Grow something disgusting

Grow something disgusting

Grow your own mould

What you need:

  • Containers that can be sealed e.g. jam jars, zip-lock bags
  • Bread - you can also use fruit, vegetables or yoghurt
  • Water

How to:

Remember: some moulds are good, such as the mould in blue cheese. Other moulds can be toxic. If you suffer from allergies or asthma, we suggest you don't try this experiment as some moulds can trigger allergic reactions.

  1. Put half a slice of bread in a zip-lock bag. Sprinkle a bit of water over the food.
  2. Leave the bag open for half an hour. After half an hour, seal the bag.
  3. Leave the bag in a warm place.
  4. Check the bag daily. How long does it take the mould to grow? There should be mould after about a week. You've grown your own mould! Some supermarket breads take longer to grow mould, as the bread has preservatives added to it which inhibit mould growth.
  5. Once your mould has grown, put the bag in the bin without opening it.

You can repeat this experiment to test for lots of different things.

Try using different foods. What foods grow the most mould? Are all the moulds different?

Try using different amounts of water. Does this affect the amount of mould that grows?

Try growing mould in different locations. Does this affect the amount of mould that grows? What do you think causes this - could it be temperature, sunlight or moisture?

What's happening?

Moulds are a type of fungi. When you leave the bag open, mould spores enter the bag. All houses have mould spores in - it doesn't mean that your house is dirty!

When you seal the bag, mould spores grow into fungi that you can see. Mould grows best in warm, dark and moist conditions.

Although we don't usually want moulds on food, some moulds are helpful. Yeast is a mould which helps bread to rise. Moulds give us the flavour of blue cheese - even if it does taste like stinky feet! Moulds can even help to fight disease. Penicillin, an antibiotic that can cure many bacterial infections, is produced by moulds.

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