# A demonstration of creosote Part 1



## crankybuzzard (Feb 2, 2017)

“I have a black sticky mass building up in my smoker”

“My meat has a bitter flavor on the outside”

“I love my ribs, but my lips tingle and get numb after eating them”

These are a few things that are mentioned here on the SMF when folks have a concern with what’s happening to their meats in the smoker, and the above are generally an indication of creosote build up.

The first question we tend to ask is; “Is your exhaust port wide open?” A lot of the time we’ll get the answer that it wasn’t wide open and the next cook comes out without issue.

For the last few weeks I’ve been contemplating some ways to show the difference between an open exhaust and a closed, or only partially open exhaust on a smoker. Below, you’ll see part one of this endeavor.

First off, what is creosote? Creosote is a tar like substance that is generated through pyrolysis of organic materials. Basically, the smoldering of wood, or pellets, in a low oxygen environment. This residue will adhere to most surfaces of your BBQ pit and your meat, or other food, products that are inside of the smoke chamber, and leave you with the look, taste, or sensation listed above. Oh, it’s also carcinogenic…

To keep all tests on the same playing field I made sure of the following items:

• The heating element was turned on and was running a constant 100°, controlled by a recently tested PID.

• The same size of jar was used on both tests

• The same number of ice cubes were used on both tests

• The same amount of pellets were used in each test by weight

To perform the test, I first started the heating element inside of my electric pit. Once it was up to 100°F I then placed the pre-lit A-MAZE-N tray, with apple pellets, into the pit at the normal location I place it, a ½ pint jar of ice water was placed on a rack at about the mid-point of the smoke chamber, which is the location I seem to use the most.













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I then closed off the exhaust port on the top of the pit, and the timer was then set for 3 hours of smoke.













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After 3 hours, I removed the jar of water with tongs and brought it into the house for observation. There was a noticeable color change to the water, the exterior of the jar was quite sticky, and the smoke smell wasn’t pleasant, it was quite acrid. Using a dropper, I tasted the water and found it to be extremely bitter tasting, bitter to the point that I had to take a shot of whiskey to rid my mouth of the taste! 
	

	
	
		
		



		
			


















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I then reset the sample to the same specifications as above, but this time I opened the exhaust fully and obtained a new jar of ice water to sit in the smoke chamber for 3 hours.













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The results of this jar were quite different after 3 hours in the smoke. The exterior of the jar wasn’t as sticky, the color of the water wasn’t as yellow as the first sample, and the smell, while still strong, wasn’t as acrid as the first test. The flavor of this water was a subtle hint of bitterness, but NOTHING like the first sample was. I still cleansed my tongue with a shot though! 
	

	
	
		
		



		
		
	


	

















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As you can see, there is quite a difference between the 2 jars of water.













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So, what are my findings thus far, with the exhaust port closed, creosote has the opportunity to heavily form and condensate onto items that are within the smoke chamber. With the exhaust port open, a lighter smoke is obtained that doesn’t have the same acrid smell and bitter flavors.

Conclusion for this test, leave your exhaust port open.

Why did I do this? I’m a geek at heart and love to experiment. More will be coming to show in greater detail how creosote forms and adheres to meats…


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## SmokinAl (Feb 2, 2017)

Good experiment Charlie!

Al


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## joe black (Feb 2, 2017)

That's a really good example, Charlie.  Folks can see for themselves what this one difference makes.  Good job.


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## Bearcarver (Feb 2, 2017)

Great Test, Charlie! 
	

	
	
		
		



		
		
	


	





Another 8 or 10 tests you wouldn't care if it was smoking at all. 
	

	
	
		
		



		
		
	


	





Bear


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## dirtsailor2003 (Feb 2, 2017)

Great test! From now on, exhaust vent closed!


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## daveomak (Feb 2, 2017)

That shows cold meat....   Is it time for a jar that is up to smoker temperature ??


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## worktogthr (Feb 2, 2017)

Very cool experiment.  This should be a sticky, in whichever section the mods feel it should go.  I am sitting here at lunch and about 5 minutes before I read this, one of my colleagues whose husband just bought a smoker was telling me that she doesn't like the smoky taste of the food he makes in it.  Probably because he is brand new to it and common sense tells people they need to keep the smoke in.  I will ask her if he keeps the top vent open or closed.  

