Slow cooker lentil soup is an easy, satisfying option for busy weeknights or relaxed weekends. Toss the ingredients into the slow cooker and let the lentils slowly absorb the flavors of the vegetables and herbs. The result is a warm, nourishing soup that requires very little hands-on time and makes generous leftovers.
This recipe relies on simple pantry staples—lentils, broth, aromatics, canned tomatoes, and a splash of vinegar to brighten the finished dish. Cooking slowly yields a naturally creamy texture while keeping enough bite so the soup remains interesting. It reheats and freezes well, making it ideal for meal prep or quick lunches throughout the week.
The soup is also adaptable. You can easily make it vegetarian, increase vegetables, or alter the herbs and spices to suit your taste. It’s a dependable recipe that’s easy to customize.
What You’ll Like About This Recipe
- Hands-off preparation. Once everything is in the slow cooker, the soup needs almost no attention while it cooks.
- Comforting, balanced flavor. Lentils with aromatics, tomatoes, and herbs create a warm, well-rounded base; a touch of vinegar at the end brightens the flavors.
- Nutritious pantry ingredients. Lentils add protein and fiber while vegetables add texture and nutrients.
- Flexible for different diets. Swap chicken broth for vegetable broth, omit bacon for a vegetarian version, or add extra vegetables and proteins as desired.
- Great for leftovers. The soup thickens as it chills, often tasting even better the next day. It stores well in the fridge or freezer.
Ingredient Notes
- Lentils – Use brown or green lentils; they keep their shape with slow cooking. Red lentils break down quickly and are not ideal here.
- Broth – Low-sodium broth gives you control over salt level. Choose chicken or vegetable broth to match your diet.
- Bacon – Optional. A small amount adds smoky depth. For a vegetarian soup, omit it or use smoked paprika.
- Aromatics – Onion, celery, and carrot form the flavor base. Chop evenly so they cook at the same rate.
- Tomatoes – Canned diced tomatoes contribute acidity and body. Add them toward the end so they don’t slow the lentils’ softening.
- Vinegar – A splash at the end lifts and balances the flavors. Apple cider vinegar is slightly fruity; white wine vinegar is milder.
Steps to Make Slow Cooker Lentil Soup
- Prepare and chop all vegetables so they’re ready. Rinse and pick over the lentils.
- Add the lentils, broth, bacon (if using), onion, celery, carrot, parsley, garlic, oregano, salt, and pepper to the slow cooker. Stir to combine.
- Cover and cook on low for 6–8 hours or on high for 3–4 hours, until the lentils are tender but still hold some shape.
- Stir in the diced tomatoes and vinegar, then cook on high for about 15 minutes to meld the flavors.
- Taste and adjust seasoning with salt, pepper, or a bit more vinegar. If the soup is too thick, add extra broth to reach the desired consistency.
Pro Tips
- Salt early enough to season the lentils but recheck before serving—broth sodium levels vary.
- Stir before serving to redistribute settled lentils and vegetables for a consistent texture.
- Cook low when possible for the most even texture; high heat shortens the time but can soften edges more quickly.
- Add liquid after cooking if you prefer a looser soup; lentils will keep absorbing liquid as they sit.
- Brighten the finished soup with vinegar or a squeeze of lemon if the flavor needs lift.
Recipe Variations
- Spicy: Add chili powder, cayenne, chopped jalapeño, or a dash of hot sauce.
- Curried: Swap oregano for curry powder and turmeric, and stir in a can of coconut milk in the last 30 minutes.
- Vegetarian: Omit bacon and use vegetable broth; add extra vegetables like zucchini or bell peppers.
- Meaty: Add browned sausage or diced ham for extra protein and flavor.
What to Serve With Slow Cooker Lentil Soup
- Bread: Serve with a crusty baguette, sourdough, or warm garlic bread.
- Salad: A fresh green salad helps cut through the soup’s richness.
- Sandwich: A simple grilled cheese or other warm sandwich pairs nicely with the soup.
How to Store
- Refrigerate in airtight containers for up to 4 days. Add a splash of broth or water when reheating if the soup has thickened.
- Freeze in suitable containers for up to 3 months. Thaw overnight in the refrigerator before reheating.
- Reheat gently on the stove or in the microwave, avoiding vigorous boiling to keep the vegetables from becoming mushy.
Slow Cooker Lentil Soup
Diana Rattray
Comforting and convenient slow cooker lentil soup, packed with nutritious ingredients for a cozy family meal.
Servings 8 servings
Calories 224
Ingredients
- 2 cups brown or green lentils
- 2 quarts low sodium chicken broth (or vegetable broth)
- ¼ cup cooked, crumbled bacon (optional)
- 1 cup chopped onion
- ½ cup chopped celery
- ½ cup chopped carrot
- 3 tbsp chopped parsley
- 3 cloves garlic, minced
- 1 ½ tsp kosher salt, or to taste
- ½ tsp dried leaf oregano
- ¼ tsp ground black pepper
- 1 (14.5-ounce) can diced tomatoes with juice
- 2 tbsp apple cider vinegar or white wine vinegar
- Chopped parsley (optional for garnish)
Recommended Equipment
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6-quart slow cooker or similar
Instructions
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Have all ingredients chopped, measured, and ready. Rinse and pick over the lentils.
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Add lentils, broth, bacon (if using), onion, celery, carrot, parsley, garlic, salt, oregano, and pepper to the slow cooker. Stir to combine. Cover and cook on low for 6 to 8 hours or on high for 3 to 4 hours, until lentils are tender.
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Stir in the diced tomatoes and vinegar, then cook on high for 15 minutes to combine flavors.
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Taste and adjust salt, pepper, and vinegar before serving. If the soup is too thick, add a little extra broth.
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Ladle into bowls and garnish with chopped parsley if desired.
Nutrition
Calories: 224kcalCarbohydrates: 35gProtein: 15gFat: 3gFiber: 16g
Disclaimer:
Nutrition information is an estimate based on the ingredient list. Actual values may vary with brands, measurements, and serving sizes.
Keyword lentil soup, slow cooker soup
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