Equipment
Ingredients
Vegetables
- 300 g leeks, white and light green parts only, sliced
- 400 g russet potatoes, peeled and diced
Base and Dairy
- 50 g unsalted butter
- 800 ml vegetable broth
- 150 ml heavy cream, chilled
Seasoning and Garnish
- 10 g kosher salt
- 2 g white pepper, finely ground
- 10 g fresh chives, finely minced
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 351 kcal
- Protein
- 5 g
- Carbohydrates
- 32 g
- Fat
- 24 g
- Fiber
- 3 g
- Sugar
- 6 g
- Sodium
- 1593 mg
- Saturated Fat
- 15 g
- Trans Fat
- 0 g
- Monounsaturated Fat
- 6 g
- Polyunsaturated Fat
- 1 g
- Cholesterol
- 69 mg
- Potassium
- 629 mg
- Calcium
- 90 mg
- Iron
- 2.6 mg
- Magnesium
- 49 mg
- Phosphorus
- 111 mg
- Zinc
- 0.6 mg
- Vitamin A
- 374 mcg
- Vitamin C
- 17 mg
- Vitamin D
- 0.6 mcg
- Vitamin E
- 0.7 mg
- Vitamin K
- 5 mcg
- Vitamin B6
- 0.4 mg
- Vitamin B12
- 0.1 mcg
- Thiamin
- 0.13 mg
- Riboflavin
- 0.15 mg
- Niacin
- 1.3 mg
- Folate
- 16 mcg
- Water
- 298 g
Sources: Aggregated Public Data, USDA FoodData Central
Method
Submerge the sliced leeks in a bowl of cold water. Agitate them to release any dirt, let the dirt settle to the bottom, and carefully lift the leeks out. Drain completely.
Melt the unsalted butter in a heavy-bottomed pot over medium-low heat. Add the cleaned leeks and saute gently until soft and translucent, about 10 minutes. Do not let them take on any brown color, as this will ruin the pure pale aesthetic of the soup.
Add the diced potatoes, vegetable broth, and kosher salt. Bring to a gentle boil at 100°C/212°F, then reduce the heat to maintain a steady simmer at around 90°C/195°F. Cook until the potatoes are completely tender and easily crushed against the side of the pot.
Remove the pot from the heat. Carefully transfer the hot soup to a blender in batches, and puree until completely smooth.
Pass the pureed soup through a fine mesh strainer into a clean bowl, using a ladle or spoon to press it through. This step is essential for the classic silky texture.
Whisk in the heavy cream and white pepper. Cover the bowl and chill in the refrigerator until completely cold, at least 4 hours.
Taste the chilled soup and adjust the salt if necessary, as cold temperatures dull flavor perception. Ladle into chilled bowls and garnish with minced fresh chives.
Chef's Notes
- Using white pepper instead of black pepper is a classic French technique to maintain a pristine, unblemished color in light-colored sauces and soups.
- The choice of potato matters. Russet or starchy potatoes will give a fluffier, lighter texture when blended, whereas waxy potatoes can turn slightly gluey if overworked.
- Do not skip the straining step. The fibrous nature of leeks means that even high-powered blenders leave microscopic fibers behind. Straining is what elevates this from rustic to refined.
- For an extra touch of elegance, chill your serving bowls in the refrigerator for 30 minutes before plating.
Storage
Refrigerator: 3 days — Store in an airtight container to prevent absorbing refrigerator odors. Keep cream incorporated.
Troubleshooting
Soup is gritty or sandy
Cause: Leeks were not washed thoroughly enough to remove deeply trapped soil
Fix: Pass the soup through the finest mesh strainer available, or a cheesecloth-lined strainer
Prevention: Always slice leeks before washing, and agitate in a large volume of water rather than rinsing in a colander
Soup is yellow or brown instead of pale cream
Cause: Leeks were sauteed over too high heat and caramelized, or black pepper was used
Fix: Cannot be fixed, though it will still taste delicious
Prevention: Keep heat medium-low when sweating leeks and use white pepper
Soup tastes bland despite adding salt initially
Cause: Cold temperatures suppress our perception of salt and flavor
Fix: Whisk in additional salt a pinch at a time before serving
Prevention: Always perform a final seasoning adjustment after the soup has completely chilled
Cultural Context
Although rooted in the traditional hot leek and potato soups of France (Potage Parmentier), Vichyssoise was famously invented in 1917 by French chef Louis Diat at the Ritz-Carlton in New York. Remembering how he and his brother used to cool down their mother's hot soup with cold milk during summers in Vichy, France, he recreated a refined, chilled version that became an instant classic of mid-century fine dining.
