What is the effects of salt on shell during boiling
Answers
The primary reason we add salt when we are boiling food in water is to season the food as it cooks. This is especially important in cases where some of the water will be absorbed, such as with pasta and potatoes. Otherwise, we might water the flavor of the food down, and salting the surface of the food might not completely remedy the situation.
Salt does affect the boiling point of water and can even subtly alter proteins. However, significant effects require quite a bit of salt — more than you’d usually add to a pot of cooking water. I was unable to find any references that confirm any effect on the boiling of eggs by adding salt, either through altering the boiling temperature, modifying the coagulation of egg proteins, or salt passing through the egg shell in such a short time.
Far more likely is that the habit of salting boiling water carried over to boiling in-shell eggs. It may even have developed as an “old chef’s tale” due to the fact that in commercial kitchens, eggs would sometimes have been boiled in water scooped from the pot that was kept heated for all other cooking — water which would have been salted.
I wouldn’t bother salting the water for boiling eggs. However, I also recommend steaming eggs rather than actually boiling them: