Generally speaking, after placing shrimp in boiling water, it takes about 1 minute for small shrimp, 2-3 minutes for medium shrimp, and possibly 4-5 minutes for large shrimp. Shrimp are judged to be cooked when the surface changes color and the meat becomes white and tender. Overcooking may result in hardened shrimp and poor texture, so be flexible with blanching time based on personal preference and the size of the ingredients.