VOC/Acrid Smoke question

tfoutch · January 2012

I know we have to let the egg stabilize and wait for the smoke to clear. My question is, if bad smoke happens while lighting, how come when you do a long cook, you don't almost continually get "bad smoke" everytime the fire gets to a new piece of lump or chunk of smoking wood?

I know it really doesn't, just can't logic why. My only theory is the quantity of bad smoke is gradual during the cook, as opposed to a larger quantity at start-up, so it burns off as we go without ruining the food.

Hungry Joe · January 2012

I've often wondered about the same thing, but I believe it has something to do with getting the fire hot enough to burn clean.

ChokeOnSmoke · January 2012

Heard the same thing, lump initially burning when the egg is hotter.

stilllaughing · January 2012

VOC's should be considered trapped organic vapors. The heat is what dries/ drives them out not contact with fire.

tfoutch · January 2012

Makes sense!

bluegrasstiger · January 2012

Somewhat related question. Are the VOCs gone from lump that is leftover from a previous cook?

I clean out the egg every time I use it and save the leftover lump. I often will use the leftover lump for a quick burger or steak when I want to get things up and going quickly. I am assuming that it could be used as soon as it is up to temp since it has been used and previously burned clean.

stilllaughing · January 2012

bluegrasstiger,

You are correct unless you put the old lump in a container with new lump. I never add new lump unless I don't have enough to complete the cook I'm about to do. If I pour new lump in on top of old I wait until it burns clean.

stike · January 2012

here's the deal... open a fresh bag of charcoal. jam your head in and smell it. you are smelling mainly VOCs, or "Volatile Organic Compounds". "volatile" doesn't mean (in this case) that they catch fire (which they also do), but that they are fleeting, and likely to become fumes. perfume has many volatile compounds. whether that means they are flammable is not what is meant by volatile. it means they readily become vapor.

back to the bag. pour it out on a tarp, leave it to sit for a couple days, then come back to it.

put it back in the bag and smell it. not as many fumes.

so, no fire. what happened? well, the 'volatile' compounds became volatile. they evaporated in a sense.

when you light a fire, sure, the lit piece of charcoal is being purged of the VOCs just by the fact that they are burning along with the charcoal and/or being carried away by the exhaust. what's also happening though is your pile of unlit charcoal is getting very hot simply by hanging out in a hot (at least 250, right?) environment. you want to get rid of the fumes that something has, heat it up. that will speed the volatile compounds 'boiling' off the charcoal. more like be driven out. and the continual draft does a lot to drive them off.

if you light a well filled BGE, and cook, then shut down. the next day you will see a lot of still black unlit charcoal. but that charcoal isn't 'new'. it won't smell all 'petro-chemically' (actually hydrocarbons) fuel-like like a new bag would.

you're airing it out with the draft, and accelerating the volatility by heating up the lump even when it's unlit.

bluegrasstiger · January 2012

Thank you Stike....I always appreciate your very thorough explanations.

Botch · January 2012

That makes me wonder if airing out my lump for a week before using it will shorten the "white-smoke" phase... :-?

stike · January 2012

botch
sure. dump your lump on a 10x10 tarp in your yard in an area protected from weather, spread out in a single layer, and preferably not on your grass, which would be killed from choking out the sun. turn each piece of lump over halfway thru the week. then, after a week of walking around the tarp and not using a 10 x 10 area of your yard, take the tarp and have someone hold the other end as you dump it all back into the bag. then clean and fold the tarp and store it somewhere to keep it dry.

this should save you much valuable time when lighting the egg

:-\"

VOC/Acrid Smoke question

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