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For the Silkiest Mushroom Bisque, Add Egg Yolks

Learn how to make the best mushroom bisque using a French technique that gives you rich, ultrasmooth results without dulling flavor.

Published Feb. 3, 2023.

When I’m out to dinner, if I see any kind of bisque on the menu, I will order it. 

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Whether it’s lobster, shrimp, tomato or my favorite—creamy, earthy mushroom bisque—I’m on board. 

Bisque traditionally refers to a rich, creamy soup made with shellfish. Nowadays, the word is used to describe any dairy-enriched soup, shellfish-based or not, thats a step up in flavor and refinement from plainer creamed soups.

I love how a healthy (you know what I mean) dose of cream gives bisque its thick, velvety consistency.

But it can also work against some versions, making them taste flat. As usual, Andrea Geary has a fix for that. 

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Why Can Cream Make Bisque Taste Flat?

The fat droplets in cream thicken a liquid by getting in the way of water molecules and slowing their movement.

At the same time, the fat coats your tongue, preventing flavor molecules from reaching taste receptors, muting flavor. 

In Andreas mushroom bisque recipe, she wanted both ultrasatiny body and pronounced mushroom flavor. So she turned to an old-school French technique called a liaison.

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Why Does a Liaison Make Better Bisque?

Traditionally used to thicken creamy sauces, a liaison replaces a large portion of the cream with egg yolks. 

As the egg-enriched bisque heats, proteins in the yolks unfold and bond together into long, tangled strands. Just like the fat in cream, these interfere with the movement of water molecules. 

Egg yolks also contain the powerful emulsifier lecithin, which has a twofold effect: 

  1. It holds the fat droplets in smaller particles that disperse more completely throughout the liquid, obstructing more water molecules, for an even thicker consistency. 

2. It keeps the bisque smooth by holding the fat droplets suspended in the liquid so they don’t separate out. 

Essentially, the egg is a much more powerful thickener than cream alone, so you can use less—keeping that mushroomy flavor pronounced. 

If yolks can do all this, why even have cream in bisque? Because the fat it contains provides an appealing mouthfeel and consistency that just yolks can’t match.

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Mushroom Bisque Recipe

Serves 6 to 10

Time: 1½ hours

  • 1 pound white mushrooms, trimmed
  • 8 ounces cremini mushrooms, trimmed
  • 8 ounces shiitake mushrooms, stemmed
  • Kosher salt and pepper
  • 2 tablespoons vegetable oil
  • 1 small onion, chopped fine
  • 1 sprig fresh thyme, tied with kitchen twine
  • 2 tablespoons dry sherry
  • 4 cups water
  • 3½ cups chicken broth
  • ⅔ cup heavy cream, plus extra for serving
  • 2 large egg yolks
  • 1 teaspoon lemon juice
  • Chopped fresh chives

Before You Begin: Tying the thyme sprig with twine makes it easier to remove from the pot. For the smoothest result, use a conventional blender rather than an immersion blender. Our Fried Shallots can replace the garnish of cream and chopped chives.

  1. Toss white mushrooms, cremini mushrooms, shiitake mushrooms, and 1 tablespoon salt together in large bowl. Cover with large plate and microwave, stirring every 4 minutes, until mushrooms have released their liquid and reduced to about one-third their original volume, about 12 minutes. Transfer mushrooms to colander set in second large bowl and drain well. Reserve liquid.
  2. Heat oil in Dutch oven over medium heat until shimmering. Add mushrooms and cook, stirring occasionally, until mushrooms are browned and fond has formed on bottom of pot, about 8 minutes. Add onion, thyme sprig, and ¼ teaspoon pepper and cook, stirring occasionally, until onion is just softened, about 2 minutes. Add sherry and cook until evaporated. Stir in reserved mushroom liquid and cook, scraping up any browned bits. Stir in water and broth and bring to simmer. Reduce heat to low and simmer for 20 minutes.
  3. Discard thyme sprig. Working in batches, process soup in blender until very smooth, 1½ to 2 minutes per batch. Return soup to now-empty pot. (Soup can be refrigerated for up to 2 days. Warm to 150 degrees before proceeding with recipe.)
  4. Whisk cream and egg yolks together in medium bowl. Stirring slowly and constantly, add 2 cups soup to cream mixture. Stirring constantly, slowly pour cream mixture into simmering soup. Heat gently, stirring constantly, until soup registers 165 degrees (do not overheat). Stir in lemon juice and season with salt and pepper to taste. Serve immediately, garnishing each serving with 1 teaspoon extra cream and sprinkle of chives.

Cook along with Andrea as she makes her mushroom bisque in the video below. 



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