If you love rich chocolate desserts, these Guinness brownies are about to become your new favorite. They’re deeply fudgy, intensely chocolatey, and topped with a creamy Guinness-infused frosting. I promise you don’t have to like beer to love these St. Patrick’s Day-perfect brownies!
I originally published this recipe in 2018, and I’ve since updated it with new photos and extra success tips for consistently excellent results.
Before you worry—these brownies do not taste like beer. Instead, Guinness stout enhances the chocolate flavor with roasted, coffee-like notes and a hint of caramel sweetness. It’s the same reason stout is often paired with chocolate desserts, such as this Guinness chocolate cake. The flavors naturally complement each other.
These Guinness brownies are decadent and deeply chocolatey, but not overly sweet. A chocolate dessert for a grownup palate!
- Texture: dense, moist, and fudgy
- Flavor: dark chocolate with roasted malt notes
- Frosting: creamy, with hints of espresso and caramel
Why You’ll Love These Guinness Brownies
These brownies stand out from typical chocolate brownies because of their deep, complex flavor and ultra-fudgy texture.
Here’s what makes them special:
- Complex chocolate flavor: Guinness stout intensifies the pure melted chocolate with its roasted, coffee-like notes.
- Ultra-fudgy texture: Close in texture to my seriously fudgy homemade brownies.
- Creamy Guinness frosting: Light, smooth, and slightly espresso-forward with subtle malty caramel notes.
- A wonderful dessert recipe for St. Patrick’s Day… or anytime you’re craving a rich chocolate dessert!
What Does Guinness Add to Brownies?
Dark, smooth, and creamy, Guinness stout contains roasted barley, which contributes flavors similar to roast coffee, cocoa, and caramel. Guinness is often used in baking and almost always paired with chocolate. The two work well together because Guinness, like coffee, intensifies chocolate’s natural flavor.
- Have you ever had this chocolate cake with hot coffee in the batter before? It’s just like that.
Truly, you don’t have to like beer to love desserts made with Guinness! Desserts like my Guinness cupcakes don’t taste like beer. Rather, they have a more complex chocolate flavor with a malty background.
Reducing the beer first intensifies these flavors while preventing excess liquid in the batter. We take that same first step in this recipe for Guinness chocolate cake. More on this below!
Other Ingredients You Need
Besides a bottle of Guinness, the rest of the ingredients are all pretty typical brownie staples:
- Butter: You can make brownies with butter, oil, or both; but in testing, we liked these brownies best with all butter.
- Chocolate: Use 8 ounces (2 standard baking bars) of semi-sweet or bittersweet chocolate. Since this is the only chocolate in these Guinness brownies, use a good-quality brand—I typically use Ghirardelli brand.
- Sugar: Sugar does more than sweeten brownies. As the batter bakes, it liquifies to create a softer center and rises to the top, forming that shiny, crackly surface.
- Eggs: Eggs bind, add richness, tenderize, and provide structure. This recipe uses 3 eggs for a tight crumb and melt-in-your-mouth texture.
- Flour: More flour makes cakier brownies. For dense, fudgy brownies, you only need 1 cup.
- Salt & Vanilla: To balance all the flavors.
- Espresso Powder: Optional, but I recommend it for a deeper chocolate flavor. It’s added to both the brownie batter and frosting. You can find espresso powder in the baking or coffee aisle at the grocery store or online.
- Confectioners’ Sugar: For sweetening the frosting.
Why is there no baking powder or baking soda in these brownies? Adding baking powder or baking soda lifts brownies up and creates a cakier result. But today, we want a brownie so dense and fudgy that it’s basically 1 step up from eating pure chocolate—just like these seriously fudgy homemade brownies.
The Key Step: Reduce the Guinness
The secret to bold Guinness flavor in your brownies without ruining their texture is reducing the beer first. Simmering the beer concentrates its flavor while preventing excess liquid in the batter, so the brownies stay dense, moist, and perfectly fudgy instead of cakey.
By reducing a full bottle of Guinness on the stovetop, the water evaporates while the flavor intensifies. The result: malty stout flavor without compromising the brownie texture.
Here’s the process:
- Pour one bottle (or can) of Guinness stout into a saucepan.
- Let it simmer until it reduces to about 2/3 cup (takes about 20 minutes, totally hands off). This is less than half the liquid we started with, but triple the flavor.
- Let it cool slightly. Or reduce the Guinness in advance, and refrigerate until you’re ready to make the brownies.
This technique is similar to reducing fruit or champagne for baking—less liquid, more flavor. We do the same thing to concentrate strawberry flavor for strawberry cake, apple cider flavor for apple cider donuts, and champagne for champagne cake roll.
