Safe Food Handling and Temperature Control
This is the highest-yield topic on the paper. You must know the danger zone, holding and cooking temperatures, cooling and thawing rules, and how to use a probe thermometer correctly.
The danger zone
Bacteria multiply fastest between 5 °C and 60 °C (41–140 °F), with the optimum near 37 °C. Keep cold food at 5 °C or below, frozen food at −18 °C or below, and hot food at 60 °C or above.
Cooking temperatures
Poultry and stuffed meats 74 °C; minced and ground meat and sausages 71 °C; whole cuts of pork, beef and lamb 63 °C with a 3-minute rest; fish and eggs 63 °C; reheated leftovers 74 °C for at least 15 seconds, once only.
Cooling and thawing
Cool from 60 °C to 21 °C within 2 hours, then 21 °C to 5 °C within a further 4 hours, using shallow pans, ice baths and stirring – never the counter. Thaw in the fridge at 5 °C or below, under running potable water at 21 °C or less, or in a microwave if cooking follows immediately. Never thaw on a counter and never re-freeze thawed food.
Thermometers
Clean and sanitise the probe before and after use. Check accuracy with an ice-point test: crushed ice and water should read 0 °C. Measure the thickest part or centre; insert sideways into thin foods.
Worked example. A 20-litre pot of oxtail stew finishes at 92 °C at 2 p.m. and goes into the fridge at 5 p.m. It is still 55 °C, so it has spent three hours cooling and the centre will take far more than four hours to reach 5 °C. Correct action: portion into shallow containers no more than 5 cm deep, use an ice bath, record temperatures at the 2-hour and 6-hour marks, and discard if the limits are missed.
Traps. The zone is 5–60 °C, not 0–100. Reheating more than once. Judging doneness by colour or by the outside of the food.