Not thawing properly

Because shrimp spoils quickly, freezing it is a good way to keep it fresh. If you buy shrimp during your weekly market trip but don't plan on using it for a few days, freezing it will keep it from spoiling before it's time to cook. But don't be fooled by their size; thawing them out takes longer than you might think. Defrosting them in warm water or the microwave is also not recommended.

To ensure that your shrimp are completely thawed and remain raw before cooking, remove them from the freezer the day before and place them in a colander set in a bowl. The water will drain out as the shrimp defrost, keeping your shrimp from becoming soggy. If you need cooked shrimp right away, putting them in an airtight bag and submerging them in cold water will thaw them in 10 to 20 minutes. Shrimp cooks rapidly. Submerging frozen shrimp in water or defrosting them in the microwave will start the cooking process too soon. When it comes time to cook the shrimp, they will be more prone to overcooking and uneven cooking.