Recipe and Picture Tutorial: Swiss Meringue Butter Cream Icing

Peggy Does Cake presents…
SMBC (Swiss Meringue Butter Cream)

(Click any photo for an enlarged, "close-up" view.)

The first time I ever tried SMBC, I couldn’t figure out what the big deal was. To me, it was a mouthful of gently sweetened butter. It didn’t taste like icing. It tasted, and worse, it FELT, like butter. Constantly hearing from my cakey bakey friends that it was earth shatteringly delicious, I was sure I was missing something.

Then a brilliant cake friend of mine shared with me that the traditional structure of SMBC (which calls for 1 part egg whites, 2 parts sugar, and 3 parts butter) was too buttery for her, too. Tweaking the recipe down to only 2 parts butter was the perfect remedy. This icing has completely revolutionized my kitchen and I can’t believe I was living in a world without it for 45 years. Ok, I exaggerate, as I’ve only been baking for just under two years. Still, I can’t believe I was living in a world without SMBC for 2 years even! With a few little tweaks to the more traditional recipes you’ve probably seen and tried, you COULD become a believer, and this icing could rock your world.

Tools/Materials

• Pan of shallow hot water, simmering with no visible “boiling” air bubbles
• Your Kitchen Aid mixing bowl, clean and oil free
• Spatula, clean and oil free
• Candy thermometer
• Digital Kitchen Scale

Ingredients

• 8 large egg whites (or cheat like me and use them straight from the carton) – about 250 grams
• 500 grams sugar (granulated sugar, confectioner’s sugar, or a combination of both)
• About 6 sticks (690 grams) of cool butter, chopped into tablespoon-ish sized pieces (5 sticks unsalted, 1 stick salted)
• 1 tablespoon best quality vanilla extract

Directions
When I begin making SMBC, I take my butter cold, from the fridge, and let it sit out while I cook my egg whites and sugar. As they cook, I unwrap the butter and chop it into tablespoon(ish) sized pieces. By the time the sugar mixture is ready, the butter is about the right softness: softened a bit, but still cool.

Always start SMBC right in your Kitchen Aid bowl – but make sure it’s perfectly clean and oil free or your icing could fail. Wipe your bowl clean with a paper towel or a cloth dampened with vinegar or lemon juice to ensure it’s squeaky clean. 

Note: As long as your ratios are 1/2/2-ish, you can make any amount of SMBC you want. When I first began making it, I was always more comfortable making small batches, so this recipe is written as such. Just know that you can begin with any amount of egg whites - as long as you keep your ratios in tact.

Add 250 grams of egg whites to your mixing bowl (whether you’re using egg whites from a carton or using 8 large eggs, when you're learning, you should always weigh your ingredients until you get the hang of this). I still weigh mine, just for thrills. If you don’t have a kitchen scale, get one. I happen to have this one from Ozeri and LOVE it. If using real eggs, reserve the yolks for another use.

Pour your weighed sugar into your KA mixing bowl with the egg whites and whisk together. Simmer whisked mixture over a pan of hot water. Do NOT let water boil, as you don’t want to cook the eggs. Make sure that your mixing bowl is NOT touching the water. You want to use the steam from the hot water to heat your pan. Use a candy thermometer and cook, whisking regularly, until the temperature reaches 150°. This is hot enough to make the eggs safe for consumption and will melt the sugar. At 150° the sugar should be completely dissolved and if you test it by rubbing it between your pointer and thumb, you should NOT feel any sugar grain. Once you’ve reached 150°, move the mixing bowl back to your Kitchen Aid and using the whisk attachment, whisk on medium for about 2 minutes. After the first 2 minutes, turn your mixer to high and let it run for about 7 minutes. Before you know it, you'll have yourself a bowlful of the most gorgeous meringue you've ever seen.

But you're not ready to make icing yet. (Although at this point you could use the meringue for other recipes that call for meringue...) Next, you'll turn down your mixer to low and mix until the meringue is cool enough so that it won’t melt the butter when it's added. 

 This will take another five minutes or so, until the mixing bowl, when touched with the palm of your hand, has become neutral to the touch and is no longer warm.  You can't tell that it's no longer too warm by looking, but here's the meringue, room temperature, and finally ready for the butter!

Once your meringue is perfect and no longer warm, swap to the paddle attachment and turn your mixer back to medium speed. Drop in the cool butter pieces one at a time until incorporated, moving quickly. I just toss them in one after another, as fast as I can go really. Mix on high until you reach a silky smooth texture. This has taken me anywhere from three (3) to eight (8) minutes. If your icing curdles or looks soft and gooey, keep mixing and it will come together.  Here's a picture of my icing BEFORE it's ready.  See how it's grainy and won't hold onto the paddle blade?

One of the coolest things about SMBC is that you can actually “hear” when it’s ready. The mixer changes pitch and takes on a noticeable, pleasant slapping sound. You can’t miss it if you’re listening for it. Here's the same batch about 4 minutes later, now ready. See the paddle blade? And see how thick and full the icing is on my spoon compared to the photo above where it's looking a bit flat and limp?

Once your icing is lush and perfectly smooth, you can add your extracts or other flavorings. Be careful to only add room temperature liquids though. (Ask me how I know…) If you’re adding, for example, fresh strawberries or strawberry puree, you definitely do NOT want to add them unless they are room temp. Cold additives to your SMBC will cause the butter to curdle and separate. As long as your flavor additives are room temperature, you can add just about anything:  preserves, nutella, chocolate ganache, tempered chocolate, caramel, peanut butter, etc. The sky is the limit.

If your buttercream is too runny, your butter may not have been cold enough. Place the entire KA bowl in the fridge for about ½ an hour and then try beating it on high again. If it’s still too soft or runny, add more butter a few pieces at a time, continuing to mix on high, until it comes together. Icing is ready to use immediately, but keeps well in the fridge for several weeks and freezes beautifully!  No more wasted icing! 

If you haven’t tried SMBC yet, I hope you will. It’s so easy, so fast, totally mess-free, and the taste is utterly and completely amazing!  Let me hear from you!

Oven’s on – I’ll be back soon!

~ Peggy