Sandra This velvety Alton Brown Potato Leek Soup is made with buttery Yukon Gold potatoes and a unique splash of buttermilk, ready in about 1 hour and 40 minutes. The hero moment happens when you stir in the chilled dairy blend, transforming the hot puree into a silky, tangy masterpiece. I love how the white pepper adds a subtle heat that doesn’t ruin the pristine ivory color.
Why This Classic Works
Most potato soups rely on flour or russet potatoes for thickness, but Alton Brown’s method uses the natural starch of Yukon Golds. I learned that using waxy potatoes prevents the soup from turning into a gluey paste when blended, keeping the texture light and smooth.
The real secret, however, is the combination of heavy cream and buttermilk. While heavy cream provides richness, the buttermilk adds a necessary acidic tang that cuts through the fat, making every spoonful complex rather than just heavy.
Alton Brown Potato Leek Soup Ingredients
- 1 pound leeks (approx. 4-5 medium), cleaned and dark green parts removed
- 3 tablespoons unsalted butter
- 14 ounces Yukon Gold potatoes, peeled and diced small
- 1 quart vegetable broth
- 1 cup heavy cream
- 1 cup buttermilk
- 1/2 teaspoon white pepper
- 1 tablespoon fresh chives, snipped
- Kosher salt, to taste
How To Make Alton Brown Potato Leek Soup
- Prep the Leeks: Chop the white and light green parts of the leeks into small pieces, then rinse thoroughly in a colander to remove any hidden grit.
- Sweat the Vegetables: Melt the butter in a 6-quart saucepan over medium heat, add the leeks with a pinch of salt, and sweat for 5 minutes before reducing heat to medium-low; cook for another 20-25 minutes until very tender but not browned.
- Simmer the Soup: Add the peeled, diced potatoes and vegetable broth to the pot, increase heat to bring to a boil, then reduce to low, cover, and simmer for 45 minutes until potatoes are soft.
- Puree the Mixture: Turn off the heat and use an immersion blender to puree the soup until completely smooth (or carefully transfer to a standard blender in batches).
- Finish the Soup: Whisk the heavy cream and buttermilk together in a small bowl, then stir the mixture into the soup along with the white pepper and chives before serving.
Recipe Tips
- Temperature Control: Do not let the soup boil after adding the buttermilk and cream, or the dairy may curdle and ruin the silky texture.
- Cleaning Leeks: Leeks trap dirt deep inside their layers, so if they are very sandy, submerge the chopped pieces in a bowl of water and lift them out rather than just rinsing.
- White Pepper: Using white pepper instead of black pepper keeps the soup looking creamy and pale without black specks, while adding a more earthy, floral heat.
What To Serve With Potato Leek Soup
Serve this soup with crusty French bread or garlic croutons to add a necessary crunch to the creamy bowl. For a non-vegetarian option, crispy crumbled bacon makes an excellent salty topping that pairs perfectly with the leeks.
How To Store
Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheating should be done gently over low heat; freezing is not recommended as the emulsion of cream and buttermilk will likely separate and become grainy.
FAQs
Can I use Russet potatoes instead?
No, Alton Brown specifically recommends Yukon Golds because Russets have too much starch and can turn the soup gluey and sticky when pureed.
Can I serve this soup cold?
Yes, this recipe is essentially a variation of Vichyssoise, so it is delicious served chilled, though you may need to thin it slightly with more broth or milk.
Why do I need to mix the cream and buttermilk first?
Mixing the two dairy products together helps stabilize them before they hit the hot soup, reducing the chance of the buttermilk curdling upon contact.
Nutrition
- Calories: 320
- Total Fat: 22g
- Saturated Fat: 13g
- Cholesterol: 70mg
- Sodium: 600mg
- Total Carbohydrate: 24g
- Protein: 6g
Try More Recipes:
- Alton Brown Chicken Soup Recipe
- Alton Brown Butternut Squash Soup Recipe
- Alton Brown Lentil Soup Recipe
Alton Brown Potato Leek Soup Recipe
Description
A silky, refined version of the classic Vichyssoise that utilizes a low-and-slow sweating technique for the leeks and a specific dairy blend to achieve a perfect balance of richness and acidity.
Ingredients
Instructions
- Prep the leeks by slicing the white and light green sections into small pieces; submerge them in a bowl of cold water and agitate to ensure all grit and sand are removed before draining.
- Sweat the leeks in butter with a pinch of salt over medium-low heat for 25 to 30 minutes; the goal is to break down the cellular structure until completely tender without triggering the Maillard reaction (no browning).
- Simmer the soup by adding the diced Yukon Gold potatoes and vegetable broth; bring to a boil, then immediately reduce to a low simmer, covering the pot for 45 minutes until the potatoes are completely soft.
- Puree the mixture using an immersion blender until the suspension is entirely homogenous and velvety.
- Finish the soup by stirring in a mixture of heavy cream and buttermilk, then seasoning with white pepper and fresh chives.
- Adjust the salt levels just before serving, as the potatoes will have absorbed much of the initial seasoning.
Notes
- Utilizing Yukon Gold potatoes is a specific choice based on starch content; their medium-starch levels provide enough amylopectin to thicken the soup during pureeing while maintaining a creamy, buttery mouthfeel that waxy or starchy potatoes lack.
- The 30-minute sweating phase for the leeks is essential for flavor development; it allows the sulfur compounds to mellow and the natural sugars to release without caramelizing, which would ruin the soup’s characteristic pale aesthetic.
- The inclusion of buttermilk provides a critical acidic counterpoint to the heavy cream and butter. This lactic acid cuts through the fat, brightening the earthy notes of the leeks and preventing the soup from tasting heavy or one-dimensional.
