Big Green Egg - EGGhead Forum - The Ultimate Cooking Experience...
Welcome to the EGGhead Forum - a great place to visit and packed with tips and EGGspert advice! You can also join the conversation and get more information and amazing kamado recipes by following Big Green Egg at:

Facebook  |  Twitter  |  Instagram  |  Pinterest  |  Youtube  |  Vimeo
Share your photos by tagging us and using the hashtag #EGGhead4Life.


In Atlanta? Come visit Big Green Egg headquarters, including our retail showroom, the History of the EGG Museum and Culinary Center!  3786 DeKalb Technology Parkway, Atlanta, GA 30340.

Creosote: what causes it and how to prevent it?

jkvestjkvest Posts: 2
edited July 2012 in EggHead Forum

For the last year or so, all the meat coming off our BGE has had the same chemically taste to it on the outside.  After googling a bit, we decided it might be creosote causing the problem.  So I took a wire brush and cleaned out the Egg.  Shiny black flaky stuff was covering most of the inside surfaces. 

We use lump charcoal but add a split log of oak as needed for smoking.  It is the same oak we bought for indoor firewood.  Can't be totally sure of the age and it has come from different sources.  The stack we have out there now has been there ~8 months.  When we smoke we don't use a water pan.  We did once a while back use a green piece of oak from our yard after we trimmed a tree. 

Now that the BGE is pretty cleaned out, I'm hopeful the food will start tasting good on the outside again...like the rub or whatever seasoning...not chemical flavor.  Now I just need to know exactly what we might've done to cause it and how we can prevent it in the future.

 

Thanks!

 

Comments

  • Intersting post. I'm interested as well. This might be in Stike's wheelhouse but not sure. We'll see.
    1- LGBE
    1- KBQ C-60 (The Dishwasher)
    I- Blackstone 36" Griddle
    1- Sweet-A$$ Roccbox Pizza Oven
    1-Very Understanding and Forgiving Wife
  • lousubcaplousubcap Posts: 16,194
    I'm riding along on this one as well.  I have never had the experience you describe and I don't subscribe to the clean burn philosophy either.  Can't believe it would be the oak smoke wood as you have been air-drying that for several months.  Time to learn something new today!
    Louisville;  L & S BGEs, PBC, Lang 36; Burnin' wood in the neighbourhood. # 38 for the win.  Life is too short for light/lite beer.  
  • BGE4LifeBGE4Life Posts: 34
    I'm not sure of your situation, but when I got my egg, I had the same taste.  I followed the directions and was shutting down the egg using the dwell method.  I figured out after a half dozen cooks that maybe the closing of the vents was causing the flavor and sure enough when I quit shutting down the vents the taste went away.  I also made the mistake a couple times of putting the meat on before the egg was ready and the initial smoke not stabilized.  I now wait more than 20 minutes before beginning my cook.  I have never clean burned.
  • ribnrunribnrun Posts: 174
    The nasty smoke from incomplete combustion can taste kinda chemical like. That smoke can come from lump, smoking wood or drippings. I always leave my daisy wheel open and also never shut the bottom vent completely. Also wait for the smoke from your oak to run clear or 'blue' before putting food in the egg. Gonna 'lurk' on this thread for a while to see what comes of it.

    Make sure to update if anyone's solution works for ya jk, some of us will be watching, lol.
  • rickHPrickHP Posts: 49

    No real idea, but I wonder how much wood is in a "split log of oak" compared to the handfuls of chips and chunks most people add. Maybe most people aren't seeing creosote buildup because they don't use nearly the same amount of wood.

  • nolaeggheadnolaegghead Posts: 26,331
    Creosote is one of the reasons we like the taste of food cooked over wood.

    From Wiki:

    Creosote is the portion of chemical products obtained by the distillation of a tar that remains heavier than water, notably useful for its anti-septic and preservative properties.[1] It is produced in some quantities from the burning of wood and coal in blast furnaces and fireplaces; commonly found inside chimney flues when the wood or coal burns incompletely, producing soot and tarry smoke, and is the compound responsible for the preservation and the flavor of meat in the process of smoking. The name is derived from the Greek kréas (κρέας), meaning "flesh", and sōtēr (σωτήρ), meaning "preserver".[2]

    In moderation, it's responsible for the smokey taste.   Trick is to keep it in moderation.  Creosote is released more in anaerobic  conditions - oxygen poor, and under high heat.  What's this translate to? 

