News and Best Practices

Understanding Sample Testing, Part 3: Selecting Samples

October 4, 2016

Now that you understand the basics of lab testing, it’s critical to understand how sampling is done.

You’ve seen this already. You walk in to a dispensary, you find a strain that sounds appealing, and there’s a number next to it. It might say “20% THC” or something along those lines. But what does that mean, exactly?

The THC percentage is a measure of how much THC is in that product. If we say a bud is 20% THC, we’re saying—by weight—that 20% of that bud is made up of THC. That may sound like a lot (and quite frankly, compared to most strains, that is), but consider the bud should be relatively dry. The plant matter has weight, but not as much weight as the oils and fats—which is where we find THC.

Now, here’s the kicker: Is that value accurate? In short, no, it isn’t. And here’s why.

When businesses report their THC figures, assume those values were determined from just one part of the plant. If they’re clever, they would’ve selected buds from the bottom-most portion of the plant, and submitted that to a lab.

Why the bottom-most portion? The lower sections of the plant are the oldest. Since those sprouted first, those buds have been producing THC longer than the top-most portions of the plant. On any given cannabis plant, the highest concentrations of THC are found near the bottom, even in plants that were hung upside-down during the cure.

Unfortunately, no state has strict requirements for accurate sampling or reporting. Some states, like Colorado, require separate tests for individual batches (a “batch” defined as any harvest that used specific chemicals in its cultivation). But where those buds get pulled for sampling isn’t monitored by the state or by the lab. So that means the THC values we typically see on labels are the highest THC values available on that plant, not necessarily the actual values in what was sold.

Toward More Accuracy

How would we collect—and report—more accurate THC percentages?

First, we’d need to designate sections of the plant. Something along the lines of “top,” “middle” and “bottom.” This might be designated by branch count or by a millimeter measurement from the top down. That means we’d conduct at least three sample tests based on how high (or low) on the plant we pulled our sample from. We would report percentages only for those particular sections, even when those samples come from the same plant.

Second, we’d need to note which batches we pulled these values from. From a business perspective, sampling every single plant in a harvest is impractical—and expensive. From a statistical, scientific perspective, we don’t need to sample every single plant. We just need to sample a few from a single batch, then average those values.

Third, we’d require more open lab testing policies. In Colorado, one lab—The Good Lab—will test samples for consumers. Just about every other lab tests only for licensed businesses. Other states, such as Maine, also permit open testing, but only at a specific, non-permanent location.

Accurate results help your business

Right now, we usually see the term “top shelf” reserved for the pricier buds. Any business can say a particular product is “top shelf” and sell it for whatever price they wish. If consumers really, really want those buds, they’ll fork over the cash. That’s how capitalism works.

Now, imagine we have a hot seller. We’ll take Alien Rock Candy as our example. Because this particular strain has an incredibly deep and complex terpene profile, we can charge more for it. It tastes really good, its buzz is legendary, and it smells amazing. But what if your customers can’t afford—or just aren’t willing—to pay a top shelf price for your Alien Rock Candy?

That’s where the lab values for THC, CBD or terpenes come in.

If your results show that the top-most portion of your Alien Rock Candy batch has a lower THC (or terpene) potency than the bottom-most buds, you can charge less for the less potent buds while still charging top-shelf prices for the most potent ones. This way, your customers get more options, and you, possibly, could generate more sales.

In the end, just remember that lab results—as they currently stand—serve as general guidelines rather than tried-and-true reports. Testing is necessary to ensure that we’re dealing with safe products. But when it comes to potency values, there’s still a large gray area. We can anticipate that this system will change in the near future, especially as regulators and consumers grow more aware of these little nuances.

You can always use these changes to your advantage—and as an entrepreneur, you should.

By Randy Robinson
Dispensary Management Today articles are for informational purposes only and should not be considered legal guidance or advice on dispensary operations. You should contact an attorney or a qualified cannabis consultant for specific compliance and dispensary/retailing advice.
© 2016 CAN Performance Group, LLC. All rights reserved.


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