Prepare the shrimp and place them in a gallon-size resealable plastic storage bag. Refrigerate.
Comments: Achiote (ah-she-O-tay) is a paste that figures prominently in the cooking of the Yucatan Peninsula, where it is used as a marinade for meats. It comes in a small block that looks like Sculpey clay. I like it because the color is the orangey-red of a dramatic sunset and the flavor has the appealing characteristic of being very subtle yet very persistent and permeating. (It reminds me a little of iodine.) The principal ingredient is annatto seeds, which are used as a dye in butter and cheddar cheese.
I find that the flavor works well with shrimp and makes for a dramatic presentation. It is routinely combined with oranges - for good reason, as you'll see. I like the shrimp with only a squeeze of lime, some rice and black beans and a vinegary slaw. But you could easily serve a spicy dipping sauce or salsa with them.