I asked readers about St. Patrick’s Day dessert recipe requests recently. The outpouring of “anything with Guinness” convinced me to pick up a 6-pack and begin recipe testing. My kitchen smelled like a brewery at 9 a.m. on a Tuesday morning, but the result was well worth my boozy wake up call.
Before you run away at the thought of beer brownies, let me explain. These Guinness brownies do NOT taste like beer. Guinness stout, with its roast coffee and caramelized flavors, is often paired with chocolate in baking. They’re a natural duo because Guinness not only intensifies chocolate, but adds a malty background.
A quick internet search for “Guinness brownies” will spew out a million results. Even still, I wanted to try my hand at this popular dessert because even though brownies seem pretty basic, it’s difficult to maintain a desirable texture when you begin adding all sorts of stuff. And I was ready for the challenge.
Let’s Talk Flavor + Texture
Dark chocolate comes to mind first. These Guinness brownies aren’t overly sweet, so you’ll find yourself grabbing another. (If it’s not the brownies that are addicting, it’s the frosting. More on that below!) If we’re talking texture, they’re very dense and very moist. In fact, they’re the moistest brownies I’ve ever baked… because they’re the only brownies I’ve ever baked with Guinness! Unlike my chewy fudgy frosted brownies, these Guinness brownies are not particularly chewy. They taste like fudge. A square of dark chocolate fudge.
How It Works
To impart enough flavor into the brownies, we’d have to use a lot of beer. But adding liquid to brownies makes absolutely no sense. So let’s take what we learned from homemade strawberry cake and reduce the beer down on the stovetop first. The heat evaporates the liquid, but leaves the flavor. Little liquid, lots of flavor, won’t turn our brownies into cake. We also do this with champagne in mimosa cupcakes. And I do the same thing with my Guinness chocolate cupcakes and Guinness chocolate cake, too!
This step is really easy and requires zero effort from you. Pour an entire 12 oz bottle of Guinness into a saucepan. (The whole bottle! Nothing to waste!) Leave it alone to simmer for 20ish minutes, until it’s reduced down to 2/3 cup. This is less than half the liquid we started with, but triple the flavor.
We’ll use 1/2 cup of reduced Guinness in the brownie batter and the remaining 2 and 1/2 Tablespoons in the frosting.
The rest of the brownie ingredients are usual suspects. Butter, sugar, eggs, flour. Instead of cocoa powder, we’re using pure solid chocolate. Sometimes I use a combination of pure chocolate AND cocoa powder in homemade brownies, but I wanted to keep things really simple since we’re taking extra time to reduce beer on the stove.
Besides Guinness, you know what else intensifies chocolate’s flavor? Coffee. I add espresso powder to both the brownie batter and frosting on top. It’s optional, but if you really want a deep dark chocolate brownie, don’t leave the espresso powder out. You can find it in the coffee aisle at the grocery store or online.
Guinness Frosting
The brownies are great alone, but better with this frosting. Their decadent nature screams for something creamy! (That being said, eat one with a pint of Guinness in the other hand.)
This caramel colored frosting is an interesting flavor. Interesting in a good way! It’s mostly espresso flavored, though there are lingering notes of maple too. Not sure how it tastes like maple, but I suspect it’s the combination of reduced Guinness, vanilla, and confectioners’ sugar. Whatever the reason, it’s SO GOOD because it’s SO DIFFERENT.
Other St. Patrick’s Day Recipes
- Mint Chocolate Brownies
- Guinness Brownies
- Lucky Charms Treats
- Baileys and Coffee Cupcakes
- Irish Soda Bread
- Mint Chocolate Swirl Bark
- St. Patrick’s Day Cookies
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 powder and Guinness infused frosting!
Ingredients
- one 12-ounce (355ml) bottle Guinness 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
- 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, about 20-22 minutes. Set aside to cool for at least 10 minutes. You will use 1/2 cup 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 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 with wet batter, the brownies are not done. 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 wire rack to cool completely before frosting or cutting into squares.
- 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, add a splash of milk.
- Frost cooled brownies.
- 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 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 had my doubts when I thought I may have undercooked this and the frosting was not like any frosting I’d made before but these were SO good! It’s pretty easy and quick to throw together. I’ll definitely be making these again.
Loved the texture and bitterness of the brownie! My only adjustment was melting the butter in the baking pan till very lightly browned and then pouring that over the chopped chocolate (I used 65% Cordillera – look them up, much better choice for the environment and working conditions!)
For me though, the frosting was just not needed. It was sooooooo sweet, and I did add a Tbls of cocoa to try to counteract it, but who needs the frosting really? The brownies are just fantastic as is.
Go raibh maith agat!
Hey there, do you think these would do alright if I made them in a muffin tin with a shorter cooking time?
Hi Katherine, we can’t see why not!
I have a bag of Ghirardelli melting chips on hand…can I use those for the chocolate part? Just trying to avoid a trip to the store. Thanks.
Yes, those should work. Enjoy!
I want to bake today and frost tomorrow, can the reduced guinness sit overnight before going into the frosting?
Definitely! We would refrigerate overnight and bring back to room temperature before using in the brownies and frosting.
Am I the only one having trouble “Saving the Recipe”? Not a problem with saving your other recipes. Just wondering.
Hi Elaine, We tested it and it seems to be working for us. Let us know if you are still having problems!
I love this brownie recipe! I’m a bit of a chocolate freak, so I was wondering if I could make a chocolate version of this frosting. I was thinking about adding unsweetened cocoa powder to it. What do you think
Hi Niki, you can certainly try adding some cocoa powder to the frosting. You’ll likely need to tinker with the confectioners’ sugar amount a bit. Let us know what you try!