I would also like to give you Points, for making the sacrifice of drinking whiskey in the name of science.  You make us all proud and your selflessness should be an example for all.  In fact if I wasn't at  work right now, I would have one in your honor haha

Great post!


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## gr0uch0 (Feb 2, 2017)

Great analysis.


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## ab canuck (Feb 2, 2017)

Good experiment...


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## wade (Feb 2, 2017)

Good example of the two extremes 
	

	
	
		
		



		
		
	


	





. I am not at all surprised that with no air flow through the smoker that it was not at all nice. As part 2 are you planning on repeating the test with the vent half open to see if it is closer to the fully open or fully closed result?


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## crankybuzzard (Feb 2, 2017)

DaveOmak said:


> That shows cold meat....   Is it time for a jar that is up to smoker temperature ??


YEP!  This test was for basically an almost cold, to warm, smoke scenario. 

The next test will be just that.  Same scenario, but at 225-250°, and I'll probably extend the smoke time to roughly 6 hours, kind of the "middle range" of time for the regular items we smoke (chicken, ribs, brisket, etc...)  Also, 2 (larger) jars per test will be utilized, one with ice water and the other with ~70° water to simulate cold meat vs. room temp meat going in.

I also have another test I'm writing up the plan for now, but I need to find a couple of mediums to use.


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## mr t 59874 (Feb 2, 2017)

This is a good illustration of how over smoking cheese is accomplished.

If you had pulled the jar with the vent closed when it reached the same color as the one with the vent open, wouldn’t they have tasted the same? This is why I suggest smoking to a desired color rather than by time. The color that you smoke too will depend on your individual taste. In addition, by cleaning the smoke, you will find more smoke flavor without the creosote buildup.

Example: http://smokingfoodwithmrt.com/smoke-direct-vs-indirect

If you continue with your test, you will notice that the closer the smoke and jar temperatures are to one another, there will be fewer deposits accumulated on the jar.

Good job, point,

Tom


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## johnmeyer (Feb 2, 2017)

First of all THANK YOU for the a truly amazing, well-done test, and for taking the time to document it and post the result. This is really useful.

I'm still not entirely satisfied with my MES 30 Gen 1, specifically because of the smoke quality. I'm pretty sure that many things I did when I was a newbie fifteen months ago ended up creating creosote. I sure did get some tongue-numbing nuts, and believe me, you don't want your nuts to numb your tongue.

I switched to using the AMNPS, and that helped some, but I found that I still got bad smoke at low temperatures. Your test reveals some of what may be happening, although I always keep the vent wide open, and also added a mod in place of the chip loader which significantly increases the airflow through the smoker

I know there are threads about the importance of TBS, and other posts about improving the quality of the smoke. Some of these talk about the water pan (pretty clearly a bad idea to use in an MES); some talk about temperatures (the colder the smoking temperature, the more likely to have creosote problems); the venting (the subject of this thread); the source of the smoke; and more.

Of all of these, the mailbox mode seems like the most likely thing that would further reduce the bitterness. Do you have a mailbox mod and, if so, would you be willing to do one more test using that? I have been meaning to build some variant of the mailbox mod, in hopes that creosote would condense in the mailbox and/or the duct connecting the mailbox to the smoker, but since it requires an hour or two of work, I was looking for some additional, concrete reasons why it would be a good thing.

If you do the test, I'll pay for the whiskey.

[edit]P.S. I'm simultaneously following this thread:

Clean, Cool Smoke via Thermodynamics

That thread leads to this blog post:

Smoke Direct vs. Indirect

which begins to answer some of my questions about using an external smoke box.

These two threads together are providing all sorts of great ideas of how to get a better result.


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## wade (Feb 2, 2017)

CrankyBuzzard said:


> The first question we tend to ask is; “Is your exhaust port wide open?” A lot of the time we’ll get the answer that it wasn’t wide open and the next cook comes out without issue.


The word "wide" is quite important here as many discussions revolve around the difference between the top vent being "Wide" open or "Partially" open. Having the top vent fully closed is obviously a problem (as you have shown) but is it necessary that it is "fully" open? The previous test with 1/4, 1/2 and 3/4 open would be helpful.


