"There are generally two types of scallops that you can see at the store: wet and dry scallops," says Molly Birnbaum, executive editor of Cook's Science at America's Test Kitchen. "There's a big difference."
She also shared a recipe for Pan-Seared Scallops.
[More from Birnbaum]
Sally Swift: I've been buying scallops lately. I realize I know so little about them. What part do we actually eat?
Molly Birnbaum: Scallops are really fascinating, surprisingly so. The part of the scallop that we actually eat is called the adductor muscle, which is one small part of a scallop as a whole. It's the muscle that helps it open and close its shell.
But there are many more parts of the scallop, ones that we never see in the actual grocery store, including the mantle, the roe, the reproductive glands. Scallops have eyes. They have more than 100 eyes right around the mantle at the edge of their shell, each one with its own lens, retina and optical nerve.
Scallops swim. When we started researching scallops at America's Test Kitchen, I went down the rabbit hole of YouTube videos of scallops swimming; there is a surprising number of them. Scallops can open and close their shells pretty quickly to escape from predators. They swim in a slightly awkward, slightly graceful, very cute way. They swim up into the water, and then fall back down slowly. Their adductor muscle, the one that we end up eating, has a very strong purpose, which is moving them around in the water.
SS: When we shop for scallops, the only thing I see -- they call them wet scallops. What's the difference? What are we looking at when we're buying scallops?
MB: There are generally two types of scallops that you can see at the store: wet and dry scallops. There's a big difference. At America's Test Kitchen, we have pretty strong opinions on which ones you should be buying.
Wet scallops are treated with a solution of water and sodium tripolyphosphate, or STPP, which preserves them as soon as they are harvested at sea. Then they're often frozen. This preserves them, but it also helps them to hold on to a lot more water weight.
Dry scallops are scallops that are not treated in this way.
SS: Which are better?
MB: Dry scallops, hands down. The STPP helps retain moisture in the scallops, but it also imparts a soapy taste and a bouncy texture after they're cooked. We really don't prefer them.
When we started researching scallops for a book that we're working on, we decided to try it out ourselves. We tested a number of scallops by soaking them in a solution of STPP ourselves, and then freezing them, thawing them and cooking them to see how they were.
They weren't that good. They had a lot more water in them; they weighed a lot more. When you cook them, they release a lot more water, because there is so much more water trapped within them. Releasing water when you cook them prevents them from getting that good, brown, crusty sear on them, because there's so much moisture.
Dry scallops haven't been treated in that way. They are a little bit sweeter and fresher tasting, much more preferable.
SS: Often they're not marked dry or wet, so how do we know what we're buying? Is there a test?
MB: First, ask. That's always the best first step.
If you are at home with a bunch of scallops and you're not sure if they're dry or wet, there is actually a test that you can do to determine for yourself. Put a scallop on a paper towel on a plate in the microwave, and microwave it for 15 seconds. If they're dry scallops, there'll be very little moisture released on the paper towel. If they're wet scallops, there will be a noticeable ring of water around the scallop. You can still use that scallop to cook either way.
SS: Is there any way to freshen up wet scallops, or any trick to making them a little bit better?
MB: Yes, we do have a little hack to help make wet scallops better, to cover up that chemical flavor taste. Soak them in 1 quart of cold water with 1/4 cup of lemon juice and 2 tablespoons of salt for 30 minutes. You almost can't tell the difference.
SS: Almost every restaurant these days has beautifully seared scallops on their menus. Can you give us an idea of how to do that at home? Is there a trick?
MB: The trick is high heat. What you want to do is sear the scallop. Pat the scallop dry so that it doesn't have extra moisture on it -- you don't want that to steam and prevent a good crust from forming. But high heat -- stick that scallop down in there, and let it get a nice, crusty, brown, Maillard reaction. Flip it. Then we often add butter and baste the scallop in a little bit of butter so it finishes cooking all the way through.
SS: You start with a really hot pan, put the scallop in and then don't touch?
MB: Exactly. You wait for that perfect crust.
Courtesy of America's Test Kitchen