This is really cool! It will amaze your kids and teach them some science all at once. Time needed: 4-7 days
Put an egg in a cup and fill it with apple cider vinegar till egg is covered. Cover tightly and let it sit. Each day give it a swirl. At the end you rinse off the egg and VIOLA! A rubber egg! Just be careful…it will bounce but is still delicate and very smelly when it breaks. LOL …Not rotten — just smells like vinegar. Always keep it in the fridge during the whole process!
Added tip: If you place the “naked egg” in corn syrup, it will shrink/shrivel up. The vinegar inside the egg moves through the semi-permeable membrane.
You can then place it in water with food coloring and “color” the inside of the egg and it will fill up again due to osmosis