Vacuum in a way is much like agitation
You agitate the mixture when you decarb to help with the removal of the co2 atom that breaks off during the process.
Vacuum allows you to pull the co2 atom off instead of just using the vapor pressure of the liquid to push it out
This makes a difference, even with the same agitation and temps
There is no need to remove the CO2 from solution to achieve decarb…but it’s certainly helpful if you want to keep you cannabinoids contained
can you give a viable explanation for how vacuum changes the energy required to break the bond and release that CO2 molecule?
I can’t…
Don’t have G.O.D. on my side, so not in a position to argue 
I just did read above.
It has nothing to do with energy but with “releasing” the co2
Can you explain how “agitation” increases/effects decarb speed and vacuum wouldnt?
You just said agitation matter and can speed the process up so why wouldnt vacuum?
The energy requirement is the same, doesnt mean vacuum wont help pull the co2 atom off easier.
I guarantee a co2 atom will take less energy with vacuum to remove from solution then one under vac, as the vacuum will immediately pull the co2 off
This means more heat transfer for your actual solution
Agitation helps with heat distribution and vacuum with degassing. Movement of gas bubles could be considered agitation but the same bubles affect the heat transfer in a negative way. The energy reguired for decarb is the same regardless of pressure.
@borysses is answered that one.
I did attempt to transmit it.
How do you measure done?
When no more bubbles?
I can see sucking giving a faster positive vs just stirring.
Exactly! MgO or other catalysts can change that energy requirement. Presumably an enzyme can be had as well
Nice, MgO is food safe. And if I really wanna be trve I can dig it as free range “organic” periclase in magnesite mine near me 
What about less heat transfer loss under vacuum?
That’s got to have a little affect on how much energy it takes to atleast reach the decarb temp
Now we are back to Gigs Of Data 
And I don’t need to start any religious wars…
I’ll toss my experiences on the pile, why not …
While working at a licensed testing lab, I had the opportunity to do a buncha R&D on decarbing, results were measured by HPLC method with verified standards from k-prime, the goal was to achieve 99% decarbed material with under 1% THC-a or CBD-a (I like to see that we were not burning it).
We decarbed biomass in sealed canning jars, 125c for 26-28mins allowed for good heat within the jars and got us to our best numbers consistently, sealing the jars and letting them cool to RT before opening them really helped retain terps but this is moot if going to distillate… Capping terps from decarb always resulted in a degraded terp profile in the GC analysis.
With oil based decarbing, we found best results in a stainless reactor while under mild positive pressure to a slightly higher temp of 140c, agitation allowed for a shorter time in our trials (5-8mins less). because of the psi, higher temp and agitation we no longer had to watch for muffin bumping into a vac line and the trade off of the higher temp did not hurt the cannabinoid profile.
These tests did not yield the same results with hash and kief because of their density.
Overall I would say the easiest & safest method of decarbing on the cheap is course milled biomass in sealed mason jars at 125c for 26-28mins but for scale decarbing oil is much more efficient
2¢,
-Vac = Good for pulling volatiles
-Vac does not accelerate decarb time (I’ve done side-by-side testing)
-Rotovap works ok, but there are better ways
-Instead of a chilled condenser, there’s other glassware that’ll improve terpene removal from the material. It employs a fluid effect (rhymes with penturi) that’ll help the escaping CO2 entrain the volatiles.
How do you suggest this should be done?
In the cold trap rf.
@Kingofthekush420 & @cyclopath & @Myrrdin… all excellent points that tie together into a cohesive theory from a hypothesis I’ve kicked around for a while to answer my obsequious question, “Wtf do they mean by pseudo-first order rxn?” Hypothesis: The effects of product concentration and pressure (which steer 2nd order rxn mechanisms) on the rxn rate are present, but fairly limited.
Here is how your results coalesce the theory of “pseudo-1st-order” for me, along with my and many others’ observations that almost ALL decarboxylation seems to actually occur at the interfaces of the fluid… most especially right where the liquid resin contacts the heated solid surface.
In the herb, this is practically impossible to observe, but each resin gland also has a lot of interface with air, which IS the heated surface in a baked sample. This would explain why we see that herb generally decarboxylates faster than larger volume aliquots of resin (as @Myrrdin observes here), and why even old school heads know that spreading the honey out thin in a pan works to decarb much faster than deep resin in a pot or jar.
Also, nanoscale materials science and common sense tells us that interfaces have greater energy than the bulk beneath them. Nucleation of bubbles in boiling and crystals in precipitation are both phenomena of the interface. A pointed needle penetrates a given surface (interface) with less force than a flat-end rod of equal mass… in many ways this surface area phenomenon is about the difference in energy of the interfaces.
Pressure does affect the rate of the decarb rxn, and it’s backward from what one might expect from CO2 being a gas and the product. This speaks to @Kingofthekush420’s point regarding energy removal by the escaping gas… similar to that seen in simple evaporative cooling. Instead of pressure slowing down the rxn (as might be the case in any 2nd order rxn involving 1 solid reactant breaking into 2 products), pressure speeds it up a little (as would be the case in a 2nd order rxn involving 2 gaseous reactants condensing to 1 solid product). Why? Well, if we treat the heat energy AS a reactant, this backward and limited effect of pressure may become clearer…
A. Pressure traps the heat by keeping the gas from expanding and leaving with its heat, AND
B. It keeps the bubbles smaller and therefore more numerous as they are unable to expand and coalesce, which increases the heated surface area in the immediate vicinity, allowing more molecules to react, BUT
This is naturally limited by the fact that
C. The majority of the molecules in that area have already reacted to create the gas bubbles in the first place, AND
D. Heat energy also dissipates by convection through a medium, (which is minimized as pressure increases, keeping new molecules from entering the more stationary hot zone) and by radiation through space, spreading over a larger area, which attenuates the exposure strength by the inverse square law… so at even one nanometer distance, the energy available to any molecule in the field along the expanded radiant area has been cut significantly.
Incidentally, such power attenuation at distance is probably why ONLY molecules right at the heated interface (where direct heat conduction occurs) will react in the first place… there’s just not enough energy left as the heat spreads outward with distance from its point (molecule) of origin! Although there might be faster convection with lower pressure as @cyclopath may have been guessing, IF it weren’t that the product is a gas able to expand and cool!
So the decarboxylation rxn really is just a 1st order (thermodynamically mediated) reaction, but because of the nature of its products (in this case, the molten dilatant fluid of generally amorphous solid: cannabinoids, and a highly linear non-polar molecular gas: CO2), it also has limited capacity to be driven apparently backwardly, but not reversed (which would be 2nd order) by pressure!
No wonder chemists just summarize that obvious but overtly complicated explanation as “pseudo”! 
Does your oil smell like burnt toast when decarbing prior to extraction? I get higher yields when decarbing first but haven’t figured out the best parameters for running CBD-A.
Agitation and application of vacuum are very different. While applying vacuum may result in mild agitation, if you’re decarbing in a roto then the difference won’t matter.
Edit: refer to @Photon_noir’s post
Pay me!
@Krative has some niffty way s and has spend a lot of time in finetunning these sop well worth the $$$
Haha thanks buddy. It’s true!
I’m keen on this, when the time is right I’ll be in contact