We’ll use 1/2 cup (120g/ml) of reduced Guinness in the brownie batter, and the remaining 2 and 1/2 Tablespoons (40g/ml) in the frosting.
How to Make the Best Guinness Brownies
Once you’ve reduced the Guinness, the batter comes together quickly.
Melt the butter and chocolate together to create a smooth base for these dense, fudgy brownies. It helps to cut the butter into pieces so it melts evenly. You can use the microwave or stovetop. Whisk in the sugar and the reduced Guinness, then the eggs and vanilla, and finally the dry ingredients. The batter will be thick and shiny.
Spread it into a lined 9-inch square metal baking pan (not glass or ceramic) so the brownies bake evenly.
Guinness Frosting
The brownies are fantastic on their own, but their decadent nature begs for something creamy. While you could enjoy a creamy pint of Guinness alongside these brownies, I prefer topping them with this Guinness frosting instead!
It’s creamy, lightly sweet, and flavored with more of the reduced Guinness, espresso powder, and vanilla.
The flavor is hard to describe but completely delicious—espresso-like with subtle malty, caramelized notes from the stout.
These Guinness brownies would also be fantastic topped with vanilla ice cream, homemade whipped cream, or the mocha whipped cream from my flourless chocolate cake recipe.
No. Guinness brownies do not taste strongly like beer. Instead, the stout enhances the chocolate flavor with subtle roasted notes similar to coffee or dark caramel. The result is a richer, deeper chocolate brownie rather than a beer-flavored dessert.
Classic Guinness Draught stout works best for baking brownies. It has a smooth, slightly roasted flavor that complements chocolate. Extra stout or other dark stouts can also work, but they may produce a slightly stronger malt flavor.
No. Reducing Guinness concentrates its flavor while removing excess liquid. Brownie batter can easily become too thin if extra liquid is added, which can lead to cakey or gummy brownies. Simmering the stout first ensures the brownies stay dense, moist, and fudgy.
Yes. Although the brownies contain Guinness, the alcohol content is reduced during simmering and baking. If you prefer an alcohol-free version, you can substitute a stout-style nonalcoholic beer for a similar flavor.
Brownies are done when a toothpick inserted in the center comes out with a few moist crumbs—not coated in wet batter (underbaked), and not completely clean (overbaked). Overbaking can make brownies dry, so it’s best to remove them from the oven when the center is just set.
Guinness Brownies
- Prep Time: 45 minutes
- Cook Time: 35 minutes
- Total Time: 3 hours
- Yield: 16-20 brownies
- Category: Brownies
- Method: Baking
- Cuisine: American
Description
These Guinness brownies are made from reduced Guinness Stout. They’re fudgy, rich, and topped with espresso- and Guinness-infused frosting!
Ingredients
- one (11.2–12-ounce (330–355ml) bottle Guinness Draught Stout beer
- 3/4 cup (12 Tbsp; 170g) unsalted butter
- two 4-ounce bars (226g) semi-sweet chocolate, coarsely chopped*
- 1 and 1/4 cups (250g) granulated sugar
- 3 large eggs, at room temperature
- 1 teaspoon pure vanilla extract
- 1 cup (125g) all-purpose flour (spooned & leveled)
- 1/2 teaspoon salt
- optional: 1/2 teaspoon espresso powder
Guinness Frosting
- 1/2 cup (8 Tbsp; 113g) unsalted butter, softened to room temperature
- 2 cups (240g) confectioners’ sugar
- 2–3 Tablespoons reduced Guinness (from step 1)
- 1 teaspoon espresso powder
- 1/2 teaspoon pure vanilla extract
- 1/4 teaspoon salt
Instructions
- In a small saucepan, bring the Guinness to a boil over medium-high heat. Once boiling, reduce to medium heat and allow to simmer until reduced down to 2/3 cup (160g/ml), about 12–15 minutes. Set aside to cool for at least 10 minutes. You will use 1/2 cup (120g/ml) in the brownies and the rest in the frosting.
- Preheat the oven to 350°F (177°C) and grease a 9-inch square baking pan or line with aluminum foil or parchment paper, leaving an overhang on the sides to lift the finished brownies out (makes cutting easier!). Set aside.
- Place the butter and chopped chocolate in a large microwave-safe bowl. Melt in 30-second increments, whisking after each, until completely smooth. Whisk in the sugar and 1/2 cup (120g/ml) of reduced Guinness until completely combined. Whisk in the eggs and vanilla extract. Finally, whisk in the flour, salt, and espresso powder (if using). The batter will be thick and shiny. Pour/spread evenly into prepared pan.
