The Perfect Vichyssoise (Cold Potato Leek Soup)

If there is one soup that is an absolute must for me in summer and early fall (in addition to Gazpacho of course), it is the cold, silky, incredibly reviving amalgam called Vichyssoise (vih-she-swaz).

I have been known to make a gallon at a time and polish it off easily in a week. (Luckily, one can actually survive healthily on a diet of only potatoes supplemented with dairy.)

The origin of the soup is contested, but seriously, how much creative invention was required to take a sip of leftover hot potato soup that had been refrigerated and decide, wow, this is incredibly delicious? As far as thinning the congealed soup with milk or cream to get the desired consistency, that’s a no brainer too. This soup must have been invented shortly after the domestication of the potato.

Nevertheless, what surely began as poor man’s leftover cold soup was elevated to the culinary stratospheres in 1917 when Chef Lois Diat of the Ritz Carlton in New York City reimaged the cold, leftover potato and leek soup of his French childhood and served it to the swank patrons of the Ritz. On that fortuitous occasion, one of the great soups of the world was officially, if not born, well then, baptized.

Essentially, Vichyssoise is one of the simplest, most basic soups in a cook’s repertoire. It’s just potatoes, onions or leeks, stock or water, and a bit of milk or cream to finish. Anyone can make it and the ingredients are almost always on hand.

But don’t let the simplicity fool you. Because the soup is so basic and because potatoes and onions have such wide affinities for other flavor partners, Vichyssoise is one of the most versatile soups ever. There are five variations below, but you can dream up dozens more. Just keep the following Tips & Tricks in mind.

Tips & Tricks for the Best Vichyssoise Ever

• Although you can concoct a hundred variations on a basic Vichyssoise (five of them below), it isn’t Vichyssoise unless it is a cold, pureed soup that contains potatoes and leeks or onions in the starring role. Beyond the basic concept, almost any novel addition is fair game.
• Potatoes require a seemingly exorbitant amount of salt. Don’t hold back though or the soup will taste bland.
• Cold foods require more salt than hot foods. Thus, your hot soup may be seasoned perfectly, but after chilling, will likely need more salt. Always taste and adjust before you serve.
• Always submerge peeled potatoes in cold water until you are ready to cook them. This will prevent surface browning.
• To save about 20 minutes of cooking time, grate the potatoes rather than cube them.
• Most classic Vichyssoise recipes call for a combination of stock (or water) and cream. However, to get more mileage out of this basic and very versatile soup, consider swapping all or part of the cream for cream fraiche, Mexican crèma, sour cream, yogurt, or buttermilk. I especially like part buttermilk for its lemony tang. Sour cream is great too, but it will dominate the flavor of the potatoes if too much is used. Taste as you go to get the balance right.

• Russet potatoes are usually specified for classic Vichyssoise, but there is no law against using other types, such as Yukon Gold for the gorgeous color.
• If you’re like me, you don’t always have leeks in the kitchen. Although leeks are classic and divine, yellow onions make a wonderful soup as well. If you have shallots on hand, toss in a few of those too.
• To my palate, the perfect ratio of stock to cream is four to one. At this ration, the flavor of the potatoes dominates, with the cream adding a velvety richness that rounds out the soup. Play around with this ratio to determine your own preference.
• Although classic Vichyssoise often has no herbs other than perhaps chives or parsley (and even no garlic), this luscious soup is the perfect vehicle for whatever fresh herbs are in your garden. Try fresh bay leaf, sorrel, tarragon, thyme, or a combination.

• Although potatoes are the official star for Vichyssoise, I love adding other vegetables in a supporting role. Try using 2 pounds of potatoes and 1 pound of cauliflower, parsnips, carrots, pumpkin, or sweet potatoes. Your soup will still be deliciously creamy and have added flavor and color nuances.
• You might also want to try a combination of potatoes and sweet peas, asparagus, broccoli, spinach, kale, or other green vegetable or herb. In this case, add the supporting vegetable after the potatoes are fully cooked and then cook just until the green vegetable is tender. You want to obtain as much of the vibrant color as possible.
• Another easy way to change the character of this soup is to simply add a cooked, pureed vegetable after the vichyssoise is chilled.

• Potatoes are surprising high in acid, but this soup may benefit from a bit more in the guise of lemon juice, white wine, or even a drop or two of excellent vinegar. If you opt for the wine, be sure and add it with the stock to allow plenty of time to evaporate the alcohol.
• For dramatic effect, try layering two different colored soups in a clear glass to serve.

