Blanching, or quick-cooking in boiling water, is commonly performed on vegetables to prepare them for freezing. It halts enzymatic damage and helps the veggies to retain their texture and taste during long storage. The method is also used to briefly cook items such as shrimp to kill any surface bacteria and ready them for fresh preparation in otherwise raw dishes such as ceviche, as well as for other cooked preparations served cold such as salads and shrimp cocktail. After blanching, it is important to submerged the ingredients in an ice-water bath to stop the cooking process quickly.

To blanch frozen shrimp, bring a large pot of water to a rolling boil. Add the frozen shrimp and cook for two to 10 minutes, depending on the size of your shrimp. As soon as the shrimp turn pink, promptly remove them from the water and submerge them into an ice bath until they are cool. Drain them well and dry the shrimp before adding them to your final dish. If using in a cold dish, refrigerate the shrimp at this time.

Shrimp are briefly blanched before use in fresh dishes like ceviche where they are finished "cooking" in the acids of lemon and lime juice. They are also cooked in this manner before use in sushi rolls, nigari-style sushi and shrimp cocktails, though all of these preparations require blanching until the shrimp are completely cooked through. Additionally, some recipes call for the blanching of shrimp before they are included into the dish to ensure a good texture and to avoid overcooking in the final dish. In this case, the blanched shrimp would be added to the dish shortly before serving as opposed to being cooked together with the dish where shrimp can become tough.

Unless you live in a coastal area, buying frozen shrimp is a better choice than buying fresh, as most fresh shrimp are simply thawed frozen shrimp and will only last for two days refrigerated. However, shrimp tend to have a better texture and you are better able to control their doneness based on time when they are cooked from fresh. To thaw shrimp before blanching, run them under cool water in a colander for 10 to 15 minutes. Add salt and even sugar to the blanching water to amp up the flavor of your shrimp. Always use an ice bath to cool blanched shrimp to avoid toughness; never allow shrimp to cool in the blanching water.