How to Tell If a Hard-Boiled Egg Is Done Cooking

Is it just a mystery until you crack it open? We tested four methods (and have one final verdict) for figuring out if your eggs are cooked.

March 18, 2022
By: Rachel Cox
A row of hard boiled eggs showing the order of hard boiling an egg, peeling, and cutting.


A row of hard boiled eggs showing the order of hard boiling an egg, peeling, and cutting.

Photo by: Laurie Ambrose/Getty

Laurie Ambrose/Getty

Eggs are one of the most versatile ingredients we’ve got in our fridge, but they can be surprisingly confounding to cook. And hard-boiled eggs can be especially mysterious since there’s no way to know if they’re done without cracking them open — or is there? Some popular hacks floating around the internet claim that they can determine whether an egg is cooked or raw. I put four tricks to the test, comparing a cooked egg and a raw one to see if any of the hacks were effective. Here’s what happened.

The Spin

To test this popular trick, I laid both eggs on a smooth, flat surface and gave them a light spin. The boiled egg spun quickly, smoothly, and without any wobble. But the raw egg spun very slowly and wobbled back and forth because the liquid inside of the raw egg sloshes around, causing the egg to be less stable. Surprisingly, this test worked well, but it’s not very exact since a nearly cooked egg might also not wobble — more on that later.

The Flashlight

This trick takes you back to science class. In a dark space, hold up an egg and put a flashlight behind it so that the egg is between you and the light. With the light on the raw egg, the entire thing was lit up from within. But when I tested it on the hard-boiled one, very little light passed through except around the edges. The solid cooked white prevented light from breaking through. This one was the most fun to see, but unfortunately, I didn’t find it as reliable as the spin. While the white of the egg appeared cooked, there was no way to determine the degree of the yolk’s doneness.

The Air Bubbles

For this hack, grab a clear bowl or cup and fill it up with warm water. Gently place your egg in the warm water and observe closely. With the cooked egg I saw no bubbles, but with the raw one I saw small air bubbles form close to the surface — but it was difficult to judge, and I’m not sure it really tells you much about how cooked the egg is.


Photo by: Claudia Totir/Getty

Claudia Totir/Getty

The Shake

Very simple, hold each egg and give it a gentle shake. When put close to your ear, you can hear the raw egg slosh a little and feel the liquid moving around. This method required quite a bit of practice. I did it a few times so I could listen carefully, but also to get a "feel" for what the cooked egg was supposed to be like. Ultimately, I ran into the same issue as with the flashlight method — there was no way to be sure of the yolk’s doneness. Cooked eggs sounded different from raw, but I couldn’t determine what the inside would look like until I cut it open.

Final Verdict

If you want some extra reassurance about whether your eggs are cooked, the spin test was the winner. It was super easy to perform, the differences between the raw and boiled eggs were noticeable, and the results were consistent.

That said, this test might not tell you how cooked your boiled egg is — an egg that’s still a little jammy on the side might still spin better than the raw egg, but won’t be exactly what you want for egg salad. Instead, check for feel: if you peel an egg and it still feels really soft, leave it whole and pop it back in the boiling water for 1-2 minutes more.

If you’re still unsure, slice one open and get eyes on the yolk. If the sliced egg is undercooked, place it on a microwave safe plate and heat it in 1-minute increments until the yolk darkens and becomes firm. And place any other uncracked eggs you were boiling back into the hot water.

The tried-and true method for perfect boiled eggs starts with setting a timer — follow our recipe to get it just right. It might take a little trial and error with your stove, but once you know the time that works best for how you like your eggs, you’ll be able to replicate it with ease.

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