July is grilling month so it’s officially steak season. And it is fair to say that nothing will have a greater impact on the taste and quality of the steak you feed your friends and family than your ability to accurately gauge the internal temperatures of the steak.

Testing Doneness

There are many different methods people use to test doneness. Some people use timers (i.e. 4 minutes on each side). Others press on their steaks to feel the resistance of the fibers (the old press on the heel of your palm trick). Some people go on visual cues alone or even, heaven forbid, cut into one of their steaks to see what it looks like inside.

None of these methods are reliable. Steaks on a grill cook quickly and the doneness window closes fast. As Jeff Potter puts it in Cooking for Geeks,

…the error tolerance of when to pull the meat off the grill is smaller than pulling the meat from the oven, because the slope of the curve is steeper. That is, if t¹ is the ideal time at which to pull the steak, leaving it for t¹+2 minutes will allow the temperature of the grilled steak to overshoot much more than one cooked in the oven.

—Jeff Potter, Cooking for Geeks

Really, the only effective way to gauge the doneness of your steak is with a fast and accurate digital thermometer. And with a thermometer as fast and accurate as the Thermapen^® ONE, you can actually get a reading on the thermal center of the steak (it’s coolest part) and be assured of consistent results every time.

A fast, accurate thermometer is one of the simplest ways to improve the safety and quality of your food. We use our favorite thermometer, the ThermoWorks Thermapen, every day. —Master of the Grill, America’s Test Kitchen

The Thermodynamics of Steak

There are three types of thermal energy transfer at work on a steak while it cooks on a grill:

1. Radiation: Burning charcoal emits radiant heat—up to 2,000°F (1093°C) down in the charcoal, but typically around 650°F (343°C) at the grill surface, itself.
2. Conduction: Metal grill grates heat up to around 400°F (204°C) and are in direct contact with parts of the meat, searing the meat through a process called conduction.
3. Convection: The air circulating around the steak in a grill also heats up (particularly when the lid is kept closed) to several hundred degrees and works like a convection oven.

Notably, all of three of these methods work on the outside of a steak.

Over time, conduction carries the thermal energy from the steak’s surface deep into the center of the steak. But while the steak is cooking, it actually has many different temperatures going on inside it all at the same time—a hot crust and a cool center. We call these different temperatures inside the same piece of meat gradients. They can make it challenging for you to get a trustworthy reading when you try to take the temperature of your steak.

There’s Water Moving Around in There, Too

Depending upon the cut, steak is actually 75% water and only 20% protein (with fat, carbohydrates, and minerals accounting for the remaining 5%). Most of the water is hidden inside the muscle fibers, but as your steak gets to temperatures above 104°F (40°C), the muscle fibers begin to shrink and force water out into the center of the steak.

Since water is a significant conductor of thermal energy, this process actually helps bring up the interior temperature of your steak. All of this contributes to the dynamic flow of energy through your steak. There’s a lot going on in there. It takes some skill to know what you should be measuring with your thermometer to get the results you want.

Resting and Carryover Cooking

Before we finally dive into temping technique, it’s important to consider for a moment what will happen to your steaks after you remove them from the grill. One thing that happens is that the muscle fibers relax again and reabsorb their water. This redistributes the water throughout the steak again and should make each bite of the finished steak as succulent and juicy as the next.

During the critical resting period that follows grilling, another thing that happens is that conduction continues to drive thermal energy toward the center of your steak. Even as the outer layers of your steak cool dramatically, the temperature at the center of the steak will continue to rise, until the gradients meet in the middle. The thermal system wants to find equilibrium. This is what we call the resting temperature of your steak. And if you prepare your steaks properly, it should match the doneness temperature you picked from the chart above.

“Carryover cooking” is what we call this rise in temperature at the thermal center of the steak after the steak has been removed from direct heat. Two factors affect the amount of carryover cooking you are likely to experience:

1. The temperature of the cooking environment.
2. The mass of the meat being cooked.

Hotter cooking environments (like grills) experience more carryover, but smaller cuts of meat (like steaks) experience less.

