According to science
Properly cooked scrambled eggs can be a godsend. When they’re soft and creamy with custardy curds they’re a satisfying, healthy breakfast. While egg scrambling technique is paramount, there is another key step that is often overlooked: when you should season eggs. If you use salt, when you salt your eggs can make a world of difference no matter how sound your egg-cooking technique may be. Salt is a magical ingredient that is responsible for a myriad of culinary transformations. And when it comes to cooking scrambled eggs, salt does some pretty cool stuff on a molecular level. Like always, we can look to our food-science overlord Harold McGee for the answers.
Egg proteins have a mostly negative electrical charge, which keeps their proteins separated and untangled. The addition of salt and time allows for the salt to break down into negatively and positively charged ions that essentially negate the charge on the proteins, allowing them to bond more easily when cooked without forming tighter bonds that you’d see if you cooked eggs for an extended period of time. Simply put, salting eggs before cooking them yields more tender eggs.
As with brines and cures, salt takes some time to do its magic. The question is how long? Do you really want to wait half an hour for your morning scrambled eggs? Even if they are the best eggs you can make? Probably not.
For my test, I added salt to scrambled eggs at three different stages: right before cooking, ten minutes before cooking, and during cooking.
The benefits of living with roommates is that I always have taste testers available to make them eat a lot of food in the name of science. While the differences weren’t dramatic, they were very noticeable.
The most tender eggs were definitely those salted ten minutes before cooking. One tester called them “rich and creamy.” A close second were the eggs salted right before cooking. The eggs salted during cooking were far and away the driest of the three. They were called “dry” and “not creamy.” That's because if salt is added after the proteins have unwound themselves and bonded together, all the salt will do is draw out moisture and make the eggs tough and weep liquid on the plate.