Easy Slow Cooker Lentil Soup
This easy slow cooker lentil soup is made with simple pantry ingredients like green lentils, celery, carrot and makes a wonderfully filling and hearty vegetarian dump and go slow cooker meal! Simple stovetop and Instant Pot instructions provided, too.
About this Slow Cooker Lentil Soup
Lentil soup is just one of those staple recipes you need in your back pocket, as it’s not only easy to throw together, made with simple pantry ingredients, and budget friendly; but also delicious, filling, and completely nourishing.
Plus, it’s a vegetarian slow cooker meal that will please both meat eaters and plant lovers alike!
In this case, though, I’m singing the praises of a big bowl of green lentil soup, and if you’ve never made homemade lentil soup, now is the time to try it!
Trust me, it’s easier than you think, especially since you don’t need to cook or soak the lentils ahead of time.
In fact, since this is a simple dump and go slow cooker recipe, you just add the lentils straight to the crockpot along with the other ingredients, hit start, and you’re well on your way to a delicious, hearty meal!
This lentil soup is especially easy as most of the cooking time is hands-off due to the magic of the slow cooker, making it perfect for busy weeknights or slow weekends at home.
This version is also vegan, vegetarian, and naturally gluten-free and dairy-free, so it makes a great option when feeding people with different dietary preferences.
If you prefer meat, though, be sure to check out our recipe variations below for how to make this crockpot lentil soup with ham, sausage, a ham bone, Italian sausage, or bacon.
Lentil Soup Process & Tips
For the slow cooker version of this recipe I opted to skip the saute step to keep prep easy and streamlined.
If you prefer the added depth of flavor, feel free to saute the onions first in a bit of olive oil and salt over medium heat.
Pureeing a bit of the cooked soup at the end using an immersion blender or regular blender lends a creamy quality without any dairy, so don’t skip this step.
Be sure to check the recipe card below for Instant Pot and Stovetop instructions too.
Tip: Lentil soup goes well with a simple green salad and crusty bread. I especially love it with this Easy Fall Harvest Salad!
Crockpot Lentil Soup Recipe Variations
Slow Cooker Lentil Soup With Ham: Add 1-2 cups chopped cooked ham to the slow cooker along with the lentils. Proceed with the recipe. Top with additional cooked ham, crisped up in a pan over medium high heat.
Crockpot Lentil Soup with Sausage: Add 1 pound kielbasa or Italian sausage to the crockpot along with the lentils. After the soup has cooked, remove the sausages, slice, and add back to the soup along with the spinach.
Slow Cooker Lentil Soup with a Ham Bone: Add a ham bone to the slow cooker along with the lentils. After the soup has cooked, remove the ham bone and discard. Proceed with the final steps of the recipe.
Crockpot Lentil Soup with Bacon: Cook one pound bacon until crisp. Crumble half the cooked bacon and add it to the crockpot along with the lentils. Proceed with the recipe. Top with remaining cooked, crumbled bacon.
Key Ingredients & Substitutions
Lentils: Either green or brown lentils work in this recipe. Do not use red lentils, as they produce an entirely different consistency and result. If you’re looking for a red lentil soup recipe, try this simple, delicious Red Lentil Soup with Coconut Milk or this Easy Carrot Lentil Soup instead.
Baby spinach: Kale can be used in place of baby spinach. Just be sure to add a few extra minutes of cook time at the end to wilt the kale.
Stock: Vegetable stock or chicken stock can be used, but be sure to use vegetable stock to keep this recipe vegan and vegetarian.
Red wine vinegar: Finishing the soup with red wine vinegar adds a much needed flavor boost after a long cooking time. If you don’t have red wine vinegar then balsamic vinegar, white wine vinegar, or lemon juice will also work.
How to Store or Freeze Lentil Soup
Homemade vegetarian soups keep well in the fridge for up to 3-4 days, in a sealed container.
This recipe also freezes well, store in a sealed freezer friendly container for up to 2-3 months.
Tip: Lentil soup thickens as it cools. Add a splash of stock when reheating to return it to the original consistency.
This Recipe Is…
Easy Slow Cooker Lentil Soup
- 1 medium yellow onion, chopped
- 1 cup chopped celery
- 2 cups chopped carrot
- 2 cloves garlic, minced or finely grated
- 1 ½ teaspoon kosher salt, divided
- 1 ½ cups dry green lentils (or brown lentils), rinsed and picked over
- 1 (15-oz) can petite-diced tomatoes
- 6-8 cups vegetable stock, or chicken stock
- 1 large bay leaf, or 2 small bay leaves
To Add at the End
- 4 cups baby spinach
- 1 teaspoon red wine vinegar
Optional Serving Suggestions
- Extra virgin olive oil, freshly cracked pepper, freshly grated parmesan cheese (traditional or vegan), fresh parsley, red pepper flakes, crusty bread
Slow Cooker Directions
- Add the onion, celery, carrot, garlic, 1 teaspoon salt, lentils, tomatoes, stock and bay leaf to a 6-quart slow cooker, stirring to combine. Do not add the spinach, it will be added at the end.
- Cover and cook on high for 4-6 hours or on low for 6-8 hours, or until the veggies and lentils are soft.
- Remove the lid, remove the bay leaf, add the vinegar, and stir to combine. Add an additional 1-2 cups of stock to thin the soup if necessary. Taste and add the remaining ½ teaspoon salt, plus additional vinegar if desired.
- Using an immersion blender, blend for 5-10 seconds. Alternatively, carefully, remove ½ to 1 cup of cooked soup to a blender. Cover, blend on high, then add back to the soup, stirring to combine. Note: Blending for just a few seconds will add a creaminess to the soup, while leaving the texture of most of the lentils and vegetables intact.
- Add the spinach, and stir to combine. Serve with a generous drizzle of olive oil, and any other toppings you like.
Instant Pot Directions
- Set a 6-quart pressure cooker to saute mode for 8 minutes. Add 1 tablespoon olive oil, onion, a pinch of salt, and cook, stirring occasionally, until the onions are soft.
- Cancel the saute function. Add the celery, carrot, garlic, 1 teaspoon salt, lentils, tomatoes, stock, and bay leaf, stirring to combine.
- Secure the lid, select the manual setting, and set it to high pressure for 15 minutes.
- When the pressure cooker timer is done, allow to naturally release for 15 minutes.
- Follow remaining slow cooker steps 3-5.
- Heat 1 tablespoon olive oil over medium high heat in a large Dutch oven. Add the onion and a pinch of salt, stirring to combine. Cook until the onions soften, about 8 minutes, stirring occasionally.
- Add the celery, carrot, garlic, and 1 teaspoon salt, stirring to combine. Cook for an additional 2 minutes, stirring occasionally.
- Add the lentils, tomatoes, bay leaf, and stock, stirring to combine. Cover, bring to a boil, then reduce to a simmer.
- Cook, covered, until the lentils are soft, about 35-45 minutes, stirring occasionally.
- Follow remaining slow cooker steps 3-5.