Which technique involves cooking food briefly in boiling water and then plunging it into ice water?

The technique that involves cooking food briefly in boiling water and then plunging it into ice water is called blanching. This method is particularly useful for preserving the color, flavor, and nutrients of vegetables, as well as for loosening the skins of fruits and vegetables, such as tomatoes or peaches.

When food is blanched, it is first immersed in boiling water for a short period of time, typically ranging from a few seconds to a couple of minutes, depending on the type of food and the desired outcome. After the initial cooking, the food is immediately transferred to a bowl of ice water; this process, known as shocking, stops the cooking process abruptly. As a result, the food remains bright and fresh while ensuring that it is partially cooked, making it easier to handle in preparation for further cooking or freezing.

In contrast, sautéing involves cooking food quickly in a small amount of fat over relatively high heat, while poaching gently cooks food in water or broth at low temperatures, and steaming uses the vapors from boiling water to cook food. These techniques differ significantly from blanching, as they do not involve the rapid temperature change facilitated by plunging food into ice water.