Thermoworks Thermapen MK4 Thermometer Review
Is It Worth Buying?

In order to achieve an agreeable flavor for your finished brew, you need to be able to control the temperature of the fermenting wort. If the temperature is too high, the final taste might be too fruity or exhibit harsh characteristics.

In the past, there was no reliable way to control fermentation temperatures other than brewing your beer during the winter months.

Today, however, we have the thermometer. And one of the most popular ones amongst homebrewers is the Thermapen.

Below we’re going to look at the new Thermapen Mk4 instant-read thermometer and see if it’s a worthy addition to your homebrew kit.

Thermapen Mk4: Highlights & Benefits

Red Thermapen with PackagingThe ThermoWorks Thermapen Mk4 is super easy to use and provides an instantaneous digital display of the temperature on the large, easy to read LCD screen.

There’s no waiting for the thermometer to find the right temperature, no wavering within a temperature zone and no doubt that the reading is accurate.

That’s because the ThermoWorks Mk4 uses professional grade thermocouple technology to arrive at the temperature, not the more popular but less precise thermistor technology.

A thermocouple produces a voltage that is temperature-dependent and which the software interprets to arrive at a precise temperature reading.

One thing most people will notice right off the bat is that the ThermoWorks Thermapen is more expensive than many other digital thermometers. So why, they wonder, should they spend more on the Thermapen Mk4?

The answer is simple: you shouldn’t. Unless of course, you want fast, accurate temperature readings that will help you brew the best beer possible.

The ThermoWorks Thermapen uses a single AAA battery. The same ones you’ll find at any 7-11 or other convenience stores. So powering it is no problem.

It won’t cost you a fortune in batteries either as a single battery will provide you nearly 3,000 hours of use.

Another great feature of the Thermapen thermometer is that, no matter how you hold it, the temperature is always displayed right side up.

Sort of how your smartphone display changes from portrait to landscape as you rotate the phone. No more having to cock your head at odd angles to read the display with the Mk4 Thermapen.

And then there is the automatic sleep mode that monitors how long since the device has moved and automatically shuts it down to save battery life.

Lastly, the Thermapen Mk4 is available in 10 different colors, so there’s bound to be one that appeals to you.


  • Intelligent backlight senses a dark room.
  • Super-fast, precise temperature readings.
  • Auto rotating display adjusts to you.
  • Fully waterproof.


Any Shortfalls?

hand holding the ThermapenThe Thermapen Mk4 provides super-fast, totally accurate readings and runs for years on a single AAA battery.

So what’s not to like?

Well, mostly the price.

As we mentioned earlier the ThermoWorks Thermapen is more expensive than most other digital thermometers and that by itself is going to put some people off. But it shouldn’t.

The Thermapen by Thermoworks is without a doubt one of the best, most accurate brewing thermometer products out there and is built to last.

So whatever you spend on it should be considered an investment in the quality of your product.

Beyond that, there isn’t much of anything to complain about. Some might want to see the Thermapen screen backlit at all times. But what would be the point of that really?

As it is the backlight comes on when the sensor determines it is needed. We call that smart. For more brewing thermometers, see our main guide here:


  • There’s no getting around the price. But it’s worth it.

Thermapen Mk4 Review: Is It Worth Buying?

Thermaworks MK4 Thermapen PreviewThermoWorks super-fast Thermapen Mk4 provides near instantaneous temperature readings that are precise and dependable.

There’s no twisting the device around to read the temperature either as it has an auto-correct feature that always presents the display “right side up” as it were.

Yes, some other thermometers won’t cost you as much, but lower price alone almost never guarantees you’re going to get what you want.

At the end of the day, the thing that should matter most is the quality of your home brew. And the ThermoWorks Thermapen Mk4 will provide you the best chance of producing a product you can be proud of.

As such we recommend the Thermapen Mk4 without hesitation.