Thursday
Aug052010

The Thermodynamics of Pipe-Smoking

Originally Posted Tuesday, February 7, 2009

 

A great deal has been written about how smoking technique changes the pipe smoker’s experience. While smoking technique seems to apply only to the strength and pace of draw, we know that a number of other variables also impact the experience: the pipe selected, chamber shape, the tobacco blend selected, and the density at which the tobacco is packed into the bowl.

Most pipe smokers focus first on their pipe and/or tobacco selection, secondarily on their tobacco-packing technique, and finally on tamping technique.

From my experience, however, the method by which the pipe is lit seems to warrant far less attention than other considerations.

One recent Saturday as I commenced lighting a bowl of G.L. Pease Stonehenge – a particular favorite of mine – when I reached for my old boy lighter I realized I had left it at home, so I asked my tobacconist for a box of wooden Swan Vesta matches. As I lit the tobacco, I was struck immediately by how different my experience of Stonehenge was upon my palate. This is a tobacco I know and love. It is one with which I have considerable experience, yet it tasted markedly different.

It is not unusual to have a favorite tobacco taste somewhat different from time to time. For example, I find that if I’m drinking espresso or strong black coffee that the first tobacco sip will yield a somewhat more subdued mix of flavors. If I’m drinking bourbon whisky, the taste will be stronger and more sugary. But this difference constituted an order-of-magnitude difference in flavor. There was considerably more sweetness and muskiness in the smoke. The sugars took on the typical smoky molasses quality found in Stonehenge, but the typical burnt caramel note I had come to expect was missing.

As I sat and wondered what was going on, I inspected the moisture of the tobacco. In a moment of epiphany, I realized that I had probably never lit this tobacco with a match as opposed to with my lighter. In that moment, I decided to experiment for a month or so by lighting my pipes solely with matches. I put my lighters in the drawer and I have been using matches exclusively since then.

I also decided to do some research on the science of igniting – or pyrolizing (as scientists call it) – tobacco. This little research project has taught me a great deal more than I bargained for.

First, I had no idea that my lighting method could impact my experience so significantly nor second, that thermodynamics would so clearly explain the differences in my experiences.

Not unsurprisingly, I discovered that medical researchers and scientists had been exploring the effects of tobacco burning temperatures on the development of aromatic carcinogens in tobaccos. Two Finnish scientists Ermala and Holsti published extensively on their research in the ‘50s. Their research compared and contrasted combustion dynamics in cigars, cigarettes, and pipes. Using thermocouple devices, Ermala and Holsti established that cigarette, cigar, and pipe burning dynamics are quite different from one another, despite the fact that tobacco is burned by the smoker in each of the delivery systems.

For example, pipe tobacco burns on average (in the combustion zone) at about 500 degrees Celsius. Cigarettes burn at about 670 degrees Celsius, and cigars burn at an intermediate average between pipes and cigarettes. With each smoking instrument, however, there is variability in temperature. For example, the maximum temperature a pipe smoker might achieve is 620 degrees Celsius whereas someone who has cultivated a slow, cool smoking style might smoke as low as 380 degrees Celsius. As you might surmise, this variability in temperature significantly impacts smoke temperature on the tongue, sensitivity of the palate, and most important, the actual flavor of the tobacco blend being smoked. How is flavor affected?

Ermala and Holst established that there are three zones in the pipe chamber:

“In principle, three main zones are distinguishable in burning tobacco (cigarette and pipe) : (a) the actual glowing point, where oxidation takes place, called in the following the “combustion zone,” (b) the “distillation zone,” where no actual glowing occurs but where the temperature is high and dry distillation quite strong, and (c) the zone farthest from the glow point, where the temperature is low and where, for that reason, condensation of dry distilled material can take place, and which is hence called the “condensation zone.”

As Ermala and Holst explained the dynamics of pipe tobacco combustion, they discovered that even at relatively low combustion temperatures the heat spread out in an extensive area outside the combustion zone (the actual glow point), and that within this heated area - the distillation zone -  fractions of various substances (tars, oils, moisture) escaped into the smoke stream without being pyrolized. Ermala and Holsti noted that the distillation zone within a pipe is quite large. Further, a third zone - the condensation zone – produces condensation of dry distilled materials.

