Measure the Difference Between "Good" and "Bad" Smoke

[gilbertpilz]

This is a general question that applies to anything that burns wood (either primarily or as an supplement to the primary fuel source) to produce flavor in whatever is being cooked. If you spend any time learning about barbecue you soon learn about the difference between thick, white smoke and thin, blue smoke and why this difference is important. I've been wondering if there is some way you can measure this difference? Can you measure the density of particulates in the air leaving your pit and use that to gauge the quality of your smoke? Is it possible to do this in a way that is commercially viable (i.e. in a product that was within the price range of the people on this site)?

[TripleB]

You can use a light meter to measure illuminance, usually within the 50 - 200 lux range. Though usually used for indoor usage. I use to have to do emission observations for an abrasive blast cabinet. It was an Air Quality permit requirement. However, that was for industrial environmental compliance.

So I don't really think it would help you since you already know what your looking for and the difference between a bit of white smoke and clear/blue smoke is minimal.

White smoke - moisture in the wood (heat your splits)
Black smoke - Incomplete combustion, smoldering, acrid.
Blue/clear smoke - Complete combustion, heaven

[Troutman]

To go along with Blue=way too rare, Light Pink=rare, Pink=medium rare (heaven), Gray=you ruined it and Black=throw it out.

[Mosca]

I don't know the answer. I will say that my experience (kamado) is that 10-15 minutes of "bad" smoke is of no consequence, and you shouldn't worry about it.

Bad smoke is more common in cookers that are air regulated, like kamado, because they are indicative of the temperature of the flame front. In a cooker that is volume regulated, ie fire size, the smoke color is a function of the overall fire temperature.

[Attjack]

Perhaps a piece of paper held over the exhaust would reveal clean and dirty smoke?

[Troutman]

My simplistic (or moranistic however you want to perceive it) formula is if you see smoke = bad, if'n you don't see it = good.

[gilbertpilz]

From Meathead’s article on the free site;

"Smoke is a combination of tiny particles that we can see in an aerosol mixed with water vapor and a complex cocktail of gases. The exact mixture is crucial and it can add elegant vanilla and brown spice notes or coarse bitter or even ash tray taint."

I’m interested in measuring the ratio of particles to gases that is surrounding the food.

[Bkhuna]

gilbertpilz - commercial particle counters for gasses can be had for about 2-3 thousand dollars. You could get an air pump with a consistent output of say 1 standard cubic foot per minute, some aerosol filters, and a used micoscope for less and count the particles. Of course, you would have to factor in the size of the filter, the size of the grids on the filter, the flow from the pump and get some training on microscopy.

Or just use the Troutman rule which works.

[gilbertpilz]

Bkhuna - the problem is that, in kamados for example, you sometimes never get to the point where there is no visible smoke. It is tricky to burn a fire hot enough to generate clear smoke while simultaneously keeping the temps at the grate in the low 200s. So, given that there will be some amount of visible smoke, how much is okay and how much is too much? If you had a way of measuring what is coming out of the cooker, you could take notes and remember "anything above NNN tastes nasty".

[DavidNorcross]

I am following this thread. I have no clue how to measure it. I really just go by sight and temp. But am interested...

[Mr. Bones]

Sight an temp workies jus fine, with some practice, an experience.

[bbqLuv]

My Pellet Grill no problem, to EZ, bring it to set temp, light clear blue smoke, add the meat, time for a PBR Tall Boy.

[Jerod Broussard]

Like Troutman alluded to. The best ever smoked sausage I ever smoked I never saw hint of smoke. You could taste the hickory with every bite.

I will add that when I was cooking on the Pit Barrel I would get the thickest, whitest smoke you could ever get, at the stall. Which meant there was plenty of water vapor mixed in with that stuff too.

[HawkerXP]

Not to mention from the 5 hanging briskets...

[gilbertpilz]

I think that Pit Barrels are a different beast in this regard. Aren't their fires always choked for oxygen? Also some of that smoke is from the burning drippings, right?

[HawkerXP]

I wouldn't say "choked" They like to run at 270ish, if you try to bring down to 225, yes you are chokings it. But you are correct the dripping meat creates a fog in the barrel the makes it a different type of cooker. gilbertpilz

[Bkhuna]

gilbertpilz - I have no experience with Kamodo style cookers. I just try to keep my charcoal grills producing very faint wisps of light smoke.

I think trying to determine ratios of smoke to particles to water vapor, etc., is a tilting at windmills.

[gilbertpilz]

I was thinking of something that would measure the amount of diffraction from a light source shot through the exhaust gasses but, yeah, condensed water vapor diffracts light so the thing I’m thinking of would have to either be calibrated for dew point or dynamically adjust itself somehow. Hmmmm ...

[Old Glory]

Ambient outside temperature and humidity is also a factor. I feel like in colder winter months the smoke is usually whiter for some reason.

[gilbertpilz]

Yeah, dew point is a factor,

[Mr. Bones]

Th wood, or even charcoal is also always gonna be a factour, even from th same cord, bag, or what have ya; climate conditions, temps, humidity, altitude, rainfall, geographical location, etc.) soil composition, varyin density from one part of th tree(s), seasonin time...

Scientifically, yupper, yer smoke can be measured, an compared to other smokes, to find out ppms of this an that.

A commercially viable (affordable) way to do this is extremely unlikely, at this point in time.

Every piece of meat also cooks differently...

Havin Constants are critical, in ammassin Scientific data to analyze, an draw Scientific Conclusions from, with multitudes of repetitions ...

Very few Constants, in Th Wide Wide World of smokin up some BBQ...

That bein done said, I wish ya Much Luck with yer pursuit(s)

[Donw]

There are devices that can determine the quality of smoke. A combustion analyzer is designed to do this. Another way is to use a white sampling paper inserted into the exhaust and compare it to the Ringelmann scale. In cooking I just eye it, but one caveat is that you need to be aware of the direction of light when viewing which can affect the apparent whiteness of the smoke. (Finally something I learned in marine engineering school that just might apply BBQ.🙂)