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’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