I’m not making this up: while I was photographing today’s cake, a rainbow actually appeared in my yard—not in the sky, in front of the trees in my actual YARD. I knew it was good luck; this cake was DELICIOUS. And fortunately, you don’t need to find the end of the rainbow to make this chocolate Guinness cake. You just need 2 Guinness stout beers, and some basic baking ingredients.
Why Bake With Guinness?
You don’t have to like beer to love this cake. Dark, smooth, and creamy, with roast coffee and caramel undertones, Guinness stout 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. Desserts like Guinness cupcakes and Guinness brownies don’t taste like beer, just a more complex chocolate with a malty background. We’re also incorporating the Guinness flavor in the chocolate cream cheese frosting, which is sweet and silky and complements the dark, fudgy chocolate cake perfectly.
Best Way to Make Guinness Chocolate Cake: Reduce the Beer
The heat evaporates the liquid (and cooks off the alcohol), 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.
Why You’ll Love It
Chocolate cake is rich, moist, and fudgy, with a hint of Guinness flavor Malty undertones with notes of caramel and coffee Extra creamy, silky chocolate cream cheese frosting also incorporates the reduced Guinness concentrate for another kiss of flavor
But, this is baking. And, as I often say, baking is a science. You can’t just pour a couple of beers into cake batter. So how can we pack real Guinness flavor into chocolate cake and frosting, without turning everything into soup? The trick is to reduce the beer on the stove first, to concentrate the flavor into a small amount of liquid. This step is really easy. Pour 2 bottles of Guinness stout into a large saucepan. Let it come up to just boiling—keep a close eye on it, because it will foam up a lot at first—then turn down the heat and leave it to simmer for about 30 minutes, until it’s reduced to just about 3/4 cup (180ml). You’ll be left with less liquid, but more flavor.
Other Ingredients in Guinness Chocolate Cake
Whisk together the dry ingredients, whisk together the wet ingredients, then pour the wet mixture into dry and whisk to combine. The last step for the cake batter is to add in the hot reduced Guinness. We’ll use 1/2 cup (120ml) of hot reduced Guinness in the cake batter, and set aside the remaining to cool completely for the frosting.
Success tip: Use a larger saucepan/pot than you think you need, with high sides. When the beer starts boiling, it will get very foamy and threaten to boil over. Reduce the heat to low; then, as the foam settles back down, slowly increase heat to medium.
Once the Guinness is simmering away, start mixing together the rest of the cake ingredients.
All-Purpose Flour: The structural base of this recipe. Cake flour is great for vanilla cake; but when combined with ultra-light cocoa powder, it’s too fine for this cake. Stick to all-purpose here. Unsweetened Natural Cocoa Powder: Do not use dutch-process cocoa powder. If you’re interested, see dutch-process vs natural cocoa powder for an in-depth explanation. Granulated Sugar: Sweetens this cake. Baking Soda + Baking Powder: This is a fairly dense cake, but these 2 leavening agents provide the lift. Espresso Powder: Espresso powder accentuates the chocolate and Guinness flavors. Salt & Vanilla Extract: Flavor and more flavor! Vegetable Oil: Cocoa powder is a particularly drying ingredient, so oil is needed to ensure the cake is moist. Eggs: Eggs add structure and bind the ingredients together. Sour Cream + Buttermilk: While you could use just one or the other, you’ll have the best success with a combination of both, which makes for a moist and soft yet sturdy crumb.
Why use hot liquid? Hot liquid helps the cocoa powder “bloom,” drawing out its rich flavor. We use hot coffee in this chocolate cake and these cream-filled cupcakes, but today we’re using reduced Guinness instead.
Chocolate Guinness Cream Cheese Frosting
Draught vs. Extra Stout—Which Type of Guinness to Use
Guinness Draught is richer and creamier, because it’s carbonated with nitrogen. It has an ABV of 4.2%. Extra Stout is a little sharper and crisper, because it’s carbonated with carbon dioxide like most beers. ABV is a bit higher, at 5.6%. Either one works in this recipe. I also decorate the cake with gold shimmer sprinkles, the same I use on these St. Patrick’s Day cookies. Totally optional.
