Confused on how to burn wood chunks in Stumps/gravity fed

[Paul R]

Have a Stump's baby for BBQ and I'm not satisfied with how my BBQ is turning out on it so am working on dialing in as many variables as I can to get it right and consistent.

Right now much confused on how to use wood chunks in this thing. From TONS of reading and video tutorials on BBQ my understanding is that you do NOT want smouldering wood, you want BURNING wood for clean smoke. Granted, this advice comes almost exclusively from folks running stick burners (precious few sources on how to run a clean fire in a gravity fed).



If I put wood chunks in the ash pan of the Stumps and let the coals fall down on it the wood smoulders. There are times I've done this and I've gotten good smoke, but lots of times I get acrid, yucky smoke - I can't seem to put my finger on how to consistently get good smoke using this method.



I typically use a Rock's Stoker to keep my temps at 250-275 for my smokes - still have the same problem with usually getting bad smoke but occasionaly good smoke with chunks in the ash pan. Could the stoker be creating bad smoke by cutting off the air when not blowing??

Lately I've tried adding coals to the ash pan and lighting them along with the column, letting them get good and red, then adding some wood chunks to start building a coal bed in the ash pan. Only after I have a good, red coal bed in the ash pan I add the meat and then add pre-heated wood chunks. When I add the chunks I hit them with a propane torch to get the combustion going and leave the fire door open until I see the fire has set on the chunks. I don't get the bad smoke as much, but this is also 5x the work.

Pulling my hair out on confirming the best way to run these wood chunks and would appreciate any experience/guidance.

Thanks!

 

[RacrX]

Don't know if it's any different than my GF< but I add to the ash pan and the hopper.

 

[BuckN BBQ]

Is your wood dry? I've put up to a 1/2 a split in my Assassin. I've never had any rancid flavors or acrid smoke any of my cooks. Make sure you have really dry wood. and only put the wood on after the smoker is up to temp and the food is on.

 

[Paul R]

Don't know if it's any different than my GF< but I add to the ash pan and the hopper.

For the chunks you add to the pan do they smoulder or burn (flame)?

 

[Paul R]

Is your wood dry? I've put up to a 1/2 a split in my Assassin. I've never had any rancid flavors or acrid smoke any of my cooks. Make sure you have really dry wood. and only put the wood on after the smoker is up to temp and the food is on.

Good question and on the path down ANOTHER rabbit hole variable I'm looking in to but also cannot get consistent arguments on. I use roughly fist-sized wood chunks. By moisture meter the outside of the wood is about 6% water content. Out of concern the chunks may be too big for the ash pan/coal bed I've started splitting them in half. I measured moisture on the inside of the chunks and they are about 8-10% moisture content. From reading/videos I've watched this is too dry (ideal being 15-25% MC), whereas other sources don't seem to care about moisture content as long as it's not too much (i.e. no such thing as too dry)

 

[El Ropo]

Never operated a GF, but would think that mixing ~briq sized chunks of wood throughout your charcoal hopper would be the most effective?

 

[pjtexas1]

I don't care for "fist sized" chunks. In my experience they are too big for a cooker with low airflow. For the chunks you put in the chute cut them in half and if that does not work cut in half again. For the wood in the ash pan, mine have always caught fire. Doesn't matter if it was a mini split or big chunks they always caught fire. Keep tinkering... you're almost there.

Sent from my SM-G996U using Tapatalk

 

[RacrX]

For the chunks you add to the pan do they smoulder or burn (flame)?

They definitely burn.

 

[Chester]

What charcoal are you using? Are you sure it isn’t the charcoal impacting the flavor that you find rancid.

What type of wood are you burning? I know is blasphemy to some, but I don’t care for the taste mesquite on anything but beef, and I have to be in the right frame of mind for that. I prefer apple, cherry, hickory and pecan wood.

 

[darita]

Well, in my GF I use 1/2 splits so they fit in the ash pan. With the first one, I make sure a lit coal piece falls on it and begins smoking. I let it go for at least 15 minutes before putting any meat in the chamber. I use an FB2 Drive for temp control. My feeling is, the best chance for good airflow and flame will be in the ash pan because that's where the air blows in from the controller fan. My experience is that wood in the chute tends to give more dirty smoke. I go thru 1/2 split in about 1/2 hr to 45 minutes.
I could be wrong I know, but in my mind, I get good airflow and flame because the cook chamber is not very well insulated nor sealed. As a result, there's lots of heat loss and the fan kicks in often. In a really efficient cooker, you'll have little heat loss, therefore little airflow. Is your exhaust full open all the time? Just a thought.

