Omelette is one of my favourite suppers. Here it’s paired with a fun science experiment that needs just two ingredients: vinegar and an egg. You need to leave it overnight to see the results but it takes seconds to prepare and is worth the wait.
Ingredients for Science
Ingredients for Supper
- Butter or oil
- Salt and pepper
- Milk (optional)
- Cheese (optional)
- Firstly pop your egg into the jar and cover with vinegar
- Watch as tiny bubbles form on the shell, pop a lid on and set aside
- Now make the omelette: crack three eggs into a bowl, add salt and pepper plus a dash of milk and whisk well
- Heat a knob of butter in a non-stick frying pan, then add the whisked eggs and cook on medium for a couple of minutes
- Reduce the heat; use a spatula to gently lift the edges and tilt the pan so the runny egg flows into the gaps
- Grate some cheese on top and cook on a low heat for a couple of mins before serving
- Leave your egg in vinegar for at least 24 hours, ideally 3 days
- When it looks translucent (a bit see through) carefully rinse the egg with water and then see if it bounces!
The Science in a Sentence
Egg shell is made of calcium carbonate that reacts with the acidic vinegar releasing bubbles of carbon dioxide, dissolving the hard shell and leaving just the rubbery membrane (skin).
This BBC Good Food omelette recipe gives more detail on how to involve the kids in the cooking plus ideas for fillings. If you want to go gourmet then how about Jamie Oliver’s tomato and basil omelette.
You may notice the egg gets bigger. This is because some of the water in the vinegar has moved through the membrane into the egg.
Bang Goes The Theory has a super explanation of osmosis and also a fun follow-up experiment: you can shrink your egg and dye it with food colouring – that is if it’s not gone splat already like ours did!
You can use any type of vinegar for this but a clear one is best, for example distilled vinegar. If the shell is not coming off easily, put your egg back into the vinegar for another day. When you bounce your egg, start off small and do it in the sink or on a tray to catch the mess if it breaks.