What does “monter en neige” mean in French cooking?

French recipes often say monter les blancs en neige: beat the egg whites until they hold stiff, snow-like peaks. Monter is “to raise” and en neige is “into snow,” which is what the white foam looks like once it is firm — battre and fouetter work too, but this is the phrase recipes reach for. Just des blancs en neige names the result.

The image is old — the Académie française was already defining œufs à la neige in 1798 as eggs beaten so that the foam resembles snow. The name survives as a dessert: œufs à la neige, poached meringue floating on custard, sold in French restaurants as île flottante.