Food spoilage

Yeast

• Yeast are microscopic fungi which reproduce by budding.
• Yeast grow on sugar and produce carbon dioxide.
• Yeast can attack sugary foods such as fruit and jam and cause spoilage.
• Yeast is used usefully to make alcohol.

Bacteria

• Bacteria are single celled organisms which are widely found in soil and air.
• Some bacteria are useful but others cause food spoilage and are poisonous.
• Useful bacteria are used to make yoghurt and cheese.

Moulds

• Moulds are a form of fungi.
• Moulds are carried on wind and settle on food.
• They grow on the surfaces of food such as bread, meat and cheese.