Does it make sense to burn pot until the embers stop glowing?

[psood0nym]

Apologies if this has been asked before, but I don't know how to search for this if the thread exists. My question is based on simple considerations that I'm not sure most cannabis smokers are actively aware of. Given that the active constituents of marijuana vaporize at temperatures substantially lower than the temperature of burning cannabis embers, does it make sense to keep hitting the bowl until it stops glowing in most cases? If, for instance, inside a 1 cm by 1 cm cube of brick weed, the entirety of the volume of the cube has reached vaporization temperatures after a few direct applications of flame, then does anybody who hits that cube of weed after get high at all? If so, why, exactly? If not, why are bowls almost universally considered "finished" when the embers die out? Does this mean that, typically, those who take hits later in the first rotation of a shared bowl take in lesser amounts of cannabinoids, or none at all? If not, why not, scientifically speaking? It seems like people who hit the bowl late in the rotation still get substantially high, but according to Google the average Bic lighter flame is 1977C or 3590.6F, which is far, far higher than the vaporization temperatures of psychoactive cannabinoids. How much shielding could the outer leaves of the typical shared bowl provide? Are the people who hit later experiencing placebo effects then?

 

[ComfortablyNumb95]

sorry but I didn't quite understand the question.
are you asking if you can get high "smoking" leftover ashes from a bowl?
people get high from a bong/pipe that's been already hit because weed doesn't burn all at once (unless you take a huge rip and you don't leave any un-smoked weed) and needs multiple hits to be finished. (in most cases)

 

[RTrain]

I have taken the last hit or 2 off a pipe that was just sitting around with the mostly smoked remains of a past bowl in it. Its gotten me high if there is enough to get a full hit or 2 out of it. Sometimes I feel this can lead to a bad high, though, so maybe the more pleasurable chemicals are burnt away quicker, leaving the less desirable in the charred bud that remains.

 

[psood0nym]

sorry but I didn't quite understand the question.
are you asking if you can get high "smoking" leftover ashes from a bowl?
people get high from a bong/pipe that's been already hit because weed doesn't burn all at once (unless you take a huge rip and you don't leave any un-smoked weed) and needs multiple hits to be finished. (in most cases)

What I'm saying is that there's reason to think that vaporization of the psychoactive chemicals in cannabis occurs long before the bowl is finished because the temperature that cannabis ignites and burns at is higher than this vaporization temperature. Because of this, at some point before there's any combustible material left in the bowl the "un-smoked" weed no longer contains anything that's getting those who inhale it high. When this occurs depends on how deep the bowl is, since the deepest leaves will be shielded from heat by the other leaves, though what I'm asking is when does this occur roughly speaking in different sized bowls assuming the bowl is kept "rolling" the whole time? There are other factors involved beyond what I've named here of course, but I mostly just bringing it up because I know most people "finish" the bowl, when there's reason to believe there's a point at which by doing so they're not getting themselves any higher. Rather, they're just inhaling more potential carcinogens. It only matters if the point at which this occurs is typically X number of "hits" before the bowl is finished, since then people can casually and practically adopt that rule of thumb and save themselves inhaling pointless and potentially unhealthy byproducts of pyrolysis.

 

[skillet]

I think you need to completely cash it to get everything.

For one, a lighter flame is nowhere near 2000 degrees C, read the edit a bit further down this page and see the melting points of metals.

And two, the numbers thrown around for boiling points of cannabinoids are ridiculous, everyone seems to forget that they were measured under pretty hard vacuum and quote them as if they're at atmospheric pressure. Even wikipedia gives the boiling point of THC simply as 157 degrees C, while it's actually going to be more like that listed in this MSDS - 200 degrees C at 0.02 mmHg. Plug those numbers into a nomograph and you get something like 500 degrees C at atmospheric pressure.

This page says you'll get embers at around 450 degrees C, probably a bit more since you're drawing fresh air over it, so you could probably vapourise all the THC before that point if you could control the temperature well enough. That's not really possible with a lighter though.

 

[freehugs]

Given that the active constituents of marijuana vaporize at temperatures substantially lower than the temperature of burning cannabis embers, does it make sense to keep hitting the bowl until it stops glowing in most cases?

