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
This might be the best brownie I have ever tasted. The recipe was super easy. The brownie came out rich and fudgey and the coffee in the frosting is a perfect match. I will make this over and over.
I love brownies but hate beer any kind …do you taste the beer in these?
Hi Baum, the Guinness adds a rich flavor to these brownies. You may love these homemade brownies without beer instead. Enjoy!
These sound delicious and I plan to make them for a party this weekend! Is the frosting thick enough to put in piping bag an pipe a swirl?
Hi Theresa, You should be able to make simple swirls. You can always add more confectioner’s sugar to thicken it up if needed for more intricate piping tips.
Hi I would like to know have you try to heat it up in the microwave before you serve?
Hi Caryn! If you leave your brownies unfrosted you can certainly heat up each individual brownie for a few seconds (depending on your microwave strength) to warm before enjoying.
Hi Sally. I’ve made these brownies a couple times now and the flavor is amazing! The first time my icing turned out perfectly but the last two times it seemed to almost separate? I’m not sure what I did differently. Could my butter be softened too much? Too much liquid? Other thoughts?
Hi Christine, it’s likely the butter is too soft– make sure it’s still cool to the touch. And reducing the liquid would also help. Glad you love these!
I love these brownies! I often use a local brew that is a chocolate peanut butter stout instead of Guinness. Is there a way to modify this recipe to make it in a 9×13 pan? My friends loke these so much, a 9×9 is sometimes not big enough for all of us
Made these last night for an Irish then night out family was doing, and they were delicious! Paired really well with a glass of Guinness too :). My frosting came out a little weird looking though. It was smooth at first but then maybe I mixed it for too long, and the texture ended up kind of grainy/bubbly looking. It still tasted great though!
these looked great and i was excited to make them, but i only own an 8×8 pan. i made these with your exact directions, but i ended up using guinness draft because that was all i had on hand. (also used a mixture of semisweet baking chips and leftover unsweetened baking chocolate, added a little sugar so that it all balanced out.)
baked them for about 34 minutes since they were a little thicker, kept checking every two minutes like you instructed, and at 40 minutes i just decided to pull them from the oven, as i was nervous about overbaking them. they still seemed to need more time. was getting strange mixed readings when pricking the brownies with a cake tester – in some spots it came out covered in batter, and in other spots it came out almost clean. (the middle appeared to be the most baked, oddly – it was the sides that looked to need more time.)
three whole hours of cooling time later, they were still slightly warm on the bottom – so i decided to cut and pull them from the pan to let them finish cooling that way, so i could make the frosting without waiting until tomorrow. to my horror, some brownies appeared to be perfectly cooked, some slightly undercooked and fudgy (but still edible) and a few had the consistency of mostly raw batter, falling apart in my hands!
what did i do wrong exactly? i know that an 8×8 yields thicker brownies than a 9×9, but does this surface area difference really change the baking process THIS much? why did the brownies end up differing so much in the same pan? i’d be glad to try to make these again if i at least figure that out.
Even though it’s only an inch smaller around all sides, that does make a big difference in baking– I really do recommend a 9-inch pan for these brownies. Smaller pan does mean thicker brownies as you know, but if the brownies are too thick, they may not ever bake properly without browning on top/around the edges. I’m not surprised the brownies needed longer time and if you try the recipe again in an 8-inch pan, tenting the pan with foil after about 20-25 minutes and extending the bake time will help. (Use a 9-inch square pan if you can though!)
Can I double this recipe for a 9×13 pan?
Absolutely! You can double this recipe for a 9×13 inch pan. We’re unsure of the exact bake time.
I’ve tried a lot of from-scratch brownies over the years, and to be honest never liked them as much as boxed brownie mixes. I decided to try these since Guinness is one of the only beers I like. Instead of the Guinness Extra Stout, I used a Guinness Nitro Cold Brew Coffee (beer with coffee). I kept the rest of the recipe exactly the same, even adding the espresso powder (although I didn’t make the frosting). And let me say… NEW FAVORITE BROWNIE!! I’m a little embarrassed to say that two of us ate half of the pan in less than 24 hours… but oh my they are DELICIOUS and totally worth it! Will 100% be making these again. Another amazing recipe, Sally!
Hello Sally, been following your recipes for a few weeks and all I can say is WHERE HAVE YOU BEEN ALL MY LIFE! Lol. I plan on making this recipe but I want to use coco powder in place of the chocolate bars. Is it possible to switch? If yes please let me know how. Thank you.
Hi Pearl, we’re so glad you’re enjoying out recipes! Using cocoa powder in these brownies would require more recipe testing. Best to stick with the recipe as written for best results but let us know if you try anything!
Hi Sally!
I tried this recipe and loved it! But my friends commented that they couldn’t really taste the Guinness flavour (well not as much as their expectation I guess). How would you recommend to improve on the Guinness flavour?
Hi Baun, We are so glad you loved the recipe! Your friends are right, the brownies do not taste like beer. The Guinness role is to intensify the chocolate and add a malty background flavor. You will taste it more in the frosting if you try that!
Thanks!
Also, I once followed all your steps and this recipe, but I ended up with very liquid-batter and it turn out to be too thin (even though I use the 8×8 square pan). Any advise on where I messed up? Should I reduce butter or egg?
AB. SO. LUTE. LY DELICIOUS!
Best brownies I’ve ever made. My husband has just eaten 3 in a row and I’ve had to hide them. This is such a great recipe. The only need-based changes I made were:
-Was out of vanilla so used bourbon instead in the batter. Why not?
-Replaced the vanilla in the icing with an extra spoonful of the Guinness.
-Icing was a bit too thick and I didn’t have milk, but I had kefir. I used that and I think the tang from the kefir added such a delicious taste to the icing that I will use it again next time. Maybe sour cream or greek yogurt or cream cheese would have a similar effect?
