Planets and Pancakes

Cook up some yummy pancakes for supper then use food colouring and washing-up liquid to make beautiful milk planets and find out how detergent breaks up fat molecules. This milk art video gives you an idea of what you can do.

Make amazing planet patterns like this using milk, food colouring and a little washing-up detergent

Ingredients

Pancakes:	Planets:
Milk	Milk
Eggs	Food colouring
Flour	Washing-up liquid
Salt	Cocktail stick
Toppings	Saucer

RECIPE

1. Make the pancake batter
   • Measure 60g plain flour into a bowl and add a pinch of salt
   • Break one egg into a jug, pour into the bowl and mix with a fork or flat whisk
   • Gradually add 120ml milk, whisking until you have a smooth-ish batter
2. Let it stand while you do some science
   • Pour some milk into a saucer
   • Add a drop few drops of different food colourings
   • Dip a cocktail stick in washing up liquid
   • Touch it gently onto the milk surface
   • Experiment with different colours
3. Cook your supper
   • Heat a knob of butter or oil in a frying pan
   • Pour in about two tablespoons of batter and swirl round the pan
   • Cook on a medium heat until golden brown
   • Flip with a spatula to cook the other side
4. Serve with your favourite savoury toppings
   • Savoury ideas: cheese, ham, tomato, mushrooms, baked beans
   • Sweet: try jam, chocolate spread, syrup or the classic sugar and lemon.

Notes

What’s going on? The science in a sentence…
The fat droplets in milk break up when detergent is added, the food colour helps us see this happening. The second part of this blog post explains this in more detail.

You can also do a similar experiment with ground black pepper and milk or water. I like this pepper trick video from DaveHax.

Update March 2020: This video uses the pepper trick to help children understand the importance of hand washing with soap.

Other ideas for supper…
If you fancy something even easier then supermarkets sell pre-made pancakes and batter mixes or if you fancy going gourmet then check out these savoury pancake ideas.

And finally….
Using full fat milk works best for this experiment but you should still get some effect with semi-skimmed. Some of the food colourings available in supermarkets work better than others – experiment with different colours and types if you can.