Blanching is a method of cooking which involves plunging food into hot, boiling water for a short duration of time, after which it is removed from the water and placed in chilled water, so as to stop the cooking process. Blanching is generally applied to foods which need to be partially or completely cooked. Blanched recipes include dishes such as blanched greens, blanched almonds and blanched vegetable salad.
Origin of Blanching
The origin of blanching can be traced back to the origin of boiling, as blanching is a sub-method of boiling, and blanched dishes undergo the process of boiling, although for a very short period of time. Blanching originally translates to whitening, which relates to the bright color attained by vegetables when they are blanched. However, blanching can also be used to soften, semi-cook, or even fully cook various types of dishes, especially vegetables and fruits. As blanching is more of a technique for processing food, it had various benefits and hence become highly popular across all cuisines of the world.
The Process of Blanching
Blanching is carried out by first cutting vegetables or fruits as required for the blanched dishes, and then throwing them into vigorously boiling water for a few minutes, although the time depends on the food being blanched and the desired level of doneness. Once cooked, the food is immediately plunged into ice cold water, so as to put an end to the cooking process as the food continues to cook when hot. Blanched recipes require two different vessels, one for boiling water and one for dipping the food in chilled water. Blanching is an extremely fast process as the food is generally removed from the heat when semi-cooked or tender.
Popular Blanched Dishes
Blanched almonds and vegetable salad are two popular blanched preparations. In fact, blanching is also used as a supporting cooking technique for dishes that require very little cooking time, e.g. in case of stir fried dishes the vegetables that require more time to cook can be blanched till semi cooked, so that all the ingredients are evenly cooked after a few seconds of frying. Blanching is also preferred for foods that need to be kept frozen, as it neutralizes any bacteria in the food which may spoil the food. Vegetables, especially greens, are very suitable for blanching as it enhances the color and flavor of the vegetables, and also keeps them crisp. Blanching is practiced in almost every cuisine, either for cooking or processing purposes.
Advantages and Disadvantages of Blanching
Blanching has several advantages. Blanched dishes are healthy as there is minimal loss of nutrients because of the short cooking time. Blanching also enhances the color of green vegetables, and the time taken is also lesser than other moist heat cooking methods.
However, one disadvantage is that blanching cannot be used for every type of food item. Also, blanching often needs to be coupled with another cooking process so as to provide more flavor to the final dish.
Techniques Similar to Blanching
Boiling is a technique that is very similar to blanching, as blanching itself includes boiling the food in order to cook it, and the difference lies in the duration of time required, which is much less for blanching, and it also requires immediate cooling of the food, which is not so in the case of boiling.
Blanching: Trivia 
Blanching helps to inactivate the enzymes present in food which needs to be frozen, as the enzymes and bacteria, if active can lead to the deterioration in food quality.