We get this question a lot: “What kind of thermometer do I need?”
The simplest answer is that you actually need two thermometers: 1) a digital instant-read and 2) a cooking alarm thermometer.
Why two? Because they do different things.
Two Kinds of Food Thermometers
An instant-read thermometer allows you to quickly check the temperature of a food in different places in rapid succession at a single point in time, while a cooking alarm thermometer allows you to track changes in temperature at a single fixed point in the food over time. (Think of it like having both an odometer and a speedometer on your car. One tells you how far you’ve come, and the other tells you how fast you’re going right now.)
It all has to do with something called temperature gradients. Most people think of foods being at one single temperature throughout. As in, “That chicken breast is now 159°F (71°C).” The truth is that foods are almost always at many different temperatures at the same time while they are cooking. A chicken breast on the grill may be at 159°F (71°C) in one spot, at 176°F (80°C) closer to the surface, and way down at 143°F (62°C) nearer to the center of the breast.
Dealing with Gradients & Temperature Changes
A super-fast instant-read, like the ThermoWorks Thermapen, will show you all of those gradients. The numbers on the display will change as you pull the probe tip through the meat (or cake or yogurt or whatever else you are cooking) in different places.
But you can’t leave a Thermapen in the oven to track changes over time. And all of those temperatures will continue to change as the chicken breast continues to cook, from the outside in. That’s where cooking alarms come in.
Cooking alarms, like the ThermoWorks ChefAlarm, come with a probe that you can leave in the oven (or smoker) and a cable made to withstand being shut in the oven door. Carefully place the probe tip as near to the center of the food being cooked as possible and you can monitor cooking over time to see when you’re getting close to being done. The ChefAlarm comes with an alarm that beeps and flashes when the temperature of the food as measured by the probe at that single point gets to the number you entered as your final temperature. But the cooking alarm probe doesn’t move, it just stays where it’s put.
That’s why you need an instant-read, as well, to verify that there aren’t, in fact, any lower temperatures to be found elsewhere in the food. When your cooking alarm sounds, simply open the oven door and quickly check for the lowest temperature in the food with an instant-read by pulling the probe tip through the food in different places to see if any of the numbers you see are lower. If they are, return the food to the oven and check again in a few minutes.
Instant-Read Thermometers & Cooking Alarms
Instant-read thermometers and cooking alarms go together like Abbott and Costello, like salt and pepper, or like cookies and milk, but you need both to do it right.
ThermoWorks sells many different models of cooking alarms, from the simple DOT, the workhorse ChefAlarm, and the BBQ alarm Smoke, all the way up to the speedy, highly accurate thermocouple ThermaQ series of alarms.
ThermoWorks also sells different models of instant-read thermometers, from pocket digitals like the RT600C, to the top-rated, affordable digital thermometer, the ThermoPop, on up to our gold standard Thermapen. Higher end ThermoWorks instant-read thermometers are fast and accurate enough to show you all the gradients in your food as you pull the probe tip through. Dial thermometers or lesser quality digital instant-reads from other manufacturers can’t do this because their response time is too slow.
So now you know. Next time someone muses aloud, “What kind of thermometer do I need?” you can reply, “I believe you mean ‘thermometerS.’ You need a cooking alarm and a fast and accurate instant-read.” And you’ll be right.
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One thing I would add to the above recommendations (at the risk of scaring away the novices) is that for the all the various culinary activities, we need at least three different thermometers. In addition to the instant-read and continuous-read (cooking alarm) thermometers, the third general type is an infrared (IR) thermometer for accurately assessing the temperature of cooking surfaces like skillets, griddles, and grills.
Experienced cooks know that while guesstimating can suffice, when it doesn’t, the results can be embarrassing and expensive.
An important accessory for the continuous-read type of thermometer is an air probe. In addition to the most commonly-used food probe, the air probe allows us to accurately measure the internal temperature of our smokers and grills (with lid closed), and to confirm the temperature of our ovens. Some models allow both probes to be used at the same time.
Love the products and services of Thermoworks. I highly recommend this company to everyone.
Thanks, Dave. These are good points. As you intuited, we were trying to keep this introduction to the basic thermometer categories as streamlined and straightforward as possible. Our customer care team has been asking for this basic intro. We do discuss infrareds and air probes and many other highly useful temperature tools elsewhere on the blog, of course. And thanks for the recommendation!
Great and easy to understand article!
David Walter says
I agree. This is a very useful article for us novices. However, I ran into a puzzling situation the other day while using my kettle grill to “sear and roast” a thick steak. I was using my new ThermoPop to test the doneness of my steak during the “roast” period, and I found that the coldest temperature was always on the top. I know that in another of your blogs you say always to flip a steak before taking the temperature, but flipping the steak over indirect heat always seemed to leave the coldest temperature on top. Should I have been taking the temperature from the side in this situation?
That is very curious. While it is true that the cooked meat on the top of a steak will start to cool after being flipped, it shouldn’t normally cool so dramatically that the lowest internal temperature is near the surface (unless you are cooking with the lid open or there is an extreme draft). The cooker should normally keep hot air circulating around the steak while it cooks. I would recommend keeping the lid closed until you want to check the temperature and then flipping the steak just before taking its internal temperature to ensure that the top surface temperatures have not yet had a chance to cool. You should see the hotter, cooler, hotter pattern we describe in this post. That will give you a clearer sense of temperature at the thermal center of the steak. You can, of course, try taking the temperature from the side, as well, but you won’t be 100% certain that you are measuring the temperature of the thermal center that way. Hope that helps!
Michael Robinson says
Thanks for teaching me more about the different kinds of thermometers that are available. One thing that stood out to me was that some instant-read thermometers work really well because of how quick they are. This information would be perfect for anyone who might be looking to see how hot things get! Thanks!
Hi, I read that infrared measuring doesn’t work properly on shiny surfaces like stainless steel. Can you explain please? How about your product? Thanks
That is correct! Since what you’re measuring with an IR gun is the infrared light that is being emitted by the surface, if there is reflection the light collected by the sensor is, well, tainted by it. You get all sorts of other light going into the sensor that ‘dilutes’ the infrared. Ours is no different! Though we make them to be extremely accurate, they are subject to the laws of physics as well. That being said, if you slick the surface with some cooking oil, you will be able to read the temperature of the oil, which will be the temperature of the hot pan.
I hope that helps!
John MacEachern says
We have your Thermopen and love it. Do you have an oven thermometer? Our oven tends to fluctuate in temperature and is never the same temperature we set it at. Very frustrating.
Yes! We recommend the ChefAlarm for checking your oven, especially if you get an air-probe to go with it.
Jan Connell says
I was trying to oder on of your Thermopen’s recently because they were on sale..but I ordered the wrong color cause it was not on sale..and I could Not manage to change it..so I gave up..
when will you have a sale again.
I lost my Thermo pop 2 months ago, and have No idea what happened to it…I was so disappointed..I Love that one…
The best way to learn about our sales is to subscribe to our emails. If you have already subscribed, then keep watching!
Bob B says
Durability is important to me. A few months ago I purchased a Thermopop with the intention of using it for cooking and measuring fluid temperatures at home. When I grew to appreciate how easy to use and accurate the Thermopop is, I started taking it with me to a friend’s horse barn where I wanted to check the water temperature in automatic horse waterers that had just frozen solid, and then repaired by plumbers. Temperatures had dropped to -27ºF. My intention was to probe the water and see if the thermostats in the waterers needed to be adjusted. The heated portion of the barn had also frozen, so I used the Thermopop to monitor room temperature and water temperature from faucets once the lines thawed. While I had it with me, I checked the refrigerator temperature and adjusted that. I started carrying the Thermopop in an inside breast pocket of my goose down parka. Today I went to put on the parka, and saw the Thermopop had fallen out, and was damaged. Where the slip-on cover meets the body, the probe was bent at about a 30 degree angle. I foolishly tried to straighten the probe, and it snapped like a twig. I will be looking at a folding probe to replace the Thermopop, either the Classic or the Mk4. I’m not upset with the Thermopop, but I see that I would be better served by a folding probe that could be carried with less risk of damage.
Thank you for sharing your experience. We often say that thermometers have wide-ranging applications, but you really are putting that idea into practice! I think you’ll be thrilled with either the Classic or the Mk4, but it sounds to me from the ways you use it that the Mk4’s features may make it a better fit for you. It’s more waterproof and the auto-lighting display may be of use in cold, frozen barns!
I own a thermapen and a square dot. What I’d really like is a probe thermometer that will alarm when a descending temperature is reached*. I can’t see a way for the square dot to do that. Maybe I’m missing something about how it works – or maybe I need yet another thermometer?? (*one specific application – waiting for heated milk to cool to the point where yogurt starter can be added).
The ChefAlarm has that feature, as does the whole Smoke line. Yogurt making is exactly the example I use when I explain to people why it’s a useful feature!