Blanching is a food preparation technique in which food is briefly immersed in hot liquid, like boiling water often but not always as a prelude to cooking it further. Fruits, vegetables, and nuts are the foods that are most frequently blanched, each for different reasons.
Delicate vegetables – particularly green vegetables can be blanched in salted boiling water and refreshed in ice-cold water to arrest the cooking process. The main reason for this is because, between the temperatures of 66°C and 77°C, chlorophyll is unstable. Chlorophyll is the green pigment in any plant that photosynthesis. For this reason it is important to get through this temperature zone as quickly as possible.
Different recipes will call for different blanching times, but with blanching, times are measured in terms of seconds rather than minutes. Typical blanching times range from 30 to 60 seconds.
Blanching can be done for salads, grill vegetables, garnish and many more.