    1. After starting the lump, let the fire establish itself.  The charcoal has a lot of creosote on it from it's original manufacturing.  You're starting a lot of charcoal when you open up the vents to start the fire.  Let that burn for a while.

    2. Don't overshoot your temperature after starting and smother the fire to cool it down quickly.  This creates and extremely oxygen-poor environment and lots of creosote.  If you do overshoot, stabilize the temp (more waiting) before putting on the meat.

    3. Don't smother the fire with the food in  it.  Again, extreme oxygen poor condition and very hot lump.

    4. Burning too much green wood at once (wood that isn't charcoal, being fresh or aged is just a moisture difference) will generate lots of creosote.  A little wood goes a long way for flavoring.
    ______________________________________________
    This is my signature line just so you're not confused.  Love me or hate me, I am forum Marmite.
    Large and Medium BGE, Kamado Joe Jr, Akorn Jr, smoker with a 5k btu AC, gas grill, fire pit, pack of angry cats, two turntables and a microphone, my friend.  Registered republican.
    New Orleans, LA - we know how to eat 

  • fishlessmanfishlessman Posts: 22,718
    it may be that your just using too much smoking wood and may just need to change types of wood to start tasting it again.as it sounds like you mainly use oak, i know i have to change it up. now that buildup you talk about that gives the foul taste, i get that after a summer of low and slows on one of my eggs, that egg never gets hot enough to burn out the grease and it builds up, fills the poors, gets thick in the dome and eventually flakes off in big chunks like tar paper. make the mistake of doing a hotter cook without doing a clean burn and things like a chicken breast or a hamburger are inedible. only way i know to get rid of it is a high temp burnout and beware, your gasket will be toast, i havent used gaskets in many many years
  • Hillbilly-HightechHillbilly-Hightech Posts: 966
    edited July 2012
    Do a high-temp clean burn & it'll burn all that stuff off. 

    Not much you can "do" about it as far as reoccuring, unless you wanna stop burning lump & smoking woods & switch to a gasser.  You might be able to use less "sappy" woods, and/or allow the wood to "dry" (season) longer, but even then, the creosote will still build up over time. 

    that's why there is (or at least was) a market for "chimney sweeps." 

    It's just a natural by-product of burning wood & wood products. 

    HTH,
    Rob
    Don't get set into one form, adapt it and build your own, and let it grow, be like water. Empty your mind, be formless, shapeless — like water. Now you put water in a cup, it becomes the cup... Now water can flow or it can crash. Be water, my friend. - Bruce Lee
  • stikestike Posts: 15,597
    You arent really getting any creosote from lump charcoal. If this were a stick burner with a cord of wood getting pushed thru it, maybe.

    Likely the flavor is from putting meat on too soon after lighting. The provebial 'ready in ten minutes' is bunkum. Unless on used lump which is already burned clean.

    That, or from cooking with the dome and vents closed
    ed egli avea del cul fatto trombetta -Dante
  • gdenbygdenby Posts: 5,832
    While creosote is a good candidate for the off-taste. It may not be the only culprit.

    If any of that scale ever falls into your food, you will be spitting it out.

    As I understand it, creosote is formed from partially burnt wood smoke and water vapor. It forms at a temperature a little above boiling.

    I wonder about the use of a "split log of oak." The reason is that even well seasoned wood has quite a lot of water still in it. I suppose a large amount of wood within the tight airspace of an Egg would easily form creosote. Also, while the cellulose in the wood is breaking down, it is producing a lot of unpleasant gases. Among them are furans. I've read once that that adds a "toasty" flavor, but in several other places, a burnt and acrid flavor.

    As I understand it, what one is looking for in a lump based fire is having enough charcoal burning, and as little oxygen present, that the wood does not burn, but pyrolyze. All of the cellulose and lignin breaks down, and turns to gases w. negligle amounts of combustion. Unlike an offset wood burner, there are usually no flames in an Egg, which would be the result of the bad flavored gases burning away.

    The only other thing I wonder about is the kind of oak. There are people who swear by red oak, but I've always been a little suspicious of using it for cooking smoke. The reason is that it is so porous that water can gather in it, which allows a mold to grow in the wood. A product of the mold eating the wood is urea. Not nice stuff.

