Hello. I’m going to add melted/cooled white chocolate the the mousseline buttercream, per one of Rose’s variations in TCB, but can anyone tell me WHEN to add the white chocolate? It doesn’t specify in the instructions, just says “beat in 6 oz. melted and cooled white chocolate.” Is it after all the butter is added and the icing is basically done?

Help! I’m doing this in a few hours!

Thanks to anyone who can answer.

YES!

I usually take a bit of the mouselline out of the batch and add the white chocolate to it.  My kitchen can be cool at times and I’ve had the white choc. lump when I add it directly—I suspect the mouselline is too cool.  This way I don’t lose the entire batch and because the white chocolate is warm it doesn’t usually harden in the small amount of mouselline to which I add it.

Lauriegood, hope your white chocolate mousseline was a dream!  I made this the other week to pipe along a heart-shaped red velvet cake, and it was delicious…

It was me vs. the mousseline today…not sure who won haha. I keep reading all this great feedback on the moussline, and I do love the taste of it (especially with white chocolate added), but I gotta tell you, today I was not thrilled with the final results. I could not get the surface totally smooth. It was sort of sweating all the time…I tried to convince myself the result was a “rustic” look (see photo), but I had been hoping it would come out nicer since I was so very proud of my gerbera daisies!

Can anyone tell me what might have been the reasons for the texture that was sort of sweating and always seemed to be right on the verge of breaking down?

I checked the temperature with my digital thermometer. The butter was exactly 65-67…Maybe the egg whites with the syrup were too warm? The recipe says to beat until “completely cool.” I added the syrup and then beat for about 6-8 minutes. I thought it was cool, but maybe not? I also had the air conditioner running to keep the room cool…beyond that, not sure. I used my hand mixer…This was only my second time making the mousseline buttercream…I really want to master this.

Any ideas?

Lauriegood, your cake is beautiful anyway!  I would say almost certainly that the egg white with syrup mixture was too warm, as you suspect.  When I last made this, I beat for a good 6-8 minutes and when I took the temperature, it was still around 80 degrees.  I’d been following the Cake Bible recipe, but then I remembered that in a similar recipe in Heavenly Cakes, Rose recommends putting it in the refrigerator for 10 minutes or so, stirring occasionally to equalize the temperature.  Mine probably spent 15 minutes or more in the refrigerator before it reached 70 degrees…and I don’t recall it even being a terribly hot day.

Those gerbera daisies are wonderful, magnificent, and glorious!  You have a real talent.

Just to reiterate, all of the mousseline flavorings/additions are added after the buttercream is finished and the butter is completely emulsified and creamy.

Ideally your meringue and butter should be close in temp, 65-70F, and it’s OK to put the meringue, covered, in the fridge.  If you were making a larger batch, it will take even longer to cool.  It’s also OK to dump all the meringue into the butter at once and beat, just like Rose does in her video.  Temperature differences usually affect the intermediate curdling stage the most, rather than the end product, which normally still comes together unless the meringue was so hot it melted the butter. 

So it sounds like your buttercream was almost leaking liquid, is that right?  I’m not sure exactly what caused it, but maybe we can figure it out.
A few questions:
-Was the buttercream completely emulsified and smooth before you added the white chocolate? 
-Was the sugar syrup the right quantity and at the right temp (248-250F) when you poured it in?
-Do you think either warm meringue or warm white chocolate could have caused some of the butter to melt?

The daisies are absolutely adorable! 

My home is on the cold side in winter (17-18 degrees Celsius 63 - 65F) and I have never had a batch of Mouselline cool to the appropriate temperature in the suggested time—regardless if I put it in the fridge or not.  In fact, I’ve had it mixing on low for 20+ min and I still can’t get it to the ideal 70F-65F.  I still use the old Mouselline technique—had success with it, so I don’t mess with a good thing.  I hate to say this, but I’ve had good success with adding butter when the whites are about 80F (I have a thermapen so it should not be my thermometer) and the butter about 65F.  I get a bit of curdling after about 3/4 of the butter has been added, but it smoothes out very well.

Based on my experiences, it is possible that the mouselline may have been too cool—I’ve had the Mouselline sort of separate when I’ve applied it to a chilled and crumb coated cake (looks sort of like what may have happened with your cake)...it’s a strange phenomena (the Mouselline that I applied, however was completely smooth/silky).  When it’s cool it curdles and the fat clumps together and the water/liquids separate.  Temperature can wreak havoc with this frosting ... but fortunately, it’s quite forgiving and can usually be salvaged (in fact, I actually scraped off the Mouselline that went over the crumb coat, rebeat it, and refrosted the “warmed up” cake and it turned out lovely!).

Really, really beautiful cake!!!  I think the texture give it a sort of antiquey-gardeny-cobblestoney-patio stonewary kind of look and enhances the overall effect of the lovely daisies!!  Of course, those things are always best when intended and not when forced upon one, but sometimes there is the happy accident!!!!!

The color is especially lovely!

What’s on the inside???

Sherrie may be on to something there! 

I also wondered, in addition to the questions above, if the cake/frosting was cool but in a humid room, so that there was constantly condensation forming on the mousseline as you tried to work with it.  But overly cool mousseline will curdle when beaten, or perhaps even worked a lot while frosting the cake.

Hope you figure it out!

Yes, what’s on the inside?

Just realized I never came back and responded to some of your posts. Thanks for the nice words about my cake! Now that it’s been a couple months since that stressful day, I don’t think it was so bad! I do think the temperature was the issue in my mousseline problems. I have since had a better experience.

BTW the inside of the cake (can’t remember who asked) was Rose’s chocolate butter cake and whipped light ganache filling.

Happy holidays, all! Tomorrow I’ll be working on a buche de noel and a birthday cake (Christmas Eve birthday) for a rah-rah Syracuse student…hope I can get my buttercream to the proper blue and orange colors! Nothing like adding a little more stress to Christmas week!