# Thin blue smoke, what causes it?



## crazykidbig58 (Jun 4, 2017)

I've searched for this answer on the forum, but I cannot seem to find anything on what causes thin blue smoke. Also, what is the difference between thin blue smoke and thin white/gray smoke? I never have a problem achieving thin smoke in my MES, but I'm just curious what the differences are. Here's a vid of my smoker in action today. This look good?


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## noboundaries (Jun 4, 2017)

In a nutshell, it is a chemical process call pyrolysis, the thermochemical decomposition of volatile materials in a no oxygen/low oxygen environment and high heat. 

Initially, when you first start burning wood, wood chips, pellets, etc, the fuel is cold.  The burning process is incomplete, causing the white or grey smoke as particulates and tars (aka creosote) are released from the fuel.  As the fuel heats up and the burning process reaches a state of equilibrium in the burn chamber (fuel-air-heat in balance), the burning process becomes more efficient.  The raw fuel in the woods carbonize prior to release.  They essentially become caramelized, which becomes thin blue smoke. 

White or grey smoke contains really bad stuff for flavor, most commonly ash and creosote.  There is a big dispute whether it also contains unhealthy levels of PAHs, or polycyclic aromatic hydrocarbons, which are carcinogenic. 

Bottom line, don't load your food until you see thin blue smoke.     

PS edit: as a side note, charcoal briquettes tends to have thin blue smoke right from the start.  Don't let that fool you.  One of the reasons charcoal briquette manufacturers say to let the charcoal ash over completely before use, it to prevent the stuff used in the briquette from flavoring your meat.  Just recently, after switching from Kingsford Blue Bag to Royal Oak Ridge, I was using my grill to help use up the 120 lbs of KBB I have left.  I didn't let the charcoal completely ash over before I loaded the meat.  Bad move.  Even though I did not use a liquid starter in my chimney, I tasted what could only be described as fuel.  After decades of KBB use, switching to the new RO Ridge, then back to the KBB, I tasted what people have been saying about KBB for a long time.  Bottom line, let the charcoal ash over completely before use.


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## daveomak (Jun 4, 2017)

smoke good vs evil.jpg



__ daveomak
__ Jun 4, 2017


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## crazykidbig58 (Jun 4, 2017)

Thanks for the very detailed response, NB. I always wait for any white smoke to leave the smoker before I load the food, however, when I refuel there's almost always a 5 minute or so period of heavier white smoke. When I see this white smoke start to build up I open the door and let it all out the front. The door is open for just 5 or 10 seconds and I don't lose much temp, and what I do lose quickly heats back up. Any thoughts on why this happens and how I can prevent it?


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## chef jimmyj (Jun 4, 2017)

White smoke for more than 30 minutes is a problem but the 5  10 minutes it is generated when adding fresh wood has very little impact on flavor. Remove the white smoke if you wish but l don't worry about it...JJ


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## cksteele (Jun 4, 2017)

crazykidbig58 said:


> Thanks for the very detailed response, NB. I always wait for any white smoke to leave the smoker before I load the food, however, when I refuel there's almost always a 5 minute or so period of heavier white smoke. When I see this white smoke start to build up I open the door and let it all out the front. The door is open for just 5 or 10 seconds and I don't lose much temp, and what I do lose quickly heats back up. Any thoughts on why this happens and how I can prevent it?


frankly i wouldn't even worry about it i burn 100% wood on my offset  for heat and smoke. im throwing a new split on ever so often but im ocd  about burning a clean fire. so im always  fiddling with the logs  and adjusting the coals  so the wood is burning properly. if you wanna help the wood burn preheating  is always a good option. but  as long as like 90% of the time you're burning a clean fire the few times you add wood  its  no issue


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## fwismoker (Jun 4, 2017)

More complete combustion of the fuel = thinner   As you go less complete the smoke particles get larger.


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## bluewhisper (Jun 4, 2017)

john, thanks for posting that atlas!


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