Set-and-forget vegan Slow Cooker Lentil Soup is high in plant-based protein, fiber and easy to make in the crockpot.
We absolutely love-love-love easy and satisfying lentil soups like Instant Pot lentil soup, chicken lentil soup and lentil spinach soup.
This slow cooker lentil soup is made up of 100% vegetables. You would never guess this soup is vegan because it’s so flavorful and filling. My kids call it “the best soup ever” and that is before I top their bowls with tortilla chips!
It’s like vegetable soup that cleans out your produce drawers. And just like borscht, the longer it cooks, the better it gets!
Be sure to browse my slow cooker recipes or Instant Pot soup recipes to make healthy soups all season long.
Why You’ll Love This Recipe
- Easy to make: No ingredients list a mile long here, simple ingredients are actually what makes this crockpot lentil soup stand out!
- Budget friendly: Lentils are a low priced plant based protein.
- Nutritious: Lentils are high in fiber, low in fat and packed with a host of nutrients like folate, iron and potassium.
- Set and forget: Prep it in the evening and just plug in the slow cooker as you head out the door in the morning. Then come home to a dinner ready to be served.
- Meal prep: Refrigerate up to 5 days, freeze for 3 months or even make a freezer meal to cook later.
Ingredients for Slow Cooker Lentil Soup
- Green or brown lentils: Lentils are just so easy to cook, are full of fiber and protein, and come out delicious with simple seasonings. You can use red lentils, just keep in mind they will fall apart a lot.
- Vegetables: Carrots, celery, corn (adds a touch of sweetness) and hearty potatoes.
- Seasonings: Garlic powder, oregano, thyme, peppercorns, bay leaves. My secret ingredient is soy sauce (I use Bragg liquid aminos) which gives an umami flavor to the soup.
- Broth: Vegetable broth or organic vegetable bouillon cubes.
- Garnishes: Green onion, cilantro, parsley, Greek yogurt, cheese, tortilla chips…really whatever you like or have on hand.
How to Make Lentil Soup in Slow Cooker
There is a full recipe card below.
- Prep: The only prep work is to dice the vegetables. Transfer them to a crock pot as you chop. You don’t even have to sauté the onions.
- Combine: Dump veggies, lentils, seasonings and water/broth into a large slow cooker. No need to stir but if you do, that’s fine!
- Cook: Cover and cook on Low for 8-10 hours or on High for 4-5 hours. The longer, the better as flavor develops with time and green lentils hold their shape quite well.
- Blend: Make this soup creamy using an immersion blender. First, remove the bay leaves and peppercorns. Then pulse a few times until you get the desired texture.
Tips for Best Results
- Saute onion with vegetables and seasonings for 2-3 minutes on the stovetop to bring out depth of flavor.
- Don’t use keep warm function after cooking time to deter overcooking your lentils.
- Thick and creamy really is best for this slow cooker lentil soup. If you do not have an immersion blender, remove 1 cup of soup from slow cooker, blend in a blender, then stir back into soup. You could do this until you reach desired creaminess.
- Cornstarch slurry: Alternately, if you do not have any type of blender, you can make a cornstarch slurry with cold water and cornstarch, stir into soup and let thicken.
- Use small food processor to save time chopping. Use pulse function so your vegetables are chopped in larger pieces.
- Broth: Alternatively you can use 2 organic low sodium vegetable bouillon cubes and 9 cups of water.
- Red lentils: You can use red lentils, just keep in mind they will fall apart a lot, you may not even need a blender.
- Size of a crockpot: I used a standard size crock pot, around 6-7 quart. If you only have a smaller sized crockpot, cut recipe in half.
Variations
- Tomato paste, fire roasted tomatoes or petite diced tomatoes could all be added for another layer of flavor. Choose low sodium or no salt added.
- Use sweet potatoes in place of white potatoes.
- Broth: Chicken broth or beef broth can be substituted.
- Lower carb: Use 1/2 cauliflower, 1/2 potatoes for a still hearty lentil soup.
- Add some greens: Chopped spinach or kale can be stirred in at the very end.
- Use fresh ground black pepper instead of peppercorns.
- Mix and match your spices: Smoked paprika, marjoram or Italian seasoning would all taste great.
- Parmesan rind: If you are not vegetarian or vegan, adding a Parmesan rind to the slow cooker can add so much flavor!
- Additional protein: Cooked and diced ham, chopped cooked bacon or sliced turkey, chicken or kielbasa sausage could all be added to cook with this crock pot lentil soup.
Serving Recommendations
Garnishes and soup finishers can really take this soup to another level! A squirt of lemon or red wine vinegar, finely chopped parsley or cilantro, Greek yogurt and freshly grated Parmesan are just a few options.
Here are also serving suggestions:
- Bread: Whole grain crusty bread helps soak up all the soup’s creaminess! For higher protein try with this cottage cheese bread or Greek yogurt bread.
