Help. My Egg went Fukushima

LBH

Hello,
I'm a newby. 
I picked up a large BGE 3 weeks ago.
Sometimes I get the temp right and sometimes I don't.   I installed a BBQ Guru CyberQ for long cooks.
I had it pretty well dialed in on a simple pork loin grill so I tried a longer cook.  One rack of b-backs and a small pork butt.  After getting the egg to 225deg I inserted a probe into each meat and placed them on the grill rack (Placesetter Legs Up).  

Well the probe in the ribs was stupid (I think) because the meat is thin.  The CyberQ started alarming on the ribs.  Stupidly, I ignored the alarms on my iPhone.  I assumed they were just for the ribs, and didn't pay close attention to what was happening to the overall temp of the egg.  I deserve your LOL's.

2 hours later I go to wrap the ribs and I see that the egg is at 500+deg.  $50 worth of meat is toast. 

Here is what I "think" happened.  The chunks of peach wood I used were too large. (the size of a baseball)  Once they lit up there was no way to control the temp.  It became a runaway reactor.

Is this correct?
What size should my wood chances be?

Many thanks

Luke 

lkapigian

Well, the product temp should not affect pit temp assuming you had a pit probe and sethe properly...

lkapigian

Sounds like you were controlling using product temp?

Wolfpack

Chunks shouldn't have caused run away temp- controller would have covered for them. 

If pit probe was in correct spot...

I suspect you had the top too open- it need to be almost closed and I would also verify you don't have a bunch of air leaks. If it was getting to much air it would cause a run away. 

You may need to check your probes and wires- they don't like that level of heat. 

jknudsen11

Just to check - you put a temperature probe on the grate for the grate temp, correct?  From your story, I'm picturing you putting the grate temp probe in the ribs, which would certainly drive the fan to blow and send the temp up.  Somehow your setup was off.  Wish you luck next time!

gdenby

Take this w. a grain or 2 of salt, because I've never used a controller, and not a remote therm anymore.

Flaming wood produces gasses at around 1800F. It can't stay flaming if the oxygen supply diminishes. Even chips can not burst into flames no matter what size if it isn't getting enough oxygen. The oxidation reaction between the carbon and the lump is stronger than that with wood. The wood can only burn when there is a surplus of oxygen. My guess is that the controller was just pumping too much air, and over heating the lump. Haven't the faintest idea why. If you were getting alarms, shouldn't it have shut down the fan?

The Egg by itself is pretty good at producing stable temps w. nothing but adjusted vents. As far as I know, that is what is good about ceramic cookers. The only down side to cooking w/o digital instruments is one has to go take a peak at the temp every few hours, and maybe pop the dome to see/smell how the food is doing. Typically, I find things going as expected.

Ike

if your blower as and adjustable dampener, if may be open a little too much

EggPerfection

It has to be the air coming in.  Choking the exhaust only fine-tunes the temp but to rage like that it had to be gulping Air.  Almost all of us have booted a good piece of meat or two.  I did probably too much.  Just learn and get better and you will for sure.  PS - YOU ACTUALLY HAD AN ALARM AND IGNORED IT. You could have saved it all!

nolaegghead

Ike said:

if your blower as and adjustable dampener, if may be open a little too much

Too hot is too much air.  ^^^^this. 

Your fan damper should be open about 20% or so. Keep the unit off and wait until the fire is stable BELOW your desired temp.  Now plug it it.  The fan should give it a little boost now and then to hit your set temperature.

The fan does not run backwards and let less air in.  Only more.

After you follow my process once or twice, you'll know where the damper should be and you can start off with a fresh fire and the stoker system running.

If the fan runs all the time, the damper is too closed.  Damper is bypass air.  This wasn't your problem, obviously.

LBH

Thanks for all the great input. @gdenby you are spot on.  @nolaegghead the fan damper appears to be my problem.  I went out and checked it.  (Didn't notice it before).  It was wide open.   Ouch. 

Next CyberQ question:  Where do I set the top cap vent when using the fan. 

LBH

Also.  Original question.  What size should the wood hunks be?  Lots of chips or a couple big hunks?

Bshults1

I never worry too much about the top vent.  If you have everything set up correctly below, the fan should adjust to whatever it is.  I know some people on here leave the cap entirely off the top when doing low and slows and only control using the bottom vent

Legume

I can't help with the controller, but if you're new with the egg, you should invest a little time in figuring out temp control manually.  Once you know how to manage it, everything else will make sense.

