See also: Article on Shrimp
Shrimp are properly cooked when their texture changes from mushy to firm, the color turns from brownish-gray to a warm orangey-pink, and the meat becomes opaque. Shrimp are overcooked when they curl tightly inwards and the flesh becomes rubbery.
Thawing frozen shrimp:
Thaw in the refrigerator one full day before you plan to cook the shrimp. Place the container in the refrigerator on a low shelf. Let shrimp defrost slowly for about 24 hours in a container covered lightly with plastic wrap, then remove any liquid that has collected in the packaging or the container. Use within one day. If you have less time and can closely watch the shrimp. Place shrimp in a leak-proof plastic bag (if it is not in one already.) Submerge shrimp in cold tap water and change the water every 30 minutes until the food has defrosted. Do not try to advance the process with warm water because the shrimp will begin to cook. Cook immediately after thawing.
Buying & Storing Shrimp
Select high quality, fresh shrimp for freezing. Shrimp can be frozen cooked or raw, in or out of the shell. For maximum storage life and quality, freeze shrimp raw, with heads removed but shells still on. Be sure to wash and drain the shrimp if frozen raw. Quickly chill shrimp cooked before freezing. Package in freezer containers or bags, leaving 1/4-inch headspace, seal and freeze.
Shrimp are sized and sold by count (number of shrimp per pound) either whole or headless. For example, headless shrimp of 16-20 count means there are 16 to 20 headless shrimp per pound. Counts for headless shrimp range from under 10 (the largest shrimp) to 300-500 (the smallest).
Shrimp should have a mild aroma (similar to the ocean), tightly adhering shells and firm flesh.
Store shrimp in the coldest part of your refrigerator at 32 degrees F and use within two days, or freeze at 0 degrees F for up to six months.