So. So. SO. Good.
I made this yesterday.. They should be called Edible Devils..I couldn’t find a bottle of Guinness, only a can, so used that. Also I had on hand semi sweet allergen free chocolate chips and dark chocolate chunks. I added 1 cup of sugar instead of the extra 1/4 and only made half the recipe of frosting…Reduced Guilt? LOL.. I had one for breakfast with coffee and soon after found myself on the treadmill with loads of energy. I have given a few bars out and the reaction is : omg..
I just made these with some leftover Guinness from St. Patrick’s Day. The espresso mixed with the hint of Guinness is INSANE! The frosting made such a difference too. I never knew buttercream could taste so amazing!
I made these for my co-workers for St. Patrick’s Day! Everyone absolutely loved them! I couldn’t find the Extra Stout, but the Stout worked just fine. I love the hint of coffee flavor with the espresso powder. The frosting is what really takes the brownie over the top!
Just made them this week with a home brew irish stout and they were amazing! Worth trying.
If you are torn on whether or not to make these, DO IT! I was hesitant at first, I mean beer in my brownies? No way! But I was curious so I tried them out for Saint Patrick’s Day and I am telling you, they were so freakin delicious! The brownie had such a rich, complex flavor! And the frosting?! I’m not a fan of frosting on my brownies but I was curious about how it would taste so I made it anyways and served it on the side. Absolutely fantastic! I’m not sure how Sally does it but she is the Dumbledore of baking magic! If you are the least bit considering making these, I highly recommend you do!
Our grocery store does not carry espresso powder, but has espresso instant coffee …could I substitute that with similar results?l
Hi Amy! You can, yes, but instant coffee powder isn’t quite as strong as espresso powder. You can increase the amount or simply expect a milder flavor.
OMG these are THE best brownies ever. I followed the recipe exactly. Definitely the only brownie recipe I’ll be using from now on!
Happy St Patrick’s Day 2021! I just made these and they are amazing!! I didn’t have a 9×9 pan so I used mini cupcake tins and baked at 350F on one rack for 15 minutes – it made 42 brownie bites. I also didn’t have espresso powder so I substituted Grind Espresso Shot Liqueur – swapped out half the vanilla in the batter; kept all vanilla in the frosting and added the liqueur by the half teaspoon until I got the flavor and consistency I wanted, about 2.5-3 tsp. WOW!!!!!
I are these a fudge chewy texture or it more cake like? If not, how do u make them to that texture?
They were fudgy in the middle and chewy/crunchy on the edges. Next time I plan to check at 13 minutes bc I want them less crunchy on the edges.
Hi Sally! This is me Laura, my husband is the baker in the house, a very good baker I may add….he made these Guinness brownies for our Irish dinner tonight. The flavor is so complex! A special brownie indeed. Made the frosting, tastes great as well….but his frosting looks a bite muddled, not smooth and shiny like your photo….what can we do to make it look as good as it tastes? Happy St Patrick’s Day! Laura
Hi Laura! We’re so glad you enjoyed these brownies. For smooth frosting, first make sure to beat the butter until creamy before adding the rest of the ingredients. Second, sifting your confectioner’s sugar can prevent the frosting from being grainy. Hope this helps for next time!
Fabulous complex flavor, wonderful for a special dessert, or St Patrick’s Day…..!
Hi. I don’t have espresso powder. Is there a substitute that can be used? Cocoa powder–or strong coffee in place of some of the liquid? I also plan to use Brooklyn Brewery Black Chocolate Stout–no Guinness on hand either!
Hi Barb! If you have instant coffee you could use that instead, but it isn’t quite as strong as espresso powder. You can increase the amount or simply expect a milder flavor. If you don’t have either, you can simply leave it out. Let us know how they go for you!
This recipe for brownies is fenomenal. I was looking for something special for staying home St. Patricks Day.. and here it is.. Perfect dessert.
Thank you so much for this idea!
Love this recipe! Can you reduce extra Guinness and store for later usage?
Hi Jennifer, I can’t see why not. So glad you enjoy these brownies!
Hello! I love your recipes! I am making these for St. Patty’s Day! Would it work to melt the chocolate and butter in the hot Guinness rather than the microwave?
Hi Sarah, we actually haven’t tested the recipe that exact way before but I’m sure it would be fine.
Thanks Sally for this recipe. I made a batch last night for a little market I supply bake goods to a couple of time a week. This morning I got a call for another batch. I give you credit for the recipe and every recipe I try of yours turns out perfect. Love the step by step directions and videos! Thanks so much!!!!
Hi,
Is there a reason you used the Extra Stout Guinness? Does the original Guinness not work because of the Nitro?
Any Guinness works!
Instead of unsalted butter can I use salted butter and then not add the salt?
Hi M, If you use salted butter, you can use 1/2 of the recommended salt.
These are delicious! Very subtle flavor on the Guinness. I don’t like espresso so didn’t use it, and they still were wonderful! To make it extra fun for St. Patty’s Day, I dyed the frosting green! Highly recommend adding that fun step.
I have almond bark will that work for the chocolate?
Hi Amber! You really want pure chocolate for this recipe, almond bark contains added oils.
That frosting is maybe the best part of the the brownie!
Hey Sally these look amazing and would be great for St. Patrick’s day but I really only need a smaller amount because it just my family. Is there a way I could 1/2 the recipe for an 8 x 8? And would you suggest rounding up on the eggs?
Hi Kate! You should be able to halve the recipe to bake it in a 9×4 loaf pan. They’ll be slightly thicker. Halving for an 8×8 pan would yield too thin brownies. Our general rule for halving an egg is to crack it open, beat the yolk and white together with a fork, measure the volume (should be a few Tbsp), then use half.