LBH

I think I have the manual operation down.  At least grilling and making pizzas. 

sheetmetalpete

Legume said:

I can't help with the controller, but if you're new with the egg, you should invest a little time in figuring out temp control manually.  Once you know how to manage it, everything else will make sense.

Well said.  I bought a PartyQ right away thinking that was my answer.  It's a nice tool at times but I find I don't need it now that I learned temp control - well, for the most part anyways. 

nolaegghead

Even if you know how to control temps without the stoker, I can see doing the manly thing and not reading the instructions....and not knowing about the fan damper...and overshooting your setpoint temp.

LBH

nolaegghead said:

Even if you know how to control temps without the stoker, I can see doing the manly thing and not reading the instructions....and not knowing about the fan damper...and overshooting your setpoint temp.

I did read the software instructions.    I am able to determine that my egg is imploding and the meat is now jerky while shopping at the local hardware store.  

LBH

Chip size?  Anyone?  Chip size? Buehler?

Gunnar

On a low and slow cook I use small chips and disperse them through the lump...as the fire on the coal expands the chips will be consumed...for ribs that means I have chips in the next cook or two...depending on full you fill the firebox.

nolaegghead

I use whatever I have available.  I can't tell a taste difference between chips and chunks.

Darby_Crenshaw

the amount of fuel in the egg (and chips and chunks are merely fuel) do not control the temperature of the egg.

air coming in is what counts. the lower vent is your throttle (and/or the top bent, depending how you roll).

your car does not go faster just because it has a full tank of gas. and so the large chunk of smoke wood isn't causing runaway temps

it can't even ignite, actually, unless the vents are too open

for whatever reason, the egg was getting too much air.

CanadianAnvil

It doesn't matter

Hans61

Practice makes perfect - keep your air to a minimum during long low and slows, the ceramics get heat soaked so you don't need much air to maintain temps 

BBQbutler

LBH said:

Thanks for all the great input. @gdenby you are spot on.  @nolaegghead the fan damper appears to be my problem.  I went out and checked it.  (Didn't notice it before).  It was wide open.   Ouch. 

Next CyberQ question:  Where do I set the top cap vent when using the fan. 

Yup.  Position one on the pit viper damper 

caliking

Chunks. 1 fist sized chunk per lb of meat.  I made that up. Use as many as you like , depending on how much smoke you like. 

The fan blew too much air in. Possibly because the damper was open too wide or the pit probe was not placed correctly. I once forgot to place the pit probe in the egg, but luckily caught my goof 10 mins later when I went back out to check something. The flame boss thought the egg was at 80F and so the fan was running full tilt to try and get the temp up. 

LBH

Big Chunk Solution....

LBH

BTW:
Thanks to all for the great input!

nolaegghead

I have a SOG axe too!

LBH

Darby_Crenshaw said:

the amount of fuel in the egg  do not control the temperature of the egg.....

your car does not go faster just because it has a full tank of gas. and so the large chunk of smoke wood isn't causing runaway temps.......
for whatever reason, the egg was getting too much air.

@Darby_Crenshaw
I've been thinking about your post for some time and while a your post made sense, it didn't jibe with my observation when I lifted the lid of the egg.  The large chunks of hardwood were burning significantly faster and "more intense" than the lump coal.  To use your gasoline analogy a cup of gasoline would burn much faster than coal.

After Googling "burn rate" I respectfully disagree.   

I found the attached US Forrest Service paper "Burn Rate of Solid Wood Measured in a Heat Release Rate Calorimeter" interesting.

Bojangles

your questions have already been answered, but I just want to make 1 comment.  I noticed you said you set your Egg to 225 and then got your fan and probes, etc all set up.  Since we are talking low and slow I presume 225 was your desired cook temp.....

I suggest you try to stabilize your temp LOWER than your desired cook temp before you get the fans, etc set up.  The thing about ceramic cooking is that it is easy to raise temp, and very very hard to lower it.

When I cook 225, I typically try to get things stabilized at 190-200, then set up my BBQ Guru, and let the controller, fan, and probes do their jobs to raise the temp to 225.  It is a safe play to not overshoot your temp and be stuck waiting while attempting to cool your Egg.  Just my $.02

GATraveller

The amount or type of fuel you had in your egg has nothing to do with the high cook temp.  The temp is regulated by airflow.  Air is the cause - not wood chunks.