Skip to main content

Make your own snot

This activity will take 30 minutes, is for ages 7 to 10 with supervision needed.

Snot can be gross, but it’s really interesting to scientists.

In this experiment, you will make some pretend snot and understand how it keeps you healthy.

You can even compete with friends or family in a snot race.

What you'll need

  • Washing up liquid
  • Salt
  • Green or yellow food colouring (optional)
  • A teaspoon
  • A cup or mug to mix your snot in
  • A chopping board 

Step by step

  • Add washing-up liquid

    Step 1 of 7

    Squeeze about one centimetre of washing-up liquid into your cup. 

    A clear glass beaker on a table, filled with 1cm deep of clear liquid.

  • Add salt

    Step 2 of 7

    Add a teaspoon of salt and mix it all together. 

    A spoon pouring white powder into a clear glass beaker containing 1cm deep of clear liquid.

  • Add food colouring

    Step 3 of 7

    If your washing up liquid isn't already green, add some green or yellow food colouring to turn it the colour of snot.

    Someone holding a clear glass beaker filled with green liquid, stirring it with a spoon.

  • Snot race

    Step 4 of 7

    If you’re doing a snot race, get every person to make their own snot. 

    Three clear glass beakers on a table with green liquid in them, labelled 'A', 'B', and 'C'.

  • Make a race track

    Step 5 of 7

    Prop up the chopping board to make a slope – this is your race track. 

    A chopping board propped up vertically, with a race start line and three labels saying 'Snot A', 'Snot B' and 'Snot C'.

  • Start line

    Step 6 of 7

    Everyone should put a spoonful of snot at the top of the track, and let it go at the same time. 

    People holding spoons of green liquid against a wooden chopping board, so that the liquid does not spill down the chopping board.

  • Pick a winner

    Step 7 of 7

    The winner is the person whose snot reaches the bottom first.

    Two people look at a propped up wooden chopping board with three streams of green liquid running down it.

    What's in your snot?

    The snot from your nose is a mixture of a few different things, but it is mostly a liquid called mucus. Mucus is a clear liquid mainly made out of water, lots of different proteins made by our cells and electrolytes.  

    You’ll find mucus in lots of different parts of your body. It's up your nose, in your throat and even inside your lungs. Anywhere in your body that needs to stay moist to work properly is covered in a layer of mucus. This stops it from drying out.

    If mucus is clear, why is your snot sometimes different colours? Mucus is sticky and the mucus in your nose catches germs that you breathe in. When your body fights off the germs, it makes chemicals that are green and yellow. So green or yellow snot is a sign that you’re fighting off bacteria or germs. 

    Our science

    The surfaces in your lungs are covered in lots of tiny cells that are shaped like fingers. These are called cilia.

    The cilia help to push all the mucus and any germs that it's caught out of the lungs. Lots of teams of scientists at the Crick are looking at how the cilia work. If we know how the cilia push out the germs and mucus, we can help people whose cilia work differently, or people who have more mucus.

    You might also like these...

    A DNA double helix on a window made out of post it notes, with people either side of the glass.

    What's DNA?

    Every living thing has DNA – from the smallest ant to the tallest tree.