Masterbuilt Probe

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Original poster
Aug 17, 2022
New MB 40 works well BUT temp probe read 165 in a pork loin after 1 hour! Was looking for 145. Took it out and used manual digital probe and it read 120. Using external probe it took about 2.5 to reach 145. It was first smoke. Any thoughts?


SMF Hall of Fame Pitmaster
OTBS Member
SMF Premier Member
Group Lead
Sep 12, 2009
Macungie, PA
^^^^Exactly what Norm said.^^^^

My built in Meat Probes stayed in their sheaths for their entire lives.
I considered them useless.



Master of the Pit
Apr 25, 2015
Stick it in boiling water, see how far from 212F it reads, and use that correction factor for every subsequent measurement or thermostat setting that's using that probe for a setpoint.

I'd do the same thing with any probe. But I'd rather have a calibrated probe that needs a large correction to its indicated value than an uncalibrated probe that I just THINK is reading accurately.

Others may disagree but I think we'd all agree that it's important to feel comfortable with your tools. If that means buying a new probe, more power to ya'.

JckDanls 07

Smoking Guru
OTBS Member
SMF Premier Member
Group Lead
Sep 10, 2011
Tampa area, Florida.
Yea... If there is a way to get the two (smoker probe, boiling water) close together and hold the tip of the probe in the boiling water... Should be close to 212 degrees ... a second test would be ice water .. Fill a big cup with crushed ice.. fill with water just to the top of the ice... Stir with probe and it should be close to 32 degrees ...

I would still go with a good double probed unit for chamber and meat ...


Smoke Blower
★ Lifetime Premier ★
Apr 24, 2021
I've had troubles with my probes as well. I finally broke down an got a couple of nice instant reads, and I just go oof of those. I never use the built-in probes anymore. P.S. my wife showed me a thing called mercari. And I got a great deal on some instant reads. And they work great.