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## gr0uch0 (Feb 2, 2017)

To me, this also signifies the importance of using dry pellets as well.  Leaving them in the hoppers of the pellet poopers outside for days on end can't be helpful, imho:  I'd think that they should be nuked before each burn to make sure that there's not any moisture (hello, humidity) that's been absorbed.


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## wade (Feb 2, 2017)

Mr T 59874 said:


> This is a good illustration of how over smoking cheese is accomplished.
> 
> If you had pulled the jar with the vent closed when it reached the same color as the one with the vent open, wouldn’t they have tasted the same? This is why I suggest smoking to a desired color rather than by time. The color that you smoke too will depend on your individual taste. In addition, by cleaning the smoke, you will find more smoke flavor without the creosote buildup.
> 
> ...


I agree with you Tom about how easy it is to over smoke cheese. I am not so sure about judging it totally by colour though as it will depend on the smoke. I usually find that with the thin smoke, if you can see colour it is already over smoked with some woods.

Yes, having the ice cold water in there will certainly magnify the effects of the tar in the smoke.


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## wade (Feb 2, 2017)

gr0uch0 said:


> To me, this also signifies the importance of using dry pellets as well.  Leaving them in the hoppers of the pellet poopers outside for days on end can't be helpful, imho:  I'd think that they should be nuked before each burn to make sure that there's not any moisture (hello, humidity) that's been absorbed.


When preparing the pellets, the microwave is your best friend


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## crankybuzzard (Feb 2, 2017)

Wade said:


> The word "wide" is quite important here as many discussions revolve around the difference between the top vent being "Fully" open or "Partially" open. Having the top vent fully closed is obviously a problem (as you have shown) but is it necessary that it is "fully" open? The previous test with 1/4, 1/2 and 3/4 open would be helpful.


If I get enough interest in this little project of mine, I have quite a few different tests I would like to do, 1/4, 1/2, 3/4, etc is on the list as well.

I have an MES, but I chose not to use it since it's on a cart in the garage and quite difficult to get to.  However, after getting a couple of PMs, and seeing that a lot of the potential issues folks are having are with this type of smoker, I'll probably perform the remainder of the higher temp tests with the MES.  That will also show a definite position of the exhaust port since it has a pattern, so to speak.


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## tropics (Feb 2, 2017)

Charlie that is agreat write up Points

Richie


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## crankybuzzard (Feb 2, 2017)

Wade said:


> I agree with you Tom about how easy it is to over smoke cheese. I am not so sure about judging it totally by colour though as it will depend on the smoke. I usually find that with the thin smoke, if you can see colour it is already over smoked with some woods.
> 
> Yes, having the ice cold water in there will certainly magnify the effects of the tar in the smoke.


That's another reason that I used the apple pellets, light colored and light smoke overall.

I have 20 pounds of mesquite pellets, that would make for a very different color and overall creosote experience.  But, always a but, I do plan to continue using my smoker and don't want to have to spend 8 hours burning it out and cleaning it up when this is all said and done.


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## crankybuzzard (Feb 2, 2017)

johnmeyer said:


> First of all THANK YOU for the a truly amazing, well-done test, and for taking the time to document it and post the result. This is really useful.
> 
> I'm still not entirely satisfied with my MES 30 Gen 1, specifically because of the smoke quality. I'm pretty sure that many things I did when I was a newbie fifteen months ago ended up creating creosote. I sure did get some tongue-numbing nuts, and believe me, you don't want your nuts to numb your tongue.
> 
> ...


I don't have a mailbox for my MES or my big electric vertical smoker.  I know a few local folks that do, so perhaps a 6-pack and some time on one weekend we could make this happen.  Not this weekend though, he'll be watching some game on TV.


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## HalfSmoked (Feb 2, 2017)

What another excuse for some CR better stock before disagreement between the boarder people and they raise the tariff 
	

	
	
		
		



		
			






 Great test cranky waiting to see what happens at 225.

Warren


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## mr t 59874 (Feb 2, 2017)

Wade said:


> I agree with you Tom about how easy it is to over smoke cheese. I am not so sure about judging it totally by colour though as it will depend on the smoke. I usually find that with the thin smoke, if you can see colour it is already over smoked with some woods.


