FOOD-GALLEY-3.2.1

Cooking, Core Temperature and Probe Discipline

Cooking kills vegetative bacteria but not spores or heat-stable toxins, and colour is no proof of safety - only a core temperature is, classically 75 degrees C for 30 seconds. Probe the thickest part with a disinfected probe, avoid bone, record the reading, and calibrate the probe in ice and boiling water.

The chef hands you a tray of chicken thighs off the barbecue and says "run those up". They are beautifully charred. You have a probe in your pocket. The difference between a good service and an ambulance on the quay is whether you use it, and whether you know where to put it.

Why cooking works, and where it stops

Thorough cooking destroys vegetative bacteria - the living, growing cells - by heat. It does not reliably destroy spores (Clostridium perfringens, Bacillus cereus), and it does not destroy heat-stable toxins (Staphylococcus aureus). Cooking is your biggest kill step and your most important critical control point, but it is not absolution for what happened before it or what happens after.

Colour, texture and clear juices are not proof of safe cooking. Only a core temperature is.

The standard time-temperature combinations

Core temperature Hold for Notes
60 degrees C 45 minutes
65 degrees C 10 minutes
70 degrees C 2 minutes Common reference standard
75 degrees C 30 seconds The figure taught most widely in catering
80 degrees C 6 seconds

These are equivalent lethalities. The classic exam answer is 75 degrees C for 30 seconds at the core. Remember that exact statutory figures are jurisdiction-dependent and the yacht's own food safety management system sets your working limits.

Some foods need extra care regardless of the guest's preference: poultry, minced and rolled meats, burgers, sausages, kebabs, reformed products and liver must be cooked thoroughly through, because surface bacteria have been mixed inside. A rare steak is defensible - the interior of a whole muscle is essentially sterile and the surface is seared. A rare burger is not, unless it is produced under a specific documented procedure.

Probing correctly

  • Use a clean, disinfected probe. Wipe with a probe wipe (alcohol) before and after every use.
  • Insert into the thickest part or the centre of the food - for poultry, the thickest part of the thigh, avoiding bone, which conducts heat and reads high.
  • For liquids, stir first and probe the centre.
  • Wait for the reading to stabilise, then read it.
  • Take the temperature of the worst case item on the tray, not the smallest.
  • Record the reading.

Calibrating the probe

An uncalibrated probe is a lie you write in the log. Check it regularly (most systems say weekly, and always after a drop):

  • Ice point: crushed ice and a little water, stir - the probe should read 0 degrees C (plus or minus 1).
  • Boiling point: clean boiling water - the probe should read 100 degrees C (plus or minus 1), adjusted for altitude (irrelevant at sea level, which is where you are).

If it fails, adjust it per the manufacturer or replace it, and record the check.

Onboard Notes

Yacht ovens are small, badly calibrated and cook unevenly with the boat heeled; the tray at the back is not the tray at the front, so probe more than one piece. Barbecue and beach cooking is the highest-risk cooking a yacht does: charcoal, wind, poor light, no thermometer to hand. Take the probe ashore, take spare probe wipes, and never plate poultry off a beach grill without probing it. Keep a spare probe aboard - the one you have will fail on the first day of a charter.

Scope note: xplor is not an approved centre or an accredited training provider. This lesson is preparatory study only - no certificate and no regulated qualification is awarded here, and the Level 2 food safety award must be sat and assessed with an approved centre of a regulated awarding organisation.

Practice questions

5 questions
recallcore

recall · core

What is the standard core cooking temperature, and name two equivalent time-temperature combinations.

recallcore

recall · core

How do you probe food correctly?

recallcore

recall · core

How do you calibrate a temperature probe, and why does it matter?

scenariostretch

scenario · stretch

A guest asks for a rare burger from the beach barbecue. The chef is ashore with you and says it is fine because the beef is good quality. What is your position?

oralstretch

oral · stretch

Why is thorough cooking not a complete guarantee of safe food?

Independent study. xplor is not an Ofqual-regulated awarding organisation or an approved centre, and awards no qualification. Covers the ground assessed at Level 2 food safety in catering; the regulated award itself must be sat with an approved centre.

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