GMG cold-weather cooking - external surface temp probe is an absolute must have

[jumbo7676]

Did an overnight brisket cook, a prime packer from Costco, Saturday into Sunday on my Daniel Boone. Outside temp was in the 20s. I got a GMG thermal blanket to help regulate temp and keep me from burning through pellets at a crazy rate. In order to keep the grate level temp below 250, I had to set the GMG temp to... 165! I had two Maverick XR-50 probes monitoring grate level temp, in front of and behind the brisket, that held pretty steady around 240 while the GMG was set to 165.

I never checked until after this cook, but the location of the built in temp sensor is below the grill on the side and is pretty close to the body of the grill (picture below is from the GMG website). If the thermal blanket (picture below is from the GMG website) covers that at all, it isn't by much. The freezing outside temperatures were clearly wreaking havoc on the sensor's reported temp. If I hadn't been using the additional probes, this could have been a total disaster and waste of a 15-pound prime packer.




Notes I took away from this cook:
- If cooking in cold temps on a GMG, monitoring grate level temps is an absolute must.
- Now I know how a overcooked and shriveled a few racks of ribs when using the grill without the grate level probes when I first got it. Since I don't use a meat probe when cooking ribs and cook based on time (3-2-1 method), they were so overdone that after two attempts I realized that the grill was cooking much hotter than the temp I had set it to.
- The thermal blanket had a very obvious impact on the amount of pellets I had to use. I thought $80 might be a little expensive for a this accessory, though it will definitely pay for itself in saved pellets during the life of this grill.

No pics, as I was more concerned with staying warm and getting sleep, but the brisket came out pretty tasty. Slightly overcooked, as I fell asleep and left it on a little longer than I had wanted, but still held together just enough to slice it without having it pull apart.

[jfmorris]

Ok, why would you be measuring the surface of the grill? I would think the temp you care about is the air temp at grate level where the food is cooking? I can definitely understand that the GMG sensor is off, and often those pellet cooker sensors are not at grate level either, and that you may need to set it differently, but I don't understand why you would measure external temperature, versus grate level temperature.

[Potkettleblack]

If the probe is that close to the wall, the exterior temp or any coldness in the side of the grill might dial it longer. The Grilla has a long probe that goes about halfway to the burn pot. I think that's a better design, and maybe more standard?

[jumbo7676]

Because I am sleep deprived with a 16-month-old and 3-week-old baby at home and was trying to rush this post so I could get back to work, I was saying grill surface when I should have been saying grate level. Going to make the edits now to the original post.

[jumbo7676]

I can't edit the title of the post - will have to re-post

[Potkettleblack]

A story like this is why I own a Grilla. The extra wall of sheet metal with the air gap keeps you from needing a blanky. But I think this is a worthwhile practice. Also, keep that temp probe inside clean. That's been a thing that's gotten me a bit wonky.

[jfmorris]

jumbo7676 Ok putting your probes on the grate makes a lot more sense to me now! I think that is a good practice with any smoker. I have a BBQ Guru PartyQ, and even with its probe right next to the probe for my Smoke thermometer, I sometimes see 20F difference between what the PartyQ thinks it is, and what it really is (I trust the Thermoworks readout more).