These Guinness Brownies with Frosting are a decadent, fudgy treat that pairs the deep, roasted notes of stout with rich chocolate. The brownies are moist and glossy in the center, with a slightly crackled top and a velvety buttercream that carries a gentle Guinness tang. On the nose you will notice malt and coffee-like aromas, while the espresso powder, if used, intensifies the mocha undertone. This recipe is ideal for cozy gatherings, St. Patrick’s Day, or any time you want a grown-up dessert that still feels comforting. If you enjoy pairing mains and desserts for a full menu, try a savory option like baked caesar chicken with creamy parmesan pasta with these brownies for a memorable meal.

Ingredients

• 11.2–12-ounce bottle Guinness Draught Stout beer, brings the signature stout flavor and moisture to the batter; you will reduce it first.
• 3/4 cup unsalted butter, provides richness and a tender crumb when melted with the chocolate.
• 8 ounces semi-sweet chocolate, coarsely chopped, gives deep chocolate flavor and a fudgy texture.
• 1 and 1/4 cups granulated sugar, sweetens the brownies and helps create a glossy top.
• 3 large eggs, at room temperature, add structure and help create a dense, fudgy interior.
• 1 teaspoon pure vanilla extract, rounds and lifts the chocolate flavors.
• 1 cup all-purpose flour, provides the structure while keeping the brownies tender.
• 1/2 teaspoon salt, balances sweetness and enhances chocolate flavor.
• 1/2 teaspoon espresso powder (optional), boosts chocolate intensity and adds a mocha note if you choose to use it.
• 1/2 cup unsalted butter, softened to room temperature, for the frosting base to make it creamy.
• 2 cups confectioners’ sugar, sweetens and thickens the frosting for a smooth spreadable texture.
• 2–3 tablespoons reduced Guinness, adds a light stout flavor to the frosting and adjusts consistency.
• 1 teaspoon espresso powder, in the frosting to echo and deepen the chocolate and stout notes.
• 1/2 teaspoon pure vanilla extract, for flavor balance in the frosting.
• 1/4 teaspoon salt, cuts sweetness and enhances the other flavors in the frosting.

Step-by-Step Instructions

1. Reduce the Guinness. In a small saucepan, bring the Guinness to a boil over medium-high heat, then reduce to medium and simmer until reduced to 2/3 cup, about 12 to 15 minutes. Cool for at least 10 minutes before using. Tip: watch it closely near the end to prevent burning.
2. Prepare the oven and pan. Preheat the oven to 350°F (175°C) and grease a 9-inch square baking pan so the brownies release easily.
3. Melt chocolate and butter. Place the 3/4 cup unsalted butter and the coarsely chopped chocolate in a microwave-safe bowl and melt in 30-second increments, whisking between bursts until smooth. Let cool slightly.
4. Combine sugar and Guinness. Whisk the granulated sugar into the melted chocolate and butter, then whisk in half of the reduced Guinness. Mix until uniform. Add the eggs and the vanilla extract and whisk until glossy and slightly thickened.
5. Add dry ingredients. Add the all-purpose flour, salt, and the 1/2 teaspoon espresso powder if using. Whisk just until combined and the batter is thick and shiny; avoid overmixing to keep the texture dense and fudgy.
6. Bake the brownies. Pour the batter into the prepared pan and bake for 32 minutes. Insert a toothpick into the center; it should come out with a few moist crumbs, not completely clean.
7. Cool completely. Allow the brownies to cool fully in the pan on a wire rack before frosting so the buttercream does not melt. While they cool, you can review a savory recipe to serve alongside, such as baked feta eggs with tomatoes and spinach.
8. Make the frosting. Beat the 1/2 cup softened unsalted butter until smooth, then gradually add the 2 cups confectioners’ sugar. Mix in the remaining reduced Guinness, 1 teaspoon espresso powder, 1/2 teaspoon vanilla extract, and 1/4 teaspoon salt until smooth. Adjust thickness with 2 to 3 tablespoons of the reduced Guinness as needed. Tip: add the Guinness tablespoon by tablespoon to avoid a runny frosting.
9. Frost and cut. Spread the frosting over the cooled brownies with an offset spatula and allow it to set. Once set, cut into squares with a sharp knife.
10. Store. Keep brownies covered at room temperature for up to 1 week.