- Bake for 32 minutes, then test the brownies with a toothpick. Insert it into the center of the pan. If it comes out coated with wet batter, the brownies need more time. If there are only a few moist crumbs, the brownies are done. Keep checking every 2 minutes until you have moist crumbs. My brownies take about 35 minutes.
- Remove from the oven and place on a cooling rack to cool completely in the pan before frosting or cutting.
- Make the frosting: In a large bowl using a handheld or stand mixer fitted with a whisk attachment, beat the butter on high speed until completely smooth and creamy, about 2–3 minutes. Add the confectioners’ sugar, beating on low at first then increasing to high speed. Once creamy and combined, beat in 2 Tablespoons of reduced Guinness, the espresso powder, vanilla extract, and salt. Taste. Add the remaining reduced Guinness if needed. If you want the frosting a little thinner, beat in a splash of milk.
- When cool, lift the brownies out by gripping the parchment overhangs and transfer to a cutting board. Spread frosting over cooled brownies. Use a sharp knife to cut into squares.
- Cover and store leftover brownies at room temperature for up to 1 week.
Notes
- Make Ahead Instructions: Freeze frosted or unfrosted brownies up to 3 months. Thaw overnight in the refrigerator then bring to room temperature before serving.
- Special Tools (affiliate links): Electric Mixer (Handheld or Stand) | Glass Mixing Bowls | Whisk | Saucepan | 9-inch Square Baking Pan | Icing Spatula
- Chocolate: You can find 4 ounce chocolate baking bars in the baking aisle. I like using Ghirardelli brand or Baker’s brand. You can use 8 ounces (heaping 1 and 1/3 cups) of quality chocolate chips instead, such as Ghirardelli brand.
Reader Comments and Reviews
I’m upgrading my initial review. My 1st impression was not good. But a day later, after refrigerating, they r like fudge. Sooo much better. I think I prefer traditional brownies but these r great for St Patrick’s Day or anytime u want to change it up.
I previously commented however didn’t post those well deserved 5 stars. I also tested with toothpick; however used thermometer and baked to 185-190 degrees. They were so moist
So good! They had a great flavor and texture, will definitely be making again!! I doubled recipe and baked in a 10″ x 15″ pan and they came out perfect!
I made these and while the taste was mouth watering they are the driest brownies I’ve ever made. I baked them for 32 minutes @ 350 in a 9×9 metal pan. The only change I made was using 8 ounces of organic dark chocolate chunks (Vons O organics brand) because I don’t eat soy lecithin and I couldn’t find a semi sweet bar without it. Any tips for next time? We have to drink water with them just to get them down; it’s so weird!
Hi Rachael, we’re happy to help troubleshoot! They should certainly be nice and chewy, not dry at all. How did you measure your flour? Be sure to spoon and level (or use a kitchen scale) to ensure the flour isn’t over measured, which can significantly dry out the brownies. For next time, you can also try decreasing the bake time a bit. We haven’t tested that particular chocolate to know if that is contributing at all. We hope this helps for your next batch!
These are soo good. Super fudgy and rich. The icing is incredible!!!
A huge hit last evening with the family! Moist and delicious with a mocha flavor! I will make them again very soon!
Served these as part of our St. Patrick’s Day celebration meal. Delicious.
The Guinness reduced far quicker than the 20 minute guideline, and the brownies were over baked at 30 minutes (my oven runs true to temperature). Next time I will bake them for 25 minutes, so they are more gooey-like.
I only used 1 1/2 cups of icing sugar for the icing. It was perfect and silky smooth. I did use a stand mixer and ensure the butter was well whisked and added the sugar in 1/2 cup increments, followed by the remaining ingredients.
Great flavour.
These brownies are amazing. A nice alternative to pure chocolate brownies Unique taste that’s truly out of this world. Serving them chilled is my favorite. Another winner, Sally!
Absolutely amazing! My husband and I agreed that we need these every St. Paddy’s day from now on.
Flavor was great – but so disappointing that it didn’t cook through in almost 40 minutes. Toothpick came out clean, but when I went to cut it, the inside was raw and I ended up having to microwave it to be able to eat it.
Made to take to friends house for st pattys day dinner. They are the best brownies I’ve ever made. Everyone loved them. Your directions were spot on.
I made as written and doubled
and recipe. I recommend waiting till then next day to serve, the brownies firmed up nicely and had a richer and more flavorful taste the next day! Remained delightfully fudgey too. I made these for a party and they were a huge hit, everyone loved them. This recipe is a keeper.
I’m planning on making these in a few days for St. Patrick’s day. I’m not a Guinness drinker, so I have a question. All of the recipe notes just say Guinness, but the recipe photo is Guinness Extra Stout. Do I use the classic Guinness or the Extra Stout Version?
