Chamber size, shape, does it matter?

[wmolaw]

As I have been going through numerous types of tobacco lately, working hard to really stock up on those I really enjoy and know I will enjoy for years to come, I have become a bit fascinated with the actual thermodynamics of smoking and how the taste of a tobacco is actually released so that we, the smoker, can enjoy it.

I also have some clean up work that I need to do on a chamber and before I got started on it, I began to wonder if a different shape of a bowl would produce a different flavor.

We all know about the every day profiles of a chamber from the V to the U, but what about odd shapes, less diameter and top and bottom than in the center? Hour glass shapes?

I started looking around and found two articles that were really informative about why one tastes what they taste when smoking.

http://www.apassionforpipes.com/neills- ... rentPage=2

http://glpease.com/BriarAndLeaf/?p=7

I did a search and really didn't see this issue discussed in much depth, if at all. Any thoughts, experience on different shaped bowls and how the shape might affect smokability?

[Sasquatch]

Without being hugely anal about this or just plain out to lunch, my take one the shape and size thing is that no matter what you build, someone will love it and someone will hate it. Now, there are some generalizations about chamber shapes and sizes that a lot of smokers seem to agree on.

So allow me to generalize:

Let's start with a huge big bowl, 2.5" deep and an inch across. Light this up and smoke it for 3 hours, and what happens? Firstly, the thing won't even come up to temperature for about 15 minutes, so you have to just ride it out for awhile. Once it's burning, it will burn very easily at a lukewarm temperature for about 2 hrs, providing a spectacalar array of flavors, due to the low burn temperature. BUT.... toward the bottom of that bowl, it will intensify greatly (you've been sucking smoke through a tobacco filter, as it were). The bottom tobacco will be strong, possibly sour. Some blends it's okay, some not so much. Some guys love this, some hate it.

Contrast this with a tiny pipe - you light it up, the flavor of the tobacco is pure and sharp, you smoke for 15 minutes or a 1/2 hour and it's done. Little or no progression in flavors, and a lack of that "transcendental" time where a big pipe just cruises. BUT... you get sharp and clear flavor delineation, none of the muddling of flavors that happens after and hour of sucking on a big pipe. You want that new-cut hay taste in your Best Brown? Stick with a small pipe.

Conical bowls in my mind are a packing issue rather than a flavor issue - pack them wrong and they are a wet, crappy mess. But with an air-pack or a Frank pack, they work great, no issues. Just don't cram the tobacco down at the bottom and get it all packed up down there.

So.... you get people saying that small pipes are for flakes, big pipes for burley or English mixtures... whatever. Each guy figures out what each pipe does for him. I think the idea of flake pipes being small comes down to the fact that most flakes are virginia-based tobaccos, and they do well in the un-muddled state (not to mention being maybe a bit stronger in nic than a Danish mixture, for example).

So there you go. Build whatever you like - someone will tell you it's stupid, someone will love it

[the rev]

but which are better to throw at Ernie?

rev

[Sasquatch]

Big ones. Duh.

[wdteipen]

Pointy ones also work well.

[wmolaw]

Without being hugely anal about this or just plain out to lunch, my take one the shape and size thing is that no matter what you build, someone will love it and someone will hate it. Now, there are some generalizations about chamber shapes and sizes that a lot of smokers seem to agree on.

So allow me to generalize:

Let's start with a huge big bowl, 2.5" deep and an inch across. Light this up and smoke it for 3 hours, and what happens? Firstly, the thing won't even come up to temperature for about 15 minutes, so you have to just ride it out for awhile. Once it's burning, it will burn very easily at a lukewarm temperature for about 2 hrs, providing a spectacalar array of flavors, due to the low burn temperature. BUT.... toward the bottom of that bowl, it will intensify greatly (you've been sucking smoke through a tobacco filter, as it were). The bottom tobacco will be strong, possibly sour. Some blends it's okay, some not so much. Some guys love this, some hate it.

Contrast this with a tiny pipe - you light it up, the flavor of the tobacco is pure and sharp, you smoke for 15 minutes or a 1/2 hour and it's done. Little or no progression in flavors, and a lack of that "transcendental" time where a big pipe just cruises. BUT... you get sharp and clear flavor delineation, none of the muddling of flavors that happens after and hour of sucking on a big pipe. You want that new-cut hay taste in your Best Brown? Stick with a small pipe.

Conical bowls in my mind are a packing issue rather than a flavor issue - pack them wrong and they are a wet, crappy mess. But with an air-pack or a Frank pack, they work great, no issues. Just don't cram the tobacco down at the bottom and get it all packed up down there.

So.... you get people saying that small pipes are for flakes, big pipes for burley or English mixtures... whatever. Each guy figures out what each pipe does for him. I think the idea of flake pipes being small comes down to the fact that most flakes are virginia-based tobaccos, and they do well in the un-muddled state (not to mention being maybe a bit stronger in nic than a Danish mixture, for example).

