Slow cooker potato leek soup is a rich & creamy soup that is wonderful for lunch or a first course at dinner. This Crock-Pot recipe is quick & easy with a lot of flavors. This French classic is so comforting & delicious you will wonder where this recipe has been your whole life.
Leeks and potatoes are a classic combination for a hearty yet smooth soup. It has a bit of cayenne for some heat that pairs well with the heavy cream for balance. Cream of potato leek soup has a pungent onion flavor from the leeks combined with the starchy potatoes. Finally, the rich mouth-feel of the cream gives an all-around delightful taste.
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Ingredients for Slow Cooker Potato Leek Soup
This simple recipe uses a combination of pantry staples and fresh ingredients. All are relatively inexpensive and easy to find in most grocery stores.
- Salted Butter - added flavor and perfect for sauteeing the leeks before they go into the slow cooker
- Leeks - clean & sliced leeks (about 1.5 large or 2-3 regular)
- Garlic - pairs well with leeks
- Yukon Gold Potatoes - these thin-skinned buttery potatoes work best
- Bay leaf - a classic creamed soup ingredient
- Salt & Pepper - season to taste
- Dry Thyme - the perfect accompaniment for leeks
- Cayenne pepper - the heat offsets all the richness of the cream
- Chicken or vegetable broth - use vegetable broth for a vegetarian version
- Heavy Whipping Cream - full-fat for richness & a thick creamy texture
- Cheddar Cheese - medium or sharp is best and is the secret ingredient for added flavor
See the Recipe Card for amounts & full instructions.
NOTE: This is a gluten-free soup that is still thick and creamy - thanks to the potatoes. There is no flour or roux for this recipe.
How to Make Slow-Cooker Potato Leek Soup
Begin this recipe by prepping and cleaning the leeks, since this will be the main step that is really time-consuming. Slice the leeks into rings, both the white & green parts.
Keep in mind leeks are a member of the onion family, so there will be fumes that could bother your eyes. Do not touch your face while handling cut leeks, make sure to wash your hands thoroughly.
How to Clean Leeks
Here are the simple steps for the best way to slice, clean, & prep leeks. Because they are buried in the soil, how they grow results in a gritty vegetable that needs a thorough cleaning.
- Slice the leeks into rings.
- Break the rings up and place in a large bowl.
- Add enough water to submerge the leeks
- Let them sit for 5 minutes so the grit, dirt, & sand can fall to the bottom of the bowl.
- Use your hands to agitate & move them around to get them very clean.
- Use a slotted spoon to remove them from the water and place in a colander.
- Rinse with clean water over the leeks in the colander & set aside.
While the leeks are submerged to clean, begin prepping the other ingredients. If you have more leeks than are needed for the recipe, freeze leeks easily to use later.
Wash, peel, and cube the Yukon gold potatoes. You will want them to be in about 1" cubes, as seen below.
Cook the Leeks
Cook the Soup in the Crock-Pot
This soup makes a decent batch so you need a slow cooker that is big enough to hold it all. I am using a 7-Quart CrockPot. It fits this recipe with room to spare for when blending later (contains any possible splash!)
Puree the Potato Leek Soup
One of my favorite cheap kitchen tools is an immersion blender. Using one here is the easiest way to puree the potato leek soup. This way you can keep the soup hot and blend!
To puree the potato and leek soup, use the immersion blender for 1-2 minutes moving it all around to get all the soup. Make it super smooth or leave some chunks - enjoy it your way.
Substitutions & Variations
You can adjust a few ingredients in this recipe to meet special diet needs.
- Vegetarian - use vegetable or mushroom broth for a meat-free version.
- Potatoes - if you cannot find the Yukon gold you can substitute with fingerling or red potatoes (peeled). Or even cans of drained new potatoes like I use in my Potato Enchilada recipe.
I have not tried any dairy-free milk alternatives for this recipe and do not recommend them at this time.
Toppings for Potato Leek Soup
To add more flavor and fun to potato leek soup, try one or more of these great topping ideas.
- Crumbled cook pork or turkey bacon
- Minced fresh herbs like parsley, dill, & chives
- Shredded cheddar cheese
- A drizzle of heavy cream or sour cream
- Homemade air fryer croutons or oyster crackers
- A dash of hot sauce
How to Store & Reheat Potato Leek Soup
Store in the refrigerator in an air-tight container for up to 5 days. You can also freeze it for up to a month.
Slow Cooker Potato Leek Soup
Equipment
- Slow Cooker
Ingredients
- 3 tablespoons salted butter
- 4 cups clean & sliced leeks about 1.5 large or 2-3 regular
- 3 cloves garlic
- 1 pound Yukon gold potatoes washed & peeled
- 1 bay leaf
- 1 teaspoon salt
- ¼ teaspoon black pepper
- ¼ teaspoon dry thyme
- ⅛ teaspoon cayenne pepper
- 5 cups chicken or vegetable broth
- 1 cup heavy whipping cream
- ½ cup cheddar cheese grated
Instructions
- Slice the leeks into rings, both the white & green parts. Place them in a large bowl and separate the rings so they are exposed and can clean easily. Now add enough water to submerge them. This is how you will clean them. Let the grit or sand that is inside the leeks fall to the bottom of the bowl & let them sit for at least 5 minutes in the water. Use your hands to agitate & move them around every minute or so to really work the dirt out.
- After the leeks have been soaking for about 5 minutes, using your hands or a large slotted spoon, remove them from the large bowl of water and place them in a colander. Rinse with clean water to get any last bit of dirt from the leeks. Let sit to dry a bit while prepping the remaining ingredients.
- Wash, peel, and cut the potatoes into 1" cubes. Also, peel the garlic from the clove and remove the outer skin. There is no need to cut the garlic, it will cook easily in the slow cooker and will be pureed later.
- Over medium-low heat melt butter in a large saute pan. Once melted, add the leeks. Cook for about 5 minutes until they are tender and soft.
- To the slow cooker insert, add the leeks, potatoes, garlic, and all seasonings through the cayenne pepper. Pour in your broth of choice either chicken or a vegetarian broth.
- Set the slow cooker to low for 8 hours or high for 5 hours. The potatoes should be tender and soft when the cooking stage is done. Remove the bay leaf. Let the slow cooker then sit on warm or low if your slow cooker doesn't have a "warm setting".
- Using an immersion blender, blend the soup until it is smooth.
- Add the cream and shredded cheddar cheese. Stir to combine and melt through the soup. Let the dairy products warm through for about 15-30 minutes, leaving it on warm or the low setting.
- Ladle the soup into a soup bowl. To serve you can also top with fresh herbs, crumbled cooked bacon, or more cheddar cheese.
- Store in the refrigerator in an air-tight container for up to 5 days. You can also freeze it for up to a month. To thaw, defrost for 2 days in the refrigerator. Reheat on the stove or microwave and add a touch of cream again to bring back the creamy texture.
Caroline Parrott says
I bet those leeks saute-ing made the house smell awesome!
Angela says
They sure did. The only hard part is waiting the hours for the slow-cooked soup to be done but it is worth it.
Dorothy says
This hit the spot and a good soup recipe. Creamed soups are my favorite and besides clam chowder this is my favorite and a keeper of a recipe.
Holly says
What is the serving size? This does not appear to be a low calorie soup.
Angela says
Hi - the soup makes 12 servings and is 152 calories per serving. The recipe card in the post includes full nutritional information in the notes.