This beef barley soup turns leftover prime rib bones into a deeply savory broth, then fills it out with tender vegetables, barley, and bits of beef. It is a practical, slow-simmered way to make the most of a roast, and the soup can be made ahead for an easy meal.
Ingredients
- 2 to 3 prime rib bones, with about 1 to 2 cups of meat still attached (about 2 pounds of bones)
- 10 cups cold water, plus more as needed
- 1 tablespoon olive oil
- 1 medium yellow onion, diced
- 2 medium carrots, peeled and diced
- 2 celery ribs, diced
- 3 garlic cloves, minced
- 8 ounces cremini or white mushrooms, sliced (optional)
- 1 tablespoon tomato paste
- 1 teaspoon dried thyme, or 1 tablespoon fresh thyme leaves
- 1 bay leaf
- 1 cup pearl barley, rinsed and drained
- 1 tablespoon Worcestershire sauce
- 1 teaspoon kosher salt, plus more to taste (start with less if the bones are well seasoned)
- ½ teaspoon black pepper, plus more to taste
- 2 tablespoons chopped fresh parsley
- 1 to 2 teaspoons red wine vinegar or lemon juice, to finish (optional)
Instructions
- Check the bones. Remove any large, loose pieces of fat and discard them, but leave meat and connective tissue on the bones for flavor. If the roast was refrigerated, use the bones within 3 to 4 days of cooking it. Do not use bones that have been left at room temperature for more than 2 hours.
- Make the broth. Put the bones in a large stockpot and add 10 cups cold water. Bring just to a boil over medium-high heat, then lower the heat so the liquid simmers gently. Skim off foam that gathers on the surface during the first 20 minutes. Partly cover and simmer for 2½ to 3 hours, checking occasionally; avoid a hard boil, which can make the broth cloudy and greasy.
- Strain and pick the meat. Lift out the bones with tongs. When they are cool enough to handle, pull off the tender meat, discard the bones, and cut the meat into bite-size pieces. Strain the broth through a fine-mesh sieve into a heatproof bowl. Skim off excess fat with a spoon, or chill the broth and lift off the solid fat later. You should have about 8 cups; add water if needed.
- Cook the vegetables. Wipe out the pot and set it over medium heat. Add the olive oil, onion, carrots, celery, and mushrooms, if using. Cook for 7 to 9 minutes, stirring often, until softened. Add the garlic and tomato paste and cook for 1 minute, stirring so the garlic does not brown.
- Simmer the barley. Pour the strained broth back into the pot. Stir in the thyme, bay leaf, rinsed barley, Worcestershire sauce, salt, and pepper. Bring to a boil, then reduce the heat to maintain a gentle simmer. Cover partly and cook for 35 to 45 minutes, stirring now and then, until the barley is tender but still pleasantly chewy. Check your barley package, since cooking times vary.
- Finish the soup. Stir in the reserved beef and simmer for 5 to 10 minutes, until thoroughly hot. Check the seasoning and add salt or pepper as needed. For food safety, reheat leftovers to 165°F (74°C); a thermometer is the best way to check. Remove the bay leaf, stir in parsley, and add vinegar or lemon juice if you want a brighter finish. If the soup is thicker than you like, loosen it with hot water or broth.
Tips
- Season at the end. Prime rib bones may already be salty from seasoning or au jus. Use the listed salt as a starting point, then taste after the barley cooks and the broth reduces.
- Keep the simmer gentle. A low, steady simmer extracts flavor without rapidly evaporating the broth. If the pot boils down too far, add water; if it tastes weak, simmer the strained broth briefly before adding the vegetables.
- Plan for thickening. Barley continues absorbing liquid as it sits. Add broth or water when reheating rather than trying to thin the whole batch in advance.
- Use cooked roast meat carefully. If you have extra sliced prime rib, add it only near the end so it warms through without becoming dry. Keep it refrigerated until you are ready to use it.
Serving Suggestions
Serve the soup hot in deep bowls with crusty bread, dinner rolls, or a grilled cheese sandwich for dipping. A simple green salad or lightly dressed cabbage slaw balances the rich broth. Offer cracked black pepper and chopped parsley at the table; a small squeeze of lemon can brighten each serving. Since barley makes the soup filling, a modest side is usually enough.
Variations
For extra vegetables, add 1 cup diced potatoes with the broth or stir in 1 cup frozen peas during the final 5 minutes. A teaspoon of smoked paprika adds gentle warmth, while a splash of dry red wine can be used to deglaze the vegetables before adding the broth. For a stronger tomato note, increase the tomato paste to 2 tablespoons. To make the soup gluten-free, replace the barley with ¾ cup rinsed brown rice and cook until tender, following the package timing; use gluten-free Worcestershire sauce or omit it. The texture and simmer time will differ, so check the grain as it cooks.
Storage and Reheating
Cool the soup promptly in shallow containers and refrigerate it within 2 hours of cooking. Keep it covered in the refrigerator for 3 to 4 days. For longer storage, freeze in meal-size portions for up to 3 months; barley softens after freezing, but the soup remains enjoyable. Leave a little room in containers for expansion. Thaw overnight in the refrigerator or reheat from frozen over low heat, stirring often and adding liquid as needed. Reheat only the portion you plan to eat, until it reaches 165°F (74°C). Do not leave cooked soup at room temperature for more than 2 hours, or more than 1 hour if the temperature is above 90°F (32°C).
Frequently Asked Questions
Can I make the broth a day ahead?
Yes. Strain the broth, cool it promptly in shallow containers, and refrigerate it. Once chilled, remove the solid fat from the surface. Cook the vegetables and barley in the broth the next day, then add the picked meat near the end.
Do the bones need to be roasted first?
No. Prime rib bones have already been roasted, so they can go straight into the pot. Roasting them again is unnecessary and may dry out any meat still attached.
Can I use quick-cooking barley?
Yes, but add it according to its package directions rather than simmering it for the full pearl-barley time. Start the soup without the barley, then stir it in for the cooking time specified. Quick-cooking barley can become mushy if simmered too long.
What if there is very little meat left on the bones?
The bones will still flavor the broth. If you have leftover cooked beef, chop 1 to 2 cups and add it during the final 5 to 10 minutes. You can also add a little extra mushroom or carrot for a heartier vegetable soup.
Can I cook this in a slow cooker?
Simmer the bones with the water on low for about 8 to 10 hours, then strain the broth. Cook the vegetables on the stovetop for best flavor, combine them with the broth, and add barley until tender. Slow cookers vary, so use the barley package directions and avoid leaving cooked soup on a warm setting for an extended period.