Thermapen One Review: Why I Don’t Regret the Investment

When I first saw the price tag on the Thermapen One, I nearly choked.

My trusty $10 thermometer had served me perfectly well for years. But after watching countless reviews and noticing how serious bakers seemed to talk about this tool with reverence, curiosity got the better of me.

The moment I used the Thermapen One in my kitchen, everything changed. Going back to those cheaper thermometers suddenly felt like trading a sports car for a bicycle.

Here’s a breakdown of why I think the Thermapen One is the best thermometer for sourdough.

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Pros and Cons at a Glance

Pros

• Incredibly fast (1-second read)
• Extremely accurate, consistent readings
• Long, fold-in stainless steel probe
• Bright auto-adjusting backlight
• Certified to national accuracy standards

Cons

• Expensive ($70–$120, depending on current promotions)
• Might be more than a casual baker needs

Why I Use a Thermometer for Sourdough

Dough Temperature = Fermentation Control

The temperature of your dough is a key indicator of how fast (or slow) it ferments.

If your dough is 80°F, you’re looking at a 3–5 hour bulk fermentation. But if it’s down around 65°F, that step could take 12–14 hours. 

And just because your thermostat is set to 72°F doesn’t mean your dough is the same temperature. That’s where a good thermometer comes in.

Quick tip: You can control your dough’s temperature before mixing by adjusting your water temperature. Use a water temp calculator to figure out what temp your water should be.

While dough temperature is king, ambient temperature matters, too. Just because your dough starts out warm doesn’t mean it’ll stay that way if your environment is freezing.

I keep a small room thermometer with a humidity reader in my kitchen so I know when to get out the proofing box or adjust my schedule.

End-of-Bake Internal Temperature Check

I also use my Thermapen One at the end of baking to check the internal temp of my loaf. No one wants to cut into their loaf and find an uncooked, doughy spot!

My go-to sourdough bread recipe calls for baking 30 minutes covered, then 10–15 more uncovered, or until golden brown. But sometimes, I like to double-check if it’s truly done.

Especially with some of my inclusion recipes, it can be hard to tell by just looking. So I stick the probe into the center and check for the internal temp I’m aiming for. 

For bread, the target internal temperature is usually around 205-210°F (96-99°C). Other types of dough might have different target temperatures.

Honestly, this tool takes the guesswork out of so many steps. 

What Makes The Thermapen One Worth the Money

Accuracy

This is the number one reason I’d say this thermometer is worth the money.

You can poke your dough in five different spots and get the same reading, which is more than I can say for the cheaper ones I’ve tried. 

With some, I’ve seen the number bounce around depending on how deep I stick it or where I measure. 

This thing is lab-calibrated to an accuracy of ± 0.5°F (± 0.3°C) and comes with a certificate of accuracy to prove it. 

And really, that’s the whole point of using a thermometer when you bake in the first place.

Speed

I also really appreciate that the Thermapen One tells you the temp of your dough in literally one second.

That might sound like a small thing, but it’s huge when you’re standing in front of an open oven trying to decide if your loaf is done. 

It’s also why I always reach for this one over the cheaper models I own. It saves me time!

Design

The design offers a few bonus features that make this thermometer even cooler:

• The long probe makes it easy to reach the center of your loaf
• It also folds in for easy storage
• It’s durable and waterproof, so I can wash it (though do NOT put it in the dishwasher)
• The bright backlight automatically adjusts based on the light in your kitchen
• Has a quick-access battery and settings compartment 

• The auto-rotating display is nice when you’re trying to get the right angle
• It comes in 13 colors
• It has a 5-year warranty

Versatility

While I use the Thermapen One the most for sourdough applications, it’s great for so many uses!

Here are some of the ways I’ve used it:

• Check meat temps to ensure they’re safely cooked
• Check the temperature of shipped food items that seemed too warm upon arrival (once, we bought frozen salmon that arrived completely thawed and was totally unsafe to consume!)

• Check temperature of tangzhong to ensure it’s warmed enough
• Check temperature of milk when scalding prior to making English muffins
• Check temperature of my breastmilk when I had to scald it prior to storing (it’s a LONG story, but it has to do with high lipase.. it’s a whole thing)

I’m sure there are a million other ways to use this thing, but if you need to know the temperature of something, this does it the best.

Is It Worth the Splurge?

I own a cheaper ThermoPro thermometer (not to be confused with ThermoWorks). It was under $20 and gets the job done just fine.

But there’s definitely a difference.

The technology inside the Thermapen One gives it a level of speed and accuracy that a ~$14 thermometer just can’t compete with.

Even though I keep both in my drawer, I always reach for the Thermapen One.

How to Find Thermapen One Discounts and Sales

There are ways to catch the Thermapen One on sale. The best deal you’ll usually find is around 30% off, which puts it in the $70s – and that’s typically only on the ThermoWorks website, not Amazon. 

[I don’t recommend buying this on Amazon – it’s more expensive than buying directly from ThermoWorks. And I’ve spot checked this many times over the past year.]

I got mine during a Black Friday sale, but the savings difference isn’t big enough to make it worth waiting for.

To check if there’s a sale going on, you can always visit the product listing directly, or you can check the discounts section on my Linktree page. Whenever I see a good deal, I add it there for easy access.

Final Thoughts

You don’t need all the fancy tools to start baking sourdough, but if you want more consistent results and fewer surprises, a thermometer is one of the best upgrades you can make (in my humble opinion).

In my kitchen, the Thermapen One is hands-down the best thermometer for sourdough. 

It’s fast, accurate, and built to last—and once you try it, you won’t want to bake without it.

Other product reviews:

• Krustic Bread Dome Review: Worth It for Sourdough Bakers?
• Does ALDI’s Viral Bread Dome Live Up to the Hype?