I know that terpenes directly synergize with THC to make the high better, and many evaporate at higher temperatures then does THC, so I would say that smoking a bowl until the embers are burnt out will get you higher then if you were to just hit it a few times.

 

[psood0nym]

I think you need to completely cash it to get everything.

For one, a lighter flame is nowhere near 2000 degrees C, read the edit a bit further down this page and see the melting points of metals.

And two, the numbers thrown around for boiling points of cannabinoids are ridiculous, everyone seems to forget that they were measured under pretty hard vacuum and quote them as if they're at atmospheric pressure. Even wikipedia gives the boiling point of THC simply as 157 degrees C, while it's actually going to be more like that listed in this MSDS - 200 degrees C at 0.02 mmHg. Plug those numbers into a nomograph and you get something like 500 degrees C at atmospheric pressure.

This page says you'll get embers at around 450 degrees C, probably a bit more since you're drawing fresh air over it, so you could probably vapourise all the THC before that point if you could control the temperature well enough. That's not really possible with a lighter though.

I know that terpenes directly synergize with THC to make the high better, and many evaporate at higher temperatures then does THC, so I would say that smoking a bowl until the embers are burnt out will get you higher then if you were to just hit it a few times.

These are good points. I agree that the 1977C or 3590.6F quoted figure for the temperature of a Bic lighter is high. I went with the first Google result, though this article takes issue with the source of that quote and estimates the range is more likely from "~450C to probably around ~800C." I'm not sure what to think about the ranges that digital vaporizers indicate are effective vaporization temperatures in light of all this though.

 

[pmoseman]

The lighter is burning at a higher temp because oxygen is drawn in when you suck the bong; you can probably get nearly all the THC to vaporize rather quickly (157C).
After the water content is gone, I suspect not much else remains.

 

[szuko000]

It depends on the amount you are talking about. Once I did an extract on 110g of brown vaped weed and got a good amount of oil, mind you this was brown vaped weed.

So no you never get everything unless its burnt. Even 99.9% is not "everything"

 

[papa]

if you're going to smoke weed, smoke it. all of it. if you're worried about whether or not it's safer to try to judge when the benifits have been spent so you can dump the rest, I would suggest you vape instead. smokers gonna smoke.

 

[bloodshed344]

No, there would not be any reason to keep smoking it once it was all embers, however in practice you would probably end up wasting quite a bit.

 

[psood0nym]

While ostensibly the message of "smoker's gonna smoke" above could not be a more blatant truism, the fact is that's not the case by any means since a smoker could stop smoking before everything is burned, which of course has precisely to do with the question at hand. While I agree that vaporization is the clear choice for those concerned with their health, there are other concerns which still remain unanswered. Namely, what is the qualitative effect on the high of the smoker who elects to finish a bowl to the point the embers stop glowing versus stopping short of that by various degrees? From the testaments forwarded in this thread it seems that by continuing to smoke through to the last ember one increases the overall total quantity of psychoactives they ingest, thus arguably maximizing their high in quantitative terms, but by doing so they may taint the quality of that high by pressing on to inhale less favorable psychoactive constituents that vaporize at higher temperatures.

I seriously doubt all cannabis smokers who have been finishing bowls to the last embers have been considering this trade-off, and if they had known how to make a difference in one way or the other some may very well have chosen otherwise. We still don't know what a good rule of thumb is for gauging this under different common circumstances, though, because the key questions have not been settled. I don't want to belabor a point if nobody cares about it, but it seems plausible to me that many probably do and have just never considered it previously, and that's why I asked. [smiley face thing]

 

[bloodshed344]

While ostensibly the message of "smoker's gonna smoke" above could not be a more blatant truism, the fact is that's not the case by any means since a smoker could stop smoking before everything is burned, which of course has precisely to do with the question at hand. While I agree that vaporization is the clear choice for those concerned with their health, there are other concerns which still remain unanswered. Namely, what is the qualitative effect on the high of the smoker who elects to finish a bowl to the point the embers stop glowing versus stopping short of that by various degrees? From the testaments forwarded in this thread it seems that by continuing to smoke through to the last ember one increases the overall total quantity of psychoactives they ingest, thus arguably maximizing their high in quantitative terms, but by doing so they may taint the quality of that high by pressing on to inhale less favorable psychoactive constituents that vaporize at higher temperatures.

