This creamy potato leek soup is pure French comfort - silky smooth, subtly flavored, and incredibly satisfying. With just a handful of simple ingredients, you can create something that tastes like it came from a Parisian bistro. Serve it warm on cold winter evenings, or chill it to make the elegant cold soup known as Vichyssoise.
What makes this soup so special is its simplicity. Tender leeks, starchy potatoes, and rich cream come together in a velvety puree that's both comforting and sophisticated. It's the kind of soup you can serve at a dinner party or enjoy in your pajamas on a Sunday evening.
The French Secret to Perfect Potato Leek Soup
The key to this soup is cooking the leeks gently without browning them. This keeps the soup pale and elegant while developing their sweet, mild onion flavor. In French cooking, this technique is called "sweating" - you want the leeks to become soft and translucent without any golden color.
Yukon Gold potatoes create the creamiest texture, though Russets work well too. Their starch content is what gives the soup its luxurious body, even before you add the cream. Don't be tempted to use waxy potatoes like red potatoes - they won't break down properly and will result in a grainy texture.
What is Vichyssoise?
Vichyssoise is simply chilled potato leek soup. Despite its French name, it was actually invented in New York City in 1917 by French chef Louis Diat at the Ritz-Carlton Hotel. He named it after Vichy, a spa town near his hometown in France.
To make Vichyssoise, simply cool this soup to room temperature, then refrigerate until thoroughly chilled (at least 4 hours or overnight). The cold temperature makes the flavors more subtle and refreshing - perfect for a summer starter. Some recipes call for extra cream when serving cold.
How to Clean Leeks Properly
Leeks can hide a surprising amount of dirt between their layers. Here's the foolproof method for cleaning them:
- Trim the ends: Cut off the dark green tops and the root end.
- Slice first: Cut the leek lengthwise, then slice into half-moons.
- Submerge in water: Place in a large bowl of cold water and swish around vigorously.
- Let settle: Wait a minute - the dirt sinks to the bottom while the leeks float.
- Lift out: Remove the leeks with your hands or a slotted spoon (don't pour through a strainer, or the dirt goes right back on them).
Tips for the Silkiest Texture
Getting that restaurant-quality smooth texture requires a few techniques:
- Cook potatoes until very soft: They should be falling apart, not just fork-tender
- Use an immersion blender: Blend for longer than you think - at least 2-3 minutes
- Strain if desired: For ultra-smooth soup, pass through a fine-mesh sieve
- Don't over-blend potatoes: Paradoxically, if using a high-powered blender, you can overwork them and they become gluey. An immersion blender is gentler
Variations and Add-Ins
While classic potato leek soup is perfect as-is, here are some delicious variations:
- Bacon bits: Crispy bacon on top adds smoky, salty crunch
- Blue cheese: A small crumble adds a tangy, creamy element
- Truffle oil: A few drops transform it into something luxurious
- Herb variations: Try adding fresh thyme or a bay leaf while simmering
- Cauliflower: Replace half the potatoes with cauliflower for a lower-carb version
Making It Lighter or Dairy-Free
This soup is naturally rich, but you can lighten it up:
- Use half-and-half: Instead of heavy cream for about 30% fewer calories
- Skip the cream entirely: The potatoes provide plenty of body on their own
- Dairy-free: Use olive oil instead of butter and coconut cream or cashew cream instead of dairy cream
- Vegetarian: Simply use vegetable broth instead of chicken broth
Serving Suggestions
This versatile soup pairs beautifully with many dishes:
- Warm, topped with fresh chives and a drizzle of cream
- Chilled as Vichyssoise for an elegant summer starter
- With crispy bacon bits for added richness and texture
- Alongside crusty bread and a simple green salad
- As a first course before roast chicken or fish
Creamy Potato Leek Soup
Luxuriously smooth French classic. Serve warm for comfort or chilled as elegant Vichyssoise.
Nutrition per serving
Ingredients
Instructions
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Clean and prep leeks. Slice leeks into half-moons and place in a large bowl of cold water. Swish around vigorously to release any trapped dirt, then let sit for a minute. Lift leeks out with your hands or a slotted spoon and drain well in a colander.
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Sauté leeks gently. Melt butter in a large pot over medium heat. Add leeks and cook, stirring occasionally, until very soft and translucent but not browned, about 5-7 minutes. This gentle cooking develops their sweet flavor while keeping the soup pale.
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Simmer with potatoes. Add cubed potatoes and broth. Bring to a boil, then reduce heat to medium-low and simmer until potatoes are very tender and starting to fall apart, about 15-20 minutes. Test by pressing a potato piece against the side of the pot - it should mash easily.
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Blend until silky smooth. Remove from heat. Using an immersion blender, puree the soup until completely smooth, about 2-3 minutes. Alternatively, carefully blend in batches in a regular blender (never fill more than half full with hot liquid). Stir in cream and white pepper.
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Season and serve. Taste and season with salt as needed. For warm soup: serve immediately, garnished with fresh chives and a swirl of cream. For Vichyssoise: cool to room temperature, cover, and refrigerate until thoroughly chilled (at least 4 hours). Adjust seasoning before serving cold.
Recipe Notes
- Storage: Refrigerate in an airtight container for up to 4-5 days. Reheat gently over low heat, stirring often.
- Freezing: Freeze for up to 3 months. The cream may separate when thawing - just blend briefly to bring it back together.
- Lighter version: Substitute half-and-half for heavy cream, or use an extra cup of broth instead.
- Dairy-free: Use olive oil instead of butter and coconut cream instead of heavy cream.
- Make it richer: Add a splash of dry white wine with the broth, or stir in some crème fraîche at the end.
Frequently Asked Questions
What is the difference between potato leek soup and Vichyssoise?
Potato leek soup and Vichyssoise are essentially the same recipe. The main difference is temperature: potato leek soup is traditionally served warm, while Vichyssoise is the chilled version. Vichyssoise was actually invented in New York in 1917 by French chef Louis Diat, who named it after Vichy, a town near his birthplace.
Can I make potato leek soup without cream?
Yes! For a lighter version, you can substitute the heavy cream with half-and-half, whole milk, or simply use extra broth. For a dairy-free option, use coconut cream or cashew cream. The soup will still be delicious and silky thanks to the starchy potatoes.
Why do my leeks taste gritty?
Leeks grow in sandy soil and trap dirt between their layers. To properly clean them: slice the leeks first, then submerge in a bowl of cold water. Swish them around and let sit for a minute - the dirt sinks while the leeks float. Lift them out with your hands or a slotted spoon rather than pouring through a strainer.
What potatoes are best for potato leek soup?
Yukon Gold potatoes are ideal because they're naturally buttery and create the creamiest texture. Russet potatoes also work well as they break down easily. Avoid waxy potatoes like red potatoes or fingerlings - they don't puree as smoothly.
How long does potato leek soup last?
Potato leek soup keeps well in the refrigerator for 4-5 days in an airtight container. It also freezes beautifully for up to 3 months. Note that the cream may separate slightly when reheating - just stir well and it will come back together.