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Seriously Addictive Swiss Meringue Buttercream

Stable & Silky Swiss Meringue Buttercream: Your Ultimate Heat-Resistant Frosting Recipe

This is the ultimate Swiss Meringue Buttercream (SMBC) recipe you’ll actually rely on – even when the weather is warm and humid. Forget the overly sweet and often unstable traditional American buttercream frosting; this version is exquisitely light, wonderfully silky, and boasts a perfectly balanced sweetness that won’t overwhelm your desserts. What’s more, it’s surprisingly straightforward to make, even if you’ve encountered challenges with meringue in the past. Crafted with just five essential ingredients, this recipe incorporates a clever stability secret that ensures it holds its pristine shape beautifully. I personally put it to the test outside in a sweltering 89°F (31.7°C) Florida heat, and it remained smooth and picture-perfect for over an hour. Whether you’re aiming to elegantly frost a multi-tiered cake or pipe intricate designs onto cupcakes, this is the definitive go-to recipe that promises elegance, ease, and remarkable staying power, making it the perfect choice for any occasion.

A vanilla cupcake piped with swiss meringue buttercream and colorful sprinkles.
Elevate your classic vanilla cupcakes with this exquisite buttercream.

For years, I’ve received countless requests for a frosting that is not only less sweet but also capable of withstanding warm climates. That’s precisely why I’m thrilled to share this definitive Classic Swiss Meringue Buttercream recipe (often abbreviated as SMBC). Unlike its American counterpart, which typically consists of just butter, powdered sugar, and flavoring – and can frankly be overpoweringly sweet – SMBC offers a vastly different experience.

Swiss Meringue Buttercream is created by gently heating egg whites and granulated sugar over a double boiler, then whipping them into a glossy, stable meringue. Once the meringue is perfectly whipped and cooled, softened butter is gradually incorporated, resulting in a frosting that is incredibly light, airy, and exceptionally smooth. It uses significantly less sugar (and no powdered sugar at all!), yielding a flavor that is far more balanced and refined, without compromising on any of its deliciousness. This inherent stability also makes it remarkably resilient, holding up beautifully outdoors even on hot days.

This versatile buttercream is perfect for piping lofty swirls atop white chocolate cupcakes or classic vanilla cupcakes. You can also generously slather it in a rustic style over a decadent chocolate cake, or spoon it artfully over this highly-rated banana cake. The possibilities are endless, and you truly cannot go wrong with this elegant frosting.

As a trained pastry chef and Le Cordon Bleu graduate, my goal is to demystify the process and meticulously explain exactly how to create this incredible frosting. I understand that the idea of heating egg whites or needing a thermometer can feel a little intimidating at first, and perhaps you’ve heard that SMBC is complicated or exclusively for advanced bakers. Let me assure you, it’s far simpler than it sounds, and I’ll walk you through every step to make it perfectly without needing a thermometer, eliminating any stress or guesswork.

Unmatched Heat Stability: My Florida Test

When developing and sharing this recipe, I knew it needed to pass a rigorous heat test. So, I subjected it to an intense South Florida June day, where temperatures soared to a humid 89°F (31.7°C). I am absolutely thrilled to report that after an entire hour spent in the shade outside, this buttercream still looked absolutely fantastic, maintaining its pristine texture and piped details.

See the remarkable results for yourself!

A vanilla cupcake with sprinkles on a chair.
I placed this cupcake outside at 5 PM – with the temperature at a balmy 89°F.
A vanilla cupcake and frosting on wooden slats.
One hour later, at 6 PM, still 89°F – the frosting still looks remarkably good!
A vanilla cupcake with Swiss meringue buttercream in direct sunlight.
At 6 PM, with the temperature holding at 89°F, I intentionally moved the cupcake into direct sunlight to observe its endurance.
A melty vanilla cupcake in the direct sun.

As anticipated, when exposed to direct sun, the buttercream began to show signs of melting after about 15 minutes. This test clearly demonstrates that as long as your frosted creations are kept in the shade, you can confidently expect this SMBC to maintain its structure for several hours – even in temperatures hovering around 90°F (32°C) with significant humidity. This makes it an ideal choice for outdoor gatherings, summer parties, or any event where stability is paramount.

