THC percentage quantifier

[rincewindrocks]

Hey, so I was just wondering, when you read that a certain strain of pot has, say, 20% THC, is that by weight, volume, what? Also, is it 20% of the entire bud (not plant, since stems and leaves have very little) or is it 20% of the active chemicals?

Thanks, and sorry if this has already been covered, I did a search, but couldn't find anything.

 

[Chainer]

The percent THC is the weight for weight of THC in the dry cannabis sample selected for analysis. A fresh cannabis plant contains a lower proportion of THC as fresh plant material contains a lot of water."

It's unclear what they mean by "dry". Plant material, of the sort you might buy from your dealer - even if dry in the normal sense - is still composed largely of water, so what do they mean by "dry"? It would seem that what they're talking about is a desiccated sample, that is a sample in which all the water has been removed, in effect destroying the biomass material, leaving the oils produced by the plant. We did ask for confirmation on this point, but received no answer.

It's also worth pointing out here that the measurement is actually referred to as "potency", not strength. This careful use of words is typical of the Home Office when it's being economical with the truth. The reason this is important is because the amount of oils the plant produces is not a constant fraction of the overall weight. It will depend on which part of the plant is sampled and how it's grown.

So the measurement they make is a percentage by weight of the oils in the sample, not of the overall weight of the sample.

Is potency directly comparable to strength? It's not clear that it is. In which case, the strength of cannabis over the years has never really been measured. It's also apparent from the reply that no standard system for making the measurement has been employed ("some scientists use gas chromatography")

Based on this type of measuring regime, it's clear that making meaningful conclusions about changes in strength is going to be difficult.

Hope this helps

 

[beamish]

saying what % your product is THC is tricky. as far as i know there is no standard for testing cannabis samples for thc content. i wouldnt trust much in the way of seedbank's claims - they are out to make a profit and are well aware that consumers want higher thc content.

 

[66z]

I've always been wondering why is that they say hash contains way more of THC than the buds while the high it gives is much more mellow and light?

 

[orangescrewpen]

I've never trusted those claims of so and so bud being x y and z % THC. Trichromes are not even 100% THC and there is no way they comprise 1/5 of a bud sample just from my personal experience and judgement. I am sure whatever sample they send in is the most trich'ed out, stemless, and leafless tiny chunk of bud they could find off the plant. I mean, how can the lab even tell if you sprinkle a little bit of kief on the sample?

I would like to see/find/establish a legitimate and reliable methodology of testing THC content. Honestly, I feel one can do this at home by doing a hash extraction and simply looking at yield over total starting material (by weight of course). You'll be well skilled to pull 10%-15% from even the best buds when using methods that minimize plant matter and maximize the purity of the end hash (oil). Don't forget to factor in that plant matter and other chemicals (CBD, terpines, flavinoids, etc) will be solved by your extraction method and will throw off results in terms of "pure" THC content.

I find hash highs to be dependent on your starting material. Perhaps your hash is being sourced from a different stock?

 

[66z]

Those are interesting thoughts. I should have kept in mind that those measurements were done by "them" not by "us"

In any case I've got hash from countless sources over the years so for me it's a proven rule hash in general got a lighter high..

 

[Chainer]

don't be silly, there are expensive ways to measure THC percentages and a lot of the people measuring these strains aren't out there to trick you.

I'm fairly certain Amsterdam has a facility that may do this with samples, and I believe they grow their own. Why would they use their super-expensive testing chambers on a sample that might be containminated?

 

[delta_9]

I would like to see/find/establish a legitimate and reliable methodology of testing THC content. Honestly, I feel one can do this at home by doing a hash extraction and simply looking at yield over total starting material (by weight of course). You'll be well skilled to pull 10%-15% from even the best buds when using methods that minimize plant matter and maximize the purity of the end hash (oil). Don't forget to factor in that plant matter and other chemicals (CBD, terpines, flavinoids, etc) will be solved by your extraction method and will throw off results in terms of "pure" THC content.

Trying to concentrate your bud into hash or oil would be a very poor way of determining THC content. Even the best solvent(chloroform) can only extract up to 98% of cannabinoids.
Luckily, there are ways to test THC content without much trouble. First you need to run a Beam test for CBD content, then there are several other tests that can be done to roughly quantitate THC content. The Duquenois test is one such test.