That's a big yup on digital readouts. Certainly one of the reasons the expensive Vapexhale Cloud only has a mechanical-dial temperature control, and not a numerical readout.This is a great thread and since we're talking about extraction temperature, it got me thinking that we should not take the digital readout (or the manufacturers claimed temp preset) as being the temperature we're vaping at - it's more complex than that! For example, if you've ever used one of those dual digital ceramic heater whip style machines, the set temperature stays at whatever you've wound it up to, but the temperature of the hot air going into the whip swings wildly - dropping quickly during each draw and gradually climbing back up to the set temperature between draws.
I'm a coffee geek and I think making espresso is sort of like vaping coffee but using hot high pressure water. To get consistently good espresso, temperature control is one of the major challenges and one thing you learn about making espresso is that the 'temperature' showing on the digital readout of the PID is nearly always an overestimate of the actual temperature of the water that's hitting the puck - hot water meets cold ground coffee inside a (prewarmed!) metal portafilter inside a big hunk of prewarmed brass, all subject to convection and radiant heat loss.
I'm going to bet that the temperature you record inside the plant material will vary wildly during every draw - depending from second to second on (eg):
By analogy with coffee, AFAIK, the only way to really know exactly what 'temperature' you are vaping at would be to record the temperature using (eg) a thermistor placed inside the vegetable material!
- the temperature 'set point' and the mechanics/electronics controlling the heating element
- how much moisture is left in the bud (google latent heat of evaporation) - this changes during each draw as it all eventually evaporates
- how hot the air is coming in from the heating element (which depends in turn on..)
- how fast you are drawing
- how much heat the heating element is generating
That's what some extreme coffee freaks do - you can get a thermistor (scace device eg) fitted inside your portafilter so you can monitor exactly what's happening in the puck as you pull the shot.
Funny thing is I like digital readouts and use them all the time to try to improve my technique - I don't think they can do much harm as long as you remember they don't mean what they say. My espresso machine has a simple computer PID to control the temperature. I usually use a plug in vape - old style dual digital ceramic whip model to control what range of volatiles I'm getting.That's a big yup on digital readouts. Certainly one of the reasons the expensive Vapexhale Cloud only has a mechanical-dial temperature control, and not a numerical readout.
But how does temperature affect the feeling one gets? It's releasing the same chemicals.
Call me a skeptic on this in the mean time.
fubar said:Do any commercial vapes use a PID to get hot air to a prespecified temperature?
fubar said:I'm going to bet that the temperature you record inside the plant material will vary wildly during every draw
that's what i found ... i stuck a probe into the herb during a vape session. The setpoint was 380°F, but the temp inside the herb was 50°F lower. During a toke, the temperature would rise to the setpoint -- this took less than 5 seconds. The herb temp dropped after the toke.
The setpoint is the absolute maximum temperature of the air that will hit the herb.
my pid will maintain setpoint within 1°F regardless of toke volume or speed. however, there is better extraction from the trichomes -- i.e. more vapor produced -- with a slow, steady inhale.
i don't grind ... no need to expose raw plant juice to the hot air flow ... vaporizing that stuff is not desirable. stirring is useful to redistribute the unexposed trichomes in the vial.
Is there some research someone can point me to about temperatures and effects? I don't understand how the two correlate, I would expect different effects from different strains. But how does temperature affect the feeling one gets? It's releasing the same chemicals.
Call me a skeptic on this in the mean time.
Could you explain why it isnt desirable?
well, for me, once the thc is gone, that's it. but i find i can still get a vapor from the abv - but what is the point of continuing? ... so i just quit the session.
well, for me, once the thc is gone, that's it. but i find i can still get a vapor from the abv - but what is the point of continuing? ... so i just quit the session.
Remember air is very lite compared to the herb it is touching so the air will only be most effective to the surface of the areas it touches. If you have little chunks that haven't been broken down properly, they will get left behind creating little pockets keeping them mostly untouched due to the cooling properties of plant fibers. Also, trichomes melt into liquids so some oils will be absorbed into some plant fibers which is why just looking to see if trichomes are gone isn't a good indicator to see if you vaped the oils out of the herb.
+1.
As the volume of vapour decreases during a session, the taste changes dramatically - losing all those delicious early spicy resiny strain specific flavours as it becomes increasingly 'smoky' tasting. That last few litres of thin sour vapour don't seem to do much for me so I don't see much point in keeping at it. I once tried combusting some to convince myself that it was useless and I was quite convinced - never tried eating ABV but I suspect I wouldn't get much out of what I leave behind.
I'd recommend a small flashlight and a 20x glass magnifying loupe (10x works too but I prefer 20x) near your vaping station.
Shine the flashlight into the glass bulb of the whip (you can tell what I use - but this should work for anything with clear glass in the pathway) while inhaling - sure, you can see thick clouds without the flashlight, but you'll see early and late vapour much more clearly as it passes through the flashlight beam and you can use that visual feedback to work on making it as thick and swirly as possible - eg see the effects of 'sipping' - pausing between slow small volume draws. This is especially useful for teaching new vaporists but I still do it routinely when new varieties arrive.
Looking at the raw input through a loupe, while shining that flashlight on it before packing a bowl is very revealing. You can learn a lot about the raw material trichome abundance and fatness, and how effective the grinding or crumbling is. After no more obvious vapour is visible with the flashlight even after a long slow draw at operating temperature, repeat the process with the ABV after you knock it out - you want to see uniformly brownish toasted material with no burn marks and next to none of that shiny waxy good stuff that it started out with. If there are obvious chunks of still-greenish material and or fat shiny waxy trichomes, you probably didn't stir half way through or get the material hot enough to vaporise all the goodness out.
As always, YMMV.
There's some great 'art' and personal experience distilled into this thread!
All true and agreed - but OTOH, the acid test for me is whether the material is generating vapour I can see and taste - if there's none or little after a long slow draw with air at around 180c or so, there's probably not much good stuff left. Once you're well out on the diminishing returns side of the extraction curve, you can always eat it or extract but I doubt that I'm tossing much useful material away - like I said, I've tried smoking it on an empty head and got nothing more than a headache for my trouble - but YMMV because of all the variations in equipment, plant material and technique.
It is taste, and sometimes harshness,that prevents people from going higher, which I can understand, but if you use the methods I posted earlier as well as a little water tool kit, it should help prevent this problem.
Interesting - thanks.Here's the cellulose study, they used cotton as the source for cellulose:
Aromatization of cellulose by heat
http://pubs.acs.org/doi/abs/10.1021/ja01281a005
I collect it in a little wooden box to keep my room tidy. Once it fills, I usually end up tossing it despite all my intentions of trying some abv recipes - I know for sure that it's not worth smoking but as discussed above, that doesn't mean it's lacking all medicinal qualities! I think if I ran out of fresh I'd be more strongly motivated to eat some...So if you both think that you have used up your herb sufficiently do you toss your ABV? If not what do you do with it?