Infrared Thermometer Uses and Limitations in Cooking

When we talk about precise temperature control in cooking, we often think of the internal temperature of a steak or a loaf of bread. But what about the temperature of the pan you’re searing that steak in, or the oil you’re about to fry with? This is where an infrared thermometer finds its purpose. Understanding what an infrared thermometer is used for in the kitchen—and, just as importantly, what it’s not used for—helps you leverage its unique capabilities while avoiding critical safety pitfalls. It’s a tool rooted in physics, measuring radiant heat from surfaces, and using it correctly can elevate your control over the cooking environment.

How an Infrared Thermometer Works

An infrared thermometer, often called a laser thermometer or non-contact thermometer, doesn’t measure temperature by touch. Instead, it has a sensor that detects infrared radiation—a form of electromagnetic energy emitted by all objects. The device calculates the surface temperature based on the intensity of this radiation. This is why it’s so fast; it’s reading energy, not conducting heat through a probe.

This method has immediate implications for kitchen use. It excels at giving you the temperature of a surface you can’t or shouldn’t touch, like a searing-hot cast iron skillet or a baking stone. However, because it only reads the outermost surface, it cannot see inside food or through glass or steam. Its reading can also be affected by shiny, reflective surfaces, which may not emit infrared radiation as effectively.

Ideal Uses for an Infrared Thermometer in the Kitchen

So, what is an infrared thermometer used for in kitchen tasks where surface temperature is the key variable? Its best applications are about preparing and managing your cooking equipment, not the food itself.

Preheating Pans and Cooking Surfaces

One of the most valuable uses is verifying that a pan, griddle, or baking steel is properly and evenly preheated. Different cooking techniques require specific surface temperatures. For instance, a perfect sear often requires a surface well above the boiling point of water to trigger the Maillard reaction quickly. An infrared thermometer lets you check the pan’s center and edges to ensure even heating before you add oil or food.

Checking Grill and Griddle Temperatures

On a grill, hot and cold spots are common. Scanning the grates with an infrared thermometer helps you map these zones, allowing you to place food strategically for direct searing or indirect cooking. This is far more precise than holding your hand over the heat and guessing.

Monitoring Cooking Oil Temperature

For deep frying or pan-frying, maintaining the correct oil temperature is crucial for food safety and quality. Oil that’s too cool leads to greasy, soggy food, while oil that’s too hot can smoke and degrade. You can point the infrared thermometer at the surface of the oil in your pot or pan to get a reading. For a more accurate average temperature, stir the oil first and aim at the center.

Critical Limitations and What It Cannot Do

Understanding the limitations of an infrared thermometer is essential for safe and effective cooking. Its primary constraint defines its entire role.

It Does Not Measure Internal Food Temperature

This is the most important safety point. An infrared thermometer cannot measure the internal temperature of food. It only reads the surface. Relying on it to check if chicken or burgers are done is dangerous and can lead to foodborne illness. The internal temperature must be verified with a probe thermometer, like an instant-read thermometer or a leave-in probe thermometer.

Surface Readings Can Be Misleading

Shiny metals, like a new aluminum pot, can reflect infrared energy, giving a falsely low reading. Steam, smoke, or glass (like an oven door) will block or distort the reading. It also cannot average temperatures; it reads one tiny spot. A pan might have a hot center and cooler sides, requiring multiple checks.

Not for Liquid or Air Temperatures

While you can point it at the surface of oil or a soup, the reading is just for that top layer. It will not tell you the temperature of liquid deeper in the pot or the ambient air temperature inside your oven. For those, you need a probe or an oven thermometer.

Proper Technique for Accurate Readings

To get the most reliable surface temperature, follow these steps:

1. Clean the Surface: Dust, grease, or moisture on the surface can affect the reading.
2. Get Close and Perpendicular: Hold the thermometer as close to the surface as is safe. The laser dot is a guide; the actual measured area is larger (check your model’s distance-to-spot ratio). Hold it at a 90-degree angle to the surface for the most accurate reading.
3. Mind the Material: For very shiny surfaces, you can place a small piece of matte tape (like masking tape) on the area, let it come to temperature, and measure the tape instead.
4. Take Multiple Readings: Check several spots on a pan or grill to understand the heat distribution.
5. Act Quickly: Surface temperatures can change fast when you add food or adjust heat. Use the IR thermometer for a quick check just before cooking.

FAQ

Can I use an infrared thermometer to check my oven temperature?

Not accurately. The infrared thermometer will only read the temperature of the oven walls, racks, or door glass, not the ambient air temperature which is what matters for baking. These surfaces can be significantly hotter or cooler than the air. Use a dedicated oven thermometer placed in the center of the oven for a true reading.

Is an infrared thermometer accurate for non-stick pans?

It can be, but with caution. The dark, matte surface of many non-stick pans is good for infrared reading. However, avoid pointing the laser directly at the non-stick coating from extremely close range when the pan is empty and very hot, as concentrated energy from the laser is not recommended by some manufacturers. Aim for the metal rim or side when possible.

What is an infrared thermometer used for in kitchen baking?

In baking, its primary use is to check the surface temperature of equipment. You can verify if a baking stone or steel is fully and evenly preheated, or check the temperature of a pan for recipes like focaccia that start on the stovetop. It should not be used to check the doneness of bread or cakes.

Can it tell me if my oil is ready for frying?

Yes, this is one of its best uses. To improve accuracy, stir the oil gently first to even out temperature layers, then point the thermometer at the oil’s surface near the center of the pot. Remember, it’s reading the surface, so for deep frying, the temperature a few inches down might vary slightly.

Why does it give a low reading on my stainless steel pot?

New, polished stainless steel is highly reflective and has a low emissivity, meaning it doesn’t emit infrared radiation well. The thermometer may read the reflection of a cooler room temperature instead. As the pot gets older and develops a patina, readings may improve. For a better reading on shiny metal, use the matte tape method described in the technique section.