In the particular case of grilling steaks, these two factors almost cancel each other out. Depending upon the thickness of the steaks, you can expect a resting rise (carryover) of between just 3 and 6°F (2-3°C) at the thermal center of the steak.

Calculating Your Pull Temperature

The game of grilling a perfect steak, then, is knowing the precise moment to pull a steak off of the heat so that the final resting temperature through the meat is the exact doneness temperature you want. Thermometers turn this challenge into a number.

Using the chart below, select the target temperature that corresponds to the doneness you prefer in steak:

ThermoWorks-Approved Table of Chef-Recommended Temperatures

Then subtract between 3 and 5 degrees F (2-3 degrees C) from that number to get your pull temperature.

For example, if you have a particularly thick New York strip and you like your steak temp Medium Rare, you would select 130°F (54°C) as your target resting temperature and subtract, say, 4 degrees F (2 degrees C) from that to calculate your pull temperature as 126°F (52°C). This is the number you will be watching for when measuring the thermal center of your steak. When the thermal center hits your calculated pull temperature, it’s time to remove the steak from direct heat.

Your Choice of Thermometer Matters

When you finally get your steaks on the grill and its time to take their temperature, what are you going to reach for as your tool of choice? Dial thermometers that use mechanical springs actually average the temperatures across the entire active probe area (including parts of the probe that may not be in the meat at all!). They are not reliable tools for measuring the precise temperature of the coolest gradient.

Digital thermometers have smaller sensors, but if they are too slow (some take as long as 15 seconds or more to come up to temperature), you’ll find that it’s impossible to hold the thermometer over a 650°F (343°C) grilling surface surface long enough to get an accurate reading.

Only super-fast thermometers, like the Thermapen (accurate to 0.7°F [0.4°C] in 2-3 seconds), give you a fast enough accurate reading that you can be sure that you’ve got it right.** In fact, the Thermapen is so fast that once it comes up to temperature, it basically gives you real-time information about the internal gradients in the steak.

The sensor on the Thermapen is in the very tip of the probe (the last 1/8^th inch). As you move that tip through your steak, you will see the numbers change. If you push too far past the thermal center in either direction, you’ll see the numbers on the display rise. This is not your thermometer malfunctioning, those are the actual gradients being measured by your super-fast thermometer.

This makes it easy to find the thermal center.

How to Temp a Steak! (Finding the Thermal Center)

To temp a steak, simply insert the Thermapen probe tip into the steak from the top, avoiding bone.

1. Push the Thermapen past where you think the center of the steak is.
   
2. Pull the Thermapen back until you find the coolest temperature reading. This will be the steak’s thermal center.
   
3. Take each steak off of the grill when the reading at the thermal center of the steak reaches your target pull temperature.

It’s that simple. You should see consistent results every time with this method.

Temping from the Side

Temperature gradients in steaks are wider than they are thick, just as a steak itself is wider than it is thick. For that reason, many grilling experts recommend temping the steak from the side.

To do this, grab a steak with a pair of tongs and gently lift it up from the grilling surface. Insert the Thermapen probe into the center of the side of the steak. Then, follow the same procedure outlined above to find the coolest reading in the center of the steak.

The Thermapen is so fast, that you can literally check every individual steak on your grill for doneness in a flash!

Rest and Serve

As each steak reaches your pull temperature, remove it from the heat and place it on a plate. Loosely tent it with foil (tightening the foil can cause the crust of the steak to soften and be less crispy).

Allow all the steaks to rest for at least 6 or 7 minutes. During this time the juices will be reabsorbed into the muscle fibers throughout the steak and the internal gradients will reach an equilibrium throughout the meat for perfect doneness.

Serve and enjoy!

We hope you use this method to make perfect steaks for your friends and family this 4^th of July holiday.