Guinness Chocolate Cupcakes with Mocha Guinness Buttercream

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!

One reader, JC, commented:These are some of the best cupcakes I have ever eaten. I absolutely love the flavors and they smell incredible. I don’t usually like to eat frosting on its own, but I was licking the spatula with this one. โ˜…โ˜…โ˜…โ˜…โ˜…

Guinness chocolate cupcakes

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!
Guinness cupcakes
Guinness chocolate cupcakes

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, weโ€™d have to use a crazy amount of beer, which would ruin the batter. So letโ€™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 itโ€™s reduced to just 2/3 cup. This is less than half the liquid we started with, but triple the flavor.

Weโ€™ll use 1/2 cup (120ml) of reduced Guinness in the cupcake batter and the remaining 2 Tablespoons in the mocha Guinness frosting.

Guinness beer for cupcakes

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.
ingredients for guinness cupcakes
Guinness chocolate cupcake batter

Overview: How to Make Guinness Cupcakes

After the reduced Guinness beer has cooled for 10โ€“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? ๐Ÿ˜‰

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.

Guinness chocolate cupcakes without frosting
mocha Guinness buttercream

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 vanillaโ€”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 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.

Guinness chocolate cupcakes

Other St. Patrick’s Day Recipes

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Guinness chocolate cupcakes

Guinness Chocolate Cupcakes with Mocha Guinness Buttercream

5 Stars 4 Stars 3 Stars 2 Stars 1 Star 4.9 from 61 reviews
  • Author: Sally
  • Prep Time: 35 minutes
  • Cook Time: 20 minutes
  • Total Time: 3 hours, 35 minutes (includes cooling)
  • Yield: 16 cupcakes
  • Category: Dessert
  • Method: Baking
  • Cuisine: American
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Description

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.


Ingredients

  • oneย 12-ounce (355ml) bottle Guinness beer
  • 1 cup (125g) all-purpose flour (spooned & leveled)
  • 1/2 cupย (41g)ย 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
  • 2ย largeย eggs, at room temperature*
  • 3/4 cup (180g) full-fatย sour cream,ย 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


Instructions

  1. 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 10โ€“15 minutes before using in the cupcake batter. While it’s warm, mix the rest of the reduced Guinness (about 2โ€“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.
  2. Preheat the oven to 350ยฐF (177ยฐC). Line a 12-count muffin pan with cupcake liners. Line a second pan with 4 linersโ€”this recipe makes about 16 cupcakes. Set aside.
  3. 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.
  4. Pour or spoon the batter into the liners. Fill each 2/3 full to avoid spilling over the sides or sinking. Bake for 19โ€“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 11โ€“13 minutes, same oven temperature. Allow the cupcakes to cool completely before frosting.
  5. 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 2โ€“3 minutes. Add the confectionersโ€™ 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.
  6. Frost cooled cupcakes. I piped a basic tall swirl usingย Ateco 849 piping tip.
  7. Leftover cupcakes keep well covered tightly in the refrigerator for 3 days. I recommend a cupcake carrier for storing and transporting decorated cupcakes.

Notes

  1. 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 2โ€“3 months. Thaw overnight in the refrigerator.
  2. Special Tools (affiliate links):ย 12-count Muffin Pan | Cupcake Liners |ย Glass Mixing Bowls | Whisk | Electric Mixer (Handheld or Stand) | Piping Bag (Reusable or Disposable) | Ateco 849 Piping Tip | Cupcake Carrier (for storage)
  3. 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.
  4. 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.
  5. Milk in frosting: You can use any milk, dairy or nondairy. You could also use heavy cream or half-and-half, too.
  6. 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 importantย for more information.
  7. Be sure to check out myย 10 tips for baking the BEST cupcakesย before you begin!
sally mckenney headshot purple shirt.
About the Author

Sally McKenney

Sally McKenney is a baker, food photographer, and New York Times best-selling author. Her kitchen-tested recipes and step-by-step tutorials have given millions of readers the knowledge and confidence to bake from scratch. Sallyโ€™s work has been featured on TODAY, Good Morning America, Taste of Home, People, and more.

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Reader Comments and Reviews

  1. Kayla Zeifman says:
    November 17, 2025

    Hey guys, Iโ€™ve made this recipe many times and itโ€™s always amazing! I want to make a batch for a baby shower but want to color the buttercream, could I sub the cocoa for something or am I better off doing your plain cream cheese frosting recipe? I just need the shape to hold for the next day thanks a mill!

    Reply
    1. Trina @ Sally's Baking says:
      November 17, 2025

      Hi Kayla! We would use plain cream cheese frosting with gel food coloring – hope the cupcakes are a hit ๐Ÿ™‚

      Reply
  2. Jodie says:
    October 11, 2025

    The cupcake is absolutely fantastic – super light, moist and spongy. Only thing is that the buttercream is exceptionally sweet.

    Reply
  3. Savanah Christensen says:
    September 18, 2025

    I make this EVERY YEAR for St. Patrick’s Day and Christmas. My family genuinely can’t get enough. It went from a fun St. Patty’s day potluck idea to a family favorite. Around the holidays we will heat any left over cupcakes up in the microwave and let the butter cream frosting slightly melt over their tops, creating a hot buttery coffee cake. I personally recommend halving the frosting as it creates a lot – or you can reuse the left overs on scones or something. I imagine I’ll be using this recipe until the day I die – this is year 3 ๐Ÿ™‚

    Reply
  4. Dee says:
    August 17, 2025

    First, thank you! Sally’s Baking Addiction is my go-to for every recipe I make. I get so many compliments on my baked good because of it.

    Second, would it be possible to switch out the Guinness with a chocolate stout? Or would it be too much? Thanks again!

    Reply
    1. Michelle @ Sally's Baking says:
      August 17, 2025

      Hi Dee, you can definitely use a chocolate stout!

      Reply
  5. Alex says:
    July 6, 2025

    Is whisk attachment correct for the buttercream? I’ve always used paddles for beating butter and it seems like it would be difficult to get started with a whisk.

    Reply
    1. Trina @ Sally's Baking says:
      July 7, 2025

      Hi Alex, you can use either.

      Reply
  6. Erin says:
    June 11, 2025

    I absolutely love this recipe!! So delicious. Is it ok to double the recipe?

    Reply
    1. Trina @ Sally's Baking says:
      June 11, 2025

      Hi Erin! So glad it’s a hit! We recommend making two batches for best results.

      Reply
  7. Maureen says:
    March 19, 2025

    Couldn’t decide between the guinness and baileys n coffee, so did both. Flavor was fantantic, most of us favored the guinness. Both frostings, however, appeared to be curdled. I am wondering if softening butter in micro did it. Part of the butter was melted. What do you think? MG

    Reply
  8. Jackie says:
    March 17, 2025

    Seriously amazing recipe. Thank you!

    Made them today for my husband and I and for sharing. I used Triple cocoa blend from King Arthur because itโ€™s what I have in the house and their 1 to 1 GF blend leftover from when I had to be GF for a medical thing, otherwise I followed your recipe exactly.

    The cake has fantastic flavor and a great crumb. The frosting tastes like the most delicious mocha ice cream with a subtle maltiness.

    This is why I continue to come here for recipes. Iโ€™m never disappointed!

    Reply
  9. Sarah says:
    March 14, 2025

    I love this recipe! We make these cupcakes annually for our family St. Paddy’s gathering and everyone loves them. The only change we make is to make the frosting less sweet by upping the butter to 1 1/2 c and reducing the sugar to 3 1/2 cups.

    Reply