This Slow Cooker Lemon Rosemary Lentil Soup is one of the easiest soups to ever come out of your kitchen. Fresh vegetables, lemon and rosemary become an amazingly hearty soup with minimal effort.
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Original content posted January 2015. Updated January 2019.
If you would’ve ever told me I’d be serving this Slow Cooker Lemon Rosemary Lentil Soup for dinner and my family would be convinced that lentils were not only delicious, but also an acceptable protein substitute, I likely would’ve laughed. In your face.
My dear husband is as textbook meat and potatoes as you can get. And then there is the menagerie, who will at times decide they don’t want to partake in whatever I’m serving for no particular reason. For the record, if you don’t want to eat what I’m serving, I’m totally fine after you take your obligatory bite.
Just know that your belly will be hungry in the morning and I will not be making you anything else. (And yes, this works!)
Then about a year ago, I introduced our family to Slow Cooker Lentil and Brown Rice Tacos and I can’t remember the last time I served tacos with ground beef. Miraculous! 2014 will forever be known as the year of the lentils!
So as I dreaming up new recipe ideas, I knew I wanted to combine our new love of lentils with my undying devotion for my slow cooker. I’m so thrilled with the end result, this Slow Cooker Lemon Rosemary Lentil Soup, and have no doubt that you will be too!
TIP: For those of you that insist on some type of meat in your meal, I have no doubt you’ll love my Slow Cooker Sausage Lentil and Arugula Soup.
Fresh vegetables, lemon and rosemary become an amazingly hearty soup with minimal effort. Carrots, onion, yellow bell pepper and red lentils are flavored with garlic and a dash of cayenne pepper and slow cooked until tender. Lemon zest and juice and chopped rosemary are swirled throughout to create one of the easiest soups to ever come out of your kitchen.
This Slow Cooker Lemon Rosemary Lentil Soup will definitely earn a spot on your menu plan whether it’s Meatless Monday or not. With just 15 minutes of prep time – less if you’ve got mad knife skills! – it’s simply irresistible!
Can You Make Lentil Soup in a Slow Cooker?
Absolutely! Using a crockpot or slow cooker to make lentil soup is my favorite way to do it. I’ve even used the slow cooker function on my Instant Pot.
No sautéing of vegetables in advance. For this Slow Cooker Lemon Rosemary Lentil Soup you simply add all of the ingredients to your slow cooker and let it do the work while you attend to the next item on your to do list.
TIP: I like to make this recipe in this slow cooker – it comes in 4, 6 or 8 quart options – or using the slow cooker function of my Instant Pot. If using your Instant Pot, you’ll want to use the tempered glass lid instead of the top that comes with it and is used for pressure cooking.
How Long to Cook Lentil Soup in Slow Cooker
My recipe for Slow Cooker Lemon Rosemary Lentil Soup notes you should cook on LOW temperature for six hours. With that being said, you also can adjust the cooking time according to your personal preference.
Cooking for six hours on LOW temperature will make for a more creamy, thick soup texture. If you’d rather the lentils retain their shape and have a bit more bite to them, you’ll want to start checking on then around the five hour cooking time mark.
Can You Substitute Green Lentils for Red?
You can attempt to substitute green lentils for the red lentils called for in this recipe, though their texture and flavor will differ. Red lentils tend to fall apart while they are cooking which makes them the best choice for this Slow Cooker Lemon Rosemary Lentil Soup.
Can You Freeze Slow Cooker Lemon Rosemary Lentil Soup?
Yes! In fact, I love to use this recipe for meal prep and freeze individual portions to have on hand for a quick and easy lunch or dinner. Properly stored in an airtight container, it will maintain maximum quality for six months.
How to Make Slow Cooker Lemon Rosemary Lentil Soup
 In a six quart slow cooker, add carrots, onion, garlic and yellow pepper.
 Add cayenne pepper, lentils, chicken broth, water and salt to slow cooker.
 Cook on LOW for six hours. Add lemon zest, juice and rosemary.
 Stir together to combine. Season with additional salt and pepper to taste.
If you’ve tried this Slow Cooker Lemon Rosemary Lentil Soup or any other recipe on Melanie Makes, please let me know your thoughts in the comments below. I love hearing from you and respond to each and every comment!
Slow Cooker Lemon Rosemary Lentil Soup
- 6 carrots diced
- 1 large onion diced
- 4 cloves garlic minced
- 1 yellow pepper chopped
- 1/8 teaspoon cayenne pepper
- 3 cups red lentils
- 4 cups chicken broth
- 2-3/4 cups water
- 1-1/2 teaspoons salt
- 1 lemon zest and juice
- 1 tablespoon fresh rosemary chopped
- In a six quart slow cooker, add carrots, onion, garlic and yellow pepper.
- Add cayenne pepper, lentils, chicken broth, water and salt to slow cooker.
- Cook on LOW for 6 hours.
- Stir in lemon zest, juice and rosemary.
- Season with additional salt and pepper to taste.
- Ladle into bowls and garnish with additional chopped rosemary, if desired.
Obviously I’m not the only one that’s fallen in love with lentils. My friends have made them the star of these vegetarian Lentil Meatballs, refreshing Lentil Salad with Feta, Lemon and Parsley and these decadent Cocoa Lentil Cupcakes. Lentils for the win, I say!