How to Test Thermometer Accuracy With a Flawless Ice Bath
Controlling temperature in the kitchen is crucial to avoid mistakes when cooking meat and poultry. And in many cases, your thermometer might not be giving you the real picture.
A properly made ice bath is an easy, consistent, and effective way to gauge the accuracy of your thermometer. This simple experiment compares the temperature your thermometer is reading to the freezing point of water (32.0°F/0°C).
But before you grab the ice cubes, let’s delve into the art of creating a properly made ice bath. A well-constructed ice bath ensures a consistent temperature throughout, providing the perfect reference point for testing your thermometer.
Watch the proper way to create an Ice Bath instructional video
How do I make an ice bath?
To check the precision of a thermometer, the best method is to use a well-prepared ice bath. By doing this accurately, the temperature of the ice bath should be 32.0°F with a margin of error of ±0.1°F. Failing to be meticulous could result in the ice bath being off by more than 10°F.
Here’s what you’ll need:
- A container, such as our purpose built Ice Bath Mug
- Crushed or cubed ice
- Your thermometer
Note: Specialized ice bath thermometers float in ice baths to monitor the temperature of the water over time. Use them for therapeutic purposes, such as cold plunges, but not here.
Four easy steps to make a foolproof ice bath:
The easiest way to test the accuracy of any thermometer is in a properly made ice bath. If you do this carefully, your ice bath will be 32.0°F within ±0.1°F. If you are not careful, the ice bath can be off by several whole degrees. (Just a cup with ice water in it can be 12 or more degrees too high.)
- Fill your container to the top with ice. Crushed ice is ideal, because it creates a denser environment and a more consistent temperature throughout the bath.
- Add water to the container until the water reaches about ½ inch below the top of the ice. Let the ice slurry sit for a minute to allow the temperature to even out. If the ice rises from the bottom of the container, remove some water and add more ice. The water beneath the ice will have a temperature above 32°F.
- Place your probe or thermometer tip into the center of the ice slurry and mix gently. Stirring helps spread heat evenly and prevents your thermometer from touching ice, the container walls, or the bottom (which will give you inaccurate temperature readings).
- In an ice bath, your thermometer should read 32°F (0°C). If it doesn’t, follow the manufacturer’s adjustment instructions. However, before calibrating a digital, instant-read thermometer, verify that the reading falls within the manufacturer’s accuracy range. If it does, adjustment isn’t needed. For further assistance with ThermoWorks products, feel free to contact our Utah-based tech support team by phone or email.