Adapted from my chocolate cupcakes, these moist Guinness chocolate cupcakes are made with reduced Guinness beer for deep flavor. They’re flecked with real espresso powder and topped with ultra creamy and flavorful mocha Guinness buttercream. Consider these your perfect St. Patrick’s Day dessert!
Even if you aren’t particularly into beer, I’m confident you’ll appreciate these Guinness chocolate cupcakes. Guinness stout, with its roast coffee and caramel undertones, is often used in baking and almost always paired with chocolate. The two are a natural pairing because Guinness, like coffee, intensifies chocolate’s natural flavor. The desserts don’t usually taste like beer, just an accentuated chocolate with a malty background.
But, this is baking. And, as I’ve drilled into your head, baking is a science. You can’t add a bunch of ingredients to batter without facing some consequences. So how can we pack Guinness flavor into chocolate cupcakes while maintaining a pleasant texture?
Call it a stroke of Irish luck! Because I cracked the code to infuse real Guinness flavor into soft and moist chocolate cupcakes. You’ve come to the right place today.
These Guinness Chocolate Cupcakes Are:
- Extra chocolate-y
- Not overly sweet
- Lightly flavored with real Guinness stout
- Hinted with caramel, coffee, and malty undertones
- Soft and super moist
- Piled high with mocha Guinness buttercream
- Perfect for St. Patrick’s Day!
Video Tutorial: How to Make Guinness Cupcakes
Best Way to Make Guinness Cupcakes: Reduce the Beer
Have you tried my Guinness brownies or Guinness chocolate cake before? Because I took what I learned from those recipes and applied it here. To impart enough flavor into the Guinness cupcakes AND frosting, we’d have to use a crazy amount of beer, which would ruin the batter. So let’s reduce the beer down on the stovetop first. The heat evaporates the liquid, but leaves the flavor. We also do this with champagne in my mimosa cupcakes and champagne frosting. And with strawberries in my strawberry cake, too.
- This step is really easy. Pour an entire 12-ounce (355ml) bottle of Guinness into a saucepan. (Nothing to waste!) Leave it alone to simmer for about 20 minutes until it’s reduced to just 2/3 cup. This is less than half the liquid we started with, but triple the flavor.
We’ll use 1/2 cup (120ml) of reduced Guinness in the cupcake batter and the remaining 2 Tablespoons in the mocha Guinness frosting.
Other Ingredients in Guinness Chocolate Cupcakes
These Guinness chocolate cupcakes required a lot of recipe testing, but I’m so happy with the results and know you will be too! Let’s quickly review the other ingredients and why each is crucial to your results.
- All-Purpose Flour: Flour is the base of this recipe. Use all-purpose, not cake flour. When paired with cocoa powder, cake flour is too light.
- Unsweetened Cocoa Powder: Make sure you use natural cocoa powder.
- Espresso Powder: Espresso powder complements the chocolate and Guinness flavors. Without it, the cupcakes definitely taste like they are lacking something. Espresso powder is sold in the coffee aisle of most grocery stores.
- Baking Soda: When paired with the acidic ingredients in this cupcake recipe (cocoa, brown sugar, beer, sour cream), the baking soda adds lift. I tried adding baking powder, but it created too much rise and dried out the final cupcakes.
- Salt & Vanilla Extract: Flavor and more flavor!
- Vegetable Oil: Most Guinness cupcake recipes I’ve tried in the past several years call for softened butter as the fat, and I’ve always been disappointed with how dry the cupcakes taste. Oil is a guaranteed moist-maker in cakes and cupcakes. And after testing this recipe, I concluded the perfect amount is 1/2 cup + 1 Tablespoon. An odd amount, but that 1 extra Tablespoon adds necessary moisture.
- Brown Sugar: Why use unflavored white sugar when we can add molasses-moistened brown sugar?!
- Eggs: Eggs add structure, lift, and binding.
- Sour Cream: My crowning glory in vanilla cupcakes makes its appearance here, too. Sour cream is an unbeatable ingredient in baking, adding moisture, softness, and unparalleled tenderness.
Overview: How to Make Guinness Cupcakes
After the reduced Guinness beer has cooled for 10–15 minutes, you can begin to make the cupcake batter. This is a very straightforward recipe, one I adapted from my regular chocolate cupcakes. (Truly… if you know how to whisk, you can make these cupcakes.) Whisk the dry ingredients together in one bowl, the wet ingredients together in another bowl, combine the two, pour in the beer, and whisk until everything is combined. Could this batter BE any easier? 😉
Remember when I drilled “no more than 1/2 full” into your head when filling the cupcake pans for my regular chocolate cupcakes? (Too much batter ruins them since the batter is so thin.) Today’s cupcake batter is slightly thicker, so we don’t have to be quite as particular.
In general, it’s best to fill your cupcake liners 2/3 full.
Mocha Guinness Buttercream
We’ll have some leftover reduced Guinness from the cupcakes, so why not add it to our frosting?! This buttercream is impeccably flavored with hints of cocoa, espresso, and vanilla—all of which pair perfectly with the malty flavor of Guinness. Not only this, it’s extra buttery and has a pinch of salt to balance out all the flavors.
