after owning my DB for 2 weeks, never being able to keep a constant temp, they sent me a new controller.. the grill firmware is now updated to the latest.. testing the grill tonight for a few hours, when the grill is set at 225 i have a swing from 215 to 236 according to my thermo works
smoke thermometer within 10 minutes. so, basically there is a 20 degree swing every 10 minutes or so.. im no aaron franklin but, ive heard temp swings are no good for smoking meat.. opinions?
Interesting. But I wouldn't worry too much about it at this point. However if it starts to affect results, well then I would be more concerned about it.
Some are going to tell you that it’s the “average” which matters.
But instinctively, I’d ask how much any given temperatures at any given points or periods of time, deviate from the "average" temperature.
In your above example, the average between the two temps you state, 215° and 236° is about 226°.
Sounds good if one is just concerned with an “average” over two reference points.
But consider, a 2 hr steady high temp of 272° followed by a 2 hour steady low temp of 180° would give you an average of 226° for a 4hr cook. But you would be looking at a difference of 92° between the hottest temp your food had been running and the lowest temp it had been running for that 4hr duration.
Would it make a difference? How much of a swing is too much? 20°? 40°? More?
Under such circumstances, you might or might not end up with the results you wanted if you were cooking say a rack of baby back ribs and planning on a 4hr cook or thereabouts. At the very least, you'd end up leaving them on longer to get them done enough to be tender enough to eat. That would be inconvenient in and of itself.
What I've seen with my PID controlled
Rec Tec, is very tight temps which do not deviate more than 2-3 degrees from the readings of my
Thermoworks Smoke once they equal out during and after the grill's warmup.
But I'm placing the Smoke's probe in a wine cork, not on the grates or in the metal clamp/holder that comes with the
Thermoworks Smoke. And I'm placing the wine cork, with the Thermowork's Smoke's probe through it, at the center of the grill. The probe never touches the grates. The cork does.
If you're using the metal clip and clipping it to your grates and running your
Thermoworks Smoke probe though that clamp, then I'd recommend using the wine cork or placing your temp probe slightly above your grates on a piece of wood. The grates get hot, metal gets hot, that clamp gets hot, and if your probe is in contact with hot metal, well then you're getting more of a measure of the temp of the metal that your temp probe is resting on, vs a better chance of getting what the ambient temp is inside of the grill. How high off the grates your probe is, even with cork, or a wood block, will have an effect too.
Also, the
Thermoworks Smoke, is slow. Let the grill run with the lid closed for several minutes in an attempt to let your
Thermoworks Smoke and your grill's temp probe readings equal each other or get close to it.
Then I'd let it run for at least an hour without touching the lid to see if it can (a) Hold steady to the temp you set it to, or close to it according to it's readout. If you set it for 225° does it report 225° for at least an hour after hitting it? (b) Hold steady with what the
Thermoworks Smoke is reporting or close to it. When the grill is saying 225° or whatever it's saying, and after an hour of not touching anything, what is the
Thermoworks Smoke saying? Are they close?
I check the accuracy of my grill's temp readout against my Themoworks Smoke from time to time to help me make sure that the temps that the
Rec Tec is telling me, are accurate.
Yesterday here is an example of what I saw over around a 2.5hr period.
Worthy of mention, is that my
Rec Tec's probe read 225° about 19 minutes before my Thermoworks Smoke was reading the exact same thing 225°.
The Thermoworks Smoke was reading as low as 200° by the time the
Rec Tec was reporting 225°. Thus when the Rec Tec was telling me that the temp inside of it was 225° and holding, the Thermoworks Smoke was recording around 200° and climbing.
However, over that 19 minutes, the Thermoworks Smoke climbed, while the Rec Tec reported a steady 225°, and the Thermoworks Smoke eventually made up the reported 25° difference and "caught up", and held very close, the pics below show how close, to the Rec Tec's subsequent readings for the duration of the test.
I attribute the "lag" of the Thermoworks Smoke to two possible things that I can think of. The Rec Tec's probe might read quicker or hotter than the Thermowork's probe because of the differing positions of the probes, ie the grill was hotter at one set than the other for several minutes, or because of the software used in the different temperature sensing devices used by Rec Tec vs Thermoworks.
Finally, I was waiting out a dead nuts on "225°" from the Thermoworks Smoke. If I go with the plus or minus 1.8° accuracy of the Thermoworks, Smoke well then I should probably have been looking for 223.2°. Which happened inside of that 19 minutes.
But as mentioned earlier, once the Thermowork's "caught up", it didn't go more than 5 degrees, (plus or minus 1.8°) above my set point of 225°. And consistently stayed with the Rec Tec's reported temp.
The images below, show the two temps were very close to one another for the duration and very close to 225°.
So if my average is 225°, you can see that I'm not getting very much deviation over time of the test, from that average.
That's what I want to see. That's what makes me comfortable. A 3°-5° swing over a better than 2hr period, sounds a lot better to me, and is more in line with my comfort level, than would be a 20° swing over every 10 minutes. But that's just me, and some say that it doesn't matter. On an overnight cook of say a full packer brisket, where I've placed a lot of effort and spent money and time, I don't want to find out if it does or doesn't.
I know that my Thermoworks Smoke is accurate to within plus or minus 1.8°F. It never read over 230° from my Stampede's set 225°. The Rec Tec never showed a temp higher than 229°.
I'm comfortable with my set temps being within 5° or less of what I set them. However if I am honest, I would not be entirely happy with swings of the type that you are reporting, I would not get too worried about them if the food was still turning out good however. But if the food was turning out overcooked or undercooked, well then I would be concerned, yes.
