XL Lump

MGOms

Has anyone used Kamado Joe XL lump charcoal? My last attempt at an overnight cook using this lump was a bust. It retained a temp of 240-250 for 12 hours but at 15 hours it went out. I still had about 2/3 of the fire box still full of charcoal so it wasn’t low on fuel. When I filled the Egg with charcoal, I went about 1/4 into the fire ring. So, maybe too much lump but surprised it went out with it burning this long. These pics are the settings on the BGE now and it’s been at 250 for almost two hours using the same lump. Hope it holds overnight. Doing about a 9lb pork butt. 

lkapigian

Can't have to much fuel, can have not enough oxygen...3 parts to make a fire, oxygen, heat, fuel remove 1 it goes out 

MGOms

Gonna have a fan going on the porch this time. 

stlcharcoal

My money is on you lost "heat" out of the fire triangle (better called "kindling temp")

Carbon needs 670F'ish to light off, then it burns at around 1300F.  When you're doing a low and slow, you're metering the O2, so you have a VERY small concentration of lump actually burning to maintain a dome temp of 225F.  Down in the firebox you have maybe a golf ball or racquet ball sized concentration of lump that is maintaining temp.  As that burns away, it needs to light more lump near it to keep going.  If it's too far away from the next piece, the temp might not be hot enough to complete the triangle.  It needs 670F and that 1300F might only be felt at 400F if it's more than X inches away.

That's why having smaller pieces as well is so important.  They provide a bridge to let the fire grow or move.  The temp is so low, and the O2 is in such short supply, the pieces need to be pretty well nested so that heat is transferred.  So, what happens with a temp controller if it didn't happen own it's own, the fan kicks on, introduces O2 to the burning piece, which raises the amount of heat it's putting off, thus, the next nearest piece may now feel the 670F to get it lit.

Ever here of flashover?  In a house fire all the sudden the ambient heat of the house will hit the magic temp and everything starts burning.  Back when I was EMS we watched a lot of these demos and training and it was wild how everything just ignited at once as soon as the room hit whatever that temp was.  Same thing happens in the Egg.  If you're trying to get up to a high temp to do a pizza, have a full fire box, draft door open, top off, and watch the dome temp as it passes 450-500F.  All the sudden it will accelerate like crazy and peg the needle.  What happened was that the firebox is now 700+ and ALL the charcoal ignited.

Another prime example--burping the egg.  You close it up after a hot and fast.  You still have fuel and the heat / kindling temp, you just removed O2.  You open the lid, introduce a ton of O2 rapidly, and all that concentrated heat provides a bridge for the flame to travel up and burn all you arm hair, eyebrows, etc off.

The whole marketing behind these huge chunks is so that you don't snuff the fire out because of the funnel shaped fire box.  But as long as you have a Kick Ash Basket or other replacement fire grate that lets the ash fall through, you don't need to worry much about the charcoal if it's more that 3/4"-1" in size.  It's going to burn a hole through.  I actually had a hollow cylinder the I made out of expanded stainless steel that was welded to a firegrate.....it ran the height of the firebox.  You could damn near dump fines in there and they would burn since the air always had a path to the chimney.  Really no need for it, but my point is don't fall for the marketing gimmick that these cantaloupe sized chunks of charcoal are going to last longer than smaller pieces of the same weight.  BTU/# is BTU/#.....doesn't change based off size.  And you experienced one of the several downfalls of using huge chunks.  A good mix of large, medium, and small is still the best way to go with or without a replacement grate, temp controller, etc.  Next time, stick some of those huge chunks on bottom, then top dress it with some small to medium pieces.  You'll be good to go.

lkapigian

^^^^this^^^ and is why I could care less about large chunks anymore..great explanation

MGOms

Thank you! 

Durangler

@stlcharcoal
Thank you for your post.. very informative!

QDude

The pieces are way too big!  I am going to use a hammer on them tomorrow to make them more manageable.

DoubleEgger

I used a bag and it’s junk. 

cookingdude555

It’s my favorite lump by far. But as @stlcharcoal said, you need a mix of sizes to stay lit. Any brand of lump will snuff out like this if the fire only has big chunks to use. 

Shiff

Good explanation, @stlcharcoal .  That is also a reason that carefully stacking large pieces of lump to leave lots of space for air circulation can lead to a fire going out since there is less contact between pieces of lump.  I always just dump mine in after doing a little stirring  to get some of the ash to fall through the  grate.

MGOms

Guess my fifth try at a pork butt was the charm. I fillled in the gaps with the smaller lump and also put in 4 pecan chunks on the very bottom of the fire box along with a bunch of peach chips. Dome temp stayed between 240-270 for 13 hours. This is about a 8 1/2 pounder. First one that the fire didn’t go out on an overnight cook and this one got the smoke flavor I was looking for. Hope I can repeat this!