The Types of Food Thermometers

There are several types of cooking thermometer on the market, each to serve a different purpose, and a well-equipped kitchen will probably include more than one to cover the various dishes and recipes (1). Whether your budget is modest, or you’re a gadget-junkie who loves to have all of the latest tech at your disposal, there is a unit that is right for you. You may want to use a thermometer in the oven, for grilling, in the fridge, or even on the Aga. And you may want it for a whole range of food, such as chocolate, milk, sugar or even jam.

Oven Safe Dial Thermometer (with a Bimetal strip)

A must-have is the dial thermometer that can stand up to the interior of an oven. It takes a reading in 1-2 minutes. Many cooks and bakers leave the hanging models in the oven all of the time. There are versions with a prong on them that should be inserted 5-6cm into the thickest part of cooking food, such as roasts, casseroles, and soups. You can leave it inserted the whole time the food is cooking, to ensure that interior temperatures reach the desired minimum level.

The limitations of this (prong) type is that it doesn’t work well for thin foods, and heat conduction through the exposed portion of the prong can cause false high readings. It works best if the prong is fully inserted into the item.

Digital Instant Read Thermometer (Thermistor)

These models read in about 10 seconds. The sensor probe should be inserted at least 1cm deep, so it is suitable for thinner foods as well as thick ones. It isn’t designed to remain in the food though, so you’ll have to open the oven door to check the food temperature and then close it again with the thermometer outside.

Thermometer and Fork Combo

These read in around the same time as the previous type, if not faster: from 2 to 10 seconds. It can also be used in thinner foods, as it only needs to be inserted about half a centimetre to work. It can’t be left in the food either, but can be very useful for rearranging or moving food while taking a temperature reading. It is commonly found around the grill, indoors or outdoors.

Dial Instant Read Thermometer (Bimetal)

Reading time for these is around 15-20 seconds, and they need to be inserted 5 to 6.5cm into the thickest part of the food. False high readings are less likely, as the average temperature along the probe is used. This of course does not give you the true core temperature, so there is some disadvantage to it as well. It is not designed to stay in the food throughout cooking.

Thermocouple

A thermocouple reads in 2-5 seconds and can be inserted as little as 1cm into the food. It doesn’t stay in the food during cooking, but is fast, so the oven door isn’t open for very long. Thermocouples are more expensive, and sometimes it is difficult to find one in stores.

Disposable Temperature Indicators (Single use thermometers)

These are designed to be used once and then thrown away. They read in 5-10 seconds, but are designed for specific temperature ranges, and often for specific types of food. They use a temperature-sensitive material that changes colour once the food reaches a certain temperature.

Pop-Up Thermometers

These thermometers are commonly used with large meat dishes, like roasted turkeys and chickens. The thermometer pops up when the specified temperature is reached, giving clear visual indication that the food is done and safe to eat. This thermometer is often used along with another kind, which is used to check temperatures on other parts of the food.

Oven Probe plus Cord

This is used to allow the probe to remain in the food while the reader is safely outside of the oven. It can also be used in covered pots or cookers (4). The base of the unit sits on the counter, the probe is inserted into the food, and the cord connects the two together (2).

Meat Thermometer FAQ’s

How To Use Meat Thermometers

There are two parts to a typical meat thermometer. The first is the probe, or temperature rod, which is inserted into the food. The second is the display, which shows you the temperature the probe is sensing. The display can be digital or analogue – sometimes it can even be a colour, or a pop-up device. Using a meat thermometer is important, as it can show you that the centre of the food has reached a high enough temperature to kill any harmful bacteria that may be living there.

Features of these devices often include wireless, instant read, remote control, leave-in, oven safe, bluetooth, and with a probe.

Top brands of meat thermometers include Lakeland, Maverick, Wever, Hanson, Thermapen, Lavatools Thermowand, Salter, Lavatools Javelin Pro, Souschef, and Oxo good drips leave-in.

The most popular UK retailers for meat thermometers are Argos, Tesco, Amazon, Wilko, Asda, Sainsburys, John Lewis and Ikea.

As you might expect the most popular countries for these tools are also known for loving BBQ food, aka Australia and the USA southern states.

How Do Meat Thermometers Work?

The most common type is the bimetal strip. It is made of two different types of metal, stuck together, side-by-side. Because different metals expand and contract at different rates, an increase in heat will make one piece of metal bigger than the other one, and the strip will bend. This bend moves the dial. The higher the temperature, the more it bends. The more it bends, the more it moves the dial. When it cools, the strips go back to their original sizes.

Characteristics of Meat Thermometers

Most meat thermometers will have a metal probe, like a prong, which is stuck into the food. There is then some kind of display, usually a dial of digital display. Sometimes there is a cord that attached the probe to the display, but in most cases they are directly attached to one another. A pop-up thermometer works in a similar way as other ones, but instead of displaying the current temperature, it is designed to pop up once a certain temperature has been reached. More sophisticated thermometers have features like warning alarms for temperatures going too high, or indicator alarms once the desired minimum temperature has been reached (3).

Can you use meat thermometers for liquids?

Instant-read meat thermometers can be used for other purposes, but it is always a good idea to use the right tool for the job at hand. A reasonable thermometer is not expensive, and they last a long time, so it might be best to pick up another one for general purpose temperature taking. Some thermometers come with a clip that attached to the side of a pot, for measuring liquids on the stove.

How To Calibrate Your Meat Thermometer

Not all meat thermometers can be calibrated, but most of the higher-quality ones can. You’ll need a set of pliers, or a small adjustable spanner.

First, bring a pot of water to a boil on the hob. While it’s heating up, fill a container with ice and pour in some water. Test the thermometer in the boiling water. It should read 100°C (or 212°F). If it doesn’t, adjust the small nut on the back of the display until it does. It is very sensitive, so a tiny amount of movement is likely all that is needed. Next, test the thermometer in the ice-cold water. It should read 0°C (or 32°F). If it doesn’t, adjust in the same way you did before.

Repeat the readings until both temperatures are correct.

Digital thermometers are harder to adjust, but also less likely to be out of adjustment. The best way to deal with a digital thermometer that is a little off, is to adjust the math in your head, and avoid the fee for having it adjusted by a professional. Another option is to take advantage of a warranty or other guarantee to have it replaced with a more accurate one. Be sure to do you testing carefully though; you don’t want to send back a perfectly good thermometer.

Editorial Sources + Fact Checking

1. Yang X1, Devos J1, Klassen MD2, Inactivation of Escherichia coli O157:H7 in Minute Steaks Cooked under Selected Conditions, Journal of Food Protection, October 2017.
2. Choi YS1, Hwang KE2, Jeong TJ2, Kim YB1, Jeon KH1, Kim EM1, Sung JM1, Kim HW3, Kim CJ2, Comparative Study on the Effects of Boiling, Steaming, Grilling, Microwaving and Superheated Steaming on Quality Characteristics of Marinated Chicken Steak, Korean journal for food science of animal resources, 2016.
3. Kerth C1, Determination of volatile aroma compounds in beef using differences in steak thickness and cook surface temperature, Meat Science Section, Texas A&M University, July 2016.
4. Osterdahl M1, Kocturk T, Koochek A, Wändell PE, Effects of a short-term intervention with a paleolithic diet in healthy volunteers, Department of Neurobiology, Center for Family and Community Medicine, May 2008.