Crock Pot Potato Leek Soup is thick, velvety and gentle, with soft buttery leeks, tender Yukon gold potatoes, thyme and bay leaves, all blended smooth and finished with heavy cream. It serves 8.
How to make it: Soften the sliced leeks in butter with garlic, then slow cook them with the potatoes, herbs and chicken broth on LOW for 8 hours or HIGH for 5 hours. Blend the soup, add the cream and blend again a little.
Why You’ll Love It
- Mostly hands-off: after about 10 minutes of prep, the slow cooker does the work while you get on with your day.
- Silky texture: blended Yukon golds and heavy cream make a creamy soup that coats the spoon.
- Big batch: one pot makes 8 servings, so you have lunches for later in the week.
- Easy to change: add bacon, stir in more vegetables or keep it vegetarian.
Ingredient Notes
Leeks: Two large leeks. Fresh is what you’ll usually find, but sliced frozen leeks work too.
Potatoes: Three pounds of Yukon gold potatoes, cut into 1-inch cubes. Russets are fine if that’s what you have in the pantry.
Butter and garlic: Three tablespoons of salted butter and 2 cloves of garlic, for softening the leeks in the skillet.
Broth and herbs: Seven cups of chicken broth, 2 bay leaves and 3 sprigs of fresh thyme. If you only have dried, use 1 teaspoon of dried leaf thyme, not ground.
Heavy cream: One and a half cups. Half and half or milk can stand in, but your soup won’t taste as rich.
Ingredients
- 2 large leeks, sliced, thick green ends discarded, rinsed after slicing
- 3 tablespoons salted butter
- 2 cloves garlic, minced
- 3 pounds Yukon gold potatoes, peeled if you prefer, cut into 1-inch cubes
- 7 cups chicken broth
- 2 bay leaves
- 3 sprigs fresh thyme, or 1 teaspoon dried leaf thyme (not ground)
- 1 1/2 teaspoons salt
- 1/2 teaspoon black pepper
- 1 1/2 cups heavy cream
- Fresh chives, chopped, for garnish
How to Make Crock Pot Potato Leek Soup
1. Slice and rinse the leeks. Slice the leeks, discarding the thick green pieces at the ends. Rinse the sliced leeks well, since they can have sand in them.
2. Soften the leeks. Cook the leeks with the butter and garlic in a large skillet over medium-high heat until the leeks are softened and browned.
3. Fill the slow cooker. Add the leeks to the slow cooker with the potatoes, bay leaves, thyme, salt and pepper. Pour in the chicken broth and put the lid on.
4. Slow cook. Cook on HIGH for 5 hours or on LOW for 8 hours, until the potatoes are soft.
5. Blend. Remove the bay leaves and the thyme sprigs if you used fresh. Blend the soup with an immersion blender, but do not overblend. If you use a blender or food processor, blend in small batches.
6. Add the cream. Add the heavy cream and blend again a little, until the soup is creamy and steaming hot (165°F).
7. Serve. Ladle into bowls, top with chopped chives and serve hot with crusty bread.
Common Mistakes to Avoid With Potato Leek Soup
This soup has only a handful of ingredients, so each one counts. Watch for these slips and your pot will come out smooth, clean-tasting and creamy.
Rinsing the leeks before you slice them. Leeks can have sand in them, so rinse after slicing, not before. Cut them lengthwise first, then crosswise into thin half-moons, and rinse them well in a sieve until no grit is left.
Cooking the tough tops. Use the white and light green parts only. The thick, dark green pieces at the ends go in the trash or the compost, not the pot.
Overblending. Blend just until the soup is smooth, then stop. In a countertop blender or food processor, work in small batches and pour each batch back into the slow cooker.
Adding the cream at the start. The cream goes in last, after the potatoes are soft and the soup is blended. Pour it in, give the soup one more short blend, and it’s ready to ladle.
Lifting the lid to check. USDA FSIS says to keep the lid in place and remove it only to stir the food or check for doneness. Let the potatoes cook undisturbed, and test one with a spoon near the end of the cooking time.
Tips for Success
Can I prep everything the night before?
Yes. USDA FSIS says to keep perishable foods in the refrigerator until you are ready to cook, and to store anything you cut up ahead in the refrigerator too. Slice and rinse the leeks and cube the potatoes, cover them and chill them overnight, then soften the leeks in the morning and load the crock.
