Naked egg in vinegar

Recommended age: 8+. Adult supervision required! Over two days, vinegar dissolves the shell of a raw egg, leaving a translucent 'bouncy egg' jiggling in its membrane — spectacular slow chemistry on your kitchen counter.

Photograph of a translucent shell-less egg with a rubbery membrane resting in a clear glass of vinegar, fine gas bubbles clinging all over its surface, the yolk faintly visible glo
Prep
5 min
Reaction time
10 min
Waiting
2880 min
Total
2895 min
Difficulty
Easy

Chemicals

  • 1 pc raw egg (fresh, without cracks) — fresh, without cracks
  • 300 ml household vinegar (10%) (enough to cover the egg completely) — enough to cover the egg completely

Procedure

  1. Raw egg can carry salmonella: wash your hands immediately after touching the egg or the jar, and never put the egg in your mouth! Vinegar stings the eyes — work with your goggles on.

    Safety!
  2. Using the tablespoon, slide the egg gently to the bottom of the jar.

  3. Pour in vinegar until the egg is completely covered.

  4. Look right away: tiny bubbles are beading on the shell — that is carbon dioxide forming! The bubbles may even make the egg start to dance.

  5. Cover the jar loosely and leave it on the counter. After 24 hours, pour off the liquid and add fresh vinegar — the result comes faster and cleaner this way.

  6. After another 24 hours, lift the egg out with the spoon and rinse it under a thin stream of cold water, gently rubbing off the remaining white film with your fingertips.

  7. In a dark room, shine a phone light through the egg — you will see its yolk glowing through the translucent inside!

    Technique
  8. Over the small plate, drop it gently from 2-3 cm: it bounces like a rubber ball! From higher up it will burst — the egg decides how far you dare to go.

  9. At the end, wash your hands thoroughly and wash up everything that touched the egg.

Apparatus

  • 1× jar or tall glass — kb. 0,5 l
  • 1× tablespoon
  • 1× small plate

Frequently asked questions

Why does it work?
The eggshell is calcium carbonate, which the acetic acid dissolves while producing carbon dioxide gas — that is what you see as bubbles. The elastic membrane under the shell does not dissolve: it holds the egg together and makes it 'rubbery'.
Why did the egg get bigger than it was?
The membrane is semi-permeable: water passes through it and migrates from the vinegar into the egg — this is called osmosis. If you then put the finished egg into thick sugar syrup for a day, it shrivels, because the water migrates outwards instead.
How long does the bouncy egg keep?
About a week in a closed box in the fridge. Then throw it away — remember, inside it has remained a raw egg the whole time and must not be eaten in any form.

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