Recipe Details

• Prep Time: 25 minutes active, plus 12 to 15 minutes for reducing Guinness and 10 minutes cooling.
• Cook Time: 32 minutes baking.
• Total Time: Approximately 1 hour 12 minutes, including reduction and cooling time.
• Servings: Makes about 16 squares when cut into 9-inch pan portions.
• Calories: Approximately 360 calories per brownie square. This is an estimate and will vary by portion size.

Tips, Storage and Variations

• Tip: Let the reduced Guinness cool before adding to chocolate to avoid seizing.
• Tip: For fudgier brownies, slightly underbake and allow them to finish setting as they cool.
• Storage: Store the frosted brownies covered at room temperature for up to 1 week as directed. Keep them airtight to preserve moisture.
• Freezing: Wrap uncut, cooled brownies tightly in plastic wrap and foil and freeze for up to 3 months. Thaw overnight in the refrigerator or at room temperature before serving. Frosting can be added after thawing if preferred.
• Flavor variations using existing ingredients only:
  • Omit the 1/2 teaspoon espresso powder in both batter and frosting for a milder chocolate flavor.
  • Increase the espresso powder in the batter and frosting for a stronger mocha profile.
  • Use 2 tablespoons of reduced Guinness in the frosting for a subtler stout note or 3 tablespoons for a bolder taste.

FAQ

1. Can I use a different stout for Guinness?
   Yes, you can use another stout, but flavor and sweetness may vary slightly. The reduction step remains the same.
2. Do I have to use the espresso powder?
   No, the espresso powder is optional. It enhances chocolate depth but is not required.
3. Why reduce the Guinness first?
   Reducing concentrates the flavor and removes some water so it does not thin the batter or frosting.
4. How do I know when brownies are done?
   A toothpick should come out with a few moist crumbs after 32 minutes; do not expect a completely clean toothpick.
5. Can I make the frosting thicker or thinner?
   Yes, adjust the amount of reduced Guinness between 2 and 3 tablespoons to reach your preferred consistency.
6. Are these brownies suitable for room temperature storage?
   Yes, they store well at room temperature when covered for up to one week.

People Also Ask

1. What makes Guinness brownies taste different from regular brownies?
   Guinness adds roasted malt and subtle coffee-like notes that deepen the chocolate flavor.
2. Can I skip the reduction step and add the beer straight in?
   Skipping reduction may add excess liquid and a weaker flavor; reduction concentrates flavor and prevents a runny batter.
3. Will the beer make the brownies bitter?
   The reduced Guinness adds depth rather than bitterness; the sugar and chocolate balance it.
4. How should I warm leftover brownies?
   Warm briefly in a low oven or microwave on medium for 10 to 15 seconds to revive softness.
5. Can I halve this recipe?
   Yes, you can halve ingredients and bake in a smaller pan, but baking time may change.
6. What pan size is best for these brownies?
   A 9-inch square baking pan gives the intended thickness and bake time.
7. Is it necessary to let brownies cool before frosting?
   Yes, cooling prevents the frosting from melting and sliding off.
8. How can I make the frosting more chocolatey without adding chocolate?
   Increase the espresso powder slightly to intensify the chocolate perception without adding new ingredients.

Conclusion

These Guinness Brownies with Frosting are a crowd-pleasing, slightly grown-up dessert that balances rich chocolate with stout and coffee notes. They are forgiving to make and store well, so they are perfect for parties or a comforting treat at home. For a similar take and extra baking notes, see Guinness Brownies – Sally’s Baking Addiction, and for a variation that includes a cream cheese twist, read Guinness Chocolate Brownies Baileys Frosting. I hope you enjoy making and sharing these brownies; please leave feedback or photos so others can enjoy them too.