Wade, I whole-heartedly agree with you. It is the reason I emphasize keeping good notes on your smokes including, the wood being used, the type of cheese, and the resulting color when your taste has been reached, as all can be different.

Tom


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## wade (Feb 2, 2017)

CrankyBuzzard said:


> That's another reason that I used the apple pellets, light colored and light smoke overall.
> 
> I have 20 pounds of mesquite pellets, that would make for a very different color and overall creosote experience.  But, always a but, I do plan to continue using my smoker and don't want to have to spend 8 hours burning it out and cleaning it up when this is all said and done.


Lol yes - Mesquite and Apple - the difference between a large espresso and decaf


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## crankybuzzard (Feb 2, 2017)

Wade said:


> Lol yes - Mesquite and Apple - the difference between a large espresso and decaf


I like that!  I'll also use that!


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## bellaru (Feb 2, 2017)

Great experiment! 
This is what makes this sight so great. Somebody taking the time to make the rest of us more knowledgeable. 
Thanks


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## crankybuzzard (Feb 2, 2017)

I love doing research!













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From this link

https://books.google.com/books?id=OCTzAAAAMAAJ&pg=PA152#v=onepage&q&f=false

Here it is written a bit differently...

"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"


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## gary s (Feb 2, 2017)

CB just likes doing the testing so he can drink his Whiskey 
	

	
	
		
		



		
		
	


	





     No,  great info Charlie I like the comparison  I've been saying that forever "Chimney Wide open" 
	

	
	
		
		



		
		
	


	











  
	

	
	
		
		



		
		
	


	





  
	

	
	
		
		



		
		
	


	





Gary


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## browneyesvictim (Feb 2, 2017)

I'm in for this one Cranky! Looking forward to round 2! But I'm pretty sure you already know what the outcomes will be. Further proof you are just doing this for the whisky!

point


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## bbqbrett (Feb 2, 2017)

Bearcarver said:


> Great Test, Charlie! Thumbs Up
> Another 8 or 10 tests you wouldn't care if it was smoking at all. :cheers:
> 
> 
> Bear




Bear, that is soooo funny.  Gave me a good laugh!


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## pitbulmom (Feb 3, 2017)

Cranky,

THANK YOU! 
	

	
	
		
		



		
		
	


	





 I have tried to explain to hubby why you just want TBS and the way to get it, but he just was fighting me on it, 
	

	
	
		
		



		
		
	


	





( I thought about doing a Chicken with the vent closed and let him TASTE the difference, but didn't want to hear the complaint of how it would taste. ) He is of the mind that the more smoke, the more flavor, and I really don't want him trying his method and me having to clean my smoker.

He is learning, he reads some posts, and I try to expound on them so he understands, but it is slow going. He is of the mind that if a little is good, more is better.
	

	
	
		
		



		
		
	


	





  (No real cooking ability, at all!)


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## mr t 59874 (Feb 3, 2017)

PBM, you have the right idea. When smoking foods, look at it as if you were filling a glass with milk, whether you poor fast or slow, when it’s full it’s full. To try and add more will only make a mess, as demonstrated in CB’s experiment. 

Tom


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## crankybuzzard (Feb 4, 2017)

Wow, I didn't realize I had posted a soapbox for the care and feeding of pellets and started a no nuke campaign as well...

So will part 2 start the foil/no foil debates all over?  :icon_rolleyes:


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## gary s (Feb 4, 2017)

And the story Continues   

Gary


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## gr0uch0 (Feb 4, 2017)

Thus why I bowed out some time ago and apologized for hijacking your thread, Charlie....


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## crankybuzzard (Feb 4, 2017)

gr0uch0 said:


> Thus why I bowed out some time ago and apologized for hijacking your thread, Charlie....



It's all good, I was acting like an educated donkey with my last post.  

I'm sure a mod will clean it up at some point.  If not, the first page still has good info!  :laugh1:


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## gary s (Feb 4, 2017)

CB, Excellent Post. You took the time to a side by side comparison  Great info for everyone. Looking forward to #2

Gary


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## pc farmer (Feb 4, 2017)

HUGE clean up on this tread.  

Most of you know it was hi jacked...    

Back on topic.


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## Bearcarver (Feb 5, 2017)

c farmer said:


> HUGE clean up on this tread.
> 
> Most of you know it was hi jacked...
> 
> Back on topic.


