Roasting thermometers: Determining the temperature via penetration

A roasting thermometer is required to determine the core temperature when preparing meat, fish or dough. This penetrates the food and is equipped with a probe. The penetration thermometer measures the temperature attained inside the food, since this can greatly deviate from the surface temperature. Measurement of the core temperature is important in order to comply with the safety requirements when preparing food or to meet the HACCP requirements. All food contains germs, which can be killed at temperatures of at least 65 °C. Therefore only sufficiently heated food can be enjoyed safely and without any risks to health. Roasting thermometers from Testo offer the following advantages:

  • Accurate measurement of temperatures inside viscoplastic substances (meat, fish, etc.)
  • Simple and intuitive to use
  • Interchangeable probes
  • Can also be used as an immersion thermometer

Best seller: testo 104-IR

How do you want to measure? An overview of our thermometers and penetration thermometers


For core temperature and penetration measurements in semi-solid and solid substances.

Infrared insertion

Infrared insertion thermometers
The all-rounder for surface and core temperature measurements. Ideal for incoming goods.

with connectable probes

Penetration thermometers
When you do not just want to measure core temperatures, but also surface or air temperatures.

Penetration probes

Food probes
Large selection of different models – customized products are also possible.

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Meat thermometer

Whether for roasting or barbecuing, cooking or steaming: If you want to serve safe food, you need to measure the core temperature. This is true not only in the catering trade, but also at home, which is why roasting thermometers have also become the norm in the domestic sphere. There are amateur chefs, for example, who always make an effort to ensure that a steak is not well-done, who want to keep an eye on the temperatures during roasting and on the barbecue. Then you also have health-conscious people who want to know when the perfect temperature for serving has been reached, and who opt for a roasting thermometer. Different types of thermometers come into play:

  • Penetration thermometers
    These are inserted into solid and semi-solid substances and they measure the temperatures inside. They can be used for penetration and also be used in liquids, and are then used as immersion thermometers. 
  • Penetration infrared thermometers
    These roasting thermometers combine an infrared thermometer with a penetration thermometer in one housing. These thermometers enable alternate measurement of the surface and internal temperatures of the food.
  • Thermometers with data loggers
    This type is suitable for the permanent monitoring of temperatures, the recording of data takes place regularly.
Numerous pathogens play a key role in the catering sector. These must be destroyed during cooking and roasting so that they can no longer pose any danger to humans. In the case of the aforementioned pathogens, the outer shells, which consist of protein structures, need to be broken open. This is possible from a baking, roasting and cooking temperature of 60 °C. Salmonella and listeria are also pathogenic bacteria and can only be rendered harmless by food being properly cooked.

Thermometers for the BBQ

Those who are intent on preparing food that is properly cooked through will have similarly high expectations when preparing it on the barbecue. This means that the food that goes on the barbecue also has to reach certain core temperatures so that it is safe in accordance with the HACCP specifications. It is important that the measurement is taken until the so-called t99 time is reached. That is the time which a probe needs in order to achieve 99% of its possible final value, and the 90% to 99% span takes just as long as it does to get from the start of the measurement to the 90% value. Compliance with the measuring time is particularly critical for meat thermometers, since the adjustment times are generally related to the t99 value.
Roasting thermometer
Food thermometer

Food thermometers: Roasting thermometers for catering and at home

Whether you need one for the meat in your kitchen at home, at a gastronomic facility or when preparing food on the barbecue: you should always have a barbecue or roasting thermometer by your side when preparing healthy food. However, it is important not to experience any measurement errors. The most common error is that the temperature of the measurement probe is significantly different from that of the substance being measured. This means that the temperatures at the penetration point equalize: the food becomes cooler or warmer at the measuring point, depending on whether the measurement probe of the penetration thermometer is cold or warm. In that event, the displayed results do not reflect realistic values. The barbecue thermometer should therefore be warmed up or cooled down beforehand, as should the roasting thermometer. Moreover, it is advisable to set the penetration depth to 10 to 15 times the diameter of the measurement probe and to keep an immersion probe constantly moving in liquids.

Using kitchen thermometers safely

For kitchen thermometers, the same applies as for roasting thermometers. This means that measurements can only be carried out safely and correctly if measurement errors are prevented. These points should be observed when using these instruments at home:

  • Use a roasting thermometer at least at room temperature
  • Use a thermometer with a thin measuring tip
  • Insert to a sufficient depth
  • Carry out the measurement until the display stops changing
  • Carry out multiple measurements at different locations

Digital roasting thermometers: Reliable and accurate

Digital measurement of the core temperatures using a digital roasting thermometer is a good way to prepare a healthy and safe meal quickly, safely and easily. You can use Testo's combination instruments, which are both penetrating and infrared thermometers. These are impressive thanks to their options for control from a distance, as well as their accurate measurement of core and surface temperature. The digital roasting thermometers are robustly manufactured and have a fold-out penetration probe that measures the core temperatures only when required.

Penetration thermometer