Edible shrimp range in size from market categories of extra small to extra colossal and require deveining preparation, whether fresh or frozen, before use in many recipes. Shrimp deveining tools help to make the process safe and simple in one smooth motion. Deveining tool designs range from a basic deveining knife, with a slender serrated or non-serrated curved blade, to scissor-like utensils, with curved double-blades and squeeze grips, which peel and devein shrimp simultaneously.
Place shrimp to be deveined into a bowl of ice water. This keeps the shrimp texture as sturdy as possible for the deveining process. Have another bowl of ice water nearby to place deveined shrimp into. Work in a well lit area near a cold running water source for washing exposed veins away.
Clean thoroughly the deveining tool. A non-serrated deveining knife is simplest for deveining already peeled shrimp. A serrated version allows shell-on shrimp to be deveined by piercing through the back shell. Curved seafood deveining scissors can both peel and devein the shrimp in one motion with a curved serrated blade and a curved non-serrated blade.
Remove the head of the shrimp, if peeling is desired. Split the shell with the deveining knife blade along the back of the shrimp. Slip it off by pinching the legs and pulling it away from the shrimp meat. Leave the tail on or remove it.
Grip the deveining knife with the curved tip directed down. Hold the cold shrimp in one hand, exposing the peeled back upwards. Split open along the vein line with the curved smooth tip of the tool, using the curve of the shrimp meat as a guide. Remove the exposed string-like vein by lifting it out with the tool tip or by hand. Place deveined shrimp into the ice water. If the shrimp has never been frozen, the vein can simply be washed away under cold running water.
Devein shrimp with its shell on by piercing the back of each at several points along its vein line. Use the serrated tip of the deveining tool to pierce the shell and the shrimp meat. Hook the vein with the tip and pull it out in each spot until it is fully removed.
Peel and devein shrimp simulatneously, with a scissor-style shrimp deveining tool. Remove the head and hold the body firmly by the tail and legs -- to expose the vein along the shrimp's back.
Slip the lower curved non-serrated blade below the shell sleeve at the top of the shrimp and squeeze the grips together, while pushing the scissors towards the tail. This will split the meat open and slice the shell open at the same time -- so that both the vein and shell are prepared for easy removal.
Wear a cut-resistant protective glove on the hand which holds the shrimp, to prevent accidental injuries.