Fudging Chocolate

Infused cannabis chocