Making Italian meringue buttercream is easy if everything is the same temperature, but I made it so often I came up with a risky way to make it that I wouldn’t tell anyone to try unless they were pretty experienced with it! It worked for me, though, so I’m sharing it with you in case you want to try it out.
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IMBC is an emulsion!
I used Italian meringue buttercream, or IMBC, all the time. It makes a nice, flavored buttercream filling, and it’s not as sweet as American buttercream that has confectioner’s sugar as a base.
When you make an IMBC you’re basically making an emulsion of the eggs, sugar and butter, which requires everything to be the same temperature for it to work well.
When you’re making an emulsion you’re forcing water and oil to cooperate with each other, to put it simply. The temperature is important because if it’s too cold or warm you’re not only managing oil vs water, you’re throwing hot vs, cold into the mix.
The real way to make IMBC.
This is the sensible and correct way to make an Italian meringue buttercream:
- 2 cups softened unsalted butter at room temperature. DO NOT use cold butter!
- 1 cup sugar
- 1/4 cup water
- 5 large egg whites
- 1/2 + 1/8 tsp cream of tartar
- 3 fluid ounces liqueur or other flavoring
Instructions:
- Cut the butter into pieces and set them aside for later.
- Have a greased, heatproof measuring cup near the stove, at least 2 cups capacity.
- Beat the egg whites and cream of tartar in a stand mixer until stiff peaks form. You can do this with a hand mixer but it will be a little more awkward when you get to the cooked sugar steps.
- Heat the sugar and water in a pan stirring to dissolve it, until it starts to bubble. Stop stirring and keep cooking until it gets to 248-250 degrees. USE A SUGAR THERMOMETER FOR THIS, don’t guess! The sugar has to get to the right temperature.
- When the sugar syrup is hot enough, pour it into the greased heatproof measuring cup to stop the cooking.
- Beat the sugar into the egg mixture slowly pouring a stream in as the mixer is moving on low to medium speed. Don’t use high speed or it will throw sugar onto the sides of the mixing bowl.
- Beat on medium speed until the mixture has cooled down to room temperature. You can speed this up by wrapping the bowl with cool kitchen towels, but it needs to cool down before you add the butter or you’ll ruin it! This can take some time, don’t be impatient!
- When the egg mixture is room temp, add the butter in a little at a time while the mixer is running on medium speed. Continue beating until the buttercream is smooth.
- Add the liquer in a steady, thin stream while the mixer is running on low speed.
- Use the buttercream right away, or pretty soon. If you have to refrigerate it after you use it, you’ll have to let it get to room temp and re-beat it to smooth it out, and it won’t have the same consistency.
- Store cakes covered with IMBC in the fridge, but let them warm up at room temp before serving.
My tips for this icing (I’m a risk taker.)
Okay…This icing is easy to make if the temperatures are all the same, which is why I emphasized having everything at room temperature. BUT if the butter is too cold or the meringue is too hot when you put them together, it can break the buttercream and either make it look curdled, or melt it.
If this is the first time you’ve ever made a meringue-based buttercream, make sure to have the temperatures be the same. But once you get the hand of it, you can do what I did when I was making wedding cakes.
I basically took the risk of the temperatures of each ingredient balancing each other out so that I could speed up the process. BUT THIS IS RISKY and I knew what I was doing because I made this so often. Don’t do this if it’s your first time making this icing!
What I did was make the meringue and have it ready. I cooked the sugar and when it was 248F I took the pan to the mixer and just poured it into the meringue with the mixer running, no in-between step of the mixing cup.
Then as the mixer was running to cool the meringue down, I took sticks of cold butter and put them in the microwave for 10 seconds (still wrapped up) to soften them a little. Then I opened the butter wrapper and cut the sticks up into Tablespoon-sized pieces, still in the wrapper. This avoids having to use an extra bowl for the butter.
When the meringue had cooled down to warm, not hot, I started throwing the butter into it bit by bit. The cold temperature of the butter would cool down the warm meringue as it was mixed in, and by the end I ended up with a perfect IMBC.
HOWEVER, if you don’t judge the warmth of the meringue well, or if the butter is still a little too cold, you can end up with a buttercream that’s either broken (curdled) or melted. Here’s a video on how to fix that, and you can also read this article that goes into more detail about the steps to take.
How to save a broken meringue buttercream.
When I was in culinary school the chef instructor told us that learning how to save a broken meringue buttercream was one of the most important things we could learn, and I have to agree with her on that.
In that moment when you’ve been working on your feet for 10 hours, you’ve used up your last eggs and butter, and your buttercream breaks, you’ll want to know how to fix it fast to avoid a late-night trip to the grocery store!
The problem is that when the buttercream breaks the texture won’t be the same even if you save it. It will usually be thicker and not as silky. You can still use it for fillings, but it will be really hard to ice a cake with it smoothly. It’s best to make the icing right the first time and not have to try to salvage it.
So give my risky method a try, but if you misjudge the temperatures be prepared to save the icing. Once you do my method a few times you’ll get a good idea of how warm the mixer bowl should be when you start adding the cold butter. It does save a lot of time if you’re willing to try it out!
