Bitter Shrimp Taste
What causes shrimp to taste bitter or have an "iodine" flavor?
Answer: If you have purchased wild ocean caught shrimp, you can expect a little taste of iodine. The iodine comes from plankton, which is what the shrimp eats.
If the iodine is to strong for you, you can use this recipe to pre soak them before you cook them.
In 1 quart of cold water, add 2 tablespoons of baking soda and soak for 10 to 15 minutes. Then rinse the shrimp off under cold water.
Hope that answered your question, with out see the shrimp.