My mom's a goddess in the kitchen and can whip up inventive meals without following a recipe. But she does have a set of rules, and one of the things she always makes sure to do is prick eggs before boiling them. Whether she's making soft-boiled egg for my favorite breakfast comfort food (salted soft-boiled eggs with cubed, buttered toast), or hard-boiled eggs for our annual Easter egg-dyeing operation, the eggs have to be pricked.
Until moving into an apartment where I had to fend for myself in the kitchen, I had never wondered why she insisted on pricking eggs before boiling. It was just a thing she did. But even though I've finally mastered how to boil an egg, I’ve also cracked and messed up my fair share. When I complained to her about my cracked eggs, she asked me, “Well, have you been pricking them?” Cue the eureka moment. Pricking the bottom of the larger side of your eggs not only keeps them from cracking but also makes them easier to peel.
This is because there's air in the fatter, flatter part of your egg. When water heats the egg, that air pocket expands and creates pressure inside the shell, which can crack it. Piercing it will relieve this pressure. Especially in older eggs—which are better for boiling because they are easier to peel—as they have more gas inside the shell and so crack more readily. Fortunately, pricking also allows water to loosen the membrane that attaches the albumen (white part) to the shell, making eggs easier to peel. It works especially well with farm-fresh eggs, which are notoriously hard to peel.
Pro tip: Throw some salt in the water before carefully dropping in your pierced eggs to prevent too much albumen from leaking out of the little hole. You could buy yourself a cool egg pricker or a fancy egg peeler, or you could just use a good ol’ safety pin. The choice is yours.