Lemon Swiss Meringue Buttercream

Lemon Swiss Meringue Buttercream delivers bold lemon flavor with a fluffy, pillowy texture. Using real lemon curd keeps it easy, balanced, and ready in roughly 30 minutes.

This lemon swiss meringue buttercream came from a very practical problem: I didn’t have piping bags, tips, or the patience to pipe a dam. Instead of filling layers with curd, I leaned into the same structural principles in my swiss meringue buttercream, where a stable meringue can handle softer additions beautifully.

I tested how much curd it could hold using my lemon curd recipe, and the answer was a full cup—and I LOVED IT. The flavor is brighter than lemon whipped cream, but with the structure needed for layer cakes like my recent lemon cake recipe, designed specifically for this buttercream. I especially love it on warmly spiced cakes, like carrot cake cupcakes, where the bright lemon cuts through the richness without overpowering it.

Ingredients & Substitutions

• Egg Whites: Use fresh separated eggs. Carton whites will not whip into a stable Swiss meringue. This method starts by cooking egg whites to stabilize the whipped egg whites, but even a trace of egg yolk or grease can prevent whipping. Be vigilant!
• Granulated Sugar: Dissolves cleanly when heated; extra-fine sugar helps but isn’t required.
• Kosher Salt: Added early to stabilize the meringue and balance sweetness.
• Unsalted Butter: Cool but pliable—this temperature matters for emulsification.
• Lemon Curd: Homemade or store-bought both work. The curd provides acidity safely without breaking the buttercream.

See the recipe card below for full quantities.

Variations on Lemon Swiss Meringue Buttercream

• Boost the citrus: Add up to ¼ cup lemon juice, a little at a time, after the buttercream is fully emulsified—but stop before it loosens.
• Extract-based lemon: Skip curd and use a high-quality lemon extract for a lighter citrus note.
• Layer strategy: Use this buttercream as both filling and frosting, or pipe a dam and fill with curd if you want sharper contrast.
• Other flavors: If you love this method, the same base works beautifully for richer flavors like my caramel swiss meringue buttercream, which uses salted caramel sauce and vanilla extract for depth.

Professional Tips

• Temperature matters more than ratios. Like all swiss buttercream recipes (often called smbc), temperature control matters the most. Warm meringue and cool or room temperature butter combine for a smooth buttercream.
• Broken does not mean ruined. Most issues resolve with continued mixing and short refrigeration.
• Swiss meringue improves with patience. Texture becomes even silkier after a few minutes of whipping.

How to Make Lemon Swiss Meringue Buttercream

Use these instructions to make perfect lemon swiss meringue buttercream every time.

Step 1: Set up a water bath. Heat about 1 inch of water in a medium saucepan until just simmering. This acts like a double boiler, applying gentle heat to the bottom of the mixing bowl without touching the water.

Step 2: Heat the egg whites and sugar. Whisk egg whites, sugar, and salt together in the bowl of a stand mixer. Place over the simmering water and whisk constantly for about 8–10 minutes, until the mixture reaches 120–130°F, the sugar is fully dissolved, and it feels warm and lighter (photos 1 & 2).

An instant-read thermometer removes all guesswork!

Step 3: Whip the meringue. Transfer the bowl to the stand mixer fitted with the whisk. Beat on high speed for 6–8 minutes, until stiff peaks form and the bowl feels just slightly warm (photo 3).

If you need, you can use a hand mixer, starting on low speed and increasing to medium-high speed.

Step 4: Emulsify with butter. Switch to the paddle attachment. Add all the butter and mix on medium speed for 3–5 minutes, until the buttercream becomes smooth and cohesive. It may look broken before it comes together, keep going (photos 4 & 5).

Step 5: Add the lemon curd. Once smooth, switch back to the whisk and add the lemon curd. Whip for 1–2 minutes until light, fluffy, and fully emulsified (photo 6 & 7).

Step 6: Frost immediately or store for later use (photo 8).

Recipe FAQs

Before You Go

I hope you enjoyed this bright, silky lemon buttercream. Check out my other chef-tested buttercream and frosting recipes to build cakes that look and taste truly special.