteamed for faster cooking, but after 10 minutes or so, it might seem to completely disappear into your broth.
Rice
From delicate basmati to minimally processed brown rice, there's a seed for almost any soup. Actually, soup might be the best place to take advantage of brown rice's unpolished nutritive value, because you can give it more time to simmer to a tender state. For an extra boost of flavor and texture, mix in some wild rice, though according to The Cook's Thesaurus website, it's actually the seed of a different kind of grass.
Quinoa
Pronounced "keen-WAH," this ancient South American seed has burst onto the 21st-century culinary scene from health-food obscurity. The seed of a leafier plant related to spinach, according to The World's Healthiest Foods website, quinoa is a tiny grain, about the size of uncooked couscous, that packs the most complete protein available in a grain. That makes it an especially welcome grain for vegetarian soups. Rinsing before you add it to your soup will remove a tendency to bitterness. Quinoa comes in several colors, and visual contrast may be the best way to get it noticed.
Corn
Corn is actually a grain, the ears being the equivalent of heads of wheat, barley or any other grass. The difference is that we most often eat corn in a fresher state, where other grains are dried or roasted and ground. The good thing is that we rarely remove the bran from corn. What would the classic tomato-beef vegetable soup be without corn in its mix of vegetables? But consider adding frozen or vacuum-canned corn to other soups, such as chicken vegetable. Just as with summer roasting ears, though, don't let the corn cook too long or you'll miss its sweet burst of flavor.
Derived from grains
It may be that more grain gets into vegetable soup as pasta than as recognizable seeds. Think of minestrone, and the pasta is ditalini; think of Italian wedding soup, and it's orzo, or semolina wheat doing its rice imitation. Many other small semolina pastas go into soup. Consider some of the whole-grain pastas on the 21st-century market. Simmered soup may better accommodate their somewhat denser textures and stronger flavors. Don't cook pasta in your soup any longer than you would cook it alone, though; al dente is the texture for which it's known.
Not technically grains
A number of legumes---or beans---such as lentils are also frequent and welcome additions to vegetable soups. Though they aren't grains, they're low in fat and high in fiber, come in many colors and sizes and usually contain healthy doses of iron, especially when cooked from the dry state. Lentil soups are a class of vegetable soup in themselves. The Cook's Thesaurus website cautions to hold the salt or acidic ingredients, such as tomatoes, until the lentils are almost done, or you'll wind up waiting for the beans to get tender.
Tags: brown rice, Cook Thesaurus, Cook Thesaurus website, other grains, such chicken, Thesaurus website
