Blanching, a method of cooking

Blanching is a method of cooking in boiling water, with the implication that the food will be further cooked after blanching. For example, root vegetables or tubers such as potatoes or turnips may be blanched in boiling water until barely cooked through before being sautéed, grilled or roasted. Slow cooking root vegetables would otherwise overcook on the outside before the intense heat of the sauté pan or grill penetrate the dense flesh to the interior. Large root vegetables are blanched starting in cold water so that the heat penetrates them gradually and they cook more evenly.

Older turnips are sometimes sectioned and blanched, starting in cold water, to eliminate any bitterness. Meats and bones are sometimes blanched to eliminate the scum that would otherwise cloud the poaching liquid or broth. Tomatoes and peaches are often blanched to loosen their skins and make peeling easier.

Sometimes people add baking soda to the water used for blanching green vegetables. As baking soda is alkaline, it neutralizes natural acids contained in the vegetables and turns the vegetables bright green. Unfortunately, baking soda also causes vegetables to turn mushy.