- Vegetables: A side of roasted cauliflower really adds to the cozy, comfort vibes of this soup.
- Salad: A classic pair that is restaurant quality would be lemon kale salad.
- Sandwich: Another classing pairing, serve with grilled cheese, an open faced chicken salad sandwich or healthy tuna melt.
How to Store and Make Ahead
Store: Place leftovers in an airtight container in the refrigerator for up to 5 days.
Freeze: Lentil soup freezes well for up to 3 months.
Make ahead: I love that you can prep this slow cooker lentil soup ahead of time. Just add all the ingredients, except for the garnishes, into a container or Ziploc bag, or slow cooker insert. Refrigerate for up to 2 days. Then cook as per recipe’s instructions.
Make It a Freezer Meal
Yes, you can make this into a freezer meal!
- Combine: In a large Ziploc bag, add all the ingredients except for the broth or water and the garnishes.
- Freeze: Make sure to release as much air out as possible, seal the bag and freeze for up to 3 months.
- Thaw: When you are ready to enjoy this soup, just thaw the freezer bag in a bowl or sink of hot water for 10 minutes.
- Cook: Transfer to a slow cooker, add broth or water and cook as per recipe’s instructions
- plus 1 hour.
FAQs
While it is recommended to always rinse your lentils before cooking to remove any dust or debris, it is not necessary to soak them before cooking because of their smaller size and thinner skin. Lentils, unlike many of their legume family members, do not contain sulfur. Sulfur is the main reason beans get soaked as it can aid in digestion and reduce gas.
While slow cooking your lentils is a great way to prevent them from overcooking, it can happen. Adhere to the cooking times listed in this recipe as they have been tested over and over as well as wait to add additional salt or acids (lemon, vinegar) until right before serving.
The most probable culprit is that your lentils are old. Check the date they were packaged or how long you have had them open in your pantry.
More Lentil Recipes to Try
- Red lentil soup
- Green lentil curry
- Lentil casserole with mushrooms
- Chicken and lentil casserole
- Instant Pot dal
Slow Cooker Lentil Soup
Equipment
Ingredients
- 2 medium onions, diced
- 3 large celery stalks, diced
- 3 large carrots, diced
- 4 cups potatoes, diced
- 2 cups corn, frozen
- 1 1/2 cups green or brown lentils, rinsed & drained
- 1 tablespoon garlic powder
- 2 teaspoons oregano, dried
- 1 teaspoon thyme, dried
- 3 tablespoons soy sauce, I use Bragg liquid aminos
- 3 bay leaves
- 5 whole peppercorns
- 9 cups vegetable broth, low sodium
- Green onion, cilantro, parsley, Greek yogurt, cheese, tortilla chips, for garnish and serving
Instructions
- In a large slow cooker, add onion, celery, carrots, potatoes, corn, lentils, garlic powder, oregano, thyme, soy sauce, bay leaves, peppercorns and vegetable broth. No need to stir.
- Cover and cook on Low for 8-10 hours or on High for 4-5 hours (with this soup longer is better).
- Discard bay leaves and peppercorns. Using an immersion blender, pulse a few times until desired texture – I like creamy with chunks.
- Garnish with herbs and Parmesan cheese, plain yogurt, tortillas chips and serve hot.
Notes
- Store: Refrigerate in an airtight container for up to 5 days or freeze leftovers for up to 3 months.
- Freezer Meal: In a large Ziploc bag, add all ingredients (except broth (water) and garnishes), release out air as much as possible, seal and freeze for up to 3 months. Thaw in a bowl/sink with hot water for 10 minutes, transfer to slow cooker, add water and cook as per instructions + 1 hour.
- Lentils: You can use red lentils, just keep in mind they will fall apart a lot.
- Thick and creamy really is best for this soup. If you do not have an immersion blender, remove 1 cup of soup from slow cooker, blend in blender, stir back in soup. You could do this until you reach desired creaminess.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
My broth never became creamy even after blending 2cups of it in a blender. Using 9 cups of broth must have been too much. I prefer creamier texture so will use less broth next time.
Sure thing, use less broth next time. You must scoop more of ingredients and less liquid to blend.
I sautéed the onions, carrots and celery first and added the tomato paste, a good spoonful. Turned out great! Perfect for Fridays during Lent.
I am so happy to hear this, Joyce!
Loved this recipe! Made it with sweet potatoes. It was so delicious. Crockpot cooking is the best!
So happy you loved it! Sweet potatoes sound like a cozy and tasty twist—and yes, crockpot meals really are the best kind of easy!
I took a swing and used sweet potatoes instead of a more traditional potato (I assume most people use russets, white, or yellow potatoes). Turned out great! A tad under salted, but that’s probably a matter of broth choice, and of course an easy fix to add more. Will definitely make again!
I often use sweet potatoes in lentil and coconut soups. You can use any potatoes. Glad you loved it!