Out of control Temp

ajridge35

Smoked some pastrami and beef ribs earlier in the week, maintained 250 for about 7 hours. No problems. I smoke a pork butt last night - put it on at 10:30pm and check at 8am to a butt that’s 212 degrees and an egg that’s sky rocketed to 350. I stabilized it at 250 before I put it on, had the bottom vent to width of a nickel and top smokeware chimney cap to half way open. My dollar bill test showed solid resistance everywhere except for 6 o’clock, and even there it had some resistance. My ONLY hunch is the charcoal? I’ve been egging for 10 plus years and don’t recall something like this happening. Has anyone had an experience like this? I don’t mind assuming it’s a one off but I’d like to fix this so it doesn’t happen again. Here’s a pic of the charcoal. 

Money_Hillbilly

@ajridge35 Did you clean out the egg and start with fresh lump?  We’re there lots of very small or very large pieces of lump?  Old lump or lots of small/large pieces can cause temp excursions.

lousubcap

As you are aware, the size of the fire (and associated temp) is air-flow driven.  If you were in fact stable for at least an hour at 250*F (on a calibrated dome thermo) then either there was an air-flow change (although your vent settings seem in the range for the 250 temp) or the the following naturally happened-the meat temp rose over time so the amount of energy that the protein needed was reduced. Same energy being generated by the fire so it has to go somewhere.  This caused the BGE internal temperature to rise and cycle continued til you found it.  FWIW-

BTW - I have never seen the fuel cause a change in the fire dynamics once in a stable scenario . 

danhoo

@lousubcap covered what I was thinking.

A thermometer with a remote and high low temp alarms for pit and meat is my insurance policy for this. 

ThermoWorks smoke is one example. 

I'd rather an alarm wake me up vs finding a too hot or too cold pit in the morning. 

stlcharcoal

It's not the charcoal unless it was really underkilned......in which case you finished the kilning process (burning the VOCs and wood fiber), and then it moved onto the charcoal which burns a lot more efficiently on a smaller amount of O2.  Looks like that is some sort of extruded product though.

How confident are you that the dome temp is correct?  Did you have a plate setter leg below it?  Sometimes it's just how the heat is under the dome.  It takes a VERY small amount of burning charcoal to maintain temp in the egg, and if that spot drifts to one side, then you might have a weird reading depending where that it.  

You said the dollar bill test was good, have you checked the base for cracks?

TechsasJim

ajridge35 said:

Smoked some pastrami and beef ribs earlier in the week, maintained 250 for about 7 hours. No problems. I smoke a pork butt last night - put it on at 10:30pm and check at 8am to a butt that’s 212 degrees and an egg that’s sky rocketed to 350. I stabilized it at 250 before I put it on, had the bottom vent to width of a nickel and top smokeware chimney cap to half way open. My dollar bill test showed solid resistance everywhere except for 6 o’clock, and even there it had some resistance. My ONLY hunch is the charcoal? I’ve been egging for 10 plus years and don’t recall something like this happening. Has anyone had an experience like this? I don’t mind assuming it’s a one off but I’d like to fix this so it doesn’t happen again. Here’s a pic of the charcoal. 

So you used those char logs?    I’m not a fan.   Love the normal B&B lump but didn’t enjoy the logs the one time I ran them

ajridge35

I appreciate everyone’s help. I have a kick ash basket and can and before every cook I give it a solid shake and replace with fresh charcoal. So there was some old charcoal in there and some new pieces I’d added. For the cook last night, there was a plate setter I used, just like I always use. Plus a drip pan that caught all the drippings from the pork. I checked the dome temp gauge and it was spot on in boiling water. 

I decided to empty the charcoal today and start fresh with new lump. I will say there was a TON of ash leftover from the cook last night. But I am grilling tonight, and since I’m a few hours away from dinner, I thought I’d see if I could stabilize the egg for a bit beforehand. I started the fire, let the temp get to 185-190 or so, then set the dials to what you see. It has continually climbed since I closed the lid and set the top and bottom dial.  

 

I checked for cracks and am not seeing anything to the naked eye. Smoke is only coming the top vent that I can tell. 

Can anyone help? I appreciate any and all help. Thank you!

lousubcap

ajridge35 said:

 I started the fire, let the temp get to 185-190 or so, then set the dials to what you see. It has continually climbed since I closed the lid and set the top and bottom dial.  

 

I checked for cracks and am not seeing anything to the naked eye. Smoke is only coming the top vent that I can tell. 

Can anyone help? I appreciate any and all help. Thank you!

Did you run "wide open" til shutting down in the 185-190 range?  If so, at that point what was the size of your fire? Likely quite large. The trick as you know is to catch the desired cook temp on the way up and throttle the vents around 50-75*F below the target cook temp. 

The lower vent looks like around 275-325*F range on a calibrated (key word) dome thermo.  So, you mentioned it kept rising-at what temp did it stop or is it going nuclear??

As said above, this rig is driven by air flow.  So, you need to be able to control the air in (bottom vent) or out (top vent) to manage the cook temp.  Or an undetected air leak exists.  That's all I've got.

Foghorn

I don't have a smokeware cap - I have the standard BGE "daisy wheel".  With that said, if I want to stabilize the temp at 275 or below I need to have both the top and bottom air flow regulators nearly closed.  Others may have had a different experience.

RRP

ajridge35 said:

I appreciate everyone’s help. I have a kick ash basket and can and before every cook I give it a solid shake and replace with fresh charcoal. So there was some old charcoal in there and some new pieces I’d added. For the cook last night, there was a plate setter I used, just like I always use. Plus a drip pan that caught all the drippings from the pork. I checked the dome temp gauge and it was spot on in boiling water. 

I decided to empty the charcoal today and start fresh with new lump. I will say there was a TON of ash leftover from the cook last night. But I am grilling tonight, and since I’m a few hours away from dinner, I thought I’d see if I could stabilize the egg for a bit beforehand. I started the fire, let the temp get to 185-190 or so, then set the dials to what you see. It has continually climbed since I closed the lid and set the top and bottom dial.  

 

I checked for cracks and am not seeing anything to the naked eye. Smoke is only coming the top vent that I can tell. 

Can anyone help? I appreciate any and all help. Thank you!

You have already received some great advice about your heating issue…but do you mind some advice about safety? Even though you are using that BGE stand please note the charring of the boards under your egg…please spend less than $5 and buy yourself some concrete paver bricks to put between that BGE stand and that wooden table. The more that wood chars the sooner it will begin to burn. 
 

Money_Hillbilly

I I still think it’s a charcoal problem.  Troubleshooting 101, what’s changed from an egger that has been cooking for years.  Only variable a new charcoal.  I had the same experience with KJ big block.  Not only did it have a funny smell the really large pieces led to erratic temp swings.  I am sticking to my original thought. 

RRP

And then after enlarging that bottom picture may I also add some more UNSOLICITED advice? When you go to close down your bottom vent then leave the screen protector clear to the left and then close your vent door to damper down the fire. The way you have shown then sparks can still pop out that opening as already shown in that picture! Call me an old worry wart …(I don’t care) but I see that wooden fence or wall behind your egg which could catch fire after your table did!

stlcharcoal

Get a couple floor tiles under that thing to protect the wood.....when with the table nest you need something to reflect the heat.

nolaegghead

I suspect excess air.  You can check for leaks also by shutting everything down and watching for leaking smoke (the smoke test). 

Unlikely, but not beyond the realm of possibility you got a loop current on your top vent at half open - where air could be pulled in the top because of the smokeware cap, and maybe something weird going on inside to influence the air flow.  Keep it closed almost as much as the bottom and eliminate the possibility.