    Hope this helps.
  • nolaeggheadnolaegghead Posts: 26,331
    Yep.  The nastiness is from pyrolysis - heating wood in low oxygen conditions.  That lump is by no means "pure" charcoal.  You gotta buy binchotan at $8/lb if you don't like smoke flavor.  Avoid pyrolysis conditions when your food is in the egg.
    ______________________________________________
    This is my signature line just so you're not confused.  Love me or hate me, I am forum Marmite.
    Large and Medium BGE, Kamado Joe Jr, Akorn Jr, smoker with a 5k btu AC, gas grill, fire pit, pack of angry cats, two turntables and a microphone, my friend.  Registered republican.
    New Orleans, LA - we know how to eat 

  • gdenbygdenby Posts: 5,832
    Yep.  The nastiness is from pyrolysis - heating wood in low oxygen conditions.  That lump is by no means "pure" charcoal.  You gotta buy binchotan at $8/lb if you don't like smoke flavor.  Avoid pyrolysis conditions when your food is in the egg.
    Not to be contrary. In my post I may have mis-used the term pyrolysis. I was trying to make the distinction between what kind of smoke that comes from the partial combustion of wood, and the vapors that come of of wood that is being baked by high heat, but where there is so little oxygen that combustion is negligible.

    In my understanding, "pyrolysis" is desirable, at least compared to the partial combustion that happens from a fire being smother by too little oxygen or too much water. Pyrolysis does produce flammable gases, but also the desirable flavor chemicals that makes smoked food taste good.

    I suppose I could also say that i think the wood and amount of wood the OP has been using is just smouldering, and its a damped fire that produces creosote, and lots of other nasty things.
  • Hillbilly-HightechHillbilly-Hightech Posts: 966
    edited July 2012
    Aside from all the technical analysis & chemical engineering discussions ;)

    - if ya do a high temp clean burn, that will burn off the black stuff - whether it's "soot," "creosote," "burnt fat," "caramelized sugar," or even "alien excrement" - whatever it is, and whatever ya wanna call it, a high temp clean burn will burn it off. 

    And more than likely, the next time you cook something (assuming you're letting your fire burn long enough to drive off the "bad" smoke), I'm pretty sure that, after having done the "clean burn" and after letting the "bad" smoke clear away, you shouldn't have the "chemical" taste. 

    Don't get set into one form, adapt it and build your own, and let it grow, be like water. Empty your mind, be formless, shapeless — like water. Now you put water in a cup, it becomes the cup... Now water can flow or it can crash. Be water, my friend. - Bruce Lee
  • nolaeggheadnolaegghead Posts: 26,331
    Creosote from wood is a large part of the smokey flavor.  If you have perfect combustion, you're food will taste like it was cooked on a gasser.  Its caused from low oxygen heating of wood.  When wood is heated, gases are released - lots of organic chemicals, mostly phenol based compounds.  Most of these gases are burned, which heats more wood and perpetuates the fire.  Some don't burn, because there isn't the right amount of oxygen, and we smoke - pyrolysis products, which condense on the food and make it yummy.   Depending on the amount of heat and the source wood/fuel that's used, the composition of the creosote will change, which impacts the taste.  And too much creosote and you have a bad, chemical taste on the food.  So I think we agree.  I still remember making the stuff in chemistry lab back in college.  Water and CO2 are always byproducts from oxidation, but they don't impact the taste.

    From my earlier quote from wiki:  "(creosote) is the compound responsible for the preservation and the flavor of meat in the process of smoking. The name is derived from the Greek kréas (κρέας), meaning "flesh", and sōtēr (σωτήρ), meaning "preserver""
    ______________________________________________
    This is my signature line just so you're not confused.  Love me or hate me, I am forum Marmite.
    Large and Medium BGE, Kamado Joe Jr, Akorn Jr, smoker with a 5k btu AC, gas grill, fire pit, pack of angry cats, two turntables and a microphone, my friend.  Registered republican.
    New Orleans, LA - we know how to eat 

  • fishlessmanfishlessman Posts: 22,718
    why just blame the wood, my kitchen stove doesnt burn wood yet there is grease building up on the ceiling
    :))alot of that tarpaper substance has to be grease
  • nolaeggheadnolaegghead Posts: 26,331
    Creosote gets a bad name because it causes chimney fires and the coal-tar creosote smells terrible (everyone knows how telephone poles stink).  Liquid smoke flavor is basically wood creosote.
    ______________________________________________
    This is my signature line just so you're not confused.  Love me or hate me, I am forum Marmite.
    Large and Medium BGE, Kamado Joe Jr, Akorn Jr, smoker with a 5k btu AC, gas grill, fire pit, pack of angry cats, two turntables and a microphone, my friend.  Registered republican.
    New Orleans, LA - we know how to eat 

  • stikestike Posts: 15,597
    There's no wood in an egg unless you add chips or chunks. And even when you do, there's very little wood involved.