Hi Rachael, any Guinness works!
Does it matter which type of Guinness I use? Stout, extra stout?? I didn’t notice if the recipe specified. Thanks.
Hi Iris, we usually use Guinness extra stout, but any will work here.
Are the eggs suppose to be room temperature?
Hi Nancy, yes, that is ideal here. Enjoy the brownies!
I would like to double this recipe for a 13×9-inch pan. Can you double the ingredients, or are there adjustments? Also, what is the baking time?
Hi Pam, you can absolutely try doubling this recipe for a 9×13 pan. We’re unsure of the exact bake time — use a toothpick to test for doneness. If there are only a few moist crumbs, the brownies are done.
These are amazing, fudgy — and the expresso compliments the guinness. Best brownies ever!
Will this recipe scale up linearly? I cook for a church crowd, any baked goods have to serve about 35 people.
Hi Jake, you can absolutely try doubling this recipe for a 9×13 pan. We’re unsure of the exact bake time — use a toothpick to test for doneness. If there are only a few moist crumbs, the brownies are done.
Brownies were delicious. Family all thought it was the best brownie they have had in a long time…took about 38 min to cook through. Was my first time using the expresso powder and was pleasantly surprised. Not sure that I would make frosting again though, only my daughter liked it. I kept frosting separate. Will definitely make the brownies again!
Can you freeze these and put frosting on after defrosting?
Sure can, Bernadette!
Hi, would it be possible to make it gluten free? 🙂
Hi Dominik, we haven’t tried these gluten free, so we’re unsure of the results, but let us know if you do!
We loved this recipe! So delicious. I was wondering if I could thin out the frosting to make more of a glaze. Do you think adding a bit more milk or more of the reduced Guinness would work, or should I reduce the amount of sugar? Any suggestion is appreciated!
Hi A, it may take a bit of tinkering, but a combination of both should do the trick! Start with a little less confectioners’ sugar, then add more milk/Guinness if you need to thin it out further.
Question – have made this recipe countless times to rave reviews..per Sally’s suggestion have added a teaspoon of baking powder as I prefer a “cakey” brownie..recently have found brownies are still fudgy despite the baking powder…any ideas on what I am doing different…over mixing?? Other? Many thanks!
Hi Lucille, over mixing could be the culprit if they’re still seeming extra fudgy. Glad this one is a favorite for you!
OMG, so decadent and flavorful! Thanks for the great recipe. Next time, I’m cutting the sugar in half. Just too sweet for me, but they are a hit! And that frosting…it took them to another level!
This is a great recipe. I’ve made it quite a few times always get rave reviews. I made 75 of them for my mom’s celebration of life a few years ago and the pastor emailed me the next day to let me know that many of the attendees asked him to get the recipe.
I wanted to comment that to make a 9×13 I use 1 1/2 times the recipe and baking for about 30 minutes has worked well for me. This time I used Belching Beaver peanut butter milk stout rather than guiness and a small amount of PB 2 in the frosting. So good!!
I’ve made these a few times and they turn out great. This last time I made them in mini muffin tins because I find them a bit difficult to cut and thought that would be fun. I reduced the bake time and they turned out perfect! Topped with the icing and some green sprinkles for St. Patrick’s Day. After seeing another comment about making half the icing I did the same thing, and that was the perfect amount. I love that these are rich and chocolatey but not super sweet.
Hi Sally! Haven’t made it yet but will soon. Curious if you have ever made this in mini muffin tins for brownie bites. They are easier/ neater to take to a gathering
Can’t see why not!
Not sure if I’ve already rated this 5 stars, but even if I did, it deserves a second perfect rating!!! Any time I’ve made this, it turns out amazing…the reduced Guinness gives it the most wonderful flavor
I am a chef- this recipe is slammin! Great intense flavor yet the malted caramel and espresso shine! I used 4oz Baker’s German Chocolate bar and 4oz Lily’s milk chocolate, 1.5 bottles of regular Guinness and a double shot of fresh brewed espresso from my fav local coffee shop. The frosting: I used 1c. Sifted powdered sugar. I am lactose intolerant so I used Country Crock plant butter sticks and omitted the salt for the batter and frosting. Placed a gentle amount of frosting on the top of the brownies and drizzled melted Lily’s chocolate chips over top. Once it set up, the Lily’s made a nice little intense chocolate crunch to it. Candied walnuts or pecans would be good if chopped although it would steal the true notes of the malt. Served with Guinness/killians irish red. Yeah buddy!
Hi! How do you use the espresso shots instead of espresso powder? Do you combine it with Guinness and reduce it together?
OMG! amazingggg