How To Know If Your Meat Thermometer Is Accurate

December 18, 2018

Whether you are roasting meat, baking pastry, tempering chocolate or making any kind of sauce or custard, knowing the exact temperature of your food will make or break your recipes. Read this compact guide to learn how to check whether your meat thermometer is lying to you and what you can do about it.  

roasted turkey with meat thermometer

How Often Should You Check Your Meat Thermometer For Accuracy? 

You should check your meat thermometer of choice the moment you buy it and recheck it every 6 months after purchase. On top of that, if you drop it on the ground or traumatize it in any other way, you should check it for accuracy immediately after.  

If your device reads accurate temperatures, you have nothing to worry about. If not, you should follow some of the steps we are about to list. Note that even the best meat thermometers can have an error factor of ½ – 2 degrees, which is considered acceptable.  

Testing 

You can test your meat thermometer for accuracy either by inserting its probe in boiling water or an ice bath. Doing both is also not a bad idea, just to make sure it works properly. 

Let us now see what these tests entail: 

Boiling Water Test 

At sea level, water boils at 100° C or 212° F. To test your thermometer, simply bring a bowl of water to a rolling boil, insert at least an inch of the probe in the water without allowing it to touch the sides or the bottom of the container, and read the temperature. Needless to say, you should do this with a long-handled slotted spoon or kitchen tongs to avoid burning your hands.  

As we already mentioned, if your thermometer reads 100° C or 212° F ±2°, you have nothing to worry about.  

A Pot of Boiling Water

Ice Bath Test 

Water freezes at 0° C or 32° F. For this test, you need to fit as much ice as possible in a glass of water. Fill the glass with crushed ice and put it in a larger bowl to catch the overflow. Pour the water to the very rim of the glass and pile some more ice on top. Insert the probe in the ice water (at least 1 inch deep) and be careful not to let it touch the glass. 

Your thermometer is perfectly accurate if it registers 0° C or 32° F. Note that the ice bath test has a smaller error margin – usually around 1°. 

What To Do If Your Meat Thermometer Is Not Accurate? 

If your meat thermometer is way off during these two tests, there are basically three things you can do:  

  • Live with it – If your meat thermometer reads, let’s say, 5° more than it should, you can simply do some math every time you use it and aim for a 5° higher reading. Note that you should not do this if the reading is significantly off in both directions.  
  • Recalibrate – Dial thermometers usually come with a hexagonal nut under the dial. The nut can be turned with a small wrench to account for the error shown during the test. Some of the best digital meat thermometers usually have a reset or calibration button. The recalibration process for liquid-in-glass and mercury thermometers is too technical, complicated, and time-consuming to be worth your while.  
  • Contact the manufacturer – If everything else fails, you can always contact the manufacturer and ask them to replace the thermometer. Make sure to save the receipt and the original packaging so as not to void your warranty.  

Additional Notes 

If you do not live at sea level, make sure to check the water-boiling temperature at your elevation.  

Some online sources claim that you should only use distilled water for these tests since mineral content can affect its boiling and freezing points. However, you do not require that level of accuracy for normal baking, cooking, and brewing, so you can do the tests with regular tap water.  

As already mentioned, the accuracy standard for kitchen thermometers allows for an error margin of 2° F, so you are not likely to get a replacement if the thermometer is just slightly inaccurate.