The small, tough tab on the side of a scallop is called the side muscle, and removing it takes about two seconds: pinch it between your thumb and forefinger, then peel it off. It pulls away cleanly from the main body of the scallop with almost no effort. If you skip this step, you’ll end up with a chewy, rubbery strip attached to an otherwise tender piece of seafood.
What the Side Muscle Actually Is
A scallop has two types of adductor muscle separated by a thin sheet of connective tissue. The large, round, tender part you eat is the fast-twitch striated muscle, which the scallop uses to clap its shells together for swimming. The small rectangular tab on the side is part of the slow-twitch “catch” muscle, which holds the shells clamped shut for long periods without using much energy. That endurance function is exactly why it’s so tough. It’s designed to stay contracted, and no amount of cooking will make it tender the way the main muscle is.
How to Find and Remove It
Hold the scallop in one hand and look at its side. You’ll see a small, slightly darker or more opaque strip of tissue attached to the edge. It’s roughly rectangular and feels noticeably firmer than the rest of the scallop. On large sea scallops, it’s easy to spot. On smaller bay scallops, it can be harder to see but is still there.
To remove it, just pinch the tab between your thumb and index finger and peel it away from the body. It should come off in one piece with a gentle tug. If the scallop is cold, the muscle may be slightly stiffer and even easier to grip. Don’t use a knife for this step. Your fingers give you better control, and there’s no need to cut into the scallop itself.
Set the removed side muscles aside. Some cooks save them for fish stock since they add flavor even though their texture isn’t great for eating on their own.
Sea Scallops vs. Bay Scallops
Sea scallops are the large ones, typically 1 to 2 inches across, and their side muscle is obvious. You should always remove it before cooking. Bay scallops are much smaller, sometimes the size of a thumbnail, and while they technically have the same muscle, it’s so tiny that many cooks don’t bother removing it. If you’re pan-searing bay scallops and want the best possible texture, it’s still worth a quick check, but it won’t ruin the dish if you leave them on.
Shucking Whole Scallops in the Shell
If you’re starting with live, whole scallops rather than pre-shucked ones from the fish counter, you’ll need to open the shell first before you can get to the side muscle. Place the scallops on ice for 10 to 15 minutes. The cold relaxes the adductor muscle, which makes the shells much easier to pry apart.
Use a shellfish knife with a blunt, rounded tip, or even a teaspoon. A rounded tip slides between the shells without tearing the meat. Slip the blade along the inside of the flat top shell, scraping gently to sever the muscle from that side. Remove the top shell, then slide the knife under the scallop to free it from the bottom shell. You’ll see the round white muscle surrounded by a skirt of soft tissue, including the orange or white roe (the reproductive gland), the gills, and the digestive organs.
Pull away all the soft surrounding tissue to isolate the round white adductor muscle. Then find and peel off the side muscle as described above. You’re left with the clean, round medallion that’s ready for cooking.
Storing Scallops After Cleaning
Once scallops are shucked and cleaned, they keep in the refrigerator for up to three days. Pat them dry with a paper towel, place them in a single layer on a plate lined with a fresh towel, and cover loosely. Keeping them dry on the surface is important because excess moisture prevents a good sear. If you’re not cooking them within three days, freeze them. Frozen scallops hold their quality for up to three months. Spread them on a sheet pan in a single layer to freeze individually before transferring to a sealed bag, which prevents them from clumping together.