WHAT IS YIELD?
The word “yield” in extraction language refers to how much final product results at the end of the extraction process compared in percentage terms to the volume of starting material used. The final product of extraction is often referred to as “oil.” The essential oils of all botanicals are what we target with extraction, whether it’s lavender oil from steam distillation, olive oil from cold pressing, full-spectrum CBD oil from hemp or cannabis oil from different extraction methods. In the case of cannabis, the primary extracted oil is the starting point for all concentrates from shatter to topicals, so this base oil yield is what I will focus on.
The concept of yield is pretty straight forward but I see a steady flow of misuse and misunderstanding of the concept by beginners and self-professed experts alike so I hope to provide some clarity on the topic as I understand it with this post.
WHY IS YIELD IMPORTANT?
Simple yield is an important measure for determining the value of performing an extraction in relation to the final product output achieved by your efforts. Generally, getting a ton of oil from a small amount of plant material is great value, while a small amount of oil from a large volume of plant material may be a waste of time and resources. The most basic idea is that the more oil you get from a given amount of plant material the better. Unfortunately, it’s just not that easy and to understand all the valuable feedback we get from the yield numbers we have to understand all the considerations involved in the complex balance between the extraction process and resulting yield. Understanding the balance and the yield numbers is very important for you to accurately value the extraction output value.
HOW TO CALCULATE YIELD
A simple example would be using 100g of cannabis plant material to make 20g of extracted oil, giving you a yield of 20%. You find this by dividing the weight of the final product by the weight of the starting product: 20g/100g = .20 = 20%
Notice the calculation does not include any indication of quality, potency, or how efficient the process was. It only shows the volume of output versus the volume of starting material.
NOT ALL YIELD IS COMPARABLY EQUAL
How we interpret yield numbers is vital to understanding the bigger picture of the extraction process and the resulting oil. For example, which is better: a 10% yield or a 30% yield? Most people would automatically jump to say that the higher yield is better, however, the reality is there is no single answer to this question and a lot more information is required to determine which is better for any individual case.
Efficiency: Efficiency in regard to yield refers to how successful an extraction was at collecting the oil available from the starting material. For example, if you’re working with trim and had a 10% yield you can be pretty confident that you had pretty good efficiency, unlike if you were working with flower that’s rich with oil but ends up with only a 10% yield. Both extractions had the same simple yield of 10% which you’d be happy with from trim but not flower. The low number for flower would be troubling because you can be pretty sure there was a good deal of collectible oil left behind. Good efficiency means you got as much oil as possible out of the starting material and poor efficiency means you left some behind, so while the yield numbers are equal the value of the extraction can be drastically different.
Potency: While efficiency focuses more on the value of the extraction process itself, potency focuses on the value of the actual oil output. Potency in most of our cases focuses on THC and CBD with good consideration also given to terpenes. The higher the potency per unit of measure the more valuable the oil is. Back to our example question, the 10% yield could be a very high potency, clean and beautiful concentrate made from sugar leaf or weak trim where the 30% could be a low potency heavy, black, and plant matter laden FECO. Is one better than the other? Maybe and maybe not; as far as the value per unit of measure, the extract with higher potency would be more valuable in monetary terms, but as for what’s “better” that’s dependent on an individual’s desired outcome and what works best for their personal needs. So, when you hear people throwing around blind yield numbers or just throwing out the question, “what’s your yield?” understand that any answer is pretty useless without a deeper understanding and conversation about all the inputs, components, and processes involved.
INPUTS, COMPONENTS, AND PROCESSES
Understanding the Implications of Different Inputs
The main input in extraction is the starting plant material. Many different aspects of the material influence the resulting yield you may or may not get from the extraction process. Flower is obviously the richest form of material that should produce the most amount of oil with the production numbers varying depending on of different strains, genetics, and grow conditions. Trim produces substantially less output because there’s not as much oil present to start with. I’ve heard of people running fan leaves and stems with around a 5% yield but I haven’t tried it myself and I probably won’t bother. People will automatically jump to the conclusion that you should definitely only run flower, but that’s actually hasty and possibly costly error. The considerations should be how much oil you get from the material, how much it costs, and what it’s going to be used for. If the price for flower and trim were equal the choice would easily favor flower, but in reality, trim is substantially cheaper and if you are making topicals or edibles then concentrates made from trim are perfect. At that point, it would become a question of which material is cheaper to run the extraction with for the volume of oil that will be produced.
