Temperature and Sand

[Dan N.]

OK - this is for all you physics majors out there. I had posted a reply earlier today where Brian had problems keeping temp low when he used sand. As I started thinking about my reply I came up with a theory.

When one starts up the WSM using sand and doesn't put the meat on until the cooker gets up to temp you have to keep the bottom vents fully open until the desired temperature is reached. That means that the fire is burning full blast and is continuing to heat the sand (the heat sink). When one finally starts to shut down the vents the temperature of the heat sink has to be higher than if one put the meat on at the beginning and slowly let the unit rise in temp.

Under these conditions it just seems that it is going to be more diffcult to control temps at the high end.

Any thoughts on this?

 

[K Kruger]

Yes, you're right.

If the meat you add is small you may see a negligible change in temps after several minutes but if you add a lot of meat you may very well see the scenario you describe. Further, if the meat you add is fresh out of the fridge that will add to it. Further still, if you are not careful with grate probe placement (if measuring cooker temp at grate level) and the probe is too close to cold meat the reading will be lower than it should be. Though this could happen no matter what you have in the pan it can create more of a problem with sand. Water, as we all know, won't get higher than 212 at sea level--it'll just turn to steam; sand's temp will keep on climbing.

 

[Ken Keating]

When ramping up, with or without meat I try to avoid is going from wide open to completely closed on the vents when the target temperature is reached; otherwise you will have an overshoot problem. Two ways that I do this, with or without meat are: 1) faster method: open the vents wide open, then 30 to 40 degrees before the target temperature is reached cut the vents down to what you would normally operate them. Then make adjustments accordingly, or 2) slower method: open the vents a little larger that what you would normally have them and then make adjustments when you approach the desired temperature. What you want to avoid is greatly overshooting the target temperature.