The Best Lentil Soup Recipe: Hearty, Easy and Loaded with Flavor
Brown lentils for body, red lentils for creaminess, sweet potato, fire-roasted tomatoes and warm spices in one pot, finished with wilted spinach and a whole lemon. Thick enough to stand a spoon in, vegan as written, better tomorrow.
- One pot, 60 minutes
- 18g protein a bowl
- Instant Pot and slow cooker versions
- Printable recipe
The bowl: thick, rust-orange lentil soup with soft sweet potato, wilted spinach, a drizzle of oil and a wedge of lemon.
The best lentil soup recipe is not about a secret ingredient; it is about four habits most versions skip. Cook the vegetables until golden, toast the spices in the oil, use two kinds of lentils, and finish with salt and a whole lemon. Sweet potato gives it body and a little sweetness, spinach goes in at the end, and the pot comes out thick, deeply savory and bright.
In this post:
- Why this one tastes like the best
- Ingredients, and which lentils to use
- The recipe, scaling from 4 bowls to 24
- The four rules for lentil soup that is not bland
- Six versions: Instant Pot, slow cooker, with ground meat, creamy red lentil, Greek, coconut curry
- Freezing, meal prep and reheating
- Troubleshooting, nutrition and 14 FAQs
Why This Is the Best Lentil Soup
Thick and hearty, with no cream
Red lentils melt into the broth and thicken it; brown lentils and sweet potato stay in pieces. One pot, two textures, and a spoon stands up in it.
Deeply savory, not flat
Slow-cooked onion, carrot and celery, tomato paste caramelized in the pan, and spices toasted in the oil before the liquid goes in. Then salt and lemon at the end, which is the part most lentil soups skip.
A full meal in a bowl
About 18 grams of protein and 14 grams of fiber a serving from the lentils, plus sweet potato and a bag of spinach. It is dinner on its own with bread.
Better tomorrow, and it freezes
The flavors deepen overnight and it freezes for 3 months, so a double batch is a week of lunches. The freezer table has the rules.
Ingredients for the Best Lentil Soup
Brown or green lentils
The body of the soup; they stay whole and slightly firm. No soaking needed; rinse and pick over for the odd stone.
Red lentils
Half a cup that disappears into the broth and makes it creamy and thick. The trick that makes this version taste richer than it is.
Sweet potato
A pound, diced small so it cooks in the same time as the lentils. Its sweetness balances the smoke and acid; butternut squash or regular potato work too.
Fire-roasted tomatoes
A can, with the juice, for a smoky, slightly charred tomato backbone. Plain diced tomatoes work; add ¼ teaspoon more smoked paprika.
Onion, carrot, celery, garlic
The base, cooked slowly until golden before anything else goes in. Eight minutes here is worth more than any spice.
Cumin, smoked paprika, coriander, turmeric
Warm and earthy without being a curry. Two teaspoons of cumin lead; the turmeric is mostly for color. A pinch of cayenne wakes it up.
Tomato paste
Two tablespoons, cooked until it darkens, for savory depth and a richer color than the canned tomatoes alone give.
Spinach, lemon and herbs
Added at the end: the spinach for color and greens, the lemon because lentils need acid, the parsley or cilantro for freshness. Do not skip the lemon.
Broth
Vegetable broth keeps it vegan; chicken broth makes it a touch richer. Low-sodium either way, so you control the salt.
Which Lentils to Use
| Lentil | Texture in soup | Cook time | Notes |
|---|---|---|---|
| LentilBrown | Texture in soupHolds shape, earthy | Cook time25 to 30 minutes | NotesThe all-purpose soup lentil |
| LentilGreen | Texture in soupHolds shape, peppery | Cook time30 to 35 minutes | NotesSwap for brown |
| LentilRed or yellow (split) | Texture in soupCollapses, creamy, sweet | Cook time15 to 20 minutes | NotesThickens the broth; the whole-soup option is in the tabs |
| LentilFrench green (Puy) | Texture in soupVery firm, nutty | Cook time25 to 30 minutes | NotesBest in brothy or salad-style soups |
| LentilBlack (beluga) | Texture in soupFirm, rich | Cook time25 minutes | NotesBeautiful, pricier |
| LentilCanned lentils | Texture in soupAlready cooked | Cook timeAdd in the last 10 minutes | NotesUse 3 cans, drained, and cut the broth by 2 cups |
The Best Lentil Soup Recipe
The card makes 6 bowls in a 5 to 6-quart Dutch oven. Tap a size and everything, including the pot, updates.
