Swiss Meringue Buttercream aka The Stuff Dreams Are Made Of

Have you ever tried a meringue-based buttercream? If not, you are really missing out!

I confess that I used to be a frosting-hater. Maybe hate is a strong word. I was always the one who scraped the icing off of the cake, then ate only the cake. Maybe I would pick at the icing a little, but it always seemed to overpower the flavor of the cake. I recently discovered why. It is because the typical American buttercream is nothing but shortening, a LOT of powdered sugar, a little milk or water, and some flavoring, usually vanilla. Yep, that's it. Many people don't even put real butter in their "butter"cream! No wonder I didn't like it!

Now, if you love American buttercream, I don't mean to offend you! There are people who prefer it. But wait until you taste a meringue buttercream!

There are lot of recipes with different ratios of egg whites to sugar to butter out there. Play around with it and see what you like. You do have some wiggle room here. The one I like the best is the 1-2-3 ratio. That's one part egg whites to two parts sugar to three parts butter. It always comes together nicely; it tastes sweet but not sickeningly so and does not taste too buttery. But you can really taste the butter in this buttercream, so be sure to use a nice one.


Swiss Meringue Buttercream
5 ounces egg whites (about 5 egg whites)
10 ounces granulated sugar
a pinch of salt
1 pound good-quality unsalted butter, softened overnight at room temperature (I use Kerrygold)

You may have noticed that there are only weights listed in this recipe. Well, you can't make my recipe without a kitchen scale. Sorry! If you simply must use regular measurements, know that 10 ounces of granulated sugar is just under 1 1/2 cups and 1 egg white weighs about an ounce. The weight of an egg white can vary, so I do recommend weighing those too.

Whisk together the egg whites, sugar, and salt in the top of a double-boiler or in the bowl of your stand mixer. You can make this with a hand-held mixer, but I highly recommend a stand mixer so that you are free to do other things while it all mixes away for 10 minutes or more at a time. That's a lot of time to be standing there with the hand mixer!

A quick note about the egg whites. You can use liquid egg whites that come in a carton from the store, but make sure there are no added ingredients. I personally just crack fresh organic eggs for my buttercream. I save the egg yolks to use in my yellow cake recipe. But there are wonderful uses for egg yolks besides yellow cake. You can make amazing custards, like creme brulee, and cream fillings with them. I haven't tried a lot of these yet, but I will be trying some soon and will share if possible! (I just made some white cakes and now I have 25 egg yolks to use!)

Bring about an inch of water to a boil, then set your egg white mixture in your bowl over the top. Make sure that the bottom of your bowl is NOT touching the boiling water or you will cook your eggs, ending up with little bits of scrambled eggs in your icing. That, my friend, is definitely not creamy goodness. Keep those eggs moving. I stand there with a whisk and swirl them the whole time. Trust me, if you stop for even a few seconds, your eggs may start cooking at the edges. Can you tell I discovered that one by experience? :) You will want to lower the heat a little so that the water is simmering and keep whisking those eggs gently until they are foamy and the sugar is completely dissolved. You need your eggs to be between 145 and 160 degrees F in order to kill any harmful bacteria that may be living in them. You can use a candy thermometer for this, but you can also just tell by sight. If your sugar is completely dissolved, you are in the right range. By 160 degrees, your eggs will be foamy and pretty clear underneath the foam.

When the eggs are ready, place your eggs in the mixing bowl and fit your mixer with the whisk attachment. If you are using your mixing bowl as your double-boiler, then just place it on the mixer stand and start whisking! Whisk on high until you reach stiff peaks and the bowl is cool to the touch. Your egg whites should be VERY stiff. It is possible for the bowl to be cool before the eggs are stiff enough; keep whisking! By the same token, if your eggs are stiff and your bowl is still slightly warm, you aren't finished; keep whisking! This can take 10 minutes are more. I do find that it takes a little longer if you used your mixing bowl as your double boiler. Make sure this bowl is cool to the touch, though. If it is warm still, the butter will melt a little and you will end up with icing soup. Don't fret too much if this happens; just pop the whole thing (after mixed together and creamy) into the refrigerator to firm up a bit. It is definitely better if you can avoid this though!

Here are the stiff peaks. Sorry for the poor picture. Check out the top of my whisk, though. The egg whites are shiny, standing at attention, and not too dry. Perfect!

Now let's talk about the butter. Lots of recipes will tell you to use butter that is still cool in the middle, but your butter should be so soft that you can barely pick it up. Don't worry about leaving it out overnight at room temperature. It will be fine and will not spoil! Trust me! And the warmth of the butter will allow it to incorporate into the egg mixture more quickly, more smoothly, and with very few air bubbles, which is exactly what you want! Do not try to rush the process by microwaving or heating the butter, though. Melted butter will not work!

When your eggs are ready, switch to the paddle attachment and throw your butter in there. All of it. All at once. It's okay! I do not recommend actual throwing though. That could get messy!

Mix on LOW until the creamy goodness reveals itself. Don't start hating me and my recipe when you see your eggs start to deflate. Don't fear if your buttercream looks like a soupy, curdled mess. It's supposed to go through that stage and has to in order to become the stuff dreams are made of. So, just look away, exercise some patience and let your mixer do it's work. Don't try to speed it up by turning your mixer to medium or, heaven forbid, high speed. It may come together, but it won't be the same. Think buttery lumps. Not so delicious. This is science, baby! Sit back and enjoy the absolute coolness of what is happening here. You are transforming simple butter, sugar, and eggs into something that is light, creamy, and totally delicious!

Here is the "curdled" stage.

When the buttercream comes together, you will know it. It will be fluffy, light, and creamy looking. The process could take 10 minutes or more, so hang in there. I've had it come together really quickly and I've also had it take more time. Once it comes together, you can add your flavoring. I often will just add about a tablespoon or so of pure vanilla extract or vanilla bean paste. Vanilla bean paste is delicious and will add little flecks of vanilla bean into your icing. It's pricey, but totally worth it if you can find it. You can also add other flavorings, like fruit purees. Add about 1/4 cup to start and then more to taste. To make chocolate buttercream, add melted and cooled chocolate and mix until it is incorporated. Be careful not to add too much liquid or you will break your buttercream. I have found this recipe to be pretty forgiving, so play around with it and have some fun!

When you are finished, layer it into a nice homemade cake. Or spread it on a cookie. Or a brownie. Or just eat it with a spoon. Not that I've ever done that. Not me. Really.

Your buttercream will keep in the refrigerator for two or three weeks, though if you are going to keep it for more than a week, I recommend freezing it. To use it again, let it come to room temperature (do not try to help it with the microwave, oven or anything else!) and re-whip it to restore it to it's original fluffiness. If you ice a cake with it, there is no need to refrigerate your cake. You can, though, if you prefer. I wouldn't leave it out for more than a couple of days though. If you do refrigerate your buttercream, let it all come to room temperature before serving. The Stuff Dreams Are Made Of will have the texture of butter straight out of the frig and will have a more heavy buttery flavor. At room temperature, you won't notice the texture of the butter at all, but you will get the flavor in the background and the icing will melt in your mouth with subtle sweetness. A perfect compliment to any cake!

For a truly wonderfully-written and excellent version and explanation of Swiss Meringue Buttercream, check out my fellow blogger, FromScratch SF. You can read her tutorial here.