Good Job Adam!!

Nice clean up!

Bear


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## crankybuzzard (Feb 5, 2017)

gary s said:


> CB, Excellent Post. You took the time to a side by side comparison  Great info for everyone. Looking forward to #2
> 
> Gary



#2 will be this coming week if all goes as planned.


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## crankybuzzard (Feb 5, 2017)

Thanks Adam, it was starting to get messy.


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## wade (Feb 5, 2017)

Bearcarver said:


> Good Job Adam!!
> 
> Nice clean up!
> 
> Bear


Yes thanks Adam it needed cleaning up.


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## wade (Feb 5, 2017)

CrankyBuzzard said:


> The first question we tend to ask is; “Is your exhaust port wide open?” A lot of the time we’ll get the answer that it wasn’t wide open and the next cook comes out without issue.
> 
> For the last few weeks I’ve been contemplating some ways to show the difference between an open exhaust and a closed, *or only partially open* exhaust on a smoker.


Charlie. Did you do the scenarios of the vents being partially open at the same time or are these to come later. From the tests so far you can recommend that the top vent should not be fully closed - but you cannot extrapolate from this to say that it should be *fully* open - which was the inference of your original question.


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## ghoster (Feb 6, 2017)

Point for the nice work Cranky.  Just reading this reminded me of some of my early cooks and of that unpleasant taste it gives the meat. I think I should follow your lead with a shot.


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## meatstick (Feb 6, 2017)

Thanks for the post.. I think I am having the same problem. I have started using the amnps tube smoker..which produces a lot of smoke. I have just been laying it inside the chamber on the bottom. The last few times I have used it the food tasted ashy/bitter. I only have 1 vent on this and it is on top and wide open. I don't know how to fix this. After reading this and talking with others it seems like I really need to find some time and make the mailbox mod. for this. Any other suggestions? Thanks


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## crankybuzzard (Feb 6, 2017)

Wade said:


> Charlie. Did you do the scenarios of the vents being partially open at the same time or are these to come later. From the tests so far you can recommend that the top vent should not be fully closed - but you cannot extrapolate from this to say that it should be *fully* open - which was the inference of your original question.


It will be coming.  The tests take several hours to complete, this one alone took over 6, so the next few I have planned will take 6-10 hours each test.

Part II will be LATE this week or early next.


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## crankybuzzard (Feb 6, 2017)

meatstick said:


> Thanks for the post.. I think I am having the same problem. I have started using the amnps tube smoker..which produces a lot of smoke. I have just been laying it inside the chamber on the bottom. The last few times I have used it the food tasted ashy/bitter. I only have 1 vent on this and it is on top and wide open. I don't know how to fix this. After reading this and talking with others it seems like I really need to find some time and make the mailbox mod. for this. Any other suggestions? Thanks


What type of smoker do you have and what type of pellets are you running?


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## Bearcarver (Feb 6, 2017)

meatstick said:


> Thanks for the post.. I think I am having the same problem. I have started using the amnps tube smoker..which produces a lot of smoke. I have just been laying it inside the chamber on the bottom. The last few times I have used it the food tasted ashy/bitter. I only have 1 vent on this and it is on top and wide open. I don't know how to fix this. After reading this and talking with others it seems like I really need to find some time and make the mailbox mod. for this. Any other suggestions? Thanks


I have the same problem with the Tube Smoker. It puts out too much smoke for a small smoker at low altitudes.

The Tube works better for guys at high altitudes, and they have trouble with the AMNPS (Tray Maze).

The AMNPS works perfectly for me, because I am at a low altitude. You should try an AMNPS.

Some guys say they can tone the Tube down by filling it halfway & shaking it on it's side, but I tried everything to no avail.

But I didn't try long, because the AMNPS works perfectly for me.

Bear


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## wade (Feb 6, 2017)

Bearcarver said:


> I have the same problem with the Tube Smoker. It puts out too much smoke for a small smoker at low altitudes.
> 
> The Tube works better for guys at high altitudes, and they have trouble with the AMNPS (Tray Maze).
> 
> ...


I have the same problem too when cold smoking. The smoke from tube smoker is just a little too "robust". Like you say, the AMNPS works well for me too. I find the tube is fine for my  hot smoking though.