I seriously doubt all cannabis smokers who have been finishing bowls to the last embers have been considering this trade-off, and if they had known how to make a difference in one way or the other some may very well have chosen otherwise. We still don't know what a good rule of thumb is for gauging this under different common circumstances, though, because the key questions have not been settled. I don't want to belabor a point if nobody cares about it, but it seems plausible to me that many probably do and have just never considered it previously, and that's why I asked. [smiley face thing]

There's definitely some truth to what you say. If I just barely graze the (green) bowl with the lighter it doesnt really burn, just turns brownish-blackish and I taste the weed and breathe out vapor but its a much different feeling thing to breathe in. When I burn down to the last ember I find I get a more physical, heart-pounding type high that can leave me sleepy depending on the kind of weed. With small, grazing hits the high can be put in the background and less overwhelming, especially in regards to after-effects. It also tastes a hell of a lot better. No way I can justify not burning all of my weed though, even if it does taste bad.

 

[Tryptamino]

Cash yer bowl in one. Don't re-light the bowl until the ember goes out, and try to hit the embers until they go out, don't just let it sit there. Otherwise you waste a fair bit of pot.

 

[pmoseman]

I think you need to completely cash it to get everything.

For one, a lighter flame is nowhere near 2000 degrees C, redit a bit further down this page and see the melting points of metals.

And two, the numbers thrown around for boiling points of cannabinoids are ridiculous, everyone seems to forget that they were measured under pretty hard vacuum and quote them as if they're at atmospheric pressure. Even wikipedia gives the boiling point of THC simply as 157 degrees C, while it's actually going to be more like that listed in this MSDS - 200 degrees C at 0.02 mmHg. Plug those numbers into a nomograph and you get something like 500 degrees C at atmospheric pressure.

This page says you'll get embers at around 450 degrees C, probably a bit more since you're drawing fresh air over it, so you could probably vapourise all the THC before that point if you could control the temperature well enough. That's not really possible with a lighter though.

Why would they list the boiling point (b.p.) of THC at anything other than standard pressure?
Wikipedia had the b.p. of THC as 200 C at 0.02 mm Hg for a while and now it is listed as 199.1 C at 760 mm Hg.
Butane combustion is 2000 C and butane is in lighters. The temp is lower if not enough oxygen is present and unspent butane is absorbing the heat.
You can hold your hand over an open lighter flame without burning yourself, but your bong is a furnace. Whatever butane fumes do not burn are being sucked up the bong.
Light the weed on fire and stick a thermometer on the bowl; when it reads 200 C then it is defnitely cashed.

 

[bloodshed344]

Cash yer bowl in one. Don't re-light the bowl until the ember goes out, and try to hit the embers until they go out, don't just let it sit there. Otherwise you waste a fair bit of pot.

I can't cash my bowl in one! I'd be choking.

 

[elucidator]

^^^ Excellent advice from bfotd, this is the most efficient way to effectively utilize as much green as possible.
Bloodshed, if you can't cash/pull your cone/bowl in one slow long hit, then your bowl is too large. Try half filling it or acquiring a smaller bowl.

To psood0nym, I have noticed a vast difference between the satisfaction of having a cone ripped in one go, compared to the satisfaction of stopping before it is cashed (pulled through for those from oz). I do not know if this has any impact on the distribution of the actives present, or if it is simply superficial. IME it makes a large difference.

 

[ErgicMergic]

Cash yer bowl in one. Don't re-light the bowl until the ember goes out, and try to hit the embers until they go out, don't just let it sit there. Otherwise you waste a fair bit of pot.

Yep, get the bowl cherried, use your fingers to cover the bowl so it doesn't waste away, and keep powerhitting it and holding the hits for ~3 seconds (more than 5 is useless), and hit it until it's all ash. Vaporized and burned cannabinoids have two completely different medicinal and recreational effects, so getting the best of both worlds + getting your money's worth = yes, hit it until it's all a nice, white ash.