    We're being distracted by the assumption that it's creosote causing the problem to begin with. It's highly likely it's the far worse taste of VOCs or closed vents from the infamous 'dwell' method of screwing up, i mean cooking, a steak.
    ed egli avea del cul fatto trombetta -Dante
  • twlangantwlangan Posts: 299
    I have been around wood boilers all my life. Creosote forms from burning wood that is too wet - or letting fires smolder too long. Ideally, in a wood furnace, you want to build "flash fires". You want good dry wood, let it have plenty of air, let it burn hot and fast, and go out. That is how I burn wood myself. My furnace has a draft fan on it that has never been used. I open the bottom ash door and let it have all the air it needs. The only problem with this method is the house temp varies. During and right after a flash fire, the house may get a bit too warm - and then cools off. We let it get rather cool before building another fire. This is not ideal for many people, but we'd rather deal with the temp swings than lose the house to a chimney fire. I clean my chimney each Fall and never have creosote. 

    Sooooo, how does this apply to the Egg? Well, we are using a smoldering fire while cooking on an Egg. We limit air intake to control the temp. If you are putting a big chunk of oak in there each time you cook, it is smoldering and creating creosote just like a wood furnace would do. My suggestion would be to chop that oak up into much smaller pieces, let it dry out as much as possible, and limit how much you put in each time you cook. I believe that meat will only take on smoke flavor for a fairly short period of time - until the meat temp reaches a certain point. At that point, it is pointless to continue adding wood for more smoke.

    As for your existing creosote problem, I'm thinking that building a very hot and long cook in it might burn it out. Load your Egg with lump, light it, open the bottom vent 100% and leave the daisy wheel off the top, and let'er rip. Let it burn the full load of lump as hot as she wants to go. You should have flames rising up into the dome - and they will probably burn the creosote out. You may toast your gasket doing it, but it will clean the Egg and eliminate future off-flavors. Replace the gasket with a high heat or Rutland, and away you go.
  • ribnrunribnrun Posts: 174
    Creosote does such a good job keeping my fence posts from rotting, shame that it tastes bad.
  • nolaeggheadnolaegghead Posts: 26,331
    I'm tempted to run the pyrolysis test on some lump.....  like this

    Then I can take the extract and look for creosote and PAHs.  I work for a lab and we do that test.  This would show if there is lignin or cellulose still in the charcoal, which would explain exactly what we're dealing with.  I'm going to guess it depends greatly on the size and process used to make the charcoal.  Some charcoal is made primitively in pyres with backhoes.  Others use factories and colliers.
    ______________________________________________
    This is my signature line just so you're not confused.  Love me or hate me, I am forum Marmite.
    Large and Medium BGE, Kamado Joe Jr, Akorn Jr, smoker with a 5k btu AC, gas grill, fire pit, pack of angry cats, two turntables and a microphone, my friend.  Registered republican.
    New Orleans, LA - we know how to eat 

  • jkvestjkvest Posts: 2

    Thanks for the feedback, everyone.  We've got a brisket to cook this weekend.  We'll try using smaller chunks of wood for smoking, make sure we have a clean burning fire before we put the meat on, and also try to leave the daisy open as much as possible.  Hopefully, the brisket will turn out better.  I'll let ya know.

     

  • jkvestjkvest Posts: 2
    The brisket had amazing flavor!  So good!  We let the fire go longer before we put the meat on.  Had been putting it on after ~15mins.  This time we waited more like 45 mins..for the overwhelming smoke to die down.  Then during cooking, we tried to keep the daisy open and the bottom grid mostly closed.  This allowed the smoke to esacpe better.  It was harder to keep the temperature down, though.  For the smoke, we used to throw a split log on the coals.  This time we cut it up and put only 3 big chunks.  Don't know how much difference that last part made, though.  Anyway, the brisket had great flavor...not like a campfire.  :)  Thanks for all the help!
  • ribnrunribnrun Posts: 174
    Glad it worked out well. Nothing worse than having such an expensive cooker ruining your food, lol. Sounds like you got the method down now to have many successfully cooks!
Sign In or Register to comment.
Click here for Forum Use Guidelines.