Food Safety and Sanitation
Hazard and control framework
Food-safety questions reward precision rather than general caution. Classify hazards as biological (bacteria, viruses, parasites), chemical (cleaners, allergens) and physical (glass, bone). Bacteria need FATTOM - food, acidity, time, temperature, oxygen and moisture. TCS foods, which are high in moisture and protein and low in acid, must stay out of the temperature danger zone of 41°F to 135°F.
The seven HACCP principles
Conduct a hazard analysis; identify critical control points; set critical limits; monitor; take corrective action; verify; keep records. A critical limit is a measurable value at a CCP, such as '165°F for 15 seconds'. Monitoring is the measurement; corrective action is what you do when a limit is missed. Traps: confusing a prerequisite program such as handwashing with a CCP, and forgetting that HACCP records must be kept on site.
Numbers candidates mix up
Cooling: 135°F to 70°F within two hours, then 70°F to 41°F within four more, six hours total. Reheat to 165°F for 15 seconds within two hours. Hot hold at 135°F or above; cold hold at 41°F or below. Handwashing lasts at least 20 seconds at a dedicated sink. Sanitizers: chlorine 50–100 ppm, quaternary ammonium 200–400 ppm, iodine 12.5–25 ppm, verified with test strips and the labeled contact time.
Rule of thumb
Cool in shallow pans no more than 2 inches deep, use an ice bath, and log the times. Worked example: a 20-quart stock at 135°F must reach 70°F by the two-hour mark. If it is still at 85°F at two hours, the corrective action is to reheat it to 165°F and restart cooling, or discard it - never simply continue cooling.