I tried half filling a tube too - I think it was Dave that suggested it. I think it did produce less smoke however it did not last very long.


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## meatstick (Feb 6, 2017)

CrankyBuzzard said:


> What type of smoker do you have and what type of pellets are you running?


I have a smoking mountain propane smoker. I have been using hickory pellets that I purchased from Cabelas. I was using apple but wanted to try something different.


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## meatstick (Feb 6, 2017)

Bearcarver said:


> I have the same problem with the Tube Smoker. It puts out too much smoke for a small smoker at low altitudes.
> 
> The Tube works better for guys at high altitudes, and they have trouble with the AMNPS (Tray Maze).
> 
> ...


When you mention AMNPS you mean the tray? I hate to throw money away. Does it produce a lot less smoke?

I have been cold smoking and getting to much smoke. Have you tried the mailbox mod yet? I have everything besides the piping. I'm just kicking around the idea where to cut the hole for the pipe on the smoker. Everything I have been reading seems like this would take care of it.


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## wade (Feb 6, 2017)

Yes, The AMNPS is the tray. I find that it provides a good level of quality smoke over a long period of time. Less smoke than the tube.


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## Bearcarver (Feb 6, 2017)

meatstick said:


> When you mention AMNPS you mean the tray? I hate to throw money away. Does it produce a lot less smoke?
> 
> I have been cold smoking and getting to much smoke. Have you tried the mailbox mod yet? I have everything besides the piping. I'm just kicking around the idea where to cut the hole for the pipe on the smoker. Everything I have been reading seems like this would take care of it.


Sorry---Yes the AMNPS is the Maze Tray.

I never needed a Mailbox, except the one out by the road for my mail.

The AMNPS works perfectly in all of my MES units, all by itself. Just the right amount of smoke. IMHO

You should talk to Todd, at Amazing Smokers. He might even trade in your Tube for an AMNPS (plus any difference in cost).

Maybe yours would work like mine without the MB.

Bear


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## meatstick (Feb 6, 2017)

Wade said:


> Yes, The AMNPS is the tray. I find that it provides a good level of quality smoke over a long period of time. Less smoke than the tube.


Thanks Wade... I guess my next question is would it make sense to just buy the AMNPS and don't worry about doing the mailbox mod or stick with the tube and do the mod? I don't get a chance to smoke a lot of meats but when I do I hate wasting the meat/time by getting that ashy/bitter flavor.


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## flipman77 (Feb 7, 2017)

Awesome information supplied here.  Qview was a great idea!  Thank you !!

I told my wife I wanted to attempt this myself, she asked me why I needed a bottle of Rum to do it though...LOL


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## johnmeyer (Feb 7, 2017)

meatstick said:


> I guess my next question is would it make sense to just buy the AMNPS and don't worry about doing the mailbox mod or stick with the tube and do the mod? I don't get a chance to smoke a lot of meats but when I do I hate wasting the meat/time by getting that ashy/bitter flavor.


I had a lot of problems with that ashy/bitter flavor, and that led me to starting this thread:

Thinking of selling my MES 30

Based on all the ideas and feedback I got in that thread, I kept the unit and continued to smoke. However, I was never quite satisfied with the result.

Then, just a few days ago I finally had a few hours to spare and built my own version of the mailbox mod. I documented that here:

Mailbox (Popcorn) Mod (with a small twist)

I've only done two smokes with it, but I can definitely say two things about it: a huge amount of creosote gets deposited in the external box, and therefore does not get into the MES; it completely eliminates any issue with keeping the AMNPS lit. I still need to smoke some almonds to know if I finally have killed the bitter, tongue-numbing quality that I often got. Almonds are my canary in the coal mine, and if they come out tasting like good clean smoke, then I know for sure that the mailbox mod is the reason.

I'm also looking forward to doing a cold smoke, something else that will tell me if the mod makes the difference. I did try cold-smoking some cheese with the AMNPS placed inside the MES, but did not like the results.


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## gary s (Feb 7, 2017)

*First of all Thank you CB for posting this great comparison.*

*I asked my good friend CB if it was alright with him if I added to his post, he said sure it’s all about information.*

My take on ventilation and creosote is this:

Since I am a stick burner my experience is limited to that.

