What Does It Mean When My Frosting or Whipped Cream "Breaks?"
Let’s start with frosting. There are many types, from Italian buttercream to ganache, but most of us tend to make a basic American buttercream, which typically involves butter and sugar, plus maybe a touch of vanilla, milk, or salt (plus additional flavors such as chocolate). If your frosting has ever “broken,” you’ll remember it: It’s annoying! Whether it’s looking loose and soupy or stiff and curdled-looking, if you’ve followed the recipe correctly (and it’s a good recipe!), the culprit was likely temperature.
Marc Aumont, pastry chef of Gabriel Kreuther and Kreuther Handcrafted Chocolate in Manhattan, grew up in a patisserie, learning classic French pastry technique at his father’s shop in Tours, France. What’s happening in a buttercream, he explains, is that you’ve got a ton of fat—butter is typically 80 percent fat—mingling with water (which also comprises about a fifth of the butter), and that by melting the butter “you’ve destabilized that suspension.” If when you whipped it with sugar you caused it to “break”—you’ll know because it will look soupy or curdled—you’ll need to heat or cool the frosting to try to re-stabilize that suspension. Basically, explains Aumont, you’ve separated the fat molecules from the liquid molecules, so you’re trying to re-emulsify them as you would an oil-and-vinegar dressing.
More often than not, say while baking in the summer, people have let their frostings become too warm. If this has happened, Aumont suggests popping it in the fridge for a little bit, taking it out when it looks a bit more solid, and re-whipping it. If you want a natural stabilizer, you can look for a recipe that includes cream cheese; Aumont himself has been known to whip a bit in to help stabilize his frostings. (If you need visual references for these issues, here’s a good video, which also shows how to use a frozen towel to quickly cool down a mixing bowl, and how to use a hairdryer to warm frosting.)
As for whipped cream, similar principles apply, although now you’re incorporating air into fat and liquid molecules. This is why, when you have a perfect whipped cream and you pop it in the fridge for an hour or two, it will likely separate: The air has come out of the emulsification, and your whipped cream has drooped and separated. Fix it by simply whipping it again, says Aumont. If he’s set his own whipped cream aside, “I always give it a small whipping for 30 seconds just to bring back the air lost in the emulsion.
What you need to really watch out for, he says, is graininess, which is what happens when the molecules of fat are starting to stick together and there’s not enough air. You’ve concentrated the fat molecules, and you’re now making butter! “When you are in that stage it is impossible to fix it,” he warns. “What we call in French I don’t know what we call in America!” In either language, it’s no good, and you’ll have to start over.
Some would parry that, if you catch the whipped cream just as it starts to look grainy and stiff, but before it’s clumped excessively, you can rescue it by whipping in a couple tablespoons of cream by hand. You can try, but as our chef says poetically, “If I break a piece of my teacup, I will take glue, and glue it back together, if possible, but it will never be the same as if it was never broken.” And sometimes, he says, “You just have to get a new teacup.”