Italian Meringue Buttercream is a smooth and stable frosting made with whipped egg whites, sugar syrup, and butter. This classic buttercream recipe is perfect for decorating cakes, cupcakes, and macarons. With its silky texture and rich flavor, it’s an ideal choice for those seeking a less sweet alternative to traditional buttercream.

This classic frosting is smooth, silky, and stable—perfect for cakes, cupcakes, and piping. Made with whipped egg whites and a hot sugar syrup, it’s a rich and elegant alternative to traditional buttercream.

Table of Contents

Ingredients

4 large egg whites (160 g), room temperature
½ teaspoon cream of tartar
⅓ cup (66 g) white sugar (for egg whites)
1 cup (200 g) white sugar (for sugar syrup)
⅓ cup (80 ml) water
3 sticks (340 g) unsalted butter, room temperature but not too soft
1 teaspoon vanilla extract
1 pinch salt

Instructions

1. Prepare the Meringue

In a stand mixer fitted with the whisk attachment, begin whipping egg whites and cream of tartar on high speed until foamy.
Gradually add the ⅓ cup sugar to the egg whites, one tablespoon at a time. Whip for at least 30 seconds between each addition. Continue whipping until soft peaks form.

2. Make the Sugar Syrup

While the egg whites are whipping, combine 1 cup sugar and ⅓ cup water in a saucepan over medium heat.
Do not stir the mixture. Heat until it reaches 240°F (115°C) using a candy thermometer.

3. Combine Syrup and Meringue

Reduce the mixer speed to low and carefully pour the hot sugar syrup into the egg whites in a slow, steady stream, avoiding the whisk and sides of the bowl.
Once all the syrup is added, increase mixer speed to high and whip until the bowl is completely cool to the touch. This may take 10–15 minutes.

4. Add the Butter

With the mixer on medium-high speed, begin adding room temperature butter one piece at a time.
Fully incorporate each piece before adding the next. Around halfway through, the mixture may look curdled—this is normal. Keep whipping.
Once all butter is added and the mixture is smooth, whip in vanilla extract and salt.
Continue beating for one more minute until the buttercream is silky and smooth.

Tips

Use a candy thermometer to get the sugar syrup to the right temperature (240°F/115°C).
Butter should be room temperature but not overly soft—this helps prevent a runny texture.
If your buttercream looks split or curdled, keep whipping—it almost always comes together with continued mixing.

Variations and Substitutions

Flavor ideas: Add espresso powder, melted chocolate, fruit puree, or extracts like almond or lemon.
Coloring: Use gel food coloring to tint the buttercream without affecting texture.
Dairy-free option: Try plant-based butter substitutes (results may vary slightly).

FAQs

Can I make this ahead of time?
Yes. Store in an airtight container in the refrigerator for up to 5 days or freeze for up to 3 months. Bring to room temperature and rewhip before using.

Why did my buttercream look curdled?
This is normal mid-way through mixing. Keep whipping—it will emulsify and turn smooth.

Can I make it without a candy thermometer?
Yes, but it’s harder to get consistent results. The syrup is ready when it forms a soft ball in cold water (soft-ball stage).

Serving Suggestions

Ideal for layered cakes, cupcakes, macarons, and piping detailed decorations.
Pairs well with chocolate cake, lemon sponge, or fruity fillings.
Use it as a base frosting and build in custom flavors.

Why You’ll Love This Recipe

Incredibly smooth, pipeable texture perfect for elegant desserts
More stable than American buttercream—especially in warm conditions
Light and buttery without being overly sweet
Versatile for flavoring and coloring