Blanching

The word comes from French blanchir, to whiten; according to the Trésor de la langue française, its culinary sense is to scald vegetables in boiling water to remove their harshness. Escoffier’s 1907 guide calls the term expressly unsuitable, because it covers three different operations: blanching meat, parboiling vegetables, and a process that is really cooking. Cooking green vegetables in boiling salted water should, in his view, be called “à l’anglaise”.

Meat such as calf’s head or sweetbread Escoffier puts into cold water, brings gradually to the boil and then cools in fresh water. The US National Center for Home Food Preservation describes blanching vegetables before freezing as a short scalding in boiling water or steam that stops enzyme actions which would otherwise spoil flavour, colour and texture; it warns that under-blanching is worse than not blanching at all.