The Best Lentil Soup (Sweet Potato, Spinach and Spices)
Brown lentils for body and red lentils for creaminess, sweet potato, fire-roasted tomatoes and warm spices, simmered in one pot and finished with spinach and lemon. Tap a serving size and every amount, including the pot, updates with the printable card.
How many bowls?
Ingredients
- 1½ tbsp2 tbsp¼ cup½ cup olive oil
- 1 small1 large2 large4 large yellow onion, diced
- 23612 carrots, diced
- 23612 celery stalks, diced
- 34816 garlic cloves, minced
- 1½ tbsp2 tbsp¼ cup½ cup tomato paste
- 1½ tsp2 tsp4 tsp8 tsp ground cumin
- ¾ tsp1 tsp2 tsp4 tsp smoked paprika
- ¾ tsp1 tsp2 tsp4 tsp ground coriander
- ½ tsp½ tsp1 tsp2 tsp ground turmeric
- a pinch¼ tsp½ tsp1 tsp cayenne or red pepper flakes
- 2 cups (1 medium)3 cups (1 large, about 1 lb)6 cups12 cups sweet potato, peeled, ½-inch dice
- 1 can (14 oz)1 can (14 oz)2 cans4 cans fire-roasted diced tomatoes
- ⅔ cup1 cup2 cups4 cups brown or green lentils, rinsed
- ⅓ cup½ cup1 cup2 cups red lentils, rinsed
- 4 cups6 cups12 cups24 cups vegetable or chicken broth
- 1124 bay leaf
- 1 tsp1½ tsp1 tbsp2 tbsp salt, plus more to taste
- ¼ tsp½ tsp1 tsp2 tsp black pepper
- 3 oz (3 cups)5 oz (5 cups)10 oz20 oz baby spinach
- 1124 lemon, juiced
- 2 tbsp¼ cup½ cup1 cup fresh parsley or cilantro, chopped
Two lentils: brown (or green) lentils hold their shape; red lentils collapse and thicken the broth. Together they make a soup that is both hearty and creamy without any cream. Only one kind in the pantry? Use 1½ cups of it; see the lentil table. Vegan as written with vegetable broth.
Instructions
Soften the vegetables
Warm the olive oil in a large Dutch oven over medium heat. Add the onion, carrots and celery with a pinch of salt and cook 7 to 8 minutes, stirring now and then, until soft and golden at the edges. This slow start is where the depth comes from; do not rush it.
Bloom the garlic, tomato paste and spices
Stir in the garlic and tomato paste and cook 1 minute, until the paste darkens a shade. Add the cumin, paprika, coriander, turmeric and cayenne and stir 30 seconds, until fragrant. Toasting the spices in the oil is what makes the soup taste deeply spiced instead of dusty.
Add the sweet potato, tomatoes, lentils and broth
Add the sweet potato, the tomatoes with their juice, both lentils, the broth, the bay leaf, salt and pepper. Scrape the bottom of the pot and bring to a boil.
Simmer until the lentils are tender
Reduce to a steady simmer, partly cover and cook 25 to 30 minutes, stirring occasionally, until the brown lentils are tender and the red lentils have melted into the broth. The sweet potato should be soft but still in pieces. If it looks too thick, add a splash of broth.
Thicken, then wilt the spinach
Fish out the bay leaf. Mash a few spoonfuls of lentils and sweet potato against the side of the pot, or blend 1 cup and stir it back, for a thicker, creamier soup. Add the spinach in handfuls and stir until it wilts, about 2 minutes.
Finish with lemon and herbs
Turn off the heat and stir in the lemon juice and most of the herbs. Taste: it almost always needs more salt than you think, and a little more lemon. Lentil soup without enough salt and acid tastes flat; with them it tastes like the best one you have had.
Serve
Ladle into bowls, scatter the remaining herbs over, add a drizzle of olive oil and serve with warm bread. A spoon of yogurt on top is optional and very good.
The Four Rules for Lentil Soup That Is Never Bland
The base: onion, carrot and celery cooked golden, then tomato paste and the spices toasted in the oil.
Cook the vegetables until golden, not just soft
Eight minutes of medium heat builds the savory base. Pale onions make a pale soup.
Toast the tomato paste and spices
A minute in the hot oil turns raw paste sweet and dusty spices fragrant. It is 90 seconds that changes the whole pot.
Salt generously, and salt at the end too
Lentils and sweet potato swallow salt. Season the base, then taste and salt again after the lemon. Under-salting is why lentil soup gets a bad name.
Finish with acid
A whole lemon for a pot. Without it the soup tastes heavy and flat; with it every flavor sharpens. Vinegar works in a pinch.
