Vermont Marijuana: How To Test Homegrown Weed’s Potency

Photo Credit: Glenn Russell

A mild, barely discernable buzz — or a trip to the brink of impairment?

Recreational cannabis tokers have for centuries sought to dial in the right high, most often relying on anecdotal accounts of their pot’s potency.

With the advent of legal marijuana, discerning Vermonters can verify their hunches by testing the strength of a stash before they imbibe.

Home kits, available for sale online and rated by marijuana consumer advocates such as High Times, offer a discrete way to detect concentrations of THC, marijuana’s most significant mind-altering compound.

Before you set up your kitchen lab, consider that the Vermont Department of Health neither endorses nor makes recommendations regarding the use or accuracy of those kits.

According to specialists at the department’s Drug and Alcohol Abuse Programs, your do-it-yourself chances of getting reliable results improve if you’re familiar with sophisticated lab protocols.

After July 1, pot smokers will have easier access to more trustworthy data, courtesy local laboratories.

A quick whiff of caution for those who wish to calibrate their high: Taken alone, the percentage of THC in a batch is only a rough measure of how pot will interact with an individual’s nervous system, said Bridget Conry, director of marketing and product development at Champlain Valley Dispensary in Burlington.

More than a hundred other compounds in the cannabinoid family circulate in a bong-hit. In the absence of industry-wide lab standards, the properties of most are poorly understood, Conry said.

With that caveat, she noted that THC potency is a useful starting point in a discussion of how marijuana might affect a user:

As precise as you can get

Since 2013, the downtown dispensary has supplied marijuana buds, edibles, tinctures and salves to medical patients — and for the past three years has tested those products’ potency at its lab in Milton.

A drop-off service for flowers (or “buds”) at the dispensary’s affiliated Ceres Natural Remedies stores in Burlington and Brattleboro will soon be available for adult home-growers, Conry said.

Photo Credit: Glenn Russell

A test of the four major cannabinoid compounds in marijuana, including THC and CBD (a high-free ingredient), will cost a non-patient $75.

A test for four additional cannabinoids, many of which are thought to interact in subtle ways, and whose therapeutic and psychoactive properties are still being studied, will cost $125.

Flowers dropped off for testing should be cured to the moisture levels at which they will be smoked or vaporized, Conry said.

Later this summer, Champlain Valley Dispensary plans to also test the sex of home-growers’ young, pre-flowering plants, should a female-only (and therefore more potent, bud-yielding) crop be desired.

Although better informed, amateurs and hobbyists might still find that their buzzes stray from expectations, Conry said.

Marijuana’s chemistry (and the chemistry of most plants) varies according to differences in light exposure and soil composition, even if the crop is made up of genetically identical clones, Conry continued.

Carefully managed cultivation and processing methods deliver more consistent THC levels, she added.

Watch those numbers

Most of the buds at Champlain Valley Dispensary tout a THC content between 8 and 20 percent.

Within that spectrum, each strain’s potency is labeled within a four-percent range.

“We feel that’s realistic,” Conry said. “We’re dealing with a plant, after all.”

“Kali Mist,” for example, is rated between 12- and 16-percent THC. “Snow Drop” clocks in between 16- and 20-percent.
“Jack Herer,” a Dutch hybrid strain, boasts a 20+ percent rating.

At the other end of the potency spectrum, technicians at the Champlain Valley lab, as well as the Vermont Patients’ Alliance in Montpelier, test marijuana raised for fiber, culinary use or CBD products, to ensure that THC levels are low enough (less than 0.3 percent) to duck drug laws.

After legalization lifts the lid on recreational pot, the labs’ assessments of THC in higher-octane cannabis might — or might not — steer a user to the desired high.

“People have different tolerances. For some people, 7 percent is really potent,” Conry said. “We’re not health care professionals, so we can only offer general guidelines.”

The dispensary’s rule of thumb: begin with small quantities and low doses.

Depending on the circumstances, Conry reminds us, stronger pot isn’t necessarily better pot.

That’s a time-tested nugget of wisdom that might also apply to coffee, cigars, beer — even sunlight.