Introduction

Swiss Meringue Buttercream is a silky, smooth frosting that’s lighter than traditional buttercream but rich in flavor. Perfect for cakes and cupcakes, it offers a delicate sweetness and creamy texture that melts in your mouth.

A close-up of a clear glass jar filled with smooth, creamy white frosting swirled in multiple thick layers from the bottom to the top in a beautiful spiral pattern, with a metal piping tip held above it adding the last swoops of frosting. The background is a white marbled texture that subtly highlights the soft texture and glossy finish of the frosting. photo taken with an iphone --ar 4:5 --v 7

Ingredients

5 large (150 grams) egg whites
1 1/4 cups (250 grams) granulated sugar
3 sticks (340 grams) unsalted butter, at room temperature
2 teaspoons pure vanilla extract
1/4 teaspoon fine sea salt

Instructions

Step 1: Wipe the bowl of an electric mixer with a paper towel and lemon juice or vinegar to remove any grease. Set up a double boiler by placing the mixer bowl over a saucepan of simmering water, making sure the bowl does not touch the water.
Step 2: Add the egg whites and sugar to the bowl, whisking constantly but gently until the mixture reaches 160°F or until the sugar has completely dissolved and the egg whites are hot and foamy. Carefully dry the bottom of the bowl.
Step 3: Attach the bowl to the mixer with the whisk attachment and whip until the meringue is thick, glossy, and holds stiff peaks. The bowl should no longer feel warm. This usually takes 7 to 10 minutes.
Step 4: Switch to the paddle attachment and, on low speed, add the butter cubes one at a time, mixing until incorporated. Continue beating until the mixture is silky and smooth, which may take several minutes.
Step 5: If the buttercream curdles, keep mixing—it will come back together. If it’s too thin or runny, refrigerate for 15 minutes, then beat again until smooth. Add vanilla extract and sea salt, mixing on low speed until combined.
Step 6: Add any additional flavors, purees, or mix-ins as desired to customize your buttercream.
Step 7: To prepare ahead, store the buttercream in an airtight container in the refrigerator for up to one week or freeze for up to two months. Before use, bring it to room temperature and beat on low until creamy.
Step 8: For use under fondant, frost the cake smoothly, chill until the buttercream hardens, then cover with fondant straight from the refrigerator.

Tips & Variations

Make sure the mixer bowl is completely grease-free to achieve the best meringue rise and stability.
Use room temperature butter to help the buttercream emulsify smoothly without curdling.
Flavor variations like cocoa powder, citrus zest, or fruit purees can be added after the butter is fully incorporated for delicious twists.

Storage

Store Swiss Meringue Buttercream in an airtight container in the refrigerator for up to one week. For longer storage, freeze it for up to two months. Before using, let it come to room temperature and rewhip with a paddle attachment until smooth and creamy. This will restore its perfect texture for frosting.

How to Serve

A clear glass jar filled with creamy white frosting swirled in three distinct layers, each layer having a smooth, soft texture with visible piping ridges, and a large swirl on top that peaks in the center. The jar is placed on a white marbled textured surface with a dark blurred background, highlighting the smooth, fluffy, and light consistency of the frosting. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use pasteurized egg whites for this recipe?

Yes, pasteurized egg whites are a safe option and work well for Swiss Meringue Buttercream since the mixture is heated during preparation.

What should I do if my buttercream is grainy or curdled?

If your buttercream looks curdled, keep mixing as it often comes back together. If it is grainy or too soft, chilling it briefly and then beating again usually fixes the texture.