Update on Vinegar for Eggs

So I looked into exactly why it is that vinegar helps poaching eggs keep their shape.


The sciency among you will know that when you heat a protein, it causes it to denature, or lose its closely controlled shape. Egg white is about 8% protein by weight, and the dominant protein (albumin) is mostly responsible for the goopy, slimy behavior of raw eggs. Once it's denatured, it stiffens up pretty dramatically.

Fortunately for the hungry among us, there's more than one way to denature protein. Proteins are generally quite sensitive to changes in pH, so putting the raw egg in the vinegar-water mixture allows the acidic environment to attack and denature anything in contact with the liquid. Effectively, the acid cooks the outer portions of the egg more quickly than the heat of the boiling water can. Once the exterior portions have been cooked, they can't wisp away into the water and they help the egg form a more cohesive unit. This gives the heat time to penetrate the nicely shaped egg and form a more cohesive mass of deliciousness.