What is the secret behind this remarkable resilience? It’s a combination of a few key techniques and ingredients:

  1. My Secret Stability Weapon: Cornstarch in the Sugar. Incorporating just 1 tablespoon of cornstarch into the granulated sugar is a game-changer. This small addition significantly boosts the buttercream’s stability in high humidity and warm temperatures, all without altering the delicate flavor or texture. You won’t even detect its presence, but its impact is undeniable. Cornstarch helps absorb excess moisture and creates a more robust structure within the meringue.
  2. Strategic Reduction in Butter Content. This recipe uses slightly less butter compared to many other Swiss Meringue Buttercream recipes. While butter is essential for richness and silkiness, an excessive amount can make the buttercream overly susceptible to softening in heat. By carefully calibrating the butter quantity, we achieve a perfect balance of flavor, texture, and stability.
  3. Maintaining Ideal Butter Temperature. The temperature of your butter is absolutely crucial. It should be at room temperature, but specifically, it should still feel cool to the touch and be pliable, not overly soft, greasy, or melty. If the butter is too warm when added, it can quickly cause your SMBC to become soupy and destabilize the entire emulsion. This “cool but pliable” stage is key for proper incorporation and a stable final product.

Getting Started: Preparing Egg Whites and Sugar for Meringue

Before you begin, meticulous preparation of your equipment is vital. Ensure that your mixing bowl (preferably a stand mixer bowl) and whisk attachment are impeccably clean and completely free of any grease or fat residue. Even the slightest speck of oil can prevent the egg whites from whipping up properly into a stable meringue. As a best practice, I recommend wiping down all equipment that will come into contact with the egg whites using a paper towel dampened with white vinegar or half a lemon. This simple step effectively degreases the surfaces, guaranteeing optimal results.

Egg whites in a glass bowl.
Cold egg whites are easier to separate cleanly, but warm egg whites whip faster and achieve more volume. Separate them while cold, then let them sit out to reach room temperature before starting.
Sugar and corn starch in a glass bowl.
Always add the cornstarch on top of the granulated sugar before combining it with the egg whites. This ensures even distribution.
A double boiler on a stove top.
Creating a double boiler is simple and not scary at all. Take a small saucepan and add 1-2 inches of water. Bring the water to a boil, then reduce it to a gentle simmer. Place your mixing bowl directly on top of the simmering pot, ensuring the bottom of the bowl does not touch the water. This indirect heat is crucial.
Egg whites, sugar, and cornstarch in a mixing bowl.
Combine the room temperature egg whites, granulated sugar, and cornstarch directly into the prepared mixing bowl.
Egg whites and sugar foaming in a mixing bowl.
Continuously whisk the mixture of sugar, cornstarch, and egg whites. Initially, the mixture will appear thick and gluey, almost like a paste. However, as the sugar crystals dissolve from the gentle heat, it will gradually thin out and become more fluid. Continue whisking to ensure even heating and prevent the egg whites from scrambling.
Egg whites, sugar, and corn starch whisked into a thin foam in a bowl.
The primary objective here is two-fold: to completely melt all the sugar crystals and to safely pasteurize the egg whites, making them safe for consumption. You’ll know it’s ready when you can rub a tiny amount of the mixture between your thumb and forefinger and it feels absolutely smooth, with no trace of graininess whatsoever. If it still feels grainy, simply continue whisking over the simmering water. No need for a thermometer, just your sense of touch!

Whipping the Meringue to Perfection

Once all the sugar has completely dissolved and the mixture has transformed from a thick, gluey consistency to a much lighter and thinner liquid, it’s ready for the next crucial step. Carefully remove the bowl from the double boiler and immediately transfer it to your stand mixer, fitted with the whisk attachment. This transition from heating to whipping is where the magic truly happens.

