Dome and lower grill temperature compared, part 2

gdenby

A few days ago I posted the results of some temperature observations comparing the readings of the dome thermometer and a Maverick ET-73 probe on the lower grill. The results surprised me, because sometimes there was as much as a 150 degree variance between the two. Several other forum readers suggested that the probe readings were being influenced by its location near the edge of the grill and in proximity to food. This turns out to be true.[p]I cooked about 3 pounds of boneless pork chops last night direct on the raised grill. I clipped the Maverick probe in the center of the empty lower grill. After keeping the dome at 350 for about 15 minutes, I loaded in the probe, grills, and meat. The dome came back up to 350 fairly quickly. Within ten minutes the lower grid reached the same temperature. They stayed very close together for the next 15 minutes. I then opened the dome, took the chops' temperature, and flipped them. (I didn't use the Maverick's food probe during the cooking because the meat was thin enough that I thought it might fall out.) What followed was a bit of a surprise. [p]When I put the dome down, its thermometer read 290, but the lower grill was 380. However, within 10 minutes, the two met at 360, and began to climb up slowly. The infusion of air from opening the dome had really kicked up the fire. I began closing the vents down, and halted the temperature rise at 380.[p]At the end of an hour, I took the meat off. With the diminished fire, the dome had dropped to about 355, but the lower grill was at 295. The meat reached 170, and the bottom side was a little too toasty.[p]I guess this experiment underlines the obvious. The fire's heat rises from the coals and gathers in the dome. This happens either gradually from a slow fire, or in a wave from a fire stoked by a large amount of air. In a short cook of a little more than an hour, the dome retains quite a bit of heat, but the lower portions of the egg a still reletively cool.[p]gdenby