Should I start it on HIGH?
If you can, USDA FSIS suggests running the cooker on its highest setting for the first hour, then switching to LOW. It is also safe to cook on LOW the whole time, which is handy when you’re leaving for work.
What if the power goes out while I’m away?
Throw the soup out, even if it looks done. That’s the USDA FSIS rule when you weren’t home for the whole cook.
Variations
- With bacon: stir 8 pieces of cooked, crumbled bacon into the slow cooker with the rest of the ingredients for a smoky flavor.
- Heartier: add chopped carrots or celery along with the potatoes.
- Vegetarian: use vegetable broth in place of the chicken broth.
Storage & Reheating
USDA FSIS says to refrigerate leftovers within 2 hours in shallow, covered containers and eat them within 3 to 4 days. You can freeze leftovers for 3 to 4 months, but cream doesn’t freeze well: FSIS lists cream sauce among the foods that don’t freeze well, and cream can separate and look curdled after thawing. Reheat the soup on the stove or in the microwave to a rolling boil (165°F), not in the slow cooker. Once it’s hot, a preheated slow cooker can keep it hot for serving at 140°F or above.
What to Serve With It
Set out a thick slice of crusty bread, like this rustic German bread, and a fresh salad such as spinach salad with warm bacon dressing. If you’re on a potato soup kick, try the cheesy 5-ingredient slow cooker loaded potato soup, a hash brown crockpot potato soup, a stovetop baked potato soup with bacon and cheddar, or crockpot potato broccoli cheddar soup.
Frequently Asked Questions
How do I make leek and potato soup in a slow cooker?
Soften the leeks in butter on the stove first, then let the slow cooker simmer them with the potatoes, broth and herbs until the potatoes are soft. Blend, add the cream and serve.
What can I add to my leek and potato soup to make it taste better?
Try a sprig of fresh rosemary or 1/4 to 1/2 teaspoon of ground nutmeg in the crock. At the table, top your bowl with sour cream, crumbled bacon, sliced green onion, shredded cheddar, fresh cracked pepper or a pinch of red chili flakes, and add croutons, saltines or oyster crackers for crunch.
Do I need to peel the potatoes?
No. Yukon gold skins are thin, so you can leave them on. Peel them if you want an extra-smooth soup.
Can I keep it chunky instead of smooth?
Yes. Skip the blender, fish out the bay leaves and thyme sprigs, and stir the cream into the soup with a spoon so the potato cubes stay whole.
Can I use sour cream instead of heavy cream?
Yes. Whisk sour cream into the blended soup in place of the heavy cream, then add an extra swirl and a little fresh thyme to each bowl.
Final Notes
Give the leeks their full time in the skillet: cooking them in the butter until soft and browned adds a rich, caramelized flavor to the whole pot. If you have a question or make this soup, tell me how it turned out in the comments.
Crock Pot Potato Leek Soup
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Ingredients
- 2 large leeks sliced, thick green ends discarded, rinsed after slicing
- 3 tablespoons salted butter
- 2 cloves garlic minced
- 3 pounds Yukon gold potatoes peeled if you prefer, cut into 1-inch cubes
- 7 cups chicken broth
- 2 bay leaves removed before blending
- 3 sprigs fresh thyme or 1 teaspoon dried leaf thyme (not ground); fresh sprigs removed before blending
- 1 1/2 teaspoons salt
- 1/2 teaspoon black pepper
- 1 1/2 cups heavy cream
- fresh chives chopped, for garnish
Instructions
- Slice the leeks, discarding the thick green pieces at the ends. Rinse the sliced leeks well, since they can have sand in them.
- Cook the leeks with the butter and garlic in a large skillet over medium-high heat until the leeks are softened and browned.
- Add the leeks to the slow cooker with the potatoes, bay leaves, thyme, salt and pepper. Pour in the chicken broth and put the lid on.
- Cook on HIGH for 5 hours or on LOW for 8 hours, until the potatoes are soft.
- Remove the bay leaves and the thyme sprigs if you used fresh. Blend the soup with an immersion blender, but do not overblend. If you use a blender or food processor, blend in small batches.
- Add the heavy cream and blend again a little, until the soup is creamy and steaming hot (165°F).
- Ladle into bowls, top with chopped chives and serve hot with crusty bread.
