# Clean Smoke while Cold Smoking



## Saturday Knight Fever (Apr 8, 2022)

I'm hoping to build myself some kind of cold-smoking setup soon, and I'm trying to wrap my head around some of the issues.  Here are things I think I understand:

1.  When wood burns at low temperatures (say, below 600F), the smoke contains all sorts of volatile compounds that we generally don't want to condense on the surface of our food.  Creosote, for example, is formed when these compounds have not burned off.

2.  When a wood fire burns at sufficiently high temperatures (between 650F and 750F), the smoke itself will flame, indicating that the volatile compounds are denatured.  The smoke that remains is often referred to as "blue" or "clean" smoke, and that's the stuff that we want condensing on the surface of the food.

So, when smoking food, you want a very hot fire.  Cold smoking is especially tricky as you don't want to transfer the heat from the very hot fire to the food.

To me, this means I need to separate the fire chamber and the smoking chamber.  I need a fire chamber in which I can maintain temperatures of 650-750F (which means I need to be able to feed the fire with fuel and oxygen easily).  I need a draft arrangement that will suck the resulting blue smoke from the fire chamber to the smoking chamber.  And I need to separate the two chambers sufficiently well to ensure that the smoke has lost its heat by the time it arrives in the smoking chamber.  Does this sound sensible?

But, how much is "enough" separation between the chambers?  If I have a stainless-steel stove pipe running between the two chambers, how do I estimate the heat-loss?  If this is a matter of cutting different length pipes and experimenting, it seems like an expensive process.


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## gmc2003 (Apr 8, 2022)

Welcome to the forum SKF. First off I'd say that a cold smoker can be made from just about anything even a cardboard box. The easiest and cleanest smoke comes from burning sawdust. Wood pellets also work but can give off to much heat in certain situations. I cold smoke using a bullet type smoker(Weber Smokey Mtn). Others use an electric smoker. A favorite mode is the mailbox attachment for the electric smokers. Below is what a lot of folks use to produce cold smoke. There are others out there, but I believe this was the original.



			https://www.lowes.com/pd/A-MAZE-N-Smoke-Tube/1001366578?cm_mmc=shp-_-c-_-prd-_-sol-_-ggl-_-PLA_SOL_119_Grills-_-1001366578-_-online-_-0-_-0&ds_rl=1286981&gclid=CjwKCAjwur-SBhB6EiwA5sKtjgIqgrznkOCtnDMoGc9AC5-UTmcqPnb8yIJxksRz6N48BdNucQBJDxoCjoQQAvD_BwE&gclsrc=aw.ds
		


Chris


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## Saturday Knight Fever (Apr 8, 2022)

gmc2003 said:


> Welcome to the forum SKF. First off I'd say that a cold smoker can be made from just about anything even a cardboard box. The easiest and cleanest smoke comes from burning sawdust. Wood pellets also work but can give off to much heat in certain situations. I cold smoke using a bullet type smoker(Weber Smokey Mtn). Others use an electric smoker. A favorite mode is the mailbox attachment for the electric smokers. Below is what a lot of folks use to produce cold smoke. There are others out there, but I believe this was the original.
> 
> 
> 
> ...


 
Thanks Chris.

I'm wondering what you mean when you say "the...cleanest smoke comes from burning sawdust."  Saw dust is still just wood, so I would think that the gasses it releases would be the same as those released when burning wood in any other form.  

I might be very wrong, but I thought the cleanliness of wood smoke was determined by how hot the fire gets.  I can imagine that a pile of sawdust has access to more oxygen than a lump of wood, and so could reach higher temperatures in a given environment.  But isn't it still true that sawdust burning at, say, 600F, will give you dirty white smoke?

Do we know how hot sawdust burns in one of those A-maze-n things?


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## Bearcarver (Apr 8, 2022)

gmc2003 said:


> Welcome to the forum SKF. First off I'd say that a cold smoker can be made from just about anything even a cardboard box. The easiest and cleanest smoke comes from burning sawdust. Wood pellets also work but can give off to much heat in certain situations. I cold smoke using a bullet type smoker(Weber Smokey Mtn). Others use an electric smoker. A favorite mode is the mailbox attachment for the electric smokers. Below is what a lot of folks use to produce cold smoke. There are others out there, but I believe this was the original.
> 
> 
> 
> ...



Just to let you know, the one in the link you gave is an "AMNS"---Only good for Dust---Not for pellets.  The double interior walls "AMNPS" are needed to burn pellets.