Diced butter on a gray cutting board.
Begin dicing your butter into small pieces as soon as you start whipping the meringue. The butter should be cold but still pliable, not hard and rigid, nor soft and greasy. Dicing it into smaller pieces facilitates faster warming to the ideal pliable consistency and ensures easier, more uniform incorporation into the frosting compared to larger chunks.
Stiff peaks on a meringue in a bowl.
Begin whipping the warm egg white and sugar mixture on medium speed. The goal is to cool down the meringue while simultaneously whipping it to stiff, glossy peaks. To check if it’s cooled sufficiently, touch the bottom of the mixing bowl; it should feel completely cool to the touch, not warm. This process typically takes between 10 to 15 minutes, depending on your mixer and ambient temperature. Patience is key here to achieve the perfect meringue base.
A beater with stiff peaks of meringue.
Stiff peaks are achieved when the meringue holds its shape firmly and stands erect on the whisk attachment without drooping or collapsing, as shown here. This indicates maximum aeration and stability in your meringue.
Meringue in a mixing bowl next to diced butter.
Once stiff peaks are formed and the bowl is cool, switch from the whisk attachment to the paddle attachment. The paddle is superior for incorporating butter smoothly and prevents the meringue from curdling. With the mixer running on medium-high speed, add the diced butter one tablespoon at a time, ensuring that each piece is fully incorporated into the meringue before adding the next. This gradual process is crucial for creating a smooth, stable emulsion. Continue this until all the butter has been added. Finally, incorporate the vanilla extract and salt. Increase the mixer speed to high and whip for another 15 seconds. Congratulations, you’ve successfully made perfect Swiss Meringue Buttercream!

Troubleshooting Common Swiss Meringue Buttercream Issues

Don’t panic if your frosting doesn’t look perfect on the first try – it’s a common experience, and almost every issue with Swiss Meringue Buttercream has a straightforward fix! Understanding what went wrong will help you correct it and learn for next time. Here are the most common troubleshooting scenarios:

Is your frosting looking curdled, chunky, or separated? This is a very common occurrence and usually indicates that your butter was too cold when added, or that the mixture simply needs more whipping time. It’s almost never a sign of “over-whipping.” The cold butter causes the emulsion to break, leading to a lumpy or curdled appearance.

The Fix: Keep whipping! Sometimes, all it needs is a few more minutes on medium-high speed for the butter to soften and properly integrate into the meringue, bringing it back to a smooth consistency. If continued whipping doesn’t resolve it, the butter might be significantly too cold. In this case, carefully place the mixing bowl back over the double boiler (which should still be simmering). Warm the bowl slightly for just 5-10 seconds, rotating it constantly. The aim is to gently warm the mixture just enough for the butter to soften a bit, not to melt it completely, as that would lead to a soupy consistency. Immediately return it to the mixer and continue whipping. You should see it come together beautifully.

Is your frosting soupy, runny, or too liquid? This generally means your buttercream is too warm. This can happen if your meringue wasn’t fully cooled before adding the butter, or if your butter was too soft/melty to begin with (as discussed in the heat stability section).

The Fix: To cool it down and firm it up, place the entire mixing bowl (with the buttercream inside) into the refrigerator for about 10–15 minutes. Be careful not to leave it in for too long, or it will become too hard and difficult to re-whip. After chilling, return the bowl to your stand mixer and re-whip the buttercream on medium-high speed until it comes together into a smooth, stable consistency. The cooling period allows the butter to firm up, enabling it to re-emulsify properly with the meringue when re-whipped.

With these troubleshooting tips, you can confidently tackle any issues and achieve consistently perfect Swiss Meringue Buttercream!

3 cups frosted with Swiss Meringue Frosting on a mini cake stand.
This exceptional frosting doesn’t harden or form a crust, making it ideal for intricate piping details that not only look stunning but also melt delightfully in your mouth.
A vanilla cupcake piped with swiss meringue buttercream and colorful sprinkles.
3.50 stars (2 ratings)

The Swiss Meringue Buttercream I Can’t Stop Making

Prep: 30 minutes
Total: 30 minutes
Servings: 12 cupcakes
This is the Swiss Meringue Buttercream recipe you’ll actually trust — even on warm and humid days. It’s light, silky, and not too sweet like traditional American buttercream frosting, and it’s surprisingly easy to make even if you’ve struggled with meringue in the past. Made with just five ingredients, this version uses a simple stability trick that helps it hold its shape beautifully — I even tested it outside in 89°F Florida heat, and it stayed smooth and picture-perfect an hour later. Whether you’re frosting a cake or piping cupcakes, this is the go-to recipe that delivers elegance, ease, and staying power.
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Ingredients