I realized as I studied this that pipe tobacco flavor is actually a blend of three processes, oxidation, dry distillation, and condensation. I further understood that the smoker’s ability to regulate smoking temperature would alter the proportions of the various three flavor-production processes. A “hot smoker” would produce greater numbers of oxidation (and presumably more distillate) flavors whereas a cool smoker would more likely equalize those proportions.

As I considered this information - and reflected on its implications with respect to my smoking style - I thought about my pipe-lighting style, and also my methods of tamping and relighting. It occurred to me that 1) I almost always used my butane pipe lighter to initially light my pipe; 2) that I have recently tried to manage the light in such a way that I achieved a large combustion zone (glowing area); and 3) during re-lights I have also tried to ensure that the tobacco is well lit in a large combustion zone, applying the butane flame for a considerable period of time.

When I compared the kindling temperatures of wood and butane, (in chemistry, kindling temperature is the lowest temperature at which a substance bursts into flame) I learned that butane, when mixed with air, burns at 1,977 degrees Celsius whereas matches burn between 600 and 800 degrees Celsius, depending on the wood variety used in manufacture (most matches use Aspen wood).

When I considered that there are still people who use butane torches to light their pipes, and that these devices produce temperatures of 2,500 degrees Celsius - the temperature of the Sun - I was flabbergasted.

Obviously, the differences in temperature are so extreme as to be almost absurd. As I considered the length of time I applied the butane flame to the tobacco, I realized that I was super-heating it, which could not help but impact the flavors, especially those sugary mature Virginias that I love.

As an aside, I also learned that Turkish tobaccos burn hotter than other varieties (The highest temperature recorded, 812°C., was in a Turkish cigarette.”) When I considered those tobaccos that are present in blends of which I am particularly fond – Orientals and Latakias – I concluded that it has been my lighting and re-lighting techniques that have produced the flavor distortions that I have routinely been experiencing for years. It became crystal clear why relights of the last 30 percent of the tobacco in a bowl often yields foul flavors upon relight.

My little research project has left me both wiser and happier. I am finding that my smoking experience has been enhanced by more careful attention to managing the size and intensity of my pipe’s combustion zone. I am experiencing more complexity in my tobaccos and considerably less tongue bite.

Further, I am more aware of my own moderation of my smoking style and how important it is to match tobacco density in packing with the engineering of the pipe being smoked. Those pipes with more open draws require denser packing and more modulated sipping of the smoke stream. Most importantly, I am now aware how important it is that I refrain from periodically super-heating the tobacco when I light and re-light.

As a postscript, like many of you, I’m sure, I have often wondered at the wild inconsistency and subjectivity of tobacco reviews. I now have a better understanding of just how much one’s choices, techniques, and tools impact a smoker’s perception of a blend.

Read Ermala and Holst’s orginal article.

 

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Reader Comments (16)

Makes perfect sense to me Neill, although I never gave it much thought. That will change as of now! Thanks.

October 5, 2010 | Unregistered CommenterEd Anderson

Neill,

I just blundered across this year and a half old post of yours while looking for a source of the now hard to find 1-1/2" long Swan Vestas on the internet. Reading it (besides diverting me from a probably futile search) makes me even more interested in the condition and texture of my tobacco, and how much draft I need to create depending on tobacco blend, bowl diameter, airway size, and what's actually happening during the course of a smoke. I'm sitting in front of my computer keyboard with a pipe full of Virginia flake right now, varying the intensity from sntart to finish of each puff, like the crescendo and decrescendo of a single musical note, and it makes a tremedous difference in the quality of my experience, both in taste and my engagement in the act. Thank you for a terrifically informative post.

October 26, 2010 | Unregistered CommenterScott Stultz

Sir,

Very interesting post! I have long searched for someone with a proper scientific perspective to pipes!

Recently, I have switched from wooden matches to Bic lighters, since I find the matches leave bad flavor in the bowl. What seems to be the case is parafin boiling and leaving the match when lit. This leaves a bad taste. I tried scraping off some parafin and it was helpful. But I have too little time to scrape matches in my life, so now I use a BIC lighter until I find a better model!

Do all matches have parafin on them?

