Egg BLOWBACK

shadowcaster

So I just realized today that my dome thermometer on my medium is off. Last night I put a butt on and decided not to use my maverick and just set it and forget it. I thought everything was going great until I checked in with my wife this morning and the Egg was at 90*. Luckily I live real close to work (about 1.5 miles) and rushed home. When I opened the Egg the lump was completely burned off. I have gone 20+ hours on a single load before and this one was only about 12 hours in. I took the butt off and wrapped it in foil. I added more lump and started it up again. At this point I got out the maverick and set it up as well. I checked both probes on the maverick and they are pretty much right on. As I was letting the lump fire up the Maverick was going up in temp but the dome would not go over 120*. The maverick hit 215* at the grate and I put the daisy wheel on and shut the bottom vent to hit 250*. Here is where the blowback happened. Roughly 10-15 seconds after I closed the vents down I heard a loud gush of air and smoke came billowing out like a small explosion. I am not afraid to say I jumped back about 5 feet haha. Has anyone ever had this happen to them before? The temp shot up to about 246* immediately then slowly started to fall back down. Before I left to go back to work the maverick was reading 227* at the grid. Sorry for the long post but I have never had that happen to me. I am also going to check my dome thermometer today after the cook is done to see how off it is. 

I think the egg was running a lot hotter than I thought and that is why it burned through the lump so fast. Good news is the Butt still looked great, not burn marks and still very juicy! 

henapple

Why kind of lump?
How long was the egg down
Meat temp when the egg crashed?

lousubcap

Are you confident in the calibration of your thermos??  Temp is the one thing we have to try and understand/manage a cook.  Garbage in=garbage out!  FWIW-

shadowcaster

@henapple The meat temp was at 171* when I got home (9:00am), it was at 164* when I left for work at 6:30am

The egg was not down for long at all, when I got home it was still pretty warm when I opened it up.

The lump I was using is made by forest lumps (haven't had an issue with it except it sparks a lot when firing up)

@lousubcap I put the probes in an ice bath while I was home and one read 33 and the other 35. I have been using them quite a bit and have never had an issue with them. I didn't have time to boil water but if its accurate on the low side can it be off that much on the high end?

yzzi

Maybe you had an aerosol can in your lump.

lousubcap

@shadowcaster-what about your dome thermo?

shadowcaster

@yzzi ) 

shadowcaster

The dome thermo I have not checed yet. I will later today when I get off work. I was more worried about getting the egg going again and getting the butt back on.

yzzi

That would probably be a record for weirdest item in lump. That would beat out the ball bearing I found a few months back.

EGG_Daddy

It was probably a rock stuck in the middle of your lump.  It happens, not to me yet.  

The Cen-Tex Smoker

I've had that happen several times. Spits fire out the draft door and gasps like it's taking its final breath. usually it's really hot and being choked down but it's pretty cool. You can see it breathe (not a good time to throw the dome open if you are in to eyebrows and stuff like that).

shadowcaster

@Cen-Tex that is exactly what happened. I knew better than to try and open it after that  )

jrb06

Most likely the grate was choked off of air and due to ash and once it found enough air supply it ignited the gases. The poof blows out the ash in the grate and all will be well.

henapple

After a sixteen hour cook.. OO

shadowcaster

Show off. Yea I've never had a problem before, hopefully it's the last time

lousubcap

Yea but he was running at 60*F...