To transform this delicious Hearty Beef Barley Soup into a gluten-free version all you need to do is substitute pearl barley, with gluten-free barley or other grains like quinoa or rice that are free from gluten. Just make certain that the broth, tomato paste, seasonings and all the other elements you use are approved gluten-free. By making this adjustment people, with gluten sensitivities or celiac disease can relish this soup without any worries.