February 13, 2011 | Unregistered CommenterAxel
It makes NO sense to me. This could only have influence on the first few puffs (when you light up, you don't light up all the tobacco in the bowl, only the top part). Once it's burning the embers go from one flake to the next, the starting temperature is out of the equation, the variables are now only smoking behaviour.
March 8, 2011 | Unregistered CommenterPJN
As for the last comment, I think the author is trying to point out the initial light can cause changes in the tobacco not experienced while smoking. His comparison of lighting temperatures of various methods show that matches are most closely resembling the temperatures while smoking.
March 10, 2011 | Unregistered CommenterJohn
I read this several days ago and am returning to thank you.
Thank you so much for sharing what you have learned! I couldn't operate an 18 speed transmission until I understood the how and why of it all. Thank you so much for the "how and why" of the pipes combustion chamber!
July 29, 2011 | Unregistered CommenterBig Thanks
After moving inside for the winter season, I've been using matches almost exclusively to light my pipes. My previous attempt at using a match outside was an exercise in frustration that I quickly abandoned. After a few months using the match (lighters are Vector inserts in Zippo cases) I've come to appreciate the control I have on lighting the tobacco. My matches have been boxes from various tobacconists but I recently picked up a brick of red-tips from my local grocery store. Using a match, I've also noticed the flavor or certain tobaccos to be vastly improved. SG Full Virgina Flake, tried earlier outside with a lighter was transformed using the match to light the bowl.
January 1, 2012 | Unregistered CommenterAl Jones
I have searched the internet to some extent and did not find the temperature of the flame from a Zippo lighter. Do you have it?
February 19, 2012 | Unregistered CommenterTom Davis
I made several interesting observations this past weekend regarding the match vs. a lighter. Last year, most of my smoking during the spring/summer and fall of 2011 was outside on my patio, using a Zippo with a vector insert. When cooler weather drove me off the patio and into my workshop, I started using a match and did so all winter long.
Spring has finally come to Maryland and I was once again able to smoke outside this past weekend. I can't light a match outside to save my life, so I went back to the Zippo. Sunday night I was surprised to find I have a bit of tongue bite, something I hadn't experienced since the Fall.
I concluded that using the lighter, I was applying more heat to my tobacco and paid the price. So, I'm a fan of the match when the smoking conditions permit. (simple red top matches from my grocery store)
April 4, 2012 | Unregistered CommenterAl
If the combustion zone is so narrow, won't' there eventually be an unburned wall of tobacco around the inner perimeter of the bowl? I experienced this with my pipe (I'm very new to this, FYI), and so I had to scrape the unburned tobacco off the sides, loosen it up, you know? And it all fell to the middle, which I then tamped down. But I've never heard of other people having to do that, which seems to me to suggest that nobody else's combustion zones are as narrow as depicted in this article.
July 19, 2012 | Unregistered Commenterthechristophershow
Pipe smoking mechanism work good with good packing tobacco. As it contain tobacco, is it delivering lots of nicotine? And can we try flavors in smoking in pipe smoking?
July 27, 2012 | Unregistered CommenterAngelina
Russ Oulette has an essay on tongue burn; at the Pipes Magazine forum; that i believe does cover flame temps.
July 27, 2012 | Unregistered CommenterAl
Great post on pipes, Neill. This is something truly worth considering when buying their own tobaccos. I used to think that whatever pipe there is on the market is just the same as any pipe around. For a pipe aficionado, it is imperative that they get the right "mix" that matches their own taste. Are there some sort of 'recipes' or guides on how to mix tobacco for pipe smoking?
August 11, 2012 | Unregistered CommenterAlex Islander
A great article, thoroughly enjoyed reading it. The last paragraph also stuck me as particularly relevant, as I too have often pondered on the variety of opinons and reviews (sometimes extreme opposites) a specific brand of tobacco can earn.
December 9, 2012 | Unregistered CommenterMarko
Nice one you shared a very intresting blog. Your comparison about lighting temperatures of various methods show that matches are most closely resembling the temperatures while smoking. I"m so much thankful to read this terrifically informative post.
November 23, 2013 | Unregistered CommenterBryanSanctuary
I've been talking about this ever since I first ran across this article. This is why I use different tobacco chamber shapes when making the V2 Pipes. Changing from a U shape to a V shape tobacco chamber changes the ratio of the condensation zone to the distillation zone and therefore changes your smoking experience. If you have tried your favorite tobacco in a new pipe and didn't enjoy it, check out the tobacco chamber shape. Likewise, if trying a new tobacco you don't like it in one pipe you may like it in a different one.
March 9, 2014 | Unregistered CommenterPV2

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