Cooking and Kitchen Thermometer Buying Guide
Professional kitchens cannot operate without thermometers. Thermometers are the only way to accurately measure temperatures to ensure food safety but are also key for food preparation and monitoring temperatures in fridges, freezers and dishwashers. But there isn’t one type of thermometer that can do everything. Depending on your business, a selection of kitchen and cooking thermometers for accurate temperature readings is necessary to keep your operation in the safe zone.
Types of Thermometers
There are two main types of thermometers: mechanical and electronic. Mechanical thermometers use either liquids or metals that expand and contract to measure temperature. Electronic thermometers use electrical resistance, measurement of electricity generation or electromagnetic radiation to measure temperature.
Although you don’t need to know how these types of thermometers work, knowing the best uses for each type helps to determine which style works best for each temperature task in your operation.
The most basic of thermometers, liquid thermometers have a food safe coloured liquid inside a glass tube usually protected by a case - the liquid expands and contracts as the temperature changes. This is the type of thermometer most of us remember from public school.
Their simple, no-tech and inexpensive design make this type of thermometer a favourite for commercial kitchens. However, they are more difficult to read – especially at a distance – and don’t offer quick results. Therefore, they are best used for tasks that don’t require quick temperature changes.
Being waterproof (and steam proof) these thermometers are favoured for candy making, deep frying and chocolate tempering.
These thermometers have a round dial with the scale in a circular shape. A pointer moves to indicate the measured temperature. This durable and inexpensive type of thermometer, also called a bimetal or bimetallic thermometer, uses coiled wire that expands or contracts based on temperature that turns the pointer to the correct temperature.
Dial thermometers can be flat backed or have a probe, but the mechanics are the same.
Their durability, low cost and no need for batteries, make them a popular choice for foodservice kitchens.
Digital Instant Read Thermometers
Also called digital thermistor thermometers, these are a popular choice for many kitchens because of their compact size and quick response time. This thermometer measures temperature by determining electrical resistance. Temperature is indicated on a digital display.
With pocket friendly sizes and varying function options, chef can quickly check the temperature of their creations.
Digital Thermocouple Thermometer
Great for fast paced commercial operations, thermocouple thermometers offer quick read-out times and a wide temperature range. With a probe and digital display it is a favourite for measuring internal meat temperatures. Thermocouple thermometers determine temperature by measuring the generated electricity.
Also called a pyrometer, this thermometer measures temperature by measuring the heat that radiates from a surface. Therefore, this thermometer is unique because it does not need to come in contact with the surface to read the temperature. The distance:spot ratio determines how far away you can be from items you want to monitor. Remember these thermometers can only detect surface temperatures, not internal ones - a thermometer with a probe or stem is required for taking internal temperatures.
Best for: Food Holding, Receiving, Extreme Temperatures, No Contact, Dishwasher
Combination Thermometers - Infrared and Thermocouple
A most popular choice is an infrared and digital thermocouple thermometer. Staff can monitor internal temperature and surface temperatures with the same unit.
Digital Probe Thermometers
Monitoring foods during cooking ensures accuracy and quality results. This type of thermometer has a probe and cable that can be inserted and remain in the food in the oven while the digital display is outside the oven constantly monitoring the temperature. A great choice to use for all types of meat. This type of thermometer reduces the number of times you need to open the oven.
Best for: Meats, Oven, Grill, Catering
Thermometer Features, Functions and Accessories
Once you have determined which commercial thermometers you need for your operation there are also many features available for each type that can be helpful for busy kitchens.
Range – this is the range in temperatures that the thermometer can read. The range must meet the task and it’s always best to be in the mid-range for the majority of the time. Dial thermometers have limited ranges so be cautious and pick the correct range.
Stem/Probe – the length and the thickness of the stem or probe is an important consideration. Thin cuts of meat and seafood are more accurately measured with a thin tip thermometer. A dial thermometer in some cases needs a long probe for accurate readings. For example to reach the middle depth of a milk frothing pitcher. However, a shorter stem is preferable for a pocket thermometer.
Field Calibration – this means you are able to recalibrate the thermometer. On dial thermometers there is a nut on the back of the dial that is used for adjustment, however, not all dial thermometers can be recalibrated. On digital thermometers, there is a recalibration button, usually indicated by CAL.
Recalibration should be done on a regular basis to ensure accuracy. Thermometers should also be recalibrated after being dropped or bumped or if they have been sitting for a long period of time. Always refer to manufacturer's directions for recalibration.
Response time – this is the time it takes for the thermometer to display the final temperature. The quicker the response time the faster you can move on to the next task. However, don’t pay for quick response if you don’t need it. Fridge and freezer thermometer are a good example where response time isn’t as important as the thermometers stay in place.
Readability/Display - this the size of the read out whether a liquid, dial or digital thermometer. If you need or want to be able to check the temperature from a distance, ensure the display size is large enough to do so.
Dial and liquid thermometers can have coloured sections on their displays to assist with reading and some dial versions are even glow in the dark to assist with reading inside a dark oven. Using dial thermometers, the larger the display the more accurate the reading.
Digital thermometers can have large digit readouts, backlit displays and even audio indicators.
Accuracy – this is the increments that the thermometer can measure. In dial thermometers this is usually 2° but can be higher. In digital thermometers this can be as low as 0.5° but go up to 2°.
Sheath/Sleeve - this is a covering for the probe/stem of the thermometer for protection. These sleeves can also be used as extensions and many dial thermometer sheaths are also a tool that can be used for recalibration. Some sleeves have key temperature s printed for quick reference. Thermometers can also have folding probes to protect from damage and omit the need for a sleeve.
Mounting/Storage - depending on where the thermometers are being used, consider how it can be mounted or stored. Many units have multiple mounting options – standing, hanging, magnetic or adhesive. If you want it close at hand, consider an option with a lanyard or a pocket clip.
Clips - this can be a clip for a pocket or a stainless steel clip that can be used to attach to the side of a pot for constant monitoring as required for deep frying or candy making.
Hold – this holds the measured temperature. A feature helpful in busy kitchens, simply press the hold button to lock that temperature display until it has been recorded.
Min/Max - this allows you to determine the minimum and maximum temperature that has been detected. Important for meeting HACCP checks.
Waterproof – this doesn’t mean that the thermometer can be dumped in a sink of water and left there. Accidents happen in busy kitchens, ensuring your thermometers can handle a quick dunk or steam is an important feature to consider. Consult thermometer specifications for water tolerances as it varies between manufacturers.
Ovenproof – this means the entire unit can withstand oven temperatures. Including the casing and lens. Many thermometers can measure high temperatures, but cannot be left in an oven.
Auto Shut-off – for digital thermometers this feature will automatically shut off the thermometer after a set time of not being used. Extending battery life and ensuring you are ready to test the next batch.
Timers - many thermometers, usually probe style can have timers built in. This feature can be helpful in busy kitchens.
Programmable - this feature allows cooks and chefs to have preset temperatures and times for popular menu and production items programmed into the unit.
Probe Wipes - a fast and easy way to clean and sanitize. Thermometer probe wipes are a convenient and safe option for bustling kitchens and busy services.
No matter what type of kitchen you are operating, thermometers are an essential tool to maintain consistency, quality and safety of any food you serve.