100% Proven. Reverse Calabash pipes provide a Cooler Smoke.

100% Proven. Reverse Calabash pipes provide a Cooler Smoke.

As the reverse calabash has become more and more prevalent in the past few years and we have more and more pipe smokers trying such pipes for the first time, the common questions I hear after someone has smoked these pipes are:

1. My favorite tobacco tastes dramatically different & feels as if it has lost some of it’s flavor strength.


2. Why is this happening & what is going on inside these pipes?

Since I myself have had the exact same experience when smoking these dual chamber pipes, I decided to see if I could try and answer one question & one question only. Does the heat transfer to the tongue, in a reverse calabash pipe, decrease, when compared to a regular stemmed pipe?

From what I found, the answer is a solid yes.

I am by no means a scientist and I definitely do not have access to a full scientific laboratory. What I do have access to is a little bit of common sense and the ability to purchase tools that measure temperature. I used these tools, applied them to the best of my ability in a scientific method and recorded the results. While I used three different sets of temperature measurement devices to measure temperature changes occurring in various parts of the pipe, the best measurement tool I found was your average Barbeque thermometer. Using this thermometer to measure the smoke coming out of the slot was extremely effective. It has a stainless steel probe on the end that measures the change in temperature based on the amount of resistance a sensor inside the probe experiences. It’s a special metal that is very sensitive to temperature and I must say, it is rather accurate.

Air temperature of 69 fahrenheit as seen on thermometer

Just by holding the thermometer in the outside air, it quickly matched the temperature reading that the weather service was providing. Placing the probe inside a boiling tea pot gave a reading of 212 degrees fahrenheit and that number matches the typical boiling point of water. I even placed the device inside my mouth and in a brief 15 seconds, the thermometer read 97 degrees fahrenheit. The average human mouth has a temperature of 98.6 degrees fahrenheit so all in all, the tool was very accurate.

The three Reverse Calabash pipes used for the experiment.

To smoke, I took 3 regular stemmed pipes and 3 reverse calabash pipes. Nothing out of the ordinary with these six pipes except for one of the reverse calabash pipes. The pipe from Anthony Harris of ACME Pipes has an exceptionally large second chamber. Several hundred times more air volume can pass through Anthony Harris’s second chamber than that of the other two reverse calabash pipes.

Rolando Negoita, Reverse Calabash pipe.

Richard Friedman, Reverse Calabash pipe. Side-note: Notice how Richard has effectively ‘hidden’ the second chamber within his pipe’s design.

Anthony Harris of ACME Pipes, Reverse Calabash. The largest second chamber by far.

I took one tin of Esoterica’s Margate blend and a jar of Stonehaven and started smoking. Each temperature reading listed below was the average number of multiple rounds of testing & recording. If for example I puffed on a pipe 20x and took 20 different readings, the tallied number would be divided by 20. That average number is what you are looking at & each numbers records the temperature of the smoke passing through the slot of the stem. I did each test a total of 6 times. The total number of data points recorded is over 500.

The red dot of the infra-red thermometer points at one of the filled tobacco bowls. The temperature provided, again, a 69 degrees fahrenheit reading, corresponding to the general air temperature at the time of measurement.

I used a consistent starting point temperature inside the bowl, before I began recording temperatures coming out of the stem slot. An infra-red thermometer was used for that part of the task. I tested the infra-red thermometer on numerous surfaces from ice to the temperature of a tea pot that was boiling water. The infra-red thermometer is very accurate but it does not record smoke temperature. It simply measures the surface temperature of an object. Smoke is too porous & essentially a gas and the infra-red thermometer was not able to record it’s temperature. The surface of something is recordable and I even took measurements of the interior of the second chamber’s at various point of puffing. Interesting data was found. All that extra information however will only cloud the general purpose of this study and I will not focus on it. If anybody would like me to share that information, by all means, please ask. My focus was to see how hot the smoke is when it comes into our mouth.

Water boils at 212 degrees fahrenheit but the red dot you see is not measuring the water, it is measuring the temperature of the bottom of the tea-pot, the area closest to the flame heating the water. This reading shows 232 degrees fahrenheit.

It is not easy to find a consistent rate of temperature inside the bowl. The bowl was lit, puffing begins and the numbers rise and fall dramatically. When we light our pipes, temperatures in the bowl can reach numbers as high as 300 degrees fahrenheit and go all the way down to 110 degrees fahrenheit. The numbers varied by a few degrees but nonetheless, each bowl had a general temperature of 150 degrees fahrenheit during the ‘strong puffing’ portion of the test. During the ‘gentle puffing’ portion, each bowl had a general temperature of 115 degrees fahrenheit. That being said & applying an initial & consistent starting temperature point at the bowl, I found zero relative impact on the temperature of the smoke coming out of the stem in either case. Yes, the bowl temperature impacts the final reading at the slot, especially with furious & intense puffing. When replicating the experiment however six times over as I did and applying that consistent rate of inhale & moving beyond the temperature of the bowl when first lighting it, which is obviously when the bowl is at it’s hottest, the relative consistency in temperature output at the stem, no matter what the temperature was inside the bowl, appears to overshadow whatever is going on inside the bowl. After you light your pipe and the tobacco is lit & you apply a consistent rate of inhale, the temperature readings remain fairly standard.

