How to Know if Your Food Thermometer Is Accurate

The best way to know when any kind of meat or poultry is finished is to take its temperature. But if the tool you're using to take that temperature isn't accurate, you're in trouble.

And it's very likely that your thermometer is a few degrees (or more!) off. "Drift"—the industry term for thermometers losing accuracy—is so common that some companies recommend calibrating thermometers yearly, weekly, or, sometimes, with every use. (This depends on the type of thermometer, of course; Thermoworks lays it all out here.)

I like to check my thermometer(s) at least a few times a year to be safe, and any time I get a new one it's the first thing I do with it. Luckily, it's surprisingly easy to know if your thermometer is trustworthy of not. All you need is three minutes, and a glass of ice water.

Fill a large glass or measuring cup with ice, then pour cold water over it and stir well. Stick your thermometer into the center of the glass so the tip of the probe is submerged by about two inches. Hold it there for about a minute, making sure it stays in the center, and then check the temperature. It should read 32°F or 0°C, which, of course, is the temperature that water freezes at.

Depending on what kind of thermometer you have, you should be able to fix it so it reads true. Some digital thermometers have a reset button or a calibration feature, which the user's manual should explain how to use. Most manual thermometers have a calibration dial that you can turn until the thermometer reads 32°F when inserted in the ice bath.

If you can't fix the problem yourself, and if it's off by more than 2°, try contacting the manufacturer to see if you can send it back for a replacement or a repair. Or if you want to make do with your lying thermometer, make a note of how many degrees off it is, and write it on some tape and tape it to the thermometer so you know to always add (or subtract, as the case may be) the amount of degrees off that it is.