ThermoWorks Thermapen ONE Review: The Best Just Got Better

If there’s one thing everyone in the barbecue community from competition champs to backyard warriors can agree on it’s this; The Thermapen Mk4 is the best thermometer money can buy.

With the release of the Thermapen ONE that is now no longer the case.

I’ve been using the Thermapen ONE as my primary meat thermometer since before its official release, and in this review, I’ll be sharing my thoughts so read on to find out whether or not this thermometer is the ONE for you.

Thermoworks sent me a free ThermoWorks One in return for my honest review. All thoughts and opinions are my own.

Thermapen ONE overview and first impressions

How do you improve on a product as universally loved and recommended as the Mk4? If you ask ThermoWorks they would say it’s “the culmination of five years of research and development, involving new applications of the principles of thermodynamics and materials science.“

That’s a complicated way to say they’ve made a thermometer with faster read times, increased the accuracy, and improved the construction.

The first thing I noticed after taking the ONE out of the box is just how much DNA this thermometer shares with the original Mk4.

From a distance, the two units are identical. It’s not until you hold the thermometer up in your hand that you see some subtle differences. Mainly in the placement of the rubber grip that goes around the outside, and the screw to access the battery compartment.

This decision makes sense, ThermoWorks clearly didn’t want to mess with the design of such an iconic product.

Instead of starting from scratch, they have instead made a range of improvements to the performance and build quality.

Check out our video review where I run through everything you need to know about the Thermapen ONE.

Thermapen ONE Thermometer Review

ThermoWorks are currently clearing all Mk4 stock so once that is sold out the ONE will become their new high-end option.

I’ll run through what’s new, before going through my experience in more detail.

What’s new with the Thermapen ONE

• One second read times make it two to three times faster than the Mk4
• The accuracy has been increased to ±0.5°F
• Enhanced durability backed up with a five year warranty
• Brighter and more responsive automatic backlight screen
• New battery compartment with easier access to settings

The standout feature is of course the new one second read time. That’s why it’s called the Thermapen ONE.

You might be asking yourself “what’s the big deal, there’s not much difference between one and three seconds?”

The fact is whether you are searing a few ribeye steaks for your family, competing in a barbecue competition, or working in a restaurant, every second counts.

During my tests, I found a noticeable difference, especially when I wanted to test the temperature of a steak at multiple points at the in quick succession.

I also found the screen was noticeably brighter and more responsive. I was cooking at midday with a lot of glare and I could still easily read the screen.

What I like:

• The best got better – It takes guts to release a new product when the old one is still number one, so I have to give ThermoWorks credit for putting in the R&D time and money to keep pushing the boundaries of read speed and accuracy
• best-in-class accuracy and read speeds – One second read time is like having a super power in the kitchen
• Improved warranty – Five years for a thermometer shows ThermoWorks beleive in the improvements they’ve made to the build quality

What I Don’t like:

• Price – While there’s only a small price bump over the old Mk4 it’s still a lot to spend on a meat thermometer, even one as capable as this.

The Thermapen ONE has some noticeable improvements over the Mk4 with no discernable negatives and only a small price hike. It’s the clear choice for any enthusiast or professional.

What’s in the box

The product ships in a standard ThermoWorks branded box.

Inside the box, you’ll find the Thermapen ONE, a quick start guide, and a more detailed instruction manual that’s surprisingly helpful. It’s well worth spending a few minutes going through the manual to get to know the ins and outs of your thermometer better.

You also have the certificate of calibration hand signed by the calibration manager. Just goes to show how seriously ThermoWorks take the accuracy of their products.

Using the Thermapen ONE meat thermometer

The ONE is incredibly easy to use, although there are some more advanced settings and general guidelines that we’ll get to in a little bit.

To get started using the ONE all you need to do is fold out the probe and the screen will automatically turn on and start conttinuously measuring the temperature.

The screen turns off when you close the probe, or if you leave it sitting on a surface it will go to sleep to save battery and then turn on again when it detects movement.

There are no buttons to press, leaving you free to opperate the unit with one hand.

The ONE has a micro-thermocouple located at the very tip of the probe shaft which is where the temperature measurement happens. This means you only need to insert the probe 1/8″ to get a reading.

In most cases, you will want to insert the probe so the tip is in the center of the thickest portion. I generally test multiple points in quick succession, which is where that super fast read time comes in extra handy.

The thermometer is waterproof to IP67 so you can wash the probe when you are done, although it should not be placed in the dishwasher. It’s also rugged enough to withstand splashes, rain and generally being bashed about.

Changing settings

Thermoworks mentioned they have redesigned the battery compartment and made it easier to access. After over five years owning the Mk4 I never once had to change the battery so I can’t really compare it, but I can confirm the battery area is easy to get to, with just one screw to remove.

You can change the AAA battery, or adjust a variety of settings including the option to switch between fahrenheit and celsius, changing the display resolution from 1° to 0.1°, changing the sleep and wake up settings and calibration.

Alternative instant-read thermometers

With ThermoWorks phasing out the MK4, there isn’t a lot of competition at this price point. If you’re willing to sacrifice some accuracy and speed for a lower price then you can stick with ThermoWorks and go for the ThermoPop 2.

The read time goes up to 3 seconds, and the accuracy is ±1°F, but you are paying a fraction of the price.

The probe is always sticking out though so it’s not as durable, and the protective tip is easy to lose. I definitely prefer the Thermapen design with the probe retracting back into the case.

There are also Thermapen copycats like the Javelin PRO from Lavatools which do a reasonable job at a lower price point.

Should you buy the Thermapen ONE?

If you already have a Mk4 is it worth upgrading?

I would say for most people the Mk4 is more than capable, so I would only recommend upgrading if you are competing in comps or just want to have the latest and greatest.

On the other hand, if this is your first thermometer, or you are upgrading from a budget meat thermometer then the Thermapen ONE is hands down the best instant-read thermometer money can buy.

I’m going to repeat what I said about the Mk4 and say that if you take grilling and barbecue seriously, like to compete in barbecue competitions, or if you work in the food services industry then Thermapen ONE is the best meat thermometer on the market.

If you cook mostly barbecue and can only buy one thermometer, I would recommend going for a leave-in style thermometer like the Smoke.

It’s still early days though so I’ll be sure to update this review over the next few months as I use the ONE. I’m sure I’ll be using it a lot!