How do I cook meat without it forming an unsightly scum?

Question

When I cook any kind of meat, no matter whether roasted or sautéed, there is a scum in the midst of it.
It's also unappetizing mixed with any vegetables.

What am I doing wrong? Is the meat bad?

Answer 1

The scum is most likely albumin, the same protein found in egg whites and some salmon. It's perfectly safe water-soluble protein, and like other such proteins it can 'weep' through drip loss with freezing/thawing.

Normally it's white in colour, though like with an egg raft it can trap hemoglobin/myosin/other red muscle proteins that turn brown with cooking.

For stocks and broths, you can pre-soak your meat in cold water and slowly bring it to a simmer, then discard the water and rinse the meat to remove the albumin and other loose proteins before proceeding with the full cook. This method is used in Korean/Vietnamese/other Asian cuisines, though benefits tougher more flavourful cuts and bones as you would be losing some tasty protein-rich liquid.

It's easier to deal with on dry cooking methods like roasting, searing, or grilling, as you can just pluck it off or even keep heating the surface to turn the albumin into part of a crust.

In my experience a lower temperature allows more albumin to be expelled from the inside of a piece, and I get plenty of albumin from sous vide and reverse-seared meats prior to the finishing sear. It rarely occurs with only intense quick searing.