I am, and always have been a firm believer that proper air flow is one of the key factors in great tasting BBQ,. That means Chimney vent “Wide Open” and burning “Good Seasoned Wood”.

I do not like heavy thick smoke, to me it leaves a bitter over smoked flavor. For me there is only one kind of good smoke and that’s “Thin Blue Smoke”. But if you like heavy smoke and that bitter taste that is your prerogative.

Like a good friend of mine told me, he grew up with his dad grilling and smoking and used a half a can of starter fluid and If he couldn’t taste that Lighter Fluid taste it wasn’t any good. You develop a certain taste early in life an tend to stick with it, remembering those childhood cookouts.

Below is a great article by my friend who has a PHD in Physics , a consultant at Texas A&M and is currently a Professor at Boston University. I have consulted him many times in the past. His findings are not merely his opinion he does the testing and research.

*This is his writing Not Mine I asked his permission before I posted it, enjoy;*

Flavor is a matter of taste and familiarity. If you grow up nibbling on Hersey's milk chocolate kisses, you may never enjoy the intense bitterness of a 70% cacao chocolate bar in adulthood. If you start out life eating fermented bean paste smeared on rice, that pungent flavor may forever denote comfort food, instead of rotting garbage. And, while one guest may insist a charred, bloody red steak is their idea of perfect meal, another would rather gargle day-old cigarette ash.

So the "right" level and type of smoke flavor is a matter of taste. Especially since many, if not most diners soak their ribs or pulled pork in a pungent-tangy-sweet-pepper sauce, demoting smoke flavor from a leading role to a mere bit player.

But I do believe that some smoke flavors are more equal than others. And this opinion is held by the majority of commercial smoke operators and many competition winners- the best smoke flavor is generated by hardwood embers with an average temperature between 650F and 750F.

More than a mere opinion, this position has its basis in the chemistry of wood combustion.

Hardwoods are built from hemicellulose, cellulose and lignin. As each wood component is consumed by fire (in one of four stages), various chemicals are liberated. These chemicals, in the form of vapors, fine particles and soot, flow onto the meat. Along the path from fire to food, they continue to react, condense and morph in composition.

Your nose and tongue are amazingly sensitive instruments. Some flavors can be detected below[sup]1[/sup]  the part per BILLION level. So even tiny amounts of acrid elements can dominate the flavor and aroma profile.

Below 450F, combusting hemicellulose molecules are mostly acids and various gases. None are particularly desirable on food, but by 500F most of the hemicellulose has burned away or turned into charcoal. Cellulose releases water and acids and alcohols and tars and various combustible gases. Again, not too palatable, though much of the meat's mahogany color is a result of these chemical components. And, on a more positive note, cellulose is a sugar polymer, so it’s not surprising to discover brown caramel colors and flavors abound. By 600F the relative abundance of tarry cellulose compounds peaks and begins to decline.

Lignin is by far the more interesting ingredient from a culinary standpoint. A big messy molecule that gives wood its strength and rot resistance, bound inside the lignin molecule are the the precursors to smoke flavor, aroma and color. One is guaiacol, which is responsible for most of the smoky taste. Another is syringol, which your nose immediately identifies with fire and smoke. There are also clove and vanilla-like compounds. And literally hundreds of others. Some evaporate away in hours, some in days, others in weeks. One reason barbecue doesn't taste the same reheated.

Because the three wood components burn simultaneously, their compounds mutually interact. For example, creosote is the bitter progeny of this three way mutual relationship. A yellow, oily compound, creosote contains a mix of acids, tars and the smoky flavors from lignin. Creosote condenses at 250F and continues to flow until 150F. If you smoke above 250F, and the walls of your smoker and chimney are insulated, you won't observe creosote deposits like those in the photo..













pic.jpg



__ gary s
__ Feb 7, 2017






Which is one reason people smoke fast and hot. But, there is always one part of your smoker below 250F- the meat, which never exceeds the boiling point of water, 212F.

So creosote will condense on the surface of cool meat, adding a smoky though bitter note. Creosote is also water resistant- this is why you may notice the first time you try to apply sauce over a dark-orange bark, the sauce does not stick, and may even ball up in places. But, if you spritz and keep the surface moist during smoking, and herbs roughen the bark's surface, creosoty deposits and flavors are minimized.

