Temp Control Theory

CR

I know that most of us have accepted the theory that it is very difficult to bring the temp down, in the Egg, once you have overshot. I have had a little different experience in that, unless the Egg has sat at the high temp and for quite a long time, I can usually just open the dome briefly close again with reduced vent openings then come up to temperature.[p]I believe this is due to the great insulating properties of the ceramic. The heat is supplied by the fire, not the heated walls of the Egg. [p]Granted, if you let your Egg stay at a higher temp for a lengthy period so that the dome, plate setter, etc, soak to the higher temp it will be a somewhat lengthy process to bring the temp down. But, if the ceramic has not acheived the higher temp, and this is usually the case when you are starting your cook, then even if you overshoot you should be able to get to a lower temp fairly fast.[p]This is just my 2-bit theory and a will anticipate a bombardment of post stating that i am full of hooey but, oh well, I'll get over it.

Wise One

CR, I think that you are right however, usually when I overshoot the temperature, it is because I have forgotten about it for an hour or so. In thi scase, the fire is huge and the ceramic is heated thoroughly. Even so, I do as you say, open the dome, look at the raging fire, close the lower vent (mostly) and then close the dome and open up the top vent to allow heat to escape. After 15 minutes or so it is back into the range I want but all my lump is pretty well burned up. If I were trying to do an all-night cook at 240 and it had gotten to 600, I would just start over. If I were trying to cook at 350 and the temp has gotten to 550, the above procedure works well.

The Naked Whiz

CR,
I agree with you totally, but I have been to lazy to take the time to spell it out carefully enough not to confuse a new person. Clearly, if the egg was just lit and the ceramics are still relatively "cool", you can reduce the temp by evacuating the hot air and shutting down the fire by giving it less oxygen so that the air inside heats up less. With the ceramics not contributing to heating the air, you can adjust the temp by adjusting the fire. When the egg itself is hot, though, you can't control the heating of the air done by the walls of the egg, so you need to reduce the fire and wait for the ceramics to cool.[p]TNW

The Naked Whiz

CR,
I just validated our theory. I started my egg up and then got distracted. When I returned it was over 800 degrees. I put the daisy top on it, set for about 300 degrees and it was down to 400 within a minute or two. Wouldn't care to try that if it had been at 800 for an hour.[p]TNW

CR

The Naked Whiz, this whole theory may be why some new eggers find themselves struggling with temp control. It would seem that once the "relative" coolness of the ceramics begins getting warmer then you will need to compensate by adjusting down the vents. Otherwise the dome temp would creep up slightly. This process would repeat, each time to a lesser extent, until the ceramics stopped heating-up. In effect it would appear that you are having trouble but in reality these small adjustments should be expected.[p]I wonder if any of the MickeyT's Ring users have noticed a creep in dome temp from the initial set-point point to some time later when everything had heated-up; assuming they were not compensating with the lower vent?[p]Nothing earth shattering here but, it is interesting to think about how the BGE works.[p]Have a good evening, CR

Basselope

I have observed the same thing. The cermanic takes a long time to heat up. If you catch an over temp before the cermanic has goten, for lack of a better word, heat soaked bringing the temp down is as easy as closing the vents and every 30 seconds or so opening the dome to let the heat out. I call this burping the egg. I have brought a 700 degree egg down to under 300 in about 5 minutes this way. I posted on this once before and got flamed by someone told me I did not know what I was talking about, and my advice was wrong. it is nice to see that the laws of physics do apply to other people on this board. <insert smilie thing here>
One other thing I have only done once, but it worked great for me was when I had let the cermanic heat soak, and I neded to bring the temp down fast (middle of a long rib cook) I closed down the vents and added one more cold firebrick. Heat travels from hot to cold, the brick got hotter, the dome went down in temp. Brought me from 350+ to 250 very quickly.
$.02

Dave's Not Here

basselope,
What a great idea, adding a cold firebrick! Just last weekend I was cooking a brisket, got distracted consuming malted barley with water, and the temp rose to 400°. Every time I opened the Egg to cool it down, it just got hotter.[p]Before I started using splits (was using full size firebricks before) it took forever to stabilize the temp and it burned a whole bunch of lump.[p]A well written paragraph or two of this thread would be a good addition to the cookbook.

Basselope

Dave's Not Here,
I wish I could take credit for forulating some complex theroy and testing it out, but in real life I was trying to shield the ribs and added one brick. The temp came right down! As I always say, I would rather be lucky than good.