Q. Fresh scallops (when patted dry) sear beautifully in a matter of seconds. My "previously frozen" scallops always end up boiling in their own juices when I'm attempting to do a quick sauté in butter with garlic. Repeated draining of the frying pan: a. diminishes the flavor, and b. increases cooking time, making the scallops rubbery. In every instance, the end result is a "stewed" rather than "seared" scallop.
A. Absolutely right. Most people ask us questions, but in the absence of one from you, we'll ramble on a bit about what happens. Actually, it's a very common effect of freezing, and you find it as much with meat and vegetables as with scallops. You may notice the change more with scallops, though, because they are so delicate and benefit from such brief cooking.
As you know, when water freezes, it expands. When the water in foods freezes, it often bursts some of the cell walls that give the food its structure. When the food thaws, the water in those cells is free to run where it pleases, and in your case, that's right out of the scallops and all over the bottom of your pan.
Generally, freezing doesn't harm the taste of a food, but it certainly can alter the texture. Some foods those with thicker and stronger cell walls or those with less water content hold up better to freezing than others. If you've ever inadvertently frozen a lettuce leaf, you noticed that it became a bruised, soggy mess as soon as it thawed all the water inside it seeped out. Green beans, though, have less water and a stronger structure and hold up better to freezing. We have no objection to freezing chicken, for instance, but won't freeze a steak. You can freeze a steak, of course, but we notice enough of a change in texture with a frozen steak that we'd just as soon eat chicken.
The solution for you then, is to sear fresh scallops as often as you can find them, and use frozen scallops in a casserole, stew or other dish that will benefit from a little extra moisture.