Blanching is a cooking process wherein the food substance, usually a vegetable or fruit, is plunged into boiling water, removed after a brief, timed interval, and finally plunged into iced water or placed under cold running water (shocking or refreshing[1]) to halt the cooking process.
The meaning of blanch is "to whiten", but this is not always the purpose of blanching in cooking. Food is blanched to soften it, or to partly or fully cook it, or to remove a strong taste (for example of cabbage or onions).[2]
When almonds or pistachios are blanched, the skin of the nut (botanically the seed coat surrounding the embryo) softens and can be easily removed later.