• Another beautiful effect can be obtained by first pouring one colored soup into a serving bowl, then carefully pouring an alternate colored soup directly in the center of the first pour. As you continue to do this, perfect concentric rings will form. This is pretty as is, or you can go further and drag the back of a butter knife through the rings to create a moiré effect.
• This soup is delicious gulped straight from a pitcher in the fridge in the middle of the night, but for a more elegant presentation pay attention to the colors, textures, and flavors of the garnishes. Some of my favorites are sautéed, diced pancetta; crumbled cooked bacon; snipped chives; homemade croutons, Seeded Bread Crisps; pesto; and rouille.

The Perfect Vichyssoise

Vichyssoise is one of the simplest and most versatile cold soups ever–basically a silky smooth puree of potatoes, onions or leeks, stock, and cream, well chilled. After you master the basic recipe, be sure to try the variations below.

4 tablespoons unsalted butter

4 cups cleaned, trimmed, sliced leeks (white and pale green portion only)
-or-
3 cups peeled, chopped yellow onions (13½ ounces chopped)

6 large garlic cloves, peeled and pressed or minced
3 pounds peeled, cubed russet potatoes (about 8 cups cubed or 4 large potatoes)
8 cups chicken or vegetable stock (or water for you purists out there), plus more as needed

2 cups heavy cream
freshly ground nutmeg, optional

Garnishes, optional (use 1 or more)
minced chives
minced fresh herbs
homemade croutons
heavy cream or crème fraiche
extra virgin olive oil
pesto
aioli or rouille

1. In a large soup pot, over medium heat, melt the butter.
2. Add the leeks (or onions) and cook slowly, stirring occasionally, without browning until softened and translucent, about 15 minutes. Add garlic and cook for an additional 5 minutes.
3. Add chicken broth, stir to incorporate, and then add potatoes.
4. Bring soup to a simmer, partially cover, and simmer slowly until potatoes are falling-apart tender, about 30 minutes. Remove from the heat.
5. Using an immersion blender, puree the soup in the pot until smooth. If you don’t have an immersion blender, let the soup cool enough to dip your finger into it without burning yourself. Using a blender, slowly, and in small batches (never filling the blender too full), with the lid on and tightly secured, puree the soup at high speed. Remove each batch to a large bowl. You will have about 12 cups of soup at this stage.
6. Return soup to the cooking pot and whisk in cream and nutmeg if using. Season with salt and pepper. Return to a boil, reduce to simmer and cook 5 minutes. If you want a thinner soup, add additional stock.
7. Transfer soup to the mixing bowl and chill over an ice bath, stirring occasionally. When soup is no longer hot, refrigerate to cool, then cover with plastic wrap for longer storage
8. When ready to serve, adjust the seasoning as necessary.
9. Ladle into chilled bowls and garnish as desired.

Makes 12-14 cups.

NOTE   This soup improves over time, as long as it is stored airtight in the fridge. It will keep for about a week.

Five Fabulous Vichyssoise Variations

Arugula Vichyssoise

• At completion of Step 5, stir in 2 cups of packed arugula and simmer for one minute.
• Proceed with the recipe.

Zucchini Vichyssoise

• At completion of Step 5, stir in 2 cups of diced zucchini and simmer for 5 minutes.
• Proceed with the recipe.

Cucumber & Lettuce Vichyssoise

• At completion of Step 5, stir in 2 cups of peeled, seeded, diced cucumber and 1 small head of trimmed butterhead lettuce. Simmer for 5 minutes.
• Proceed with the recipe.

Fennel Vichyssoise

• At completion of Step 5, stir in 2 cups of chopped fennel bulb and fronds. Simmer for 5 minutes.
• Proceed with the recipe.

Sweet Potato Vichyssoise

• At completion of Step 5, stir in 2 cups of peeled, cooked, pureed sweet potato.
• Proceed with the recipe.

Cookin’ with Gas (inspiration from around the web)

• Barbara Cooks: Vichyssoise (aka “Chameleon Soup”)
• Culinary Trends: Asparagus and Potato Vichyssoise with Blue Crab Salad
• Devour This: Zucchini, Tarragon, and Saffron Vichyssoise with Seared Scallop
• Epicurious: Arugula Vichyssoise
• F for Food: Buttermilk Vichyssoise with Fennel
• Food.com: Anthony Bourdain’s Les Halles Vichyssoise
• Foodgawker: Vichyssoise
• Kate in the Kitchen: A Cold Day to Honor Chilled Soup
• Keeping with the Times: Vichyssoise, Summer in a Cup
• Nom Nom: Vegan Vichyssoise with Cauliflower & Kale Chips
• Restaurant Girl: Dovetail’s Cucumber Vichyssoise
• Serious Eats: River Cottage Cucumber and Lettuce Vichyssoise
• The Kitchn: Arugula Vichyssoise from Epicurious
• Wikopedia: Vichyssoise

Happy Cooking!

Copy­right 2013 Susan S. Bradley. All rights reserved.