I love the taste but I made a bit of a mess when trying to slice into squares. Do you have any tips on how to get clean cuts for a pretty presentation? Thank you!
Hi Nicole, Using a super sharp knife and wiping it clean between cuts will help!
My sister-in-law told me to cut brownies with a plastic knife … don’t know why, but it works like a charm every time!!
Forgot to leave a five star rating in my review!!!
The brownies turned out fantastic! Not too sweet with the right hint of tasty Guinness. My icing turned out grainy no matter how long I beat it. Is there another way to fix or avoid grainy icing? Thanks for the recipe!!!!
Hi Tracey, we’re so glad they were a hit! 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!
No matter what I try, glass, metal, aluminum foil, parchment paper, no lining, I can’t cook these brownies. The outside will burn but the inside will be raw and they are in the oven for 3 hours. I made them once and they were amazing but I can’t get the recipe to work again and am very disappointed. Any advice?
Hi Sara, we’re happy to help troubleshoot. Are you making any changes to the ingredients by chance? It’s normal for the edges of brownies to bake quicker and be a bit different in texture from the middles, but if you find them baking too quickly then you can tent the edges of the pan with aluminum foil while keeping the middle exposed. This will allow it to continue baking through. Hope this helps!
Great recipe! I subbed 26 grams of the semi-sweet for unsweetened chocolate. FYI to the team, as with many products, Guinness has “shrunk” their bottles of stout to 11.2 ounces instead of the old 12 ounces. You may want to adjust your recipe accordingly.
Omg! Best brownies ever!
These are fantastic! Everyone I’ve shared them with LOVES them and wants more. I doubled the last batch I made and put in a 9×13. But, in my opinion, it really needs to go into a 10×15. The brownies were really thick and became more cake like in the 9×13. Technically, the math works out for that. FYI to anyone who wants to double the recipe.
This turned out just ok, I followed the recipe exactly including espresso powder, and used ghirardelli chocolate. The brownie texture is semi-cakey, lacks crisp edges, and doesn’t have an intense chocolate flavor. The frosting is aggressively sweet. Overall it’s not bad but not one I’d make again.
Made these after a friend shared the recipe. Definitely recommend using really good chocolate – you will taste the difference. I also used non-alcoholic Guinness and it was great. Made into a giant brownie for a bday cake. And made some for a party and people asked to take them home. Really good! The frosting recipe made way too much frosting but it’s delicious. Can I freeze frosting?
Sally’s I loved the brownie recipe & it tasted great! I was not keen on the smell of Guinness in the icing. Don’t know why, it just got to me! I’ve used Guinness in cupcakes, too & love it. Anyway, I am going to substitute Bailey’s next time in the icing.
Best Brownies ever! Made these for St.Patrick’s Day for a festive treat (love me some Guinness too) and these may be my new go to brownie recipe. I couldn’t stop eating them. Don’t hesitate to try these anytime of the year! Thanks Sally!
Yummmmmm! Slightly cakey, but more fudgy, deep chocolate flavor, very rich. Frosting was perfection.
I made the Guinness brownies twice around St Patrick’s Day. My husband finally begged for mercy (trying to control his weight). They are absolutely amazing! Gave some to several friends; everyone said they were the best brownies ever. Thank you!
These are delicious, and the house smells wonderful while they are baking. What is the best way to freeze some of the unfrosted brownies?
Hi Rita, You can freeze frosted or unfrosted brownies up to 3 months. Thaw overnight in the refrigerator then bring to room temperature before serving.
Thank you – I almost forgot to leave my 5 star rating!
Can’t wait to try this recipe!! Could I sub black cocoa powder for chopped chocolate? If so how much should I use? Love all your recipes!!!
Hi Tracy, you really need pure chocolate for this brownies recipe – swapping for cocoa powder would require a bit of recipe testing. Hope you enjoy the brownies!
These were delicious! Somewhere between fudge and cakey. Mine were done at 30 minutes. I cut the frosting recipe in half – that was perfect for us. Highly recommend!
Very good! I used 72% dark chocolate from Trader Joe’s and Chocolate Stout, as that is what I had in the house. Not overly sweet but very rich!
Happy St. Patrick’s Day…Guinness Brownies for dessert tonight. I snuck a little corner and they are delicious. Frosting is especially good. I did add toasted pecans to the batter.
The best Brownies I’ve ever had. The Guinness and Espresso truly complement the chocolate in this recipe. We will be making these over and over again. A perfect treat for this St. Paddy’s Day dessert.
Love this recipe! Made these brownies a year ago St.Patricks Day, now have people clamoring for it this year…move over Irish soda bread, got a new family favorite!
Brownies are in the oven now! They smells amazing!! Can I add cocoa powder to the frosting for a chocolate frosting? If so, do you know how much?
Absolutely! I’m sure 2 Tablespoons would be plenty.
These are always a hit with my friends and family on St. Patrick’s Day! They are perfect! And if you’re worried about them being overly sweet with the frosting, don’t be! Thanks for an amazing and easy recipe.
I’ve just made your Guinness Brownies for my TWO St. Patrick’s Day parties…doubled the recipe… doubled the icing! No matter the errors/tweaks I made, these were to die for. I’ve found a new proven baking friend! Thank you! (And, my Guiness was the new O% alcohol…bought by mistake…{should have searched for a single bottle of Guiness STOUT, instead of the DRAGHT, but sure doesn’t seem to have made too much of a difference…next time I’ll use the real STOUT to taste the difference}. Who knew delicious velvety Guinness could simmered down to a pot ‘o’ gold!!!