Science: The Magic of Meringue—Why Timing Matters When Whipping Egg Whites and Sugar

Meringue cookies depend on whipped egg whites for both leavening and structure. The sugar that’s added to the whites contributes not only sweetness but also stability. But does it matter when you add the sugar?

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Meringue cookies and all types of sponge cake, including angel food and chiffon, depend on whipped egg whites for both leavening and structure. The sugar that’s added to the whites contributes not only sweetness but also stability. But does it matter when you add the sugar?

EXPERIMENT
To find out, we made three batches each of meringue cookies, angel food cake, and chiffon cake, adding the sugar to the whites before whipping, after a minute of whipping, or at the very end, once the foam had reached the “soft peaks” stage. We baked them and compared the results.

RESULTS
In all three recipes, the timing made a difference. Adding the sugar after a minute of whipping was clearly best across the board. In both types of cake, the crumb structure was compromised when the sugar was added at the very end: The chiffon was dense and flat, while the angel food was coarse and almost crumbly. Adding sugar before whipping was also not ideal, leading to cakes that baked up a bit too dry.

In the case of the meringues, adding the sugar at the start of mixing produced a cookie that was dull on the exterior, with a too-fine crumb within. The cookies made when the sugar was added at the very end had an overly airy texture (tasters compared it to Styrofoam) and a grainy consistency. To top it off, they took on an unappealing brown color.

EXPLANATION
When egg whites are whipped, the eggs’ proteins unfold and then cross-link to form a network that stabilizes the air bubbles. At the same time, the sugar dissolves in the water from the eggs to form a viscous liquid that helps stabilize the structure. If the sugar is added too early, the sugar granules interfere with the proteins’ ability to unfold, resulting in a weaker network that can only support small air bubbles (this is why these cakes and meringues had a finer interior texture). If the sugar is added too late, either the sugar, which is hygroscopic, draws water out of the foam and causes the structure to weaken (as in the dense, crumbly cakes), or the sugar doesn’t fully dissolve (as in the meringue cookies that were grainy and brown from undissolved sugar caramelizing). Adding the sugar after a brief amount of whipping gives the protein network time to form while leaving enough time for the sugar to dissolve.

TAKEAWAY: For ideal volume and stability, add the sugar to whipped egg whites after the eggs have started to get foamy but well before they have started to form peaks.

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[angeatsang]

Love how you experimented different timing, also included photos of the result. (Would be great if you included the chiffon cake and angel food tho)
But lots of Chiffon cake recipes I read suggest adding the sugar in three batches, about one-third at a time. First time, like you suggested, add sugar when the egg started to get foamy. But the last time often when the egg reaches to firm peaks.
What do you think of this method comparing to your adding in once after whisking one minute?

[khaderach]

at what speed should you whip the egg whites before adding in the sugar?
what effects happen when changing out granulated sugar for high fructose corn syrup?

[BoxerDogs]

Instead of just doing the steps, I like to know the purpose of each step.  Good explanation on the cross-linking of the egg white proteins.  Thank you for posting.

I just subscribed.

[paulstovall]

THANK YOU for that tip. I recently made a lemon meringue pie. My meringue came out runny and flat. Not being one to waste, I simply poured it over the top of the pie base and baked it anyway. Even tho it tasted great and formed more of a 'crust' (which was by no means unpleasant), it just wasn't quite the same. I'll try your technique on my next go around.

[realrasher]

Great... Now I'm craving meringue cookies. Thanks!

[sKIPperM]

Freshness of egg whites, temperature of egg whites, sugar crystal size, cream of tartar amount -- just a few more variables to add into the mix.

[eduardmanzhura]

Thank you! 😘 It helps a lot. Good advise!

[dodgingdurangos]

Is the science the same for other dairy products such as heavy whipping cream, milk, or even soy milk? Are the proteins in each ingredient of the same type as egg whites?

[ucsbgirlie]

You should also add the sugar slowly, not all at once.

[pengu]

I have a question, by adding a liquid food coloring will the structure be broken or interfered in any way?

[nihlify]

What about adding the sugar little by little as many receipts say?

[pimpernell]

Could you do a video explaining Swiss meringue please.

[AtheistEve]

Can you do the same test for aqua faba? And explain how to get aqua faba meringue to remain light and firm whilst baking.

[MrUnbelievableAbs]

Awesome thank you! I have to make meringue for my gluten free bread all the time

[DavidBayard]

I just made a batch following a recipe that called for 1 part egg white to 2 parts sugar. I made it with 180g egg white and 360 part sugar. The recipe said to add 1/4 of the sugar when the eggs had been whipped foamy, then whip that together before you add 1/4 more and after whipping that in for a minute add the rest of the sugar. Following these steps made it hard for the sugar to disolve, should I just add all the sugar at once once the egg reaches the right consistency?

[Zelmel]

Not gonna lie, I have a chef-y man-crush on Dan.

[mezmez]

Does the temperature of the egg whites matter in terms of the experiment? Should the whites be fridge cold or countertop warm?

[kkw]

do the whole eggs need to be in room temperature first before separating egg yolks out or you can separate the yolk from white right after the eggs are out of the fridge and let the egg whites sit in the room temperature? Or either way is fine? Thank you.

[rawshop]

Thank you so much for this knowledge.

[ryanhollist]

I would be interested to see if there are such timing issues when doing an Italian meringue. I'm still not sure when the best point is to add the sugar syrup.