You’ve just purchased a beautiful piece of salmon and put it proudly on the grill, but wait, what is that white substance that is starting to ooze out of your fillet? That white stuff is called albumin. The good news is it is completely harmless. But what exactly is it and why is it there?
Albumin is a type of protein. It’s not fat like many people mistakenly assume that exists in the dish in liquid form when it’s raw. It pushes to the surface of the salmon when you heat it. Once this protein reaches a temperature between 140 and 150 degrees, the coagulated albumin gets squeezed out and appears in the form of the strange white substance that you are probably familiar with.
The amount of albumin in a salmon fillet doesn’t seem to be, and sometimes you’ll end up with a piece that’s covered in it and sometimes hardly any if it will appear. This actually has nothing to do with the type of salmon you’re cooking, but rather with how you’re cooking it. The more aggressively you cook it, the more albumin will appear on its surface. The higher the heat, the more quickly the flesh contracts, and the more albumin will become visible.