Six Ways to Make It
Up close: whole brown lentils, melted red lentils, soft sweet potato and spinach in a thick, spiced broth.
Same pot, different route. Tap a version:
Instant Pot Lentil Soup
Sauté the vegetables, garlic, tomato paste and spices as written using the sauté setting, then add everything except the spinach, lemon and herbs. Pressure cook on high 12 minutes, natural release 10 minutes. Stir in the spinach, lemon and herbs with the lid off. Forty minutes door to door, and the lentils come out perfectly tender.
Slow Cooker Lentil Soup
Brown the vegetables and bloom the spices in a skillet (worth the 10 minutes), then tip into the slow cooker with everything except the spinach, lemon and herbs. LOW 7 to 8 hours or HIGH 4. Stir in the spinach and lemon at the end. Add the red lentils for the last 2 hours if you can, so they thicken rather than vanish.
Hearty Lentil Soup with Ground Beef or Turkey
Brown 1 pound of ground beef or ground turkey in the pot first, breaking it up, then cook the vegetables in the rendered fat and continue as written with chicken broth. Add ½ teaspoon more cumin. Meaty, filling and the version readers ask for; lamb works beautifully too.
Creamy Red Lentil Soup
Use 1½ cups of red lentils only, simmer 20 minutes, then blend the whole pot smooth with an immersion blender before the spinach goes in. Silky, golden-orange and the fastest version; swirl a spoon of coconut milk or yogurt into each bowl.
Greek-Style Lentil Soup
Drop the sweet potato, cumin and turmeric. Use brown lentils only, 2 bay leaves, 1 teaspoon dried oregano and a good glug of olive oil, and finish with 2 tablespoons of red wine vinegar instead of the lemon. Serve with feta crumbled on top and olives on the side: the classic fakes.
Coconut Curry Lentil Soup
Add 1 tablespoon of grated ginger and 2 tablespoons of mild curry powder with the spices, and replace 2 cups of the broth with a can of full-fat coconut milk added in the last 10 minutes. Finish with lime instead of lemon and cilantro. Rich, gently spiced and the one for a cold night.
Freezing, Meal Prep and Reheating
| How | How long | Notes |
|---|---|---|
| HowFridge | How long5 days | NotesThickens as it sits; loosen with broth or water when reheating |
| HowFreezer | How long3 months | NotesCool completely; flat bags or jars with headspace; thaw overnight or reheat from frozen on low |
| HowReheat | How longStovetop, medium-low, stirring | NotesAdd a splash of liquid and a squeeze of lemon to bring it back to life |
| HowMeal prep | How longPortion with the herbs separate | NotesLemon and herbs added fresh taste brightest |
| HowMake ahead for guests | How long1 to 2 days | NotesIt is better on day two; wilt fresh spinach in when reheating |
| HowDouble batch | How longSame time, bigger pot | NotesUse the 12 or 24 size on the card |
What to Serve with Lentil Soup
Soup night: the pot, torn focaccia, yogurt and lemon wedges, herbs in a bowl.
Bread, something cool on top, and the rest of the soup pot:
- For dunking: same-day focaccia or a buttermilk biscuit
- On top: yogurt, olive oil, chili flakes, a squeeze more lemon
- More lentils: curry lentil soup and red lentil curry
- The whole collection: the best lentil soups and stews
- Other weeknight pots: Instant Pot white chicken chili and steakhouse potato soup
Troubleshooting Lentil Soup
| Problem | Likely cause | Fix |
|---|---|---|
| ProblemBland | Likely causeUnder-salted, no acid | FixMore salt than you think; the whole lemon |
| ProblemThin and brothy | Likely causeNo red lentils, or not mashed | FixMash some lentils and sweet potato; simmer uncovered 10 minutes |
| ProblemToo thick (especially leftovers) | Likely causeLentils keep absorbing | FixA splash of broth or water when reheating |
| ProblemLentils still hard after 40 minutes | Likely causeOld lentils, or acid added too early | FixKeep simmering; add tomatoes with the broth, lemon only at the end; buy fresh lentils |
| ProblemMushy, everything collapsed | Likely causeOvercooked, or all red lentils | FixCheck at 25 minutes; keep the brown lentils for texture |
| ProblemSweet potato dissolved | Likely causeCut too small or simmered too long | Fix½-inch dice; it should be soft, not gone |
| ProblemSpinach turned dark and slimy | Likely causeAdded too early | FixLast 2 minutes, heat off after |
| ProblemTastes dusty | Likely causeSpices not toasted | FixBloom them in the oil for 30 seconds |
Nutrition (approximate, per bowl)
Estimates for one of six bowls with vegetable broth, before bread or yogurt. About 14 grams of fiber. Vegan, gluten-free and halal as written.
