Where does this come from, and can I check it?

The white grips the membrane less as the egg ages and its pH rises. The figure is taken from Encyclopaedia Britannica, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a food fact?

Yes. It sits on the Food shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

Older eggs are easier to peel

The white grips the membrane less as the egg ages and its pH rises

As an egg ages, carbon dioxide escapes through the porous shell and the white becomes more alkaline. That shift weakens the bond between the albumen and the inner membrane, so a boiled egg releases its shell more cleanly. This is why cooks often leave eggs for a week before boiling them for a picnic.

Where this comes from

Encyclopaedia Britannica

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

Go further

Food & Cooking trivia Science trivia

More facts like this

Heat untangles proteins in egg whites to form a solid gelWarming denatures translucent ovalbumin proteins until they bond into a firm white mesh Egg yolk lecithin stabilises oil and water mixturesPhospholipids in egg yolk prevent oil and vinegar from separating in sauces Eggshell colour depends on the hen, not the yolkBrown shells carry protoporphyrin pigment, and blue shells carry biliverdin A double yolk comes from two ovulations close togetherTwo yolks are released before the shell forms around them An ostrich egg is the largest laid by any living birdOne egg weighs about 1.4 kilograms, equal to two dozen hen eggs A green potato has been making chlorophyll and solanineLight turns potatoes green and also raises bitter glycoalkaloids in the skin

Tags: eggs, boiling, kitchen science

Older eggs are easier to peel: the short answers

Where does this come from, and can I check it?: The white grips the membrane less as the egg ages and its pH rises. The figure is taken from Encyclopaedia Britannica, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a food fact?: Yes. It sits on the Food shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.