Jeanne, I wonder if you also get the “ball of whites” stuck inside your KA 6QT whisk when making a double batch of mousseline? It happens to me after I add the hot sugar syrup and the whites expand dramatically. I have to push down the whites and stop the mixer to clear out the inside. Do you beat at a higher speed when cooling the whites?
And does your mousseline curdle? I don’t start adding the butter until the whites cool down to below 90F, perhaps your warmer mixture doesn’t curdle so much?
Thanks so much for providing those details!
Well, how the whites behave depends on a few things - their age (if they’ve been left out at rm temp for a few hours or if you use them cold or colder), when you add the sugar (my chef instructor used to say this was the hardest part - teaching people how to “read” the whites), how long they beat before you add the syrup…. plus if you have a trace of yolk in there, they won’t beat well and you’ll see it not get the height or volume you’re used to.
So usually I will let the whites stand out for a few hours sometimes even overnight if it’s winter - with my Hobart at work, I can get cold egg whites to whip beautifully, it just takes a little longer. When I let them go too far before adding the sugar, they will make that ball,so it’s a careful balance. Usually I start whipping the whites at about 225-227, if they are rm temp, they are ready for the sugar somewhere around 230-234 (this will vary depending on how much water is in the pot). When the temp probe alarm goes off at 240, I turn the mixer to speed 8 and start pouring. I let it stay at speed 8 for about 30 seconds (sometimes less, like 15 or 20) after I’m done with the syrup, then I turn it back to 6.
The “curdling” happens with the fat addition - you get to a point where the fat has to begin to emulsify and make the fluffy buttercream, but the whites have to get to a certain point and a certain “saturation” (for want of a better word) before that can happen. The fat in the butter weighs down the meringue which is why it deflates, and the next stage is that “breaking” or “curdling” you see before the emulsification takes place. The other students in school used to get a huge kick of me wanting to make buttercream; I love the part where it becomes buttercream, and to this day I still get a kick out of watching it (I’m very boring go from this hopeless mess to a big bowl of deliciousness.
If your butter is too warm, and the whites too warm, you risk floppy buttercream. Let it set up for a few hours or put it on an ice pack or bowl of ice for a little while and keep beating it every so often.
If your butter is too cold, add it when the whites are still warm, but add it in thin increments so it doesn’t cause the meringue to go flying out of the mixer bowl and make a mess. You can also use the microwave to soften it, but be very careful not to go too far.
If your butter is warmer than you like, wait til the whites are very cool, or stick the butter in the fridge to chill for about 20-30 minutes.
I can’t remember what the proportions are for the large batch size in TCB, so here’s what I use for a small batch:
12.5 oz whites
3.5 oz sugar
6 oz (minimum) water
14 oz sugar
2.5 pounds butter
Here’s what I use for the 20 qt Hobart:
30 oz whites
10.5 oz sugar
1#10 oz water
1# 15.5 oz sugar
More than that, and the whites come out of the bowl when the sugar is added.