Silverskin
A tough, silvery-white membrane of connective tissue (elastin) that covers some muscles and must be removed before cooking as it never breaks down.
Silverskin is a thin, tough, silvery-white membrane made of elastin that covers the surface of certain muscles. Unlike collagen — which breaks down into gelatin with heat and time — elastin is heat-stable. It will never become tender no matter how long you cook it.
Why You Must Remove It: Left on the meat, silverskin shrinks during cooking, causing the meat to curl and cook unevenly. It also creates a tough, chewy, unpleasant texture on the finished product. It's one of the few things in butchery where the answer is always "remove it."
Where You'll Find It: - Tenderloin (the entire surface is covered) - Ribs (between the bone and meat) - Loin muscles - Pork tenderloin - Lamb rack
How to Remove It: 1. Slide the tip of a thin, sharp knife (a boning knife is ideal) under the silverskin 2. Angle the blade slightly upward — you want to cut the membrane, not the meat 3. Grip the freed end of the silverskin with a paper towel (it's slippery) 4. Pull the membrane taut and slide the knife away from you, keeping the blade angled up 5. Work in strips — trying to remove it all in one piece often takes too much meat with it
Pro Tip: A dull knife makes this job miserable and wastes meat. Keep your boning knife razor sharp — it should glide through the membrane with almost no pressure. If you're pressing hard, you're cutting into the meat.
The Exception: Some pitmasters leave silverskin on the back of ribs (the membrane) to help them hold together during smoking. I remove it — the smoke penetrates better and the texture is superior — but it's a legitimate debate.