Question 61
Some bacteria are decomposers. They break down food and change it. Usually this makes the food unpleasant, but sometimes it changes it to something that is good to eat.
One kind of bacterium changes milk to yoghurt. When the bacteria do this, they change sugar in the milk to acid. Many people like the sharp taste that the acid provides.
Sofia makes some yoghurt.
- She washes out a plastic container with boiling water.
- She lets the pot cool down, then puts some fresh milk into the container.
- She adds a small spoonful of yoghurt she bought.
- She covers the container with cling film.
- She puts the container in the refrigerator.
Explain why it is a good idea to wash the container with boiling water.
One kind of bacterium changes milk to yoghurt. When the bacteria do this, they change sugar in the milk to acid. Many people like the sharp taste that the acid provides.
Sofia makes some yoghurt.
- She washes out a plastic container with boiling water.
- She lets the pot cool down, then puts some fresh milk into the container.
- She adds a small spoonful of yoghurt she bought.
- She covers the container with cling film.
- She puts the container in the refrigerator.
Explain why it is a good idea to wash the container with boiling water.
