Blanching
Putting food into boiling water for a short time, then cooling it quickly in cold water.
Also: blanch, parboil
Blanching is a brief plunge into boiling water followed by a dip in iced water to stop the cooking. It sets the bright green of vegetables, loosens the skins of tomatoes and almonds, and removes some bitterness from greens. It also halts enzymes that would spoil vegetables in the freezer, so it is a normal step before freezing. Bones and offal are sometimes blanched to give a cleaner stock. Parboiling is similar but takes the food further.