Lignin continues to decompose after 590F, but as the temperature rises above 800F, carcinogenic molecules like PAH arise. Many desirable flavor molecules are also destroyed by the heat of a more intense fire.

So the best smoke occurs in this "sweet zone" of 650F-750F, where acids, tars and bitter creosols are minimized, while smoky flavors are maximized.

As we discuss in the wood combustion tab, no fire burns at a single temperature, but varies from smoldering to intense to dying embers throughout the firebox. Since low temperature smoke is acrid, while the high temperature smoke is merely weak, best practice suggests building a vigorous fire which is above 650F everywhere, and thus produces the cleanest smoke. In the end, it is the skill of the pitmaster that determines the flavor profile from run to run.

*It's easy to create impressive billowing clouds of white smoke- just burn moist wood at a low temperature with little oxygen. And the meat will taste smoky but acrid- I find this bitter taste lingers on the tongue for hours. But some people grew up with this flavor, and to them, it signifies home and good times.*

Or, you can burn post oak in a roaring firebox of an offset smoker- the smoke will be sweet but very light in flavor, and might not be able to stand up to simple salt and pepper.

In addition to controlling the fire's oxygen level and how new fuel is added and mixed into the embers, the pitmaster controls the choice of wood. Certainly, it is common practice to avoid long cooks with sticky resinous woods like pine. Resin contains terpenes (which are the source of turpentine), and few guests associate oil paint with good barbecue. Cedar or redwoods, which are particularly mold and insect resistant, should also be avoided in a long cook. But in small doses, or when cold smoking, these woods strike a distinctive flavor note.

Every tree species contain slightly different types and amounts of lignin. Even within a species the flavor profile will depend on the micro-nutrients the tree absorbed- these minerals act like catalysts, tipping the combustion reaction in different directions. Not all oak is the same from year to year or place to place. And bark contains more nitrogen than heartwood, so it enhances the smoke ring.

Because barbecue is, by most definitions, is cooking low and slow and indirectly off the heat[sup]2[/sup], most smokers limit air flow to keep the temperature and fuel consumption down. But it also assures much of the fuel is smoldering rather than burning. Low oxygen levels leads to greater soot production and less nitric oxide production. So a smaller smoke  ring.

Moisture levels controls how easily the smoke particles condense together, and thus how efficiently they stick and collide with the meat's surface. Seasoned wood, perhaps 15% moisture level, is often viewed as ideal. Green wood produces more smoke, but with acrid overtones. Moisture levels in the firebox (not the smoke chamber) also adjust the amount of nitric oxide produced vs other nitrogen compounds, and thus is a second contributor to the size and color of the smoke ring. More moisture, less nitric oxide.

A uniformly glowing, well-vented wood fire is the goal. Some smokers on the market inevitably choke air from the fire, or are so well insulated; they consume too little fuel to avoid acrid smoke. It still is smoke, and it is good. Just not best.


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## gr0uch0 (Feb 7, 2017)

Regardless of someone's comprehension of chemistry or molecular biology, this is a really good read and analysis, Gary:  thanks to you and your friend for sharing.  Point.


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## crankybuzzard (Feb 7, 2017)

That is a great write up and I love the science involved in all things related to cooking!


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## gary s (Feb 7, 2017)

CrankyBuzzard said:


> That is a great write up and I love the science involved in all things related to cooking!


Thank you my friend for allowing me to post on your thread.

Gary


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## ab canuck (Feb 7, 2017)

Good and very informative article.


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## Bearcarver (Feb 7, 2017)

Very Interesting Gary!!!
	

	
	
		
		



		
			






Thank Your Friend for us!! 
	

	
	
		
		



		
		
	


	





Bear


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## nopigleftbehind (Feb 7, 2017)

So is creosote a product of wood not burning or the buildup of smoke from too much smoke "hanging around" (hence the reason to run the vent wide open).  In addition, by limiting the amount of wood or spreading out the pellets in your tray, can you limit the amount of smoke per cycle thereby limiting the amount of smoke within your smoker at any one time.  I know notes are preached here but for beginners, what should be be looking for?  (running a  MES 40 with no tray - STOCK setup).


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