Lemon Buttercream Frosting

I adore our frosting recipes at Taste of Home. The chocolate frosting is my true go-to, and the strawberry cream cheese frosting is the best I’ve ever tried (so many others are watery!). Here’s another winner from Test Kitchen editor Maggie Knoebel: lemon buttercream frosting.

Where so many recipes just flavor their lemon frostings with lemon zest and juice, Maggie had the genius idea to include a few tablespoons of thick, silky lemon curd. This lemon trio creates the most wonderfully lemony buttercream, with the egg yolks and cornstarch in the lemon curd emulsifying the frosting and making it even silkier and richer than usual. Fans of lemon desserts should keep this recipe in their back pocket for an instant upgrade to any sweets flavored with strawberry, blueberry, vanilla or lavender.

Ingredients for Lemon Buttercream Frosting

• Butter: Soften the butter to room temperature so it whips up easily. The butter should be soft enough that you can easily press a finger into it, but not so soft that the edges are melting.
• Confectioners’ sugar: Because of its fine, powdery consistency, confectioners’ sugar is best for sweetening no-cook treats like frosting. Unlike granulated sugar, it dissolves without heat, so the frosting won’t be grainy.
• Lemon curd: Lemon curd is our secret to the best lemon buttercream frosting. It’s lip-puckeringly tart but balanced with sweetness, and it’s emulsified into a rich custard with egg yolks and cornstarch. Perfect for a no-split lemon frosting!
• Evaporated milk: Evaporated milk loosens the buttercream so it’s more spreadable. You could use 2% or whole milk, but we like evaporated milk because it’s a bit sweeter.
• Lemon: Use both the juice and zest of a lemon to add even more lemon flavor to the buttercream. It’s much easier to zest a lemon while it’s still intact, so always zest lemons before juicing them.

Directions

Step 1: Beat the butter and sugar

In a large bowl, beat the softened butter and confectioners’ sugar until they’re completely smooth and lump-free.

Editor’s Tip: Use a hand mixer or stand mixer to make this step easier.

Step 2: Add the flavorings

Beat in the lemon curd, evaporated milk, the lemon zest, lemon juice and salt until everything is completely combined. Use the frosting right away on your dessert or store it in an airtight container in the fridge.

Editor’s Tip: Start with 2 tablespoons of the evaporated milk, and add more if necessary to reach your preferred consistency.

Recipe Variations

• Add an extract: There’s room for good vanilla extract in this lemon buttercream. Lavender extract adds a subtle floral touch that pairs nicely with lemon.
• Introduce more citrus: Play with the citrus flavor by using an orange or lime in place of the lemon. You’ll need more lime zest and juice than one lime provides, so use two limes.
• Change the curd: Keep the lemon juice and zest, but change up the fruit curd to something just as bright, like passionfruit (liliko’i) curd, grapefruit curd, lime-ginger curd or rhubarb curd.

How to Store Lemon Buttercream Frosting

Store leftover lemon buttercream frosting in an airtight container in the fridge for up to one week. Never store it uncovered in a bowl, or the frosting will absorb lingering fridge smells—particularly detrimental if there’s an onion nearby!

Can you make lemon buttercream frosting ahead of time?

Yes, you can make lemon buttercream frosting ahead of time. One to two days before serving, whip up the frosting to your desired consistency, then transfer it to an airtight container. When you’re ready to use it, let it sit for one hour at room temperature, then place the frosting in a large bowl and use a hand or stand mixer to whip it. If it looks curdled, warm up the outside of the bowl with a hair dryer as you whip.

Lemon Buttercream Frosting Tips

How do you use lemon buttercream frosting?

Use lemon buttercream frosting to frost cakes and cupcakes that are flavored with vanilla, strawberry, blueberry, lavender or lemon. It’s also great on bars (like lemon brownies) or blondies. Try it in macarons or whoopie pies, especially strawberry macarons for a strawberry-lemonade flavor. You could even just dip fresh strawberries in leftover buttercream for an afternoon treat.

How can you make this lemon buttercream frosting thicker or thinner?

If your lemon buttercream frosting is a bit too thin, sift in a little more confectioners’ sugar. Do this with just a few tablespoons at a time, then whip the frosting again. To make the buttercream thinner, add more evaporated milk (or lemon juice if you want it more lemony), a few teaspoons at a time, and whip the frosting again.

Can you keep lemon buttercream frosting out at room temperature?

No, you can’t keep lemon buttercream frosting out at room temperature for more than two hours. Since it contains lemon curd (a perishable ingredient), it must be refrigerated within two hours, or harmful bacteria can grow. Even if you’ve already frosted cakes or bars, monitor how long it’s been out so you can put it back in the fridge when necessary.