Help with decarboxylation of marijuana..

[Nosferatu]

I just got an ounce of LOW quality cannabis for cooking. I already powdered it with a coffee grinder because I was going to make cannaoil for brownies. Then I heard its highly recommended to do this "decarboxylation" of the weed first to make it a little more potent for cooking.

I know what that is but still cant find what temp your suppose to do it at and how long. And also is it too late since I chopped it all so finely? Does it need to be in nug form? If I can still do it what temperature should I use and for how long?

 

[jambolaya]

i think its better if its grinded and the oven should be preheated on 325 and then put it in for 5 minutes

 

[Nosferatu]

Would it not vaporizes at that temp when its in powder form? Sorry I'm sure your right I'm just skeptikal because an ounce is alot to me and I would hate to ruin it. Others say dont pass 280 so thats the only reason I ask..

 

[VWFringe]

it think it's short time, higher temp allowed, lower temp longer period

wasn't it 200F for 20 minutes, i used to do it in a steamer basket over boiling water

but i've read people doing 325 F for five minutes without damage but i can't find anything usefull right now

if you've already powdered and screened it i'd just throw it into the recipe, the baking time will certainly convert it, i'd be careful with it in powdered form.

 

[herbgirl]

i'm still fuzzy on this particular point but i do agree with short time, higher temp - longer time, lower temp. i'm just not sure what the 'sweet spot' is, if there is one.

 

[Qbit]

Now I can't find the link to where I found it, but I read a patent for an invention forprocessing MJ, and it contained some results for some experiments involving decarboxylation. The optimum cooking time and temperature was 1 hour at 120C/250F. At that temperature they got something like 98% decarboylation with virtually no vapourization of the THC (which tends to happen at higher temperatures.

Mind you this was done in an oven, rather than in cooking oil, so I don't know if that makes a difference, but I've used these figures for cooking weed in oil (just cover your weed in oil in a small pan, an use an oil thermometer - you can get one for under $10), and it produces the most potent oil I've made.

Mind you, once you have your oil you've cooked weed in, it's good to go. Just take a spoonful and toss it down the hatch. Or have it with yoghurt. The more empty your stomach the better. Cooking it in brownies might actually vapourize some of the cannabinoids, as the temperature for cooking them is higher.

 

[nicelytoasted]

Nice find, Qbit.

If you are cooking with fresh, that heat will do it for you, no need to decarboxylate it beforehand. It does not increase the potency.

The process of decarboxylation converts the natural cannabinoid acids into their more active cannabinoid form by removing the end of the molecule that makes it an acid, the COOH. (C= carbon, H = hydrogen and O=oxygen). This is a relatively weak bond and is easily converted to mostly carbon dioxide. This can be done by heating, light and/or drying, as well as strong bases (curing actually does some converting as well). While there is no exact temp, I've seen a range of 105-140C (~ 221-284F), depending on strain and amount used, to optimally decarboxylate, while retaining all the tastes/actives of our beloved medicinal phytosubstrate (aka biomass).

Grinding should help with the surface area exposed, which can allow for the lower temps and/or less time to be effective, imo.

It looks to me that ~ 60 minutes @ ~ 110-120C should work, in general. (I've even used my HA and pumped air through it @ 250F for about 10 minutes and it worked well).

Here's an excerpt from a paper I've read, taken from

http://www.freepatentsonline.com/7344736.html

Decarboxylation of cannabinoid acids is a function of time and temperature, thus at higher temperatures a shorter period of time will be taken for complete decarboxylation of a given amount of cannabinoid acid. In selecting appropriate conditions for decarboxylation consideration must, however, be given to minimizing thermal degradation of the desirable, pharmacological cannabinoids into undesirable degradation products, particularly thermal degradation of THC to cannabinol (CBN).

Preferably, decarboxylation is carried out in a multi-step heating process in which the plant material is:

i) heated to a first temperature for a first (relatively short) time period to evaporate off retained water and allow for uniform heating of the plant material; and
ii) the temperature is increased to a second temperature for a second time period (typically longer than the first time period) until at least 95% conversion of the acid cannabinoids to their neutral form has occurred.

Preferably the first step is conducted at a temperature in the range of 100 C. to 110 C. for 1020 minutes. More preferably the first temperature is about 105 C. and the first time period is about 15 minutes.

If the plant material is derived from cannabis plants having a high CBD content (defined as >90% CBD as a percentage of total cannabinoid content), the second temperature is preferably in the range from 115 C. to 125 C., preferably about 120 C. and the second time period is in the range from 45 to 75 minutes, preferably about 60 minutes. More preferably the second temperature is in the range from 135 C. to 145 C., preferably 140 C. and the second time period is in the range from 15 to 45 minutes, preferably about 30 minutes

If the plant material is derived from cannabis plants having a high THC content (defined as >90% THC as a percentage of total cannabinoid content), the second temperature is preferably in the range of 115 C. to 125 C., typically 120 C., and the second time period is preferably in the range of 45 minutes to 75 minutes, typically about 60 minutes. More preferably the second temperature is in the range of 100 C. to 110 C., typically 105 C., and the second time period is in the range of 60 to 120 minutes.

Most preferably the decarboxylation step is conducted at temperatures and for times which ensure at least 97% conversion of the acid cannabinoids to their neutral form, whilst ensuring thermal degradation of THC to CBN is less than 5%.

 

[Lo]

Nice to see you around Nicely Thanks for the informative post...missed your posts.

 

[Qbit]

Hey yeah Nicely, that's the patent I was talking about. Thanks for linking to it - I'd lost the damn thing.