So there you go. Build whatever you like - someone will tell you it's stupid, someone will love it

I was thinking of this post more last night, as I smoked a big bowl of of Escudo. The more I thought about it, the more my point re: different shaped bowls seemed bizarre and dumb as hell (like the bowl that might be shaped with a smaller diameter top, then a larger diameter middle, leading to a smaller diameter bottom. Due to the smoking characteristics described in the articles, ie, that it is not the burning tobaccos that actually produce much of the flavor but the heated tobacco around it, I thought that if you got a small area burning well with a start light, which then went down into a larger diameter shaped area which would provide more unlit tobacco to warm and taste, it might be worthwhile.

But I then came to the same conclusion as you, pretty much, whatever works, works and a rationale could be used to describe any bowl shape that works for any particular tobacco.

So, I finished the bowl happily, drained the last of my Lagavulin, then went to sleep!

Thanks for the response. I might still try to make a shop pipe with a different shaped bowl just to see how it works.

[Sasquatch]

It'll probably work just fine.

[SchmidtN]

Welp, I don't know nothing about the flavor of smoke coming from the warm tobacco or the actually on fire tobacco, but I can tell you something about air flow. It acts purdy dang close to water when it's flowing... so if you you have a tiny opening at the top of the tobacco chamber, then open up wider you're going to get violent currents. Not sure if that's what you want or not, but I'd hazard a guess that it leads to unburnt tobacco in your pipe after a smoke and most people would be against that.

BUT, I'm all for experimentation... make sure you take pictures too.

Here, read about the Venturi effect and then do some math to find out how large/small you want the opening at the top of your bowl to be.
http://en.wikipedia.org/wiki/Venturi_effect

[mcgregorpipes]

you guys smoke tobacco in your pipes?

ok seriously this made me think of something while i was grinding another 3/4" spade bit into a more roundy pointy shape.. most of the time i've seen photos of these there's more of a taper and point on the bit closer to a dull V than a U. I was leaning more to the U which one is more common?

[SchmidtN]

I think most folks do a U with a slight taper in it. In theory, for a good smoking pipe you'd want the surface area at the top opening of the bowl to be equal to the surface area just before you round out at the bottom. In practice it seems a little bit of taper between the two makes a good smoker.

What I think wmolaw is trying to make will be sort of a backwards jet engine. He wants to Suck-Expand-Burn-Blow... jets Suck-Squeeze-Burn-Blow. He'll be making a high pressure at the top opening of the tobacco chamber, then expanding that same air into a lower pressure. That might (my only concern is this might be happening at such a low flow rate that it doesn't really make any difference at all) cause a really hot burn in the center of the bowl and no burn around the walls of the bowl.

[mcgregorpipes]

that wikipedia about the venturi effect is cool.. you have me thinking of my wood stove, pipes are a furnace right? close the damper (restricted air intake) and the fuel burns more efficiently because heat loss through air carried out the chimney is slowed. too much air restriction before the fire is up to temperature and you have problems smothering it

[Sasquatch]

Which is why we tamp after charring!

[caskwith]

Personally I like a U shaped chamber and wherever possible this is what I use, normally 3/4" as well as it just seems a good size to my mind. Of course different shapes require different chambers, for those that need a tapered chamber I like to use one that tapers at the bottom but will have fairly straight sides so you still get a decent ammount of tobacco in there.

[PipesByDesign]

Here, read about the Venturi effect and then do some math to find out how large/small you want the opening at the top of your bowl to be.

No. I refuse to use math when making pipes.

[wmolaw]

I think most folks do a U with a slight taper in it. In theory, for a good smoking pipe you'd want the surface area at the top opening of the bowl to be equal to the surface area just before you round out at the bottom. In practice it seems a little bit of taper between the two makes a good smoker.

What I think wmolaw is trying to make will be sort of a backwards jet engine. He wants to Suck-Expand-Burn-Blow... jets Suck-Squeeze-Burn-Blow. He'll be making a high pressure at the top opening of the tobacco chamber, then expanding that same air into a lower pressure. That might (my only concern is this might be happening at such a low flow rate that it doesn't really make any difference at all) cause a really hot burn in the center of the bowl and no burn around the walls of the bowl.

Hm, will have to read the article. But, yeah, that is what I was kind of thinking. If the flavor of the tobacco comes from the tobacco that is not being burned, but warmed then it would seem that a singular area of burn with a larger area of warm might produce more flavor!

Then again, I have no fricking clue. I got to thinking about this after watching a guy carve the chamber with the lathe,like a bowl, not with a bit and that gave me the idea since it would give you so much more flexibility in the interior shape of the bowl.

Of course, I suspect that as noted before, 99.9999999999999999999999999% of all the stuff one can consider "new" has actually been considered, tried, and dumped!

[wmolaw]

Which is why we tamp after charring!

Right, why worry about unburned tobacco as the burn goes through the center as you can always tamp and relight to catch the unburned flake/tobacco?