French buttercream is distinguished by the use of egg yolks as well as whites. A sugar syrup is used and it is flavored with vanilla or other flavors of your choice. The combination of egg yolks and egg whites will whip into a foam that does not need to be stabilized as do egg whites alone.
This buttercream is the last of the European buttercreams based on an emulsion. This is considered to be the most stable of all of them as it uses whole eggs and yolks not a meringue as do the Swiss and Italian. Although this is not as light as the Swiss and Italian, it is by no means heavy. We are talking degrees here. I think this buttercream has a richer, deeper taste due to the added richness of the yolks.
If you research this along with the other two you will find varying amounts of the eggs, yolks and whites (for the Swiss and Italian) along with varying amounts of sugar and butter. There doesn't seem to be a definitive recipe as long as the proportions are correct. The French buttercream requires a hot sugar syrup as does the Italian. However, because whole eggs and yolks are being used, they do not need to be stabilized as do egg whites alone. Just beating them will obtain the desired effect.
This buttercream is my absolute favorite for coffee buttercream - even if you don't like coffee. The staff would always keep an eye on me at the bakery, because I would always snitch a little as I pass by when they were filling a cake. I think it is because I drink "play coffee". There is so much creamer and sweetener, you probably wouldn't really call it coffee. Maybe coffee lite!
I think the European buttercreams are becoming more and more popular because they are less sweet than the American version, they are incredible light and smooth and the flavor, whatever that may be, really pops.
There have been those that suggest you can't pipe as well with a European buttercream. The photo above, as well as the one on the previous post Italian and Swiss clearly show you can. In addition, any of the European buttercreams go on completely smooth for a perfect finish. I have included at the bottom of this post, a few of the buttercream finished wedding cakes to illustrate the finishes using European buttercreams.
The French buttercream will never be as white as the Swiss or Italian due to the egg yolks. So let's face it, you can't go wrong with any of these - it's just a matter of taste.
French Buttercream
2 whole eggs
1 egg yolk
¼ cup water
¾ cup sugar (150 grams or 5 ⅓ ounces)
¼ teaspoon cream of tarter ½ pound unsalted butter, softened but not runny (225 grams or 8 ounces)
2 teaspoons vanilla
Place the eggs and yolk in the bowl of a mixer fitted with the whisk attachment. 
Beat on medium high until very light, very pale in color and foamy. 
Continue beating until the syrup is ready. This small amount of syrup comes to temperature very quickly after it reaches 220 degrees so watch it so it does not go over 242 degrees on a candy thermometer. Place the water in a small saucepan. Add the cream of tarter and 
then the sugar. 
Stir to combine.
Bring to a boil. Wash down the sides of the pan with a brush dipped in cold water to prevent crystallization. 
Boil to 242 degrees.
Pour the syrup in slowly trying to stay between the whisk and the side of the bowl.
Do not pour in too quickly or it will sink to the bottom of the bowl where it cannot be incorporated. Beat until completely cool. When the base is cooled, add the butter a tablespoon or two at a time. 
Beat until incorporated. Do not add additional butter until the previous amount is completely mixed in. Don't worry if the buttercream curdles as it did here. 
Just continue to add butter and it will smooth out. 
When all of the butter is incorporated, add the vanilla 
and continue beating to achieve a light texture.
Yield: Approximately 2 ½ cups, 454 grams or 1 pound.
A Few Cakes - Many of our cakes were simplicity itself allowing for no mistakes or spatula marks on the finished cakes. These cakes feature buttercream only. There are no fondant finishes here. 
For the bottom layer of the cake above, we piped the lace detail from the train of the bride's dress. The groom was very romantic and wanted flowers spilling out of a box on top of the cake.
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Alicia says
I use instant espresso powder to flavor my buttercream. What (and how much) do you use to add coffee flavor to your French buttercream? Thanks in advance!
hfletcher says
Hi Alicia: For this recipe, I use 1 teaspoon instant coffee to 1/4 teaspoon water. It will be very thick, almost a paste when mixed together.
Hilda says
Lovely photos. Next blog post suggestion: Teach how to make those perfectly smooth edges and crisp corners shown in the photos.
Can the recipe be doubled with no changes to proportions?
hfletcher says
Hi Hilda: Yes, the recipes can be doubled, quadrupled ad infinitum in direct proportion which means without altering the original recipe. We made the Italian buttercream in a 60 quart mixer using 15 pounds of butter routinely. The edges just take practice but a bench scraper or other straight edge taller than the cake is necessary. I'll do a cake soon.