“Beat until the egg whites hold 2-inch peaks.” If you’re a baker, it’s an instruction you’ve read a thousand times before. With holiday baking season knocking at the door, we thought it high time to revisit a piece of advice that rebukes this statement—and the years you’ve spent dutifully following it.

London-based baker Claire Ptak of Violet Cakes (you know her from the time she baked the cake for Prince Harry and Meghan Markle’s wedding) takes a different stance.

Forget the 2-inch peaks, and slightly underwhip your egg whites, Ptak says.

And she should know. The California-born baker and author of “The Violet Bakery Cookbook” was the pastry chef at Alice Waters’ Chez Panisse before she attracted a global following for her showstopping and seasonally inspired cakes and baked goods.

Ptak’s point about egg whites is one of the standout pieces of wisdom from a visit to her London bakery, and one that she calls her “number one rule.”

As Milk Street food editor Matthew Card explains, the act of whipping egg whites incorporates air bubbles into what is essentially a solution of proteins dissolved in water. Too many air bubbles and the egg whites stretch too thin, causing the bubbles to burst. Slightly underwhipping leaves the egg whites thick and elastic enough to contain the air bubbles and expand without breaking in the heat of an oven. So you’ll end up with a fluffier end result if you don’t beat to stiff peaks.

Remember, too, that stabilizers like sugar can help strengthen the bonds of underwhipped egg whites, leaving them more viscous and resistant to breaking apart. So, again, no need to beat them so much. “Just take care to add it slowly so it dissolves into the foam; undissolved sugar weakens the structure,” Card advises.

What’s more, soft whites will incorporate more easily into batter than stiff whites.

If you need any more convincing, try this Chocolate Prune Cake, inspired by Ptak’s chocolate prune and whiskey cake.

Read more about Ptak and her bakery here, and listen to an interview with her here on Milk Street Radio.