Mousseline Buttercream

"Adopted! A fabulous buttercream that holds up well"
photo by a user photo by a user
Ready In:
4 1/2 cups




  • In a mixing bowl beat the butter until smooth and creamy and set aside in a cool place.
  • Have all other ingredients at room temperature.
  • Have ready a heatproof pouring container ready for the sugar syrup.
  • In a small heavy saucepan heat 3/4 cup sugar and the 1/4 cup water, stirring constantly, until the sugar dissolves and the mixture is bubbling.
  • Stop stirring and reduce the heat to low.
  • (If using an electric range remove from the heat.) In the bowl of a stand mixer unsing the whisk attachment, beat the egg whites until foamy, add the cream of tartar, and beat until soft peaks form when the beater is raised.
  • Gradually beat in the remaining 1/4 cup sugar until stiff peaks form when the beater is raised slowly.
  • Increase the heat and boil the syrup until the thermometer registers 248'F to 250'F (the firm ball stage).
  • Immediately transfer the syrup to the heatproof container to stop the cooking.
  • Pour a small amount of syrup over the whites with the mixer off.
  • Immediately beat at high speed for 5 seconds.
  • Stop the mixer and add a larger amount of syrup.
  • Beat at high speed for 5 seconds.
  • Continue with the remaining syrup.
  • For the last addition, use a rubber scraper to remove the syrup clinging to the heatproof container.
  • Lower speed to medium and continue beating up to 2 minutes or until the bottom of your mixing bowl feels cool to the touch.
  • If not completely cool, continue beating on lowest speed.
  • Beat in the butter at medium speed 1 tablespoon at a time.
  • At first the mixture will seem thinner but will thicken beautifully by the time all the butter is added.
  • If at any time the mixture looks slightly curdled, increase the speed slightly and beat until smooth before continuing to add more butter.
  • When butter is fully incorporated you may add any of the optional flavorings.
  • Place in an airtight bowl.
  • Rebeat lightly from time to time to maintain silky texture.
  • Buttercream becomes spongy on standing.
  • Will keep 2 days room temperature, 10 days refrigerated, 8 months frozen.
  • Allow to come to room temperature completely before rebeating to restore texture or it will break down irretrievably.

Questions & Replies

default avatar
Got a question? Share it with the community!


  1. linneaemery
    This looked beautiful when I was making it...then I tasted it. EWWW!!! It tasted like pure butter. I added a bunch more sugar trying to make it edible. Very disappointing.
  2. Kay D.
    This was incredibly buttery tasting (well, duh, it has a pound of butter in it). Very smooth, very spreadable. This is one of the oh so many items I used for my daughter's first birthday cake. This particular buttercream topped a white cake recipe from Collete Peters and a lemon cake filling. Very nice. The only reason I don't give this 5 stars is the butter flavor is simply over the top.
  3. natalie.navejar
    this is the best buttercream recipe i have ever made. i've made it several times and i've loved it every single time.
  4. WaterMelon
    This is absolutely the BEST buttercream i've ever tasted!! I love this! I made only 1/4 of the recipe and used it to fill a 2 layer chocolate cake. Oh how i regretted that decision... the texture was wonderful, so soft, smooth and velvety - it just melt on your tongue. I used coconut extract to flavor it. Usually i hate buttercream (too greasy!) but this, oh THIS.. is unbeatable! It holds up wonderfully in warm Singapore weather. And Mean Chef's instructions are clear - just follow it to the 'T' and you won't have any problems. I'm still swooning after one taste of the finished cake....
  5. KitchenManiac
    oh my goodness!!! It was my first time doing a stovetop frosting...and man was this good. Followed the directions SPECIFICALLY, didn't change a thing. Meanie you have done it again! :)


<p>Mother of 4, grandmother of 3.... <br /> <br />One of my favorite authors is Kipling, he had a way with words... <br />...when the moon gets up and night comes, he is the Cat that walks by himself, and all places are alike to him.... <br />Rudyard Kipling</p>
View Full Profile

Find More Recipes