Temperature Control, Storage and Preservation
What this domain tests
The exam checks numeric temperature limits, the reason for each, and storage controls that keep food out of the danger zone. Learn the limits as controls with a purpose, not as isolated numbers.
Key temperature limits
- Cold holding: legal maximum 8°C; best practice 5°C or below. Fridges should run at 0–5°C.
- Freezing: −18°C or colder; freezers should not be overfilled.
- Cooking: 75°C for at least 30 seconds (or an equivalent time/temperature combination) at the centre.
- Hot holding: 63°C or above; check at least every 2 hours.
- Reheating: 82°C for at least 30 seconds (best practice).
- Danger zone: 8–63°C. Limit time here; the 2-hour/4-hour guidance is for display and cooling decisions, not a licence to leave food out.
- Cooling: from 63°C to 8°C within 90 minutes, then into the fridge.
Storage and preservation
Use first in, first out; check dates; keep raw below cooked/RTE; cover food; leave air gaps; thaw in the fridge or under running water below 21°C, never at room temperature. Preservation works by removing water, lowering pH, adding salt/sugar, smoking, canning or freezing; each only slows or stops particular organisms.
Worked example
A large pot of stew is left on the hob to cool overnight. It stays between 20°C and 40°C for hours - ideal for Clostridium perfringens. The correct method is to divide into shallow containers, use a blast chiller or ice bath, record the time to reach 8°C within 90 minutes, then refrigerate. Reheating to 82°C later does not undo the growth.
Traps
- Reading the fridge air temperature only; check food probe temperature.
- Overloading a fridge so air cannot circulate.
- Thawing meat on the bench.
- Assuming freezing kills bacteria - it does not.
- Using the 8°C legal limit as a target when 5°C is achievable.