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Ultimate Guinness French Onion Soup

The addition of Guinness stout brings a deep, malty complexity to this classic soup, making it richer and more satisfying than the original. By properly caramelizing the onions and reducing the stout, this recipe builds layers of incredible flavor for a truly definitive version topped with perfectly melted Gruyère.

90 minServes 4mediumguinnessfrench onion soupsoupcomfort foodcheese
Ultimate Guinness French Onion Soup

Ingredients

  • 4 tbsp Unsalted Butter
  • 2 large Yellow Onions, thinly sliced
  • 2 large Sweet Onions, thinly sliced
  • 4 cloves Garlic, minced
  • 1 tsp Kosher Salt
  • 1/2 tsp Black Pepper, freshly ground
  • 2 tbsp All-purpose Flour
  • 1 cup Guinness Stout
  • 4 cups Beef Broth
  • 2 sprigs Fresh Thyme
  • 1 Bay Leaf
  • 8 slices Baguette, sliced into 1-inch rounds
  • 2 cups Gruyère cheese, shredded

Steps

  1. 1

    Melt the butter over medium-low heat in a large Dutch oven or heavy-bottomed pot. Add the sliced onions and stir to coat them in the butter.

  2. 2

    Cook the onions slowly, stirring occasionally, for 45-60 minutes, until they are soft, sweet, and deeply golden brown. Do not rush this process.

  3. 3

    Increase the heat to medium, add the minced garlic, salt, and pepper, and cook for one minute until fragrant.

  4. 4

    Sprinkle the flour over the onions and stir continuously for one minute to cook off the raw flour taste.

  5. 5

    Pour in the Guinness to deglaze the pot, scraping up any browned bits from the bottom. Bring to a simmer and allow the beer to reduce by about half.

  6. 6

    Add the beef broth, thyme sprigs, and bay leaf. Bring the soup to a gentle simmer and cook for 30 minutes to allow the flavors to meld. Remove the thyme sprigs and bay leaf before serving.

  7. 7

    While the soup simmers, set your oven to broil and arrange the baguette slices on a baking sheet. Toast them for 1-2 minutes per side until golden and crisp.

  8. 8

    Ladle the hot soup into four oven-safe bowls. Place two toasted baguette slices on top of each bowl and cover generously with shredded Gruyère cheese.

  9. 9

    Carefully place the bowls under the broiler for 2-3 minutes, or until the cheese is bubbly, melted, and lightly browned. Serve immediately.

Pro tips

  • Patience with caramelizing the onions is crucial. Their deep, sweet flavor is the foundation of the soup, so don't be tempted to crank up the heat to speed it up.
  • Reducing the Guinness is a key step to cook off any harsh alcohol notes and concentrate its signature malty sweetness.
  • For the smoothest, gooiest cheese topping, buy a block of Gruyère and shred it yourself. Pre-shredded cheeses contain additives that can prevent them from melting perfectly.
  • Placing your soup bowls on a sturdy baking sheet makes moving them to and from the hot broiler much safer and easier.