There is a lot of heat loss that occurs between bowl and stem slot. Where that heat goes, I do not know. I imagine that the bulk of it simply passes through to the surface of the bowl itself & a lot of it simply leaves upward, through the top of the bowl opening. Again though, if your looking for deep science in such an experiment, I suggest you replicate the experiment and find your own way of measuring all these additional factors. My intention was to focus on the smoke coming out of the stem slot. The smoke that enters our mouth. That data point is hard enough to nail down.

Probe placed into the slot. After each puff, I removed my mouth and waited for the temperature to climax.

The thermometer probe responds very rapidly. The probe was placed inside the slot and upon inhale, the temperature reading would immediately rise and it would reach a high number & then almost immediately begin falling. It was the high numbers that I recorded. The results are listed below. All numbers are in listed in fahrenheit (f) and celsius (c).

Temperature Reading with 3 strong successive puffs.

Temperature Reading with 5 strong successive puffs.

Temperature Reading with 7 strong successive puffs.

Regular pipe – Michail Revyagin – 90 f / 32 c94 f / 34 c98 f / 36.5 c

Regular pipe – Castello – 89 f / 31.5 c93 f / 33.5 c97 f / 36 c

Regular pipe – Rainer Barbi – 89 f / 32 c92 f / 33 c97 f / 36 c

Reverse Calabash Pipe – Richard Friedman – 83 f / 28 c87 f / 30.5 c87 f / 30.5 c

Reverse Calabash Pipe – Rolando Negoita – 82 f / 27.5 c86 f / 30 c89 f / 31.5 c

Reverse Calabash Pipe – Anthony Harris, ACME Pipes – 82 f / 27.5 c82 f / 27.5 c83 f / 28 c

The average heat reduction or cooling between regular stemmed pipes and reverse calabash pipes at 3 strong puffs was approximately 8% Less.

The average heat reduction or cooling between regular stemmed pipes and reverse calabash pipes at 5 strong puffs was approximately 9% Less.

The average heat reduction or cooling between regular stemmed pipes and reverse calabash pipes at 7 strong puffs was approximately 11% Less.

The results from puffing at an intense rate highlight a very clear pattern. Also visible is that the ACME Pipe, rises in temperature at a much slower rate than all the other pipes.

I applied the same testing technique to gentle puffing and got similar results.

Temperature readings of gentle puffs with 10 second intervals in between. Minimum of 5 readings taken.

Regular pipe – Michail Revyagin – 85 f / 29 c

Regular pipe – Castello – 85 f / 29 c

Regular pipe – Rainer Barbi – 84 f / 28.5 c

Reverse Calabash Pipe – Richard Friedman – 78 f / 25.5 c

Reverse Calabash Pipe – Rolando Negoita – 78 f / 25.5 c

Reverse Calabash Pipe – Anthony Harris, ACME Pipes – 75 f / 23.5

The Average heat reduction of cooling between regular stemmed pipes & reverse calabash pipes while puffing gently was approximately 9% Less.

One of the most notable data points relates to the Anthony Harris pipe. Clearly the rate of temperature increase in that pipe was not as steep as the other pipes. Anthony’s pipe also had the greatest difference in temperature between the regular stemmed pipes I used with a rate of cooling change at 12%. Anthony’s pipe recorded the lowest temperature of the lot during this gentle puffing session.

What is interesting here is that Anthony’s pipe clearly has a second chamber volume that is dramatically larger than the other reverse calabash pipes yet the rate of decrease in temperature did not seem to coincide directly to the greater volume of the rear chamber. One would think that if the second chamber volume is twice as large, the rate of temperature decrease would be twice as much. This was not the case. It does however highlight that the larger the second chamber, the cooler the smoke will be.

Essentially this is the point where the very basic ‘temperature science’ portion of the experiment ends. I set out to confirm that these reverse calabash pipes do in fact have a reduction in temperature and it appears the numbers highlight that much. How is this happening and what is occurring inside these pipes is a whole different set of questions. I am no scientist and when speaking to several luminaries in our pipe industry, the varying opinions I heard on the subject were not only so different but more important, impossible to prove without some serious lab testing to be done.

I am however comfortable to express the following general theory of what goes on inside the second chamber.

Unfortunately, that is where my sensible theorizing has to stop. I have no way to further confirm any additional concepts that may come about as to what else is occurring. The above information seems to correlate to what my experience was & what many of you also experience when smoking these pipes.

After smoking and cleaning the rear chamber with paper towels. The intense moisture build-up is clearly visible on the towels themselves in the form of dirty tobacco moisture.

