The Pot on the Stove: A Ten-Hour Power Cut
On Friday evening Mrs Nangolo cooks a 4 kg pot of chicken stew for her household of seven in Katutura. She leaves it covered on the stove to cool 'until morning'. At 05:30 on Saturday the power fails and is not restored until 15:30 - ten hours. During the day the children open the fridge door four times; the freezer, which is three-quarters full, is opened twice. Inside the fridge are two litres of milk, a bowl of cooked rice left over from Thursday, a tub of margarine, ten eggs and a jug of gravy. The freezer holds 2 kg of beef and 1 kg of fish. There is a two-year-old in the house and an aunt who is 28 weeks pregnant. By Saturday evening the family is hungry, and the stew looks and smells completely normal.
1. Decide which of the foods should be kept and which must be thrown away. Give a reason for each decision.
Read the worked answer
Work through the foods one by one, using the temperature danger zone (roughly 5–60 °C), the time spent there, and the moisture and protein content of each food.
- Chicken stew and gravy - discard. A moist, protein-rich food left at room temperature for about 24 hours has spent far longer than two hours in the danger zone. Smell and taste are not a test: some bacteria and their toxins cause no visible or odour change, and reheating does not destroy toxins that have already formed.
- Cooked rice - discard. Rice carries Bacillus cereus spores that survive cooking; the moist rice cooled slowly and then sat in a warming fridge.
- Milk - discard. The fridge rose above 4 °C and the door was opened four times. Milk supports rapid bacterial growth and is a poor risk food.
- Margarine - keep. High fat, low moisture, and it was still cool.
- Eggs - keep, but cook thoroughly. Shell eggs keep better than cooked dishes; still, use them in a hot cooked dish, not raw.
- Beef and fish - check before deciding. A three-quarters-full freezer opened twice would probably have held near −18 °C for ten hours. If the meat is still firm and shows ice crystals, cook it thoroughly today or refreeze it; if it is soft, warm or leaking, discard it.
With a toddler and a pregnant woman in the house, always take the cautious option.
2. Explain how the stew should have been handled on Friday night, and how it should be reheated if it had been kept safely.
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The mistake was cooling a large mass of food slowly in a warm kitchen. A 4 kg pot holds heat in the middle for hours, so the centre sits in the danger zone long after the outside feels cool.
What should have happened:
- Divide the stew into several shallow containers - small portions cool far faster because the surface-to-volume ratio is greater.
- Cool uncovered for no more than about 30 minutes, then cover and refrigerate within two hours of cooking.
- Store at 4 °C or below and use within two days, or freeze in meal-sized portions.
- Never reheat a whole pot twice; take out only what will be eaten.
Safe reheating: reheat the portion so that it is steaming hot all the way through - the centre must reach at least 74 °C, and the gravy must bubble, not merely warm. Stir so there are no cold spots, and use a clean spoon to taste. Reheat once only; leftover reheated stew should not be cooled and reheated again. If a microwave or stove is unavailable, rapid boiling in a pot is the only safe option - leaving it to 'warm up' slowly lets bacteria multiply before the food gets hot.
3. Give three practical actions the family should take in the first four hours of any future power cut, and explain why each one works.
Read the worked answer
1. Keep the doors shut and use a thermometer, not guesswork. Every opening lets cold air spill out and warm air in. Tape a note on the fridge and freezer doors reading 'do not open' during an outage. An unopened, full freezer holds its temperature for roughly 24–48 hours; a half-full one far less. A cheap fridge thermometer tells you whether the food actually stayed cold.
2. Group food and fill empty space. Cold mass holds cold. Before the next rainy season, fill empty freezer space with water bottles or ice packs; in this household the freezer is already three-quarters full, which is an advantage. Grouping items together in the fridge also reduces warming.
3. Act within the two-hour window. If the power is still off after two hours, move the most risky items - milk, cooked dishes, meat - into a cooler box with ice, or cook and eat them immediately. Decide early rather than hoping. The family should also keep a small stock of long-life milk and tinned fish so that one spoiled pot does not mean a hungry night.
Underlying all three is the same idea: the risk depends on time multiplied by temperature, so shorten one or lower the other.