Literally just went through this with my client after I was told I had “a lot” loss. Here’s a part of my email.
Traditionally yield is calculated by weight, and we have been running the same yield calculations below in the past as well as many others. It’s great for rough numbers but not entirely accurate.
Example:
45kg (100lbs) biomass input
10% of that is pulled crude
10% of 45kg is 4.5kg (10lbs) of crude.
while 10lbs crude from 100lbs biomass may be acceptable, we need to drill down the number further to look at actual CBD yield, as that’s what this is all about.
60% average potency of crude(4.5kg, or 10 lbs)=
2.7KG of CBD total extracted
Our interim numbers for extraction are as follows.
45kg in biomass
6.5kg crude extracted
40-44% potency
2.6-2.86KG CBD total extracted.
(we left a bit of ethanol in for the final scrub, its advantageous to reduce down to a potent thick crude when we are just going to add ethanol back in) Percentage is a range because we tested it 4 times and giving you the highest and lowest numbers)
As you can see, this matches the calculation by weight in the beginning of the email almost exactly and even exceeds rough yield calculations by weight. But, because we shouldn’t look at just the amount of crude extracted and look at actual CBD yields instead, then we can see that we need to look into where/if there was loss and how exactly much for both of ours sake. So down the rabbit hole we went.
Because the target is CBD, not weight or volume of crude in the end, a more correct calculation could be:
45kg biomass (100lbs)
12% CBD tested in flower
Calculated down to 10% due to other low/no CBD biomass present in biomass batch. (Stems, leaf, trim, debris, etc)
10% of 45kg is 4.5kg of calculated highest yield
95% target extracted efficiency
95% of 4.5kg:
4.27kg of calculated max yield CBD
That end CBD number is highly dependant on the actual potency of the biomass as a whole. I am not aware the details of how exactly your raw material is tested, and I apologize for elaborating details you already probably know, but if only the flower was tested, and we receive biomass that is not 100% pure flower only, the total CBD in that biomass will be lower than the COA before we even begin. Stems, debris, shake (we even found a few metal brackets), leaf, “dilutes” the batch. So even if the flower tested great at 12%, the remaining plant material in the batch will lower that number, it could bring it down to 10% or even 8%. Which is what our data and testing is leading us towards. While those other parts of the plant do have cannabinoids, it’s at a much lower potency, with stems and seeds having almost nothing and just extra weight. What we have learned from this is that we should be mixing the biomass first, pull a sample, pulverize, then test that so we know for sure exactly how much CBD is in that biomass. This is not only good for your calculations, but covers us as well if someone decided to give us wet hemp, bricks in a bag or whatever.
Point of the story, don’t go by biomass input. It’s been said here time and time again. Homogenize your batch, get it tested and then you can actually calculate yeild and loss.