- I used my favorite Ateco 849 tip to swirl the frosting on top. It’s a bit larger than the tip I use for St. Patrick’s Day cookies. I love this particular piping tip for cupcakes and used it for my peanut butter cupcakes too. Start in the center of the cupcake and swirl upward.
I love that the cupcakes themselves aren’t overly sweet, so adding frosting isn’t overdoing it! Truly a cupcake where the flavors (not necessarily the sugar) shine.
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
The BEST way to impart real Guinness flavor into chocolate cupcakes is to reduce it down on the stove first. This packs in flavor without altering the cupcake’s texture. Read the recipe in full before beginning.
- one 12-ounce (355ml) bottle Guinness beer
- 1 cup (125g) all-purpose flour (spooned & leveled)
- 1/2 cup (41g) unsweetened natural cocoa powder
- 1 and 1/2 teaspoons espresso powder
- 3/4 teaspoon baking soda
- 1/4 teaspoon salt
- 1/2 cup + 1 Tablespoon (135ml) vegetable or canola oil
- 1 cup (200g) packed light or dark brown sugar
- 2 large eggs, at room temperature*
- 3/4 cup (180g) full-fat sour cream, at room temperature*
- 2 teaspoons pure vanilla extract
Mocha Guinness Buttercream
- 2 Tablespoons reduced Guinness from step 1
- 2 teaspoons espresso powder
- 1 and 1/4 cups (282g) unsalted butter, softened to room temperature
- 4 and 1/2 cups (550g) confectioners’ sugar
- 1 Tablespoon (5g) unsweetened natural cocoa powder
- 1 Tablespoon (15ml) milk
- 1 teaspoon pure vanilla extract
- pinch of salt, to taste
- 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 minutes. Set 1/2 cup aside to cool for 10–15 minutes before using in the cupcake batter. While it’s warm, mix the rest of the reduced Guinness (about 2–2.5 Tablespoons) with the 2 teaspoons of espresso powder used in the frosting. Set this mixture aside for step 5. You can do this step 1 day ahead of time if needed. Refrigerate overnight. Bring reduced beer to room temperature before using in both the cupcake batter and frosting.
- Preheat the oven to 350°F (177°C). Line a 12-cup muffin pan with cupcake liners. Line a second pan with 4 liners—this recipe makes about 16 cupcakes. Set aside.
- Whisk the flour, cocoa powder, espresso powder, baking soda, and salt together in a large bowl until thoroughly combined. Set aside. In a medium bowl, whisk the oil, brown sugar, eggs, sour cream, and vanilla together until completely smooth. Pour the wet ingredients into the dry ingredients, add the 1/2 cup (120ml) reduced Guinness, then whisk until *just* combined. Do not over-mix. The batter will be on the thinner side.
- Pour or spoon the batter into the liners. Fill each 2/3 full to avoid spilling over the sides or sinking. Bake for 19–22 minutes, or until a toothpick inserted in the center comes out clean. Don’t over-bake, which will dry out the cupcakes. Begin checking for doneness at 19 minutes. For around 36 mini cupcakes, bake for about 11–13 minutes, same oven temperature. Allow the cupcakes to cool completely before frosting.
- Make the frosting: Have the Guinness/espresso powder mixture from step 1 handy. 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, cocoa powder, milk, reduced Guinness/espresso powder mixture, milk, and vanilla extract. Beat on low for 30 seconds then increase to high speed and beat until combined and creamy. Taste. Add a pinch of salt if desired. (I always add 1/8 teaspoon.) If you want the frosting a little thicker, add 1/4 cup (30g) of confectioners’ sugar.
- Frost cooled cupcakes. I piped a basic tall swirl using Ateco 849 piping tip.
- Leftover cupcakes keep well covered tightly in the refrigerator for 3 days.
- Make Ahead & Freezing Instructions: Cupcakes can be made ahead 1 day in advance, covered, and stored at room temperature. Freeze frosted or unfrosted cupcakes for up to 2–3 months. Thaw overnight in the refrigerator.
- Special Tools (affiliate links): Electric Mixer (Handheld or Stand) | Glass Mixing Bowls | Whisk | 12-Count Muffin Pan | Cupcake Liners | Ateco 849 Piping Tip
- Espresso Powder: I highly recommend this addition to deepen the chocolate and stout flavors, though you can leave it out in the cupcakes and frosting if necessary. Espresso powder is like instant espresso, found in the coffee aisle. You can also use instant coffee granules. (Not ground coffee.) Read through the recipe before beginning because you will actually use the espresso powder needed for the frosting in step 1.
- Sour Cream: Sour cream is strongly recommended for the best taste and texture. A full-fat plain yogurt would work instead, though the cupcakes may not be as light.
- Milk in frosting: You can use any milk, dairy or nondairy. You could also use heavy cream or half-and-half, too.
- Why is everything at room temperature? All refrigerated items should be at room temperature so the batter mixes together easily and evenly. See my post on why room temperature ingredients are important for more information.
- Be sure to check out my 10 tips for baking the BEST cupcakes before you begin!
Keywords: Guinness beer, beer cupcakes, chocolate, cupcakes