 

[Paul R]

I don't care for "fist sized" chunks. In my experience they are too big for a cooker with low airflow. For the chunks you put in the chute cut them in half and if that does not work cut in half again. For the wood in the ash pan, mine have always caught fire. Doesn't matter if it was a mini split or big chunks they always caught fire. Keep tinkering... you're almost there.

Sent from my SM-G996U using Tapatalk

Yeah, I was thinking that with such a small coal bed the fist-sized chunks wouldn't burn so well so I split them in half now

 

[Paul R]

Well, in my GF I use 1/2 splits so they fit in the ash pan. With the first one, I make sure a lit coal piece falls on it and begins smoking. I let it go for at least 15 minutes before putting any meat in the chamber. I use an FB2 Drive for temp control. My feeling is, the best chance for good airflow and flame will be in the ash pan because that's where the air blows in from the controller fan. My experience is that wood in the chute tends to give more dirty smoke. I go thru 1/2 split in about 1/2 hr to 45 minutes.
I could be wrong I know, but in my mind, I get good airflow and flame because the cook chamber is not very well insulated nor sealed. As a result, there's lots of heat loss and the fan kicks in often. In a really efficient cooker, you'll have little heat loss, therefore little airflow. Is your exhaust full open all the time? Just a thought.

My stumps is pretty air tight, I think - no smoke getting out anywhere. When I'm running the stoker I have the ball valve open 100% and exhaust open 100%. Fan cycles frequently but keeps temps rock solid. When the fan isn't running there's a little block that falls down and shuts off all air flow through the ball valve - fan kicks in and this block is lifted to let the air in. Not sure if those periods of no air getting in, followed by big blast of air, could contribute to a funky burn

 

[Paul R]

What charcoal are you using? Are you sure it isn’t the charcoal impacting the flavor that you find rancid.

What type of wood are you burning? I know is blasphemy to some, but I don’t care for the taste mesquite on anything but beef, and I have to be in the right frame of mind for that. I prefer apple, cherry, hickory and pecan wood.

Most recently using Jealous Devil; prior to that BGE. For wood using post oak and pecan sourced from Fruita woods, with moisture content likely in the 8% range

 

[SmittyJonz]

I mix briquettes and chunks in the chute

 

[JVM59]

I don't care for "fist sized" chunks. In my experience they are too big for a cooker with low airflow. For the chunks you put in the chute cut them in half and if that does not work cut in half again. For the wood in the ash pan, mine have always caught fire. Doesn't matter if it was a mini split or big chunks they always caught fire. Keep tinkering... you're almost there.

Sent from my SM-G996U using Tapatalk

I was having the same issue with my LSG Mini until I started splitting down the
"fist sized" in to sizes about 2"x2". The smaller chunks seem to burn cleaner.

 

[rm41400]

I’m thinking your stumps insulated GF is probably similar to a ceramic Kamado.I have no experience with the stumps but it sounds very efficient (like my primo ceramic) and therefore your gonna have to work your way up from little or no wood chips/chunks to suit your taste. This will avoid the off taste of smoldering wood.

I could be wrong but your only gonna get so much smoke taste with a low airflow cooker like that before it gets funky. Just go easy on the wood chips and work your way up

 

[rm41400]

I would eliminate the stoker for a few cooks and just get the vents dialed in. Add chips and small chunks sparingly and see how the smoke profile is.

 

[mwild103]

On your charcoal after you have it lit and it is fully up to temp does it ever stop producing white smoke (no wood added yet)? If the answer is no then that is where some of your off flavor is coming from. Change charcoal till you find one that burns completely clean after it is up to temp and settles in. I don’t ever add wood chunks till the smoker is up to temp and burning clean. That way I know any smoke I see is from the chunks. Also light it earlier and let it comp up to temp and set there for at least an hour before you add the chunks. I find this makes the chunks burn way better/faster as there are more coals to light them on fire. Just my $0.02

 

[BlackDogBBQ]

I have a stumps babygrand GF. I put the chunks or chips (whichever I am using at the time) in the ash pan once I get the charcoal going good and smoker up to heat. I tap the grate to drop some ash ontop of the chunks/chips annd shut the door and let her roll. I have not had issues with acrid smoke at least not to the point that it carries onto the final product. Mixing chips/chunks with charcoal in the chute has never worked for me I lose control of the temp. It jumps up and down with or without a fan. Perhaps someone has a fix for that.

 

[Paul R]

Hi All. Thanks for the replies!