Neil, I've found that the disparity between the dome and grate temp grows as the WSM gets hotter. For instance, when smoking butts at dome temp 200, the grate is around 225 (about 25 degrees difference). At 325 degrees dome temp, however, grate temp will be around 375 (about 50 difference). At least on my machine.
Smoker Dome Temp this far off?
- Thread starter NeilH
- Start date
Mike Leiter
TVWBB Pro
To smoke at a certain temp I would go by the grate temp the food is sitting at. That would be the temp that the food is actually sitting in and cooking to....That would be my thought and the temps I go by on mine.
That's the key and the only way to "master" it is by practice. For instance, I've used a long turkey fryer therm to help "reveal" that grate/mid section temps vary significantly from dome temp. Does that mean go out and buy an expensive probe therm to know exactly what the grate therm is? No, just get familiar with your WSM to realize/discover and thus, compensate for the difference. I really like the turkey therm trick, because those things are cheap and you can stick em anywhere (latch, through the dome air vent hole, etc.)
Mike Leiter
TVWBB Pro
I got one for Christmas and its been great to use. I clip the probe on the grate and the other goes in the meat. It will give you a better idea of temps at your food. Use the dome one to get a general visual idea of system temp and operation. If you see it dropping or raising you know you need to make some adjustments. Use the Maverick ones for the fine tuning temps on cook temp and food temps that you can watch from inside the house
Neil,
Having spent over 40 years in the HVAC industry, I learned a lot about the properties of hot air. It is less dense than cold air and always rises as I'm sure most know. And it will always seek an opening where it can escape. The problem with the Weber therm on the WSM is it's in a dead air space. In other words the rising hot air hits the dome where the therm probe is but can't escape so it starts a circular motion where it cools off somewhat by conducting it's heat through the dome hence the lower temps at the probe. I think Weber should install their thermometer on an angled bezel just below the vent so the probe is always in the rising hot air stream. Think about where kitchen oven thermostat probes are located. Most always at the top of the interior oven cabinet and in the rising hot air stream which will give the most accurate temps of the total oven load. Same with the WSM.
I always put my 732 probe in the top vent so it's measuring the total WSM load which gives me a better idea of actual cooking temps. I hope this helps you understand why the difference in temps occurs. I wish you much success for your future cooks.
Having spent over 40 years in the HVAC industry, I learned a lot about the properties of hot air. It is less dense than cold air and always rises as I'm sure most know. And it will always seek an opening where it can escape. The problem with the Weber therm on the WSM is it's in a dead air space. In other words the rising hot air hits the dome where the therm probe is but can't escape so it starts a circular motion where it cools off somewhat by conducting it's heat through the dome hence the lower temps at the probe. I think Weber should install their thermometer on an angled bezel just below the vent so the probe is always in the rising hot air stream. Think about where kitchen oven thermostat probes are located. Most always at the top of the interior oven cabinet and in the rising hot air stream which will give the most accurate temps of the total oven load. Same with the WSM.
I always put my 732 probe in the top vent so it's measuring the total WSM load which gives me a better idea of actual cooking temps. I hope this helps you understand why the difference in temps occurs. I wish you much success for your future cooks.
Dave Russell
TVWBB Honor Circle
Scotty, I agree with you completely about the gauge being located above the dead air space, out of the stream of circulation. But what about affect of the pan? I've always assumed that the reason my cooks would take so much longer than commonly recommended guidelines was because so much of the heat coming out of the top (where I was measuring) was coming up through the outside perimeter of the grate, not where my meat was. But when I went to measuring at the grate, times and temps became much closer to what I've more commonly seen and heard recommended.
Dave,
Your reply caused me to do a lot of thinking so I'll try to explain what I believe happens when cooking in the WSM. If the rising air stream exiting the pan perimeter stayed completely stratified until it exited the vent the food would cook more by radiant heat coming through the pan thus taking longer. But the pan, grates and food will cause a small degree of turbulance in the rising hot air stream around them thus causing a mixing affect of the air so the food cooks by convection and radiation. I've tried placing the 732 probe on the grate and it worked fine although the temps would be lower longer because the meat acts as a heat sink cooling off the rising hot air stream. As I said the air temp exiting the vent, I believe, gives a more accurate reading of the WSM's total load for any given cook. But that doesn't make my method better than yours, it's just what I do. If your method works better for you then keep on doing it. Bottom line is to have fun and enjoy the food you cook.
Frank Eriksen
TVWBB Super Fan
Trying to get the WSM temps just right will drive you crazy. You'll get very good results using the dome thermometer. Or you can pop for the IQ-110, BBQ Guru or Stoker. Year before last I did 6 slabs of babybacksfor the Super Bowl. Outdoor temp was about 15-20 degrees ribs turned out wonderful. Get to know your pit. It will serve you well for years. @BBQChefs. www.bbqchefs.us
Frank Eriksen
TVWBB Super Fan
When I first got my WSM, I just used the dome temp and adjusted the vents. Always got great BBQ. I added a Pitmaster IQ-110 and still get great BBQ. Someone once warned - "don't over-think" this temperature thing. BBQ is - sing it with me - done when it's done. When the end of the ribs start showing, check for doneness. For pork butt, brisket, chicken, use your meat thermometer. If you pay attention to your fire and your cooker, you'll do just fine.