  • 5 egg whites, room temperature -large- about 150g
  • 2 cups granulated sugar, 400g
  • 1 tbsp corn starch
  • 1.5 cups unsalted butter, cold but pliable- 3 sticks(340g), diced small
  • 2 tsp vanilla extract
  • 1/4 tsp kosher salt

Equipment

  • 1 Stand mixer
  • 1 Double boiler

Instructions
 

  • To ensure no grease interferes with your meringue, thoroughly wipe down your mixing bowl and all attachments (especially the whisk) with a clean paper towel dampened with white vinegar or half a lemon. This degreasing step is critical for success.
  • Prepare a double boiler: Fill a small pot with 1-2 inches of water and bring it to a gentle simmer. In your degreased mixing bowl, combine 5 large room-temperature egg whites, 2 cups of granulated sugar, and 1 tablespoon of cornstarch. Place the mixing bowl securely over the simmering water, making sure the bottom of the bowl does not touch the water.
  • Continuously whisk the egg white mixture over the simmering water. Initially, it will appear thick and glue-like. As the sugar begins to dissolve and the mixture warms, it will gradually thin out and become more fluid. Continue whisking constantly for 10-12 minutes. The main goal here is to completely melt the sugar crystals and pasteurize the egg whites. To check for readiness, rub a small amount of the mixture between your thumb and forefinger; it should feel perfectly smooth, with no grittiness at all. If you still feel sugar crystals, keep whisking until it’s entirely smooth. No thermometer is needed for this step!
  • Once the mixture is smooth and clear, remove the bowl from the heat. Transfer the bowl to your stand mixer fitted with the whisk attachment. Begin beating on medium-high speed for 10–15 minutes. The meringue will gradually increase in volume, become glossy, and form stiff peaks. It’s crucial that the meringue cools down completely during this whipping process; check by touching the bottom of the bowl – it should feel cool to the touch. This cooling is essential before adding the butter.
  • After achieving stiff peaks and a cool bowl, switch the mixer attachment from the whisk to the paddle. With the mixer running on medium-high speed, gradually add the diced, cool-but-pliable unsalted butter, one tablespoon at a time. Ensure that each piece of butter is fully incorporated into the meringue before adding the next. This slow incorporation prevents the buttercream from curdling. Continue until all the butter has been used and the mixture is smooth and creamy.
  • Finally, add the 2 teaspoons of vanilla extract and 1/4 teaspoon of kosher salt. Increase the mixer speed to high and beat for an additional 15 seconds to ensure everything is thoroughly combined and the buttercream is perfectly smooth and airy. And just like that, you’ve successfully created delectable Swiss Meringue Buttercream!
  • Now, it’s time to enjoy your perfectly piped or swirled Swiss Meringue Buttercream over delightful desserts like vanilla cupcakes.

Notes

Yield
This recipe generously yields approximately 4-5 cups of luscious frosting. This quantity is ample to elegantly fill and frost a two-layer 9-inch cake, or to pipe beautifully over a dozen cupcakes with a generous swirl.
To store:
For short-term storage (a couple of days), your Swiss Meringue Buttercream can be kept in an airtight container at room temperature, or even stored directly in a piping bag, ready for immediate use. For longer storage, refrigeration is necessary.
An excellent and simple method for storing this frosting is to scoop it onto a large piece of plastic wrap and tightly seal it, forming a compact, air-free package. This “package” fits conveniently in the fridge or freezer and eliminates the need for extra dishes when you’re ready to use it again.
To freeze your buttercream, wrap it first in plastic wrap, then seal it inside a freezer-safe zip-top bag to prevent freezer burn. When you’re ready to use it, defrost and thaw the buttercream at room temperature until it becomes pliable. Before using, give it a good re-whip in your stand mixer on medium-high speed. This will bring it back to its original light, fluffy, and smooth consistency, ready for decorating.
Serving: 1serving, Calories: 343kcal, Carbohydrates: 34g, Protein: 2g, Fat: 23g, Saturated Fat: 15g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 6g, Trans Fat: 1g, Cholesterol: 61mg, Sodium: 73mg, Potassium: 29mg, Fiber: 0.01g, Sugar: 33g, Vitamin A: 709IU, Vitamin C: -2mg, Calcium: 8mg, Iron: 0.04mg
Course: Frosting
Author: Sam Adler
Cuisine: American
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