Ask Milk Street: Why Did My Meringue Fall Apart?

Welcome to our freshest series, Ask Milk Street, where we dive into recipe and technique questions, big and small. They’re not just the questions we’ve wondered about, by the way; we’re highlighting the conundrums that have been plaguing you, our readers. We want you to know that these questions bug us too—so we found the answers.

Question: Why did my meringue collapse?

At its simplest, meringue is a mixture of sugar and egg whites. You whip the dickens out of it, and this agitation causes the proteins to unravel and link up again to trap loads of air bubbles. The more you whip it, the more bubbles you trap, until you reach capacity—also called “stiff peak” stage. Once you’re in the soft, medium and stiff peak stages (read more about getting to those stages here), the meringue is stable enough to be spread onto cakes (like our Romanian Rhubarb Meringue Cake), baked as Meringue Cookies with Salted Peanuts and Chocolate, or mixed into batters and bases as a leavening agent.

But if yours wilted unexpectedly and didn’t hold, that’s a big problem—especially since meringue is vital for lift and structure. There are a couple common reasons for this, like fat or grease on your whisk attachment or bowl (fat is the enemy of egg white proteins linking and trapping air), so your meringue never whipped up strong in the first place. Or maybe you overmixed your meringue past its limit, causing the structure to collapse, the meringue to become grainy and the water to ooze out. But, there is one other, more surprising culprit: the egg whites themselves.

Boxed egg whites are a tease

We suspected that boxed egg whites weren’t all they were cracked up to be. They’re an easy solution for fat-free omelets, but would they whip well for baking? If true, then our days of cracking and separating dozens of eggs would be over. So I ran some tests and, spoiler: using boxed egg whites makes an inferior meringue.

I did back to back tests of a simple meringue mixture using egg whites (both boxed and fresh), sugar and cream of tartar. Cream of tartar is a stabilizing agent, and while that’s not included in every meringue recipe you’ll run into, I wanted both meringue tests to have the best odds of holding their shape.

My tests and findings

Fresh egg white meringue beat out the boxed egg white version in several areas. Fresh egg whites were faster to whip up to the stiff peak stage by several minutes, had a smaller, finer bubble texture, produced more volume—3 cups versus the boxed version’s 2.5 cups—and had much better stability.

Though the boxed egg white meringue hit stiff peak stage, it didn’t last. I left both bowls of whipped meringue to sit for 30 minutes. After 30 minutes, the batch of fresh egg white meringue exhibited almost no change—it was still at the stiff peak stage. After only 15 minutes, the boxed egg white meringue was softening, and after 30 minutes it was ooze. As soon as I tilted the bowl the meringue flowed to one side.

I desperately wanted boxed egg whites to be the solution for easy meringue, but for optimum stability, it’s not worth it. The issue is the pasteurization process that boxed egg whites undergo. The heat causes structural changes to the proteins—they partially denature and are no longer able to link up and trap air the same way as they can when fresh. This causes them to take longer to whip up, and once they do, they can’t hold onto that structure for very long.

So if your meringue is taking forever to whip or seems to be wilting and falling apart soon after whipping, check a few things. Clean your bowl and beater of fats, don’t overwhip, and use fresh egg whites. You can still make omelettes with the boxed stuff.

Be sure to try our Meringue Cradle Cake with your fluffy, stable meringue. It’s one of our wildest cakes yet.

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Allie Chanthorn Reinmann

Allie Chantorn Reinmann is a Digital Staff Writer for Christopher Kimball’s Milk Street. She’s a Thai-American chef who earned her diploma for Pastry and Baking Arts at The Institute of Culinary Education and worked professionally for over a decade honing her craft in New York City at places like Balthazar, Bien Cuit, The Chocolate Room, Billy’s Bakery and Whole Foods. Allie took her know-how from the kitchen to the internet, writing about food full-time at Lifehacker for three years and starting her own YouTube channel, ThaiNYbites. You can find her whipping up baked goods for cafés around Brooklyn, building wedding cakes and trying her hand (feet?) at marathon running. She’s working on her debut cookbook and lives in Brooklyn, NY.