Material preparation will affect yield drastically so it also has to be taken into consideration. Trim doesn’t really matter because it’s usually pretty broken down already, but flower that’s ground up or milled will produce more oil than flower that’s left completely in nug form. We know that working with ground-up flower and ethanol extraction can lead to green leak even at very cold temps in commercial applications so the extra yield that’s picked up with grinding may then be given up on the back end when it has to be cleaned up. It’s all a balancing act.
Understanding Desirable Component Value
The value of the yield requires careful consideration of the final product components. When we perform extractions we target the oils of a plant; for cannabis and hemp we are after the cannabinoids, terpenes, and flavonoids which I will refer to as “desirables.” There are also “undesirables” like chlorophyll, lipids, waxes, cellulose, and other contaminants that also make up a part of the final product. Desirables are a valuable part of yield while the undesirables are non-performing components that lower quality and potency. Think of the desirables as gold nuggets in a bag and undesirables as sand added to the bag to make it heavier. The cornerstone of a meaningful yield discussion centers around accurately comparing apples to apples, or in our case desirables to desirables. Yield discussions get confused when concentrates with high desirables content get compared to other samples with higher undesirables content. This is where the important concept of potency clears the air by reporting the percentage of cannabinoids contained in any sample and giving us the ability to compare desirable content of different samples better. When we know the potency and the components contained in different samples we are able to compare apples to apples, desirables to desirables and know the real value of the end product and thus the real value of the yield number.
Understanding Different Process
Butane: A lot of people blasting butane at home come out with massive yields, often bragging about how great the process is. By now, we know anyone open blasting isn’t very smart to begin with, and we also know that they’re pulling tons of undesirables that artificially inflate yield. Good butane closed-loop systems (CLS) with dewaxing columns are usually much better, but cheaper systems or improper operation can still lead to some undesirable content. Live Resin made with fresh material and proper butane (butane/propane) process, on the other hand, is a great example of a very high desirables content end product with very low yields. The heavy wet weight of the fresh material makes the yield numbers very low, often into the low single digits.
Rosin: Rosin produces some of the most aromatic concentrates around due to the extra terpenes attached to its undesirables content. There are fats and waxes present in both the plant material and trichomes of the cannabis and hemp plants. The heat and pressure application used in the rosin process makes it very efficient at picking up undesirables that end up being a large portion of the yield. Rosin guys often claim these big yields then wonder why their banger is charred and the flavor is harsh. By squishing some form of kief rosin can eliminate the fats and waxes of the plant material itself, but it will still have fat and wax content from the trichomes. The extra fat and wax content is what holds onto the extra terpenes that would otherwise be lost if cleaned up to the point of a quality live resin. I’m sure a lot of rosin guys are going to get upset with this section but anyone can test the validity of my points two ways. First, take rosin you squish and dissolve it in ethanol in a 15:1 ratio and you will probably see the fats and lipids begin to precipitate out even at room temperature. To see the full extent of the undesirable content, put that 15:1 mixture in a freezer for 48-hours without touching it and filter out all the coagulated fats and wax to get a very clean, smoother, and higher potency end product. Second, simply test what’s left behind in the chips, pucks, and bags after they’ve been pressed and it’ll be clear how much was missed in the initial processing. The high yields claimed by many making rosin at home are simply not comparable to clean extracts.
