Lentil Soup

This is the lentil soup I’ve made more than any other recipe on this site, and the one I come back to every autumn. A single bowl has 13 grams of protein and 15 grams of fiber, which makes this lentil soup as nourishing as it is delicious.

If you’ve ever made lentil soup before and found it a bit flat, then you’ve found the soup that fixes all of that. It’s a classic lentil soup, yet different enough to be a wow soup; fancy enough to serve to friends, but simple enough to enjoy as a weeknight dinner.

It costs almost nothing to make (especially compared to other proteins) and freezes well, so you can make a batch now and store it in the freezer for a few weeks.

As a previous university dietitian, I spent a good chunk of my day talking to students about kitchen essentials. Topics included must-have appliances, pantry staples, and easy, healthy recipes that they can whip up without using Google. It was always amazing to me how many students weren’t comfortable in the kitchen! This lentil soup is one of those basic recipes that you don’t really need a recipe for. Make it a handful of times, and you’ll commit it to memory.

I call this my perfect lentil soup. Perfect in the sense that it takes limited skills in the kitchen, is incredibly flavorful, healthy, and did I mention- cheap! It checks the box for a starving student and also fits my monthly must-have meals list.

What makes this lentil soup different

Compared to other lentil soup recipes, there are four things that make this one different– and better, in my opinion!

First, it has potatoes, which break down just enough as the soup simmers to add body without any cream or flour. If you’ve found previous lentil soup recipes watery, then adding potatoes is the fix! Some of the soup is also blended before being added back in. You can use a blender or an immersion blender, but blending just a bit adds even more creamy texture, along with the potatoes.

This lentil soup also has smoked paprika, which adds a savory depth that meat would otherwise bring. It gives a slight bacon flavor often used in traditional lentil soups. And lastly, a little red wine vinegar stirred right in at the end is a game-changer! It’s my secret for almost every soup I make; a little acid helps balance the soup’s richness and enhance the saltiness.

Which lentils should you use?

Different lentils do act differently! I have a tutorial on my How to Cook Lentils page with more, but generally for a soup, you want something that’s going to hold its shape for the best texture.

• Brown Lentils: My default choice for this lentil soup, and the easiest lentil to find in your grocery store. These hold their shape reasonably well and what this soup was tested the most with.
• French Green (de Puy lentils): I love these lentils, and they are what I use in my cobb lentil salad and crispy lentil tabbouleh recipe. They hold their shape very well and have a slightly peppery taste, but cost a bit more.
• Green: These are similar to brown lentils, but slightly firmer. Don’t use split green, though, as they won’t work.
• Red or Yellow: I don’t recommend these lentils as they will dissolve completely into a puree when cooked, which is great for a soup, but not in this recipe! I have a red lentil soup that’s better for using those.
• Black Lentils: These are harder to find, but striking in this soup!

Can you use canned lentils?

You can use these in a pinch. If you want to use canned lentils, then use two 15-ounce cans, drained and rinsed, then add them in the last 10 minutes rather than at the start, as they are already cooked and will be too mushy if you simmer them for a half hour. You’ll lose a little body in the broth since the lentils won’t be cooking in it; I’d recommend reducing the broth by about a cup to start, then adding more if needed.

Tips for the best lentil soup

• Acid: Great soup includes a balance of three things: aromatics, salty/umami depth, and acid. You can have a good soup with just two of those things, but to really take it to the next level, don’t skip the acid, as it helps brighten the salty broth and rich caramelized vegetables. Just enough to cut through any richness; you don’t want to actually taste the vinegar. Don’t add the vinegar too early, though, as acid slows down how lentils soften.
• Salt in layers: A little with the vegetables, a little with the broth, then taste at the end. Salt needs to dissolve in the liquid, so salting in layers means that you won’t have an overly salted (or bland!) soup
• It will thicken: If you want to reheat this soup, or reheat after freezing, then you may need to add a little broth or water as it will thicken as it sits.
• Let the vegetables caramelize: Cook the vegetables until they are soft and slightly golden before adding in any broth or tomatoes, as this is where much of the flavor comes from.
• Don’t skip the blend! Blending some of the lentil soup gives it more body and texture, without any heavy cream or butter.

Lastly, fresh herbs make a huge difference in a soup’s freshness. Especially when you are eating this one for a few meals at a time. I love a generous handful of parsley in this, stirred in right at the end.

Variations

Add greens

Greens are great! A few big handfuls of spinach, kale or Swiss chard stirred in at the end. Kale will need a few minutes to soften, but spinach will wilt almost right away so you can add it right before serving.

Make it Curried

I know curry sounds odd, but it’s great paired with lentils! For a curry-inspired version, add a tablespoon of curry powder and a teaspoon of grated ginger with the vegetables, then add a splash of lemon and coconut milk at the end instead of the vinegar. If you like my red lentil curry soup, you’ll like this version.

Add a grain

If you want a heartier lentil soup, a cup of cooked farro, barley, or brown rice stirred in makes it substantially more filling, and that’s how my kids like it! I add cooked grains at the end so they don’t get mushy.

Slow Cooker and Instant Pot Directions

Slow Cooker

To make this lentil soup in the slow cooker, sauté the onion, celery, carrot, and garlic first, either right in the slow cooker or on the stove. This step is worth the extra pan because it helps caramelize the vegetables and adds another layer of flavor. Add everything except the vinegar and parsley to the slow cooker and cook on low for 6 to 7 hours on high for 3 to 4. Blend a portion, then stir in the vinegar and parsley.

Instant Pot

I use my Instant Pot to make lentil soup so much that I made its own post– the full directions and timings are in my Instant Pot lentil soup, which is the same soup but built for the IP!

How to store and freeze lentil soup

In the refrigerator

You can store this lentil soup for up to 5 days in an airtight container in the fridge. The soup will thicken considerably as it sits, so add a splash of broth or water when you reheat and stir it back together.

In the freezer

Store this lentil soup in the freezer for up to 3 months (I’m obsessed with these freezer cubes for soup!)

Are lentils good for you?

As a vegetarian, I don’t ever worry about my protein intake because I know we are getting enough, thanks in part to my reliance on the mighty lentil. The little legume packs 18g of protein plus 16g of fiber all for 1 cup.

I bring this point up so often because I think it’s important to note that legumes deliver quite the nutrition punch; it’s also what gives this soup amazing staying power. Since protein is the most satiating (read: fuller, longer) macronutrient, adding it to major meals allows you to feel satisfied longer. It also prevents mid-afternoon snack attacks.

In addition to protein and fiber, lentils are also a good source of iron. Plant-based iron is absorbed less efficiently than the iron found in meat, but the addition of vitamin C changes that, which is one reason that tomatoes are in this recipe.

This vegan lentil soup is perfect on it’s own or paired with a salad; however, if you have a few more moments of time, consider making a loaf of my no-knead bread alongside. Just like the soup, you don’t need to be a baker to have perfect bread. The no-knead approach is completely foolproof — just ask my college students!

If you try this recipe, let me know! Leave a comment, rate it, and tag your Instagram photos with #delishknowledge . I absolutely love seeing your creations. Happy cooking!