I dare to venture one additional brief thought as to why the heat reduction may be occurring although a strong caveat accompanies my thought. My theory is that the additional air within the second chamber, as a whole, dilutes the concentration of the smoke. In effect the space inside the second chamber allows much more air to mix with the smoke and thus, minimizing the smoke’s overall intensity as well as heat. When our tobacco tastes ‘less strong’ or has ‘less punch’ inside these pipes, it is potentially because the smoke is less potent because of the greater addition of air we are inhaling.

That being said, when I shared my idea with a fellow pipe-smoker they were convinced that this is impossible and they implied that the effect that many experience of ‘flavor intensity’ being reduced, is actually eliminated after several puffs. Why? Because at a certain point the second chamber is completely filled with smoke and thus it acts as any regular draft hole does. No matter how large or small the second chamber is, after a few puffs, it it completely fills up with smoke just as a regular draft hole fills up with smoke and the smoke ‘concentration’ as it were, becomes the same as with a regular stemmed pipe.  Perhaps he is right. I do not know.

The best article I have read on this general subject, brought to me courtesy of Matt Guss of the Seattle Pipe Club, was written by David Peterson from the Virtual Pipe Smoking Lounge in Michigan, USA. I strongly recommend this read, especially if you are the type of person who is looking for a lot of additional science. The good thing about David P’s article for me and my study, is that David P. references supporting data-points (specifically temperature) that are very similar to mine above. David P. set out to explain what occurs when a smoker experiences tongue bite and he did a great job covering many areas related to this discussion. David P. also references several other information points from some  blenders but essentially, all the extra information related to that regard is quite difficult to decipher and even more difficult to apply. You have to read the article but essentially  Greg Pease implies a strong correlation to the heat we experience in our mouth to the type of blend we are smoking. Certain blends with different ingredients inside produce dramatically different results in final temperature.

While perhaps the blenders comments are relevant on some level of deep science as it relates to tobacco, blend type and their relation to temperature & the differences in temperature we should see as a result…I myself smoked both a heavy English Blend and an essentially pure Burley blend in this experiment &  I found no data correlating to their view-point. The blender implied that we would see differences in the temperature and I did not find the same. David P’s article is a very in-depth & concise review of several areas & he provides a great analysis on the general subject of tongue bite. You can read the article here, re-posted by fellow pipe-smoker Peter Binsbergen of New Zealand.

Note that any of you can easily replicate this study very quickly in your own home. If you choose to do the test, the essential thing to do is to find a rate/depth/force of inhale and keep that item steady. If you can achieve that, then no matter how different your results in temperature may be, say for example you’re a very heavy breather and you have enormous lungs, far bigger than mine & you get a temperatures 10 degrees higher than my results. In the end, this should not matter. If your rate of inhale stays the same, the final result in terms of degree difference should stay relatively the same as well.

I hope this small study was helpful. At the very least it gives us some minor insight into the relative temperature that hits our mouths with these pipes. If that is a good or a bad thing is up for discussion. I do wonder though if one day, some blender may actually take this information into account and make a blend with a little added strength, in order to allow for the flavor of the tobacco to remain the same, while still enjoying a cooler smoke. Then again, perhaps the feeling of the blend’s flavor intensity being reduced is an altogether incorrect placebo effect. Can so many pipe-smokers including myself be wrong? You betcha.

So many fun and additional thoughts could come from looking deeper into this information. I hope the discussion is good.

Allow the questioning and comments to begin. :)

Thank you so much to Richard Friedman and Anthony Harris for lending me their pipes for this study. Without them, we would not have these data points to reference. My appreciation to both of you.

To visit Anthony Harris of ACME Pipes website, please click here.
To visit Rolando Negoita’s website, please click here.
To visit Richard Friedman’s website, you have to wait and keep your fingers crossed that he will soon be selling his pipes online.



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  1. Dan Coomer - March 5, 2014

    This was a very interesting article. I have smoked some of Anthony’s pipes on occasion and to me they seemed to smoke noticeably cooler than a normal pipe.

    The argument that the second chamber will eventually fill up with smoke and then act like a normal draft hole seems wrong. There is no way smoke could ever insulate as well as the wood around a normal draft hole. You are much more likely to reach a point where the amount of smoke drawn into the second chamber is equal to the amount drawn out of it. As the smoke enters a smoky second chamber it is still going to expand (that’s what gas does) and commingle with the cooler smoke. An expanding gas always cools.

  2. Charles Harbert - March 5, 2014

    I would perhaps attribute the cooling effect to be caused by the slowing and rapid expansion of the smoke stream as it enters the second chamber. The velocity of the stream will slow down as it passes from the airway (say .156 diameter) and suddenly enters a much larger space. The smoke starts in a large chamber (the pipe bowl) then is pulled thru a small orifice and then rapidly expands into the second chamber and in the process gives up heat. The three factors at play are temperature, velocity and pressure.

  3. MoriTakaKiyoshi - March 6, 2014


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