Lentil Soup: FAQs
What kind of lentils are best for soup?
Brown or green lentils for a soup with texture; they hold their shape and cook in 25 to 30 minutes. Red lentils collapse into a creamy broth. This recipe uses both, a cup of brown and half a cup of red, so the soup is hearty and thick at once. The lentil table above compares every kind.
Do I need to soak lentils before making soup?
No. Lentils cook in 20 to 35 minutes from dry; just rinse them and pick out any stones or shriveled ones. Soaking makes them cook a few minutes faster but is not necessary and can make brown lentils mushy.
How do I make lentil soup thick?
Add red lentils, which melt into the broth, and mash a few spoonfuls of lentils and sweet potato against the pot at the end, or blend a cup and stir it back. Simmering uncovered for the last 10 minutes thickens it further. It also thickens on its own overnight.
Why does my lentil soup taste bland?
Not enough salt and no acid, almost always. Lentils absorb a lot of salt, so season the base and salt again at the end, then add a whole lemon’s juice. Cooking the vegetables until golden and toasting the spices in oil are the other two fixes.
Can I make it without sweet potato?
Yes. Use regular potato, butternut squash or carrots for the same bulk, or leave it out and add ½ cup more lentils. The sweet potato balances the smoke and acid, so with it gone add a teaspoon of sugar or a grated carrot.
Is lentil soup healthy?
Yes: about 300 calories a bowl with 18 grams of plant protein, 14 grams of fiber, and iron and folate from the lentils, plus sweet potato and a bag of spinach. It is vegan as written with vegetable broth and naturally gluten-free.
Can I make lentil soup in the Instant Pot or slow cooker?
Yes, both. Instant Pot: sauté the base, add everything but the spinach and lemon, pressure cook 12 minutes with a 10 minute natural release. Slow cooker: brown the base first, then LOW 7 to 8 hours. The tabs above have both in full.
Can I add meat?
Yes. Brown a pound of ground beef or turkey before the vegetables and continue as written with chicken broth; lamb is excellent too. The ground meat tab has the details. Shredded leftover chicken stirred in at the end works as well.
How long does lentil soup last?
Five days in the fridge and 3 months in the freezer. It thickens as it sits, so reheat with a splash of broth or water and a fresh squeeze of lemon. Many people think it is best on day two.
Can you freeze lentil soup?
Yes, very well. Cool it completely, freeze in flat bags or jars with headspace, and thaw overnight or reheat from frozen over low heat with a little water. The sweet potato softens slightly; the flavor is unchanged.
Why are my lentils still hard?
Old lentils take much longer, and acid added early (lemon or vinegar) stops them softening. Keep simmering, add the lemon only at the end, and buy lentils from a shop that sells a lot of them. Very hard water can slow them too; a pinch of baking soda helps.
Can I use canned lentils?
Yes. Use three 15 ounce cans, drained and rinsed, reduce the broth to 4 cups, simmer the sweet potato in the broth until tender first, then add the lentils for the last 10 minutes. Skip the red lentils and mash more to thicken.
Is this lentil soup vegan and gluten-free?
Yes, with vegetable broth it is vegan, and it is gluten-free as written. Check the broth label, and serve it with gluten-free bread if needed. It is also halal as written, with beef or turkey rather than pork in the meat version.
What do you serve with lentil soup?
Warm bread for dunking, a spoon of yogurt or a drizzle of olive oil on top, and a simple salad if you want more. It is a complete meal; the serving section above has the bread recipes and the rest of the lentil collection.
Save the pin so the recipe, the lentil table and the Instant Pot version are one tap away.
More Soup Pots
The lentil collection, the curried versions, the bread and the other weeknight bowls.
Best Lentil Soups and Stews
Every lentil pot worth making this season. See the collection → CurriedCurry Lentil Soup
One pot, 40 minutes, gently spiced. See the recipe → ThickerEasy Red Lentil Curry
Creamy, rich and 30 minutes. See the recipe → For DunkingSame Day Focaccia
Soft, golden and made for soup. Bake a pan → Soup NightInstant Pot White Chicken Chili
The other weeknight pot. See the recipe → Fall SoupsWild Rice and Sweet Potato Soup
The vegetarian bowl for the rotation. See the soups →Golden vegetables, toasted spices, two lentils and a sweet potato, half an hour of simmering, a bag of spinach, a whole lemon and more salt than you think. That is the pot.
Pin this lentil soup recipe for every cold week between now and spring.