Bear


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## SmokinEdge (Apr 8, 2022)

Saturday Knight Fever said:


> I'm hoping to build myself some kind of cold-smoking setup soon, and I'm trying to wrap my head around some of the issues.  Here are things I think I understand:
> 
> 1.  When wood burns at low temperatures (say, below 600F), the smoke contains all sorts of volatile compounds that we generally don't want to condense on the surface of our food.  Creosote, for example, is formed when these compounds have not burned off.
> 
> ...


Unless you can provide scientific Annalise of the facts that you posted, I call B.S.
In old school smokers, the smoke is generated from a cool fire, then travels a distance to the smoke chamber thus cooling down. Lots of folks are cold smoking with trays or tubes with pellets. This is a cold smoldering fire. This works great, and the food is great. Produce some evidence of your statements in a scientific way, or not. I believe you are over thinking the process.


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## Saturday Knight Fever (Apr 8, 2022)

SmokinEdge said:


> Unless you can provide scientific Annalise of the facts that you posted, I call B.S.
> In old school smokers, the smoke is generated from a cool fire, then travels a distance to the smoke chamber thus cooling down. Lots of folks are cold smoking with trays or tubes with pellets. This is a cold smoldering fire. This works great, and the food is great. Produce some evidence of your statements in a scientific way, or not. I believe you are over thinking the process.



Fair enough.  I understand your skepticism.

I can't claim to have peer-reviewed, scientific articles establishing anything I said.  It all comes from websites I've been looking at, trying to get an idea of how things work.

You could look at any of the following:









						What You Need to Know About Wood, Smoke, And Combustion
					

Learn all about wood smoke and how it adds flavor to BBQ. Find out whether you should be using wood chunks, chips, pellets, logs, or sawdust in your cooker. Discover the truth behind the claim that different woods have different flavors.



					amazingribs.com
				












						What is Thin Blue Smoke? How to Avoid Dirty Smoke - Barbecue FAQ
					

Thin blue smoke is a thermochemical process called pyrolysis. Pyrolysis is the decomposition of volatile materials in a low/no oxygen environment with high heat.




					barbecuefaq.com
				









						How Wood Burns - KBQ
					

It doesn’t – at least not directly. Here’s what happens to a log after it’s thrown into a fire: Drying – that log is full of water. Green wood has ~80% (of dry weight) moisture; a 9 lb log = 5 lbs wood + 4… keep reading




					kbq.us
				




Note: this is part of a series of pages that addresses combustion.  It starts with https://kbq.us/bbq-edu-blog/how-wood-burns/

If anything is wrong, I'd be happy to hear about it.


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## pineywoods (Apr 8, 2022)

Yes and No. To have fire you have to have oxygen, fuel, and heat this is called the "fire triangle". Not only do you have to have those three things they have to be in the right proportion's. Take any of them away and you extinguish the fire. There is an alternative to the fire triangle called a fire tetrahedron that adds another element to the fire, which is chemical reaction. The chemical reaction is usually the result of a metal burning so we'll skip that as hopefully your not burning metal in your smoker or smokehouse. 
Fire temperature is not the thing to concentrate on as far as "clean" or "dirty" smoke. Proper proportions of all three sides of the triangle will deliver "clean" smoke. Mess up the proportions of any of them and you are going to get "dirty" smoke. 
I'm sorry I am pressed for time the next couple days but I will try to keep up with this thread when I have the chance. You might want to google "Fire Science" if your really interested it's kind of cool once you get into it.


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## Fueling Around (Apr 8, 2022)

Interesting read on your links.
I agree that billowing white smoke is the nastiest.
That is my biggest complain on a pellet pooper in smoke mode. (Yes, I own one.)
I don't use saw dust. I tried it and it was too much an off flavor for me.
I use pellets in a tube with lots of air to let it burn to get the desired thin blue smoke.
I use smoke tubes inside my pellet pooper and my kettles.


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## daveomak (Apr 9, 2022)

Pellets turned to dust...








Tray elevated to allow for better air flow to allow for better burning...







Mailbox and aluminum duct for a cool place to allow for condensate of tars etc... and cooling...






Creosote condensed on inside of mailbox....






Nice clean meat that tastes awesome.....


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## SmokinAl (Apr 9, 2022)

I gotta say Dave the ham & bacon look awesome!
Al


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## Marknmd (Jun 28, 2022)

And then we have MSB who now, for the first time ever, confesses that when it comes to cold smoking, the dirtier the smoke, the better!  :-D


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