Old School/RSO/FECO Ethanol Extraction: I’m a very firm believer of working with cannabis in whatever way anyone deems best for their own needs and however they enjoy because everyone’s interaction with cannabis is very personal and unique. However, you’ll run into all kinds of confusing misinformation on extraction topics with people saying “I’ve been doing this for 20-years and I know you have to soak the material in alcohol for days to get the medicinal value” which is complete nonsense in terms our current understanding of plant science. The trichomes contain the vast majority of desirables and very little exists elsewhere in the plant, with the exception of the roots.The longer cannabis soaks, especially at room temp, the more fats, waxes, and chlorophyll get collected and they don’t contribute positively to the medicine in any way, all they do is reduce the potency of the medicine and make it taste like a swamp. Some will argue the chlorophyll is good for you, which is true in general but pointless in extraction because there are only two kinds of chlorophyll on earth in all plants and algae and the chlorophyll in cannabis is not unique. Instead of polluting your concentrate, get the healthy chlorophyll from a better source like spinach, kale, and microgreens. Some will argue that the long soak is better because obviously more is better, but it’s simply not true. Another source of really bad information comes from people using ‘butter machines’ that have been terribly misled into believing they need the machine to chop the plant and have it pulverized in warm alcohol for many hours for reasons that make no sense. Those machines are designed for making soy milk and almond milk, not for cannabis and hemp extraction. There is nothing that indicates extended soaks are any more medicinal than shorter cleaner soaks but they are more efficient for obvious reasons. Long soaks will absolutely be more efficient in collecting desirables, but that comes at the cost of lower potency from picking up loads of undesirables, horrible flavor, and possible gastric distress. This kind of extraction is where the yield will be very high, but desirable content and potency very low.
*I anticipate some hate comments about this but I’m up for the debate.
Quick Wash Ethanol (QWET): ): The entire point of doing QWET is to avoid as much of the undesirables as possible to achieve the cleanest full spectrum oil possible to make shatter, wax, crumble, vape carts, and really clean edibles or topicals. This is the opposite of the old school/RSO/FECO ethanol extraction methods because it targets the desirables for inclusion and the undesirables for exclusion. Subzero temperatures are used in QWET to inhibit the ethanol’s ability to attach to chlorophyll, fats and waxes so when performed correctly should have a very low undesirable content and high potency. The main problem that people wrestle with in producing QWET is balancing the clean nature of the oil and the efficiency of the process. To make the very cleanest possible product you have to work at temperatures of around -40°F and some work down to around -70°F. The colder the temp the harder it is for the ethanol to collect undesirables but it’s also harder to collect desirables, making it difficult to maximize efficiency. To make up for the lower efficiency of low temperatures we extend the exposure time significantly, but you can only do so much at such low temperatures so you will end up with a high potency and average yields.
Cleanup and Recover Lost Yield in Rosin and QWET: Rosin and clean QWET both sacrifice efficiency and yield to achieve their desired end products, but the beautiful thing about the tradeoff is the oil that was sacrificed can be recovered. Processed rosin chips, pucks, and bags as well as the material used in the first pass of QWET can be soaked in ethanol to process a second time more aggressively to pick up the desirables left behind and realize the full value of the starting material. With this cleanup process it may have a higher content of undesirables but you will increase the combined overall total desirables pickup efficiency from the starting material by processing twice.
DO MACHINES MAKE A DIFFERENCE IN YIELD?
In many cases yield is effected by equipment and in others it’s not. This can mostly be split between equipment that loads plant material into it and those that don’t. Rosin has a number of considerations that make the equipment important to the range of possible yield, like plate material, plate size, heat, pressure and so forth. Closed loop hydrocarbon extraction and C02 systems yield expectations can vary by the quality of the equipment but more so dependent on the experience of the person running it. Conversely, ExtractCraft equipment and rotovaps are solvent recovery machines that simply process whatever’s loaded into them and have virtually no effect on yield at all, what you put in is what you get out.
PULLING TOGETHER WHAT THIS ALL MEANS
To make sense of any yield conversation you must have an idea of all the factors involved for the number to have any real meaning. Together the balance of the efficiency of pickup, potency, and overall yield provides us with the big picture and terms that allow useful comparison of different products and processes. There’s really no such thing as “bad, good, better or worse” in this balance of efficiency, potency and yield, there’s only what’s right for any person’s individual needs. Hopefully, with what I have shared here you will be armed with the knowledge to make good and informed decisions on what’s best for you.