Unbiased Thermoworks Thermapen MK4 Thermometer Review

Most reviews for the Thermapen MK4 start with how expensive it is. Is it worth the cost? Is it better because it Thermoworks Thermapen MK4 costs more? We’ll answer these questions later.

I’m here to talk about the Thermapen MK4 for grilling, cooking, homebrew scenarios, and overall how it compares to the others I have cluttering my drawers.

I have several instant digital thermometers. Most use slower and less precise thermistor technology. The Thermoworks Thermapen MK4 uses fast and precise thermocouple technology. For a backup thermometer, I have an old, analog, and battery-free thermometer. I also have an infrared “gun” model for checking surface temperatures.

For this review, I compared these instant-read digital thermometer models.

Digital ThermometerPrecisionSpeed to reading (in seconds)Battery
Thermapen MK4+/- .7°F2-3AAA
ThermPro TP03+/- .9°F4AAA
Lavatools Javelin+/- .9°F4CR2032
S2N EssentialsUnknown4-6AAA
Taylor Commercial 9842UnknownUnknownWatch
Tasbel Cooking ThermometerUnknownUnknownWatch
Inkbird Instant Digital Read+/- 1.8°F4-7AAA

I’ve owned these for varying lengths of time and for different uses. Most recently I purchased a Thermapen MK4, though I have used the MK4 at a friend’s house on brew days throughout a couple of years a few times.

I’ve only had mine for a short time. The oldest is Taylor, and the next most recent is the Inkbird.

For homebrewing (until recently) I mostly use the Lavatools, S2n, the Tasbel (long probe for getting deep into the mash), and the newer Inkbird which was supposed to replace the Lavatools which was supposed to replace the S2N. Confused yet? Try having seven instant-read digital thermometers.

I use my digital thermometers to get fast readings on food I have grilling on my Traeger, baking in the oven, simmering on the cooktop, or various homebrewing stages. I’ve relied on their advertised “instant and accurate” readings.

When smoking or grilling on the Traeger, I use a Bluetooth remote probe and track the temperature through my mobile phone app. I love being untethered and having the historical data of the cooking session. These remote probes are okay for hours of cooking, but what about right now?

For fast readings, I will use a digital thermometer inserted into whatever it is I am measuring, whether it be for a homebrew mash temperature or a slow-cooked tri-tip. I love the flexibility of measuring temperature in multiple locations with instant readings.

So what about these instant readings? Are they instant? Are they accurate?

Thermapen Mk4: Highlights & Benefits

I’ve done a few tests, and I can tell you some are instant and can be accurate. Though some are just one, or neither. What is instant? With the MK4, it’s at most three seconds! Other thermometers are usually fifteen seconds or longer.

The Thermapen MK4 is the top thermometer when it comes to fast and accurate readings. The Inkbird ranked at the bottom, which afterward I tossed out.

My top three favorite thermometers for speed and accuracy are:

  1. Thermapen MK4
  2. S2N Essentials
  3. ThermPro

My hands-down favorite is the Thermapen MK4 for its fantastic features.

At $99, it is significantly more expensive than others, and some of those were even good and budget-friendly units. The S2n and ThermPro were only $12 and $20 respectively, and both performed admirably.

But when it comes to enjoying something, it’s the little conveniences that matter.

With the MK4, I can measure the temperature and simply set it down. When I pick it up again,  it turns itself on instantly and automatically rotates the display to the current orientation, an impressive feature. Simply flipping it over and using it in my left hand reorients the display in about one second. The MK4 is not a left-handed thermometer but can be used upside down in your left hand like I sometimes do.

The MK4 will automatically turn on its backlight with a built-in light sensor, too! This is handy on brew day when moving from the sun to shade. It is ready for action, regardless of lighting.

I love the smooth open and close action of the MK4 probe. In the closed position, rotating probe thermometers like the MK4 automatically shut off. The MK4 has a smooth and well-engineered motion. With the exception of the ThermPro which has a push-button probe release, the others exhibit lower quality design for opening and closing the probe.

Some thermometers are very hard to open and have sloppy precision seating into the closed position. They can be stiff and take effort to open. The MK4 feels like every aspect was thoughtfully designed.

The MK4 along with three others (see the chart above) use common AAA batteries. The AAA battery is quite common, making it easy to find. It’s easy to change the battery too. The MK4 has a single screw at the bottom of the unit.

As I mentioned earlier, the MK4 has a battery compartment at the bottom of the unit secured by a center screw. With the bottom cover off not only can you access the battery, but the buttons for the thermometer’s settings, too. The two protected buttons allow you to personalize your Mk4 to suit your preferences.

I use Fahrenheit, the default. If you prefer Celcius, it’s just a few buttons away. The MK4 does not quickly switch between the two, however. You will have to remove the bottom cover each time you want to change it.

I also don’t use decimal values. In homebrewing or grilling, I don’t see the need. Some of the other models were set to decimal though, so I left those as they were.

Other menu settings on the MK4 are sleep mode and screen rotation. You can adjust the amount of time before it sleeps from ten seconds to three minutes. You can lock the screen in one position, as well as change from 360 degrees to 180.

Did I mention the Thermapen MK4 is waterproof? A key advantage when using during the brew day. Accidents happen. I would not want to drop it in hot wort or any hot liquid. Don’t expect any electronic thermometer to survive that.

Other typical brew day uses usually include a lot of splashing, dipping, and maybe dunking in rinse water or sanitizer (maybe a few beers spills too). The MK4 has survived over twenty brew days so far and honestly it still looks new!

Of the other water-resistant, splash-proof, or watertight thermometers I have, only two list their IEC rating. The Thermapen MK4 and the Lavatools Javelin.

The Lavatools rates at IP65 (IP is a rating for protection levels), which is a bit better than splash-proof.

The MK4 is rated at IP67, which means it can be submerged up to one meter for thirty minutes . . . almost waterproof. Dropping it in a bucket of rinse water on brew day is no big deal.

So what’s not to love about the MK4? Nothing, really.

It seems bulky at first, but after using it I found it comfortable to grip. The MK4 is flatter and a bit wider than the others. It looks big but fits comfortably in the hand. The size and weight were only noticeable when directly comparing all the units at the same time. When not comparing them, I didn’t notice.

It would be nice if the MK4 had a built-in magnet or loop of sorts to hang, a minor inconvenience. The Inkbird and Thermapen have magnets built-in though, and those two thermometers and the Tasbel one all have loops to hang them with.

Okay, the elephant in the room.

I choose the MK4. Yes, it is $99, but often there are discounts if you keep an eye on their website or sign up for their emails.

The quality of construction and components alone justify the higher price. For example, thermocouple based probes are used in scientific laboratories where fast and precise readings are critical.

The high tech features like a thermocouple are more expensive than the slower and less precise thermistor technology. The MK4 is taking advantage of the precision and speed of the thermocouple.

As a total package, with the advanced probe design concerning movement and precision, and the unique customizable menu and fast readings, the MK4 produced great value for the price.

But the tool isn’t the only gauge of quality. How is customer service?

I contacted Thermapen to ask some questions and found them to be very responsive and helpful. I felt if I had any issue, it would be promptly resolved.

If I were on a tight budget, there are a couple of thermometers from my kitchen I would suggest.

Though the S2n Essentials has a rather difficult to move probe, at twelve bucks, it was pretty good with speed and temperature accuracy.

The ThermPro at $13 would be my budget choice. It has a simple push button to release the probe which locks in place when closed. Readings were pretty fast and accurate, too.

The Taylor and Tasbel are both okay choices as well, though I find the Taylor easier to read. The display and buttons (changing from Farenheight to Celcius) are in the top, and not the side like all the other thermometers.

The Tasbel also has a long probe and has an easy to read display, making it convenient when going deep into the mash on a brew day.

Testing Thermapen MK4 And Comparison With Others

I compared the Thermapen MK4 to the others I have to see if it really is faster and more precise. There were no surprises here. It is! Here are a few real-world tests from my kitchen and grill.

As claimed in their literature, the MK4 did have a two to three-second read time in my real-world tests.

For example, I was taking several readings on a pork roast being grilled, and I moved the probe from one area to another to get readings from the center of thicker and thinner parts. If the thermometer isn’t fast, your fingers burn! The MK4 was fast. No fingers were injured in this testing.

I repeated the tests using my other thermometers and had varying results. None were as fast as the MK4 and I needed an oven glove to finish the tests.

I think most people take the same readings when grilling. If the instant thermometer isn’t . . . so . . . instant . . . you aren’t getting an accurate reading.

I usually don’t use an oven glove. I just grab the thermometer and poke the probe into the food. It only takes a couple of seconds before you start burning your fingers. If you don’t leave the probe in long enough, you do not get an accurate reading. You just don’t!

I compared the MK4 to my other thermometers. Barehanded, my readings ranged from being a fraction of a degree off to a whole 5°F off! I don’t want pork that’s five degrees undercooked!

When I am brewing beer and testing the mash temperature, I don’t want to leave the top off my mash tun any longer than needed. I don’t want to wait fifteen seconds for an accurate reading. I tend to move the probe and measure in different spots in the mash pretty quickly so I am not losing a lot of heat. I don’t want my 148°F mash at 143°F due to a slow thermometer.

For my first test, I tested all units in the same glass of water, sitting on the same counter, each in a twenty-ounce YETI tumbler for ten hours. If you know YETI, they are great at keeping a constant temperature.

These are the readings from each measurement. (I loaned my Lavatools to a friend, so it wasn’t included.)

  • The MK4 read 69°F in two seconds.
  • The ThermPro read 70°F in four seconds.
  • The Inkbird started at 64.4°F, and then three minutes later climbed to 68.3°F.
  • The Tasbel read 69.4°F in five seconds.
  • The Taylor read 68.8°F in five seconds.
  • Finally, the S2N read 70°F in fifteen seconds.

Next, I set them all on the counter and opened them all up, making sure each one was turned on. After a couple of minutes to acclimate, I checked each one, then compared with my infrared thermometer.

  • The MK4 read 76°F ambient temperature.
  • The ThermPro read 73.8°F ambient temperature.
  • The Inkbird read 74.4°F ambient temperature.
  • The Tasbel read 73.6°F ambient temperature.
  • The Taylor read 75.5°F ambient temperature.
  • The S2N read 77°F ambient temperature.
  • Finally, the Infrared read 76.5°F ambient temperature.

On another day, I tested each unit on a two and a half pound Tri-Tip that was on the Traeger for an hour. The internal Bluetooth probe read 132°F.

The Thermapen MK4 read 131°F in two seconds.

The ThermPro and S2N took fifteen seconds each to eventually read within half a degree Fahrenheit. The Inkbird was under by two degrees. I gave it one full minute. It kept reading low.

The Tasbel and Taylor were both within 1°F in about fifteen seconds each. Holding a temperature probe over a hot grill is hot! It was difficult without a grill glove.

I tried moving the probe around after three or four seconds and found that only the Thermapen MK4 could keep up. The rest varied by up to 10°F. That is the risk of moving the probe around quickly and a limitation of the thermistor models.

For my last test, I filled my Yeti with ice and water and let it sit in the refrigerator for an hour. The readings:

  • The MK4 read 34°F in three seconds.
  • The ThermPro read 34.2°F in four seconds.
  • The Inkbird read 30.2°F in seven seconds.
  • The Tasbel read 35.2°F in fifteen seconds.
  • The Taylor read 34.2°F in fifteen seconds.
  • The S2n read 34.5°F in twelve seconds.

With a drawer full of instant digital thermometers, you may never know which one is the right one to use, but my money is on the MK4. Whether I am grilling or brewing, checking chicken, or pitching yeast, I’ll grab the MK4. Always the right tool for the job.

There are some other fine budget options, but this brewmaster is thrilled with his Thermapen MK4.

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