Effect of temperature on bacteria
100°C Temperature at which water boils
82°C Disinfection using hot water
Legal requirement in Scotland for reheating
75°C Recommended minimum core cooking temperature
63°C Legal requirement to store hot food above this
20-50°C Food poisoning bacteria grow most rapidly
High-risk food too long at this temp. is probably the commonest cause of food poisoning
5-20°C Most food poisoning bacteria grow slowly
Listeria, spoilage bacteria and moulds grow more rapidly
Food more likely to be spoilt rather than unsafe
5°C Temperature at which it is recommended that high-risk foods be stored at or below
1-4°C Recommended air temperature for general refrigerator
0°C Temperature at which water freezes
-18°C Frozen food storage. No bacterial growth
To convert °F to °C deduct 32 and multiply by 5/9
To convert °C to °F multiply by 9/5 and add 32
· Each bacterial species has an optimum temperature at which cell growth is most rapid
· The growth rate falls abruptly at both the upper and the lower limits of their temperature range
· The maximum temperature for growth is usually only a few degrees higher than the optimal temperature
Use a probe thermometer to demonstrate temperature e.g. cup of tea, hot food or refrigerator