Food Safety Techniques
Senior 2 · Home Science
Food Safety Techniques
Lesson 4 of 4
22 min
Let's begin
In the 1960s, the US space agency NASA needed food for astronauts that would never cause food poisoning in space. Testing every finished meal would have used up most of the food, so NASA and the food company Pillsbury built a different approach: find the steps where things could go wrong, and control those steps every single time. That approach became HACCP.
HACCP stands for Hazard Analysis and Critical Control Points. It is now used by food factories, hotels, school kitchens and dairies around the world, including in Rwanda, and it is part of the international food safety standard ISO 22000. The same thinking works in a home kitchen.
Task: A boarding school cooks dry beans for 400 students. The steps are: receive dry beans → sort and wash → soak → boil → hold hot → serve. Carry out a simple hazard analysis and write the plan for the CCPs.
Step 1, hazard analysis:
| Step | Hazard | Control |
|---|---|---|
| Receive | Mouldy or damp beans (biological) | Reject damp, mouldy sacks |
| Sort and wash | Stones (physical); dust (biological) | Pick out stones; wash in safe water |
| Boil | Bacteria survive if undercooked (biological) | CCP 1 |
| Hold hot | Bacteria multiply if the beans cool (biological) | CCP 2 |
Steps 2 to 7, the plan for the CCPs:
| CCP 1: Boil | CCP 2: Hold hot | |
|---|---|---|
| Critical limit | Rolling boil until every bean is soft; at least 75 °C in the centre of the pot | Above 60 °C, or served within 2 hours |
| Monitoring | Cook checks softness and temperature at the end of each batch | Check temperature every 30 minutes; note the time cooking ended |
| Corrective action | Keep boiling and check again | Reheat to 75 °C if under 2 hours; throw away if over 2 hours |
| Verification | Head cook reviews the record sheet weekly; thermometer checked in boiling water | Same |
| Records | Date, batch, time, temperature, initials | Same |
Notice that sorting out stones is a control point but this school has not made it a critical one: a stone is a less severe hazard than live bacteria, and a stone missed at sorting can still be seen during washing and serving. Cooking and hot holding are critical because no later step can remove bacteria that survive or grow there. Another school could judge differently; what matters is that every CCP has a limit, a check, an action and a record.
Tip
Memory hook for the seven principles: "Harry Can Lift My Cow, Very Right". Hazard analysis, CCPs, Limits, Monitoring, Corrective action, Verification, Records.
Exam technique: a critical limit must be something you can measure or observe (a temperature, a time, a colour). "Cook well" earns no mark; "boil until the centre reaches 75 °C" does.
What do the letters HACCP stand for?
Solution: Hazard Analysis and Critical Control Points.
A dairy cooperative boils raw milk before selling it. Why is boiling a critical control point?
Solution: Boiling is the step that kills the harmful bacteria in raw milk, and no later step removes them. If it fails, the hazard reaches the customer.
Suggest a critical limit, a monitoring method and a corrective action for the boiling step in question 2.
Solution: Limit: bring the milk to a full boil (or the temperature the cooperative's procedure sets). Monitoring: the worker watches for a full boil or reads a thermometer for every batch and writes it down. Corrective action: keep heating until the limit is reached; if a batch was sold unboiled, recall it.
Put these principles in order: keep records; identify CCPs; conduct a hazard analysis; set critical limits.
Solution: Conduct a hazard analysis → identify CCPs → set critical limits → keep records.
Summary
Sources and credits
The school-beans HACCP plan, the dairy example and the practice questions are written by Ganzaa.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
