How to make a classic Italian meringue buttercream
Italian meringue buttercream (IMBC) is a thick and creamy frosting that is made by whipping egg whites with sugar syrup and softened butter.
Italian meringue buttercream is similar to Swiss meringue buttercream (SMBC) except the sugar is cooked 240ºF before being added to the whipping egg whites. The cooked sugar syrup results in a more stable and silky smooth buttercream.
People love Italian meringue buttercream because it is the most stable of all the buttercreams and it is also the least sweet. So if you live in warm environments like Florida, California or Texas, Italian meringue is going to work very well for you.
You can substitute half of the butter for vegetable shortening for more stability in high heat areas.
What ingredients do you need for Italian Meringue Buttercream?
Fresh egg whites – Don’t use boxed (pasteurized) egg whites, chances are they will not whip into a stiff meringue which is vital to a stable buttercream frosting.
Sugar – Make sure you cook your sugar to the proper temperature (240ºF) to ensure all the water has evaporated and the sugar is stable enough to be whipped into the frosting
Butter – Use softened, butter (but not melted) to whip into your cooled meringue so that it incorporates smoothly. I prefer to use unsalted butter so that I can control the amount of salt that is in my buttercream. Remember, the higher the quality of butter you use, the better your buttercream will taste.
Salt – Just a little salt helps bring out the flavor of the Italian meringue buttercream
Vanilla – I use a good amount of vanilla to flavor my Italian meringue buttercream but you can use whatever flavoring you desire. You can also use vanilla beans, emulsions or ground up freeze-dried fruit.
How do you make Italian meringue buttercream?
Here are the steps to making Italian meringue buttercream
- Wipe down your bowl and attachments with lemon juice or white vinegar to make sure there are no traces of oil or fat on them that would prevent your meringue from whipping up
- Place your egg whites into the bowl of your stand mixer with the whisk attachment.
- Combine your sugar and water together in a medium-sized saucepan and stir to distribute the water evenly.
- Cover with a lid and bring to a boil. Leave the lid on for 5 minutes to ensure all the sugar granules are dissolved or your sugar could crystallize and become grainy.
- Remove the lid and insert your candy thermometer. Continue boiling the mixture without stirring until the thermometer reaches 235ºF
- Begin whisking your egg whites on high to soft peaks
- When your syrup reaches 240ºF, reduce the speed of your mixer to low and drizzle in your hot syrup. Try to drizzle between the whisk attachment and the side of the bowl to prevent the syrup from splattering.
- Increase the speed back to high and whip to very stiff peaks. Place ice packs at the base of your mixer to cool the meringue down to room temperature as you’re mixing or remove the meringue once it’s stiff enough and place it into the fridge for 15 minutes to cool it down.
- Once your meringue is completely cool, you can whip in your butter, salt, and vanilla until the buttercream is light and fluffy and no longer tastes like butter.
- Now you can add in food coloring if you desire
Can you color Italian Meringue Buttercream?
You can add coloring by adding a couple of drops of your favorite food coloring into the bowl as it’s whipping in the final step. Or you can divide your buttercream and hand-mix in food coloring.
How long does Italian Buttercream last?
Italian buttercream can be left at room temperature for 2-3 days. I usually refrigerate leftover buttercream if I’m not going to use it in 24 hours. It can be frozen for 6 months or more. Bring the buttercream to room temperature and re-whip until it’s a smooth consistency before you use it.
Italian Meringue Buttercream
- 16 ounces (454 g) granulated sugar
- 8 ounces (227 g) water
- 1/4 teaspoon salt
- 8 large (264 g) egg whites
- 24 ounces (680 g) unsalted butter softened
- 2 tsp vanilla extract
- Stand mixer with the whisk attachment
- Candy Thermometer
- On a stovetop, mix together the water and sugar, cover with a lid and bring to a boil on medium-high heat.
- Keep the lid on the pot for 3-4 minutes and bring to ensure all the sugar granules are dissolved, otherwise, your sugar can get gritty and crystalize.
- Remove the lid, insert the candy thermometer carefully and continue cooking on medium-high until the syrup reaches 240° F.
- When the sugar solution is at about 235° F, begin whipping the egg whites on high speed. Add the salt to the egg whites.
- When the egg whites reach soft peaks, pour the sugar solution in a steady stream on to the whipping whites while mixing on low speed.
- Continue whipping the egg/sugar mixture until it reaches stiff peaks. I wrapped an apron around my bowl with an ice pack to help the meringue cool down faster. You can also cool the meringue by scooping it out of the bowl and placing it into the fridge for 15 minutes.
- Once the meringue is cooled, whip in soft butter and vanilla until the buttercream is light and fluffy and no longer has a butter taste.