10 Mind-Blowing Facts About the Science of Boiling an Egg Perfectly

5. Fresh Eggs Peel Poorly (It's All About pH!)

Struggling to peel those farm-fresh eggs? It’s not you, it’s science! A fresh egg white (albumen) has a lower pH (more acidic). In this state, it bonds more strongly to the inner shell membrane. As an egg ages over days or weeks, carbon dioxide escapes through the shell pores, causing the albumen's pH to rise (become more alkaline). This higher pH weakens the bond, making the membrane (and shell) separate much more easily after cooking. Using eggs that are at least a week old is the secret weapon here!