What's the correct temperature reading for cold water test when testing a food probe thermometer?

When testing a probe thermometer in cold water, you should get a reading of 0°C (32°F). To achieve this accurate reading, you'll need to create a proper ice bath by filling a vessel with crushed ice and adding just enough water to make the ice float. Let it stabilise before testing.

Remember to avoid touching the ice cubes directly with the probe when taking the reading, and stir gently to maintain even temperature throughout the bath.

Common misunderstanding: You can use any type of ice for the cold water test, including large ice cubes or ice packs.

For an accurate cold water test, using crushed ice is essential because it creates a uniform temperature environment. Large ice cubes or ice packs may not provide consistent temperature readings due to uneven melting, which can result in inaccurate thermometer calibration.

Common misunderstanding: Once calibrated in an ice bath, a thermometer remains accurate indefinitely.

Thermometers should be recalibrated regularly, even after an initial calibration. Changes in use, wear and tear, or mechanical impacts can alter their accuracy over time. It's best practice to routinely test and recalibrate thermometers to ensure consistent accuracy.

How do I know if my probe thermometer has failed the cold water test?

Your probe thermometer has failed if the reading deviates more than 1 degree above or below 0°C. If this happens, have your head chef verify the reading. If confirmed to be outside this tolerance, you'll need to record this in Pilla by adding comments to your test and take the probe out of service immediately.

Common misunderstanding: A thermometer that fails the cold water test can still be used if only slightly off.

Even a slight deviation from the expected reading indicates that the thermometer may not reliably measure temperatures accurately. This can lead to food safety risks, especially when precise temperature control is critical. Always replace or recalibrate any thermometer that fails the cold water test, regardless of the deviation size.

Common misunderstanding: If a thermometer fails the test, it must be discarded immediately.

A failed cold water test doesn't necessarily mean a thermometer is irreparable. Often, recalibration or professional servicing can restore its accuracy. Consult the manufacturer's guidelines or a professional service to determine the best course of action before discarding the device.

What happens if the food probe thermometer touches the ice during cold testing?

If the probe touches ice directly during cold testing, it will give you an inaccurate reading. When performing a cold calibration test, the probe should only be submerged in the water between the ice cubes, not touching the ice itself. This ensures you get an accurate reading of 0°C (32°F).

To get it right, make sure you have just enough water to make the ice float, then carefully insert the probe into the water while avoiding contact with any ice cubes. You can stir gently to maintain an even temperature throughout the bath.

Common misunderstanding: Direct contact with ice can improve the accuracy of the cold water test.

Direct contact with ice during the cold water test can lead to inconsistent and inaccurate temperature readings. The probe must measure the water temperature between the ice cubes to ensure that it captures the true 0°C (32°F) environment of the ice bath, not the temperature of the ice itself.

Common misunderstanding: Touching the ice briefly won't affect the accuracy of the thermometer reading.

Even brief contact with ice can skew the results of the cold water test, leading to misleading thermometer calibration. It is critical to maintain the probe in the water between the ice cubes, avoiding any contact with the ice, to ensure accurate and reliable readings.

UK Official Guidance

• UK Food Standards Agency guidance including food probes

USA Official Guidance

• FDA guidance including including food probes