A recipe for Guinness Onion Soup! Caramelized onions are served in a savory Guinness broth with toasted bread and bubbly Irish cheese.
This St. Patrick’s Day, give your onion soup a little Irish-inspired twist with the addition of Guinness, whiskey, and Irish cheese!
Thinly sliced onions are slowly caramelized in butter and olive oil until a deep golden brown color. Deglaze the pot with the Irish whiskey, then pour in the Guinness and allow to simmer until reduced. Mix in the beef broth along with the Worcestershire sauce, bay leaf, and fresh thyme. Allow the mixture to continue to simmer to create a flavorful, rich broth.
Immediately before serving, top each bowl with bread, a large handful of shredded Irish cheese, and broil until golden and bubbly.
A Few Tips
To caramelize the onion slices, cook over low to medium low heat until a deep golden color and softened. Don’t rush the process by turning the heat up. It takes time for the flavor to develop, around 45 minutes.
I cut the baguette into 1/2 inch (1.25 cm) thick slices, but you can also cut the bread into cubes, toast, and just cover the top of the soup in an even layer.
Don’t be shy with topping the bowls with a large handful of shredded Irish cheese. While broiling, it will quickly melt to create a thin, bubbly layer. Make sure the bread is completely covered by the cheese to keep it from burning. I have been able to find Irish cheese in the specialty cheese section of most larger grocery stores. If unavailable, substitute with a sharp white Cheddar.
Take care when serving. The bowls (make sure they are broiler-safe) will be very hot coming straight from under the broiler.
For a vegetarian version, use mushroom or vegetable broth instead of the beef. Season with salt as needed depending on the amount in the stock.
Looking for more Guinness-based recipes?
This recipe was originally published March 2015 and updated March 2021.
Guinness Onion Soup Recipe
Adapted from Seeded at the Table
Guinness Onion Soup
- 1 tablespoon olive oil
- 1 tablespoon (15 grams) unsalted butter
- 3 large onions peeled and thinly sliced
- Salt and pepper to taste
- 2 garlic cloves minced
- 1/4 cup (60 milliliters) Irish whiskey
- 1 1/2 cups (355 milliliters) Guinness
- 6 cups (1.5 liters) beef stock
- 1 tablespoon Worcestershire sauce
- 3 sprigs fresh thyme
- 1 bay leaf
- 1 baguette
- 8 ounces (227 grams) Irish cheese such as Dubliner, shredded
- Fresh parsley or chives for garnish, optional
- In a large pot, place the olive oil and butter over medium-low heat. Once the butter is melted, add the onions, sprinkle with a pinch of salt, and cook, stirring occasionally, until softened and deeply golden, around 45 minutes. Adjust the heat as needed between medium low and low to keep the onions from burning before they get a chance to caramelize.
- Stir in the garlic and cook just until fragrant, 30 seconds to 1 minute.
- Increase heat to medium-high. Pour in the whiskey and stir, scraping up the browned bits from the bottom of the pan. Add the Guinness and simmer until reduced by half.
- Pour in the beef broth followed by the Worcestershire sauce, thyme, and bay leaf. Season with salt and pepper and bring to a boil.
- Reduce to a simmer and cook for another 30 minutes, stirring occasionally, to allow the flavors to blend. Remove the bay leaf and thyme stems. Adjust seasonings to taste.
- While the soup is cooking, slice the baguette into 1/2 inch (1.25 cm) thick slices and toast under a broiler until golden.
- Divide the soup among broiler safe bowls. Top each with a toasted slice or two of baguette. Cover with a large handful of shredded Irish cheddar cheese. Place bowls on rimmed baking sheet and broil until the cheese is melted and starting to brown and bubble.
- If desired, top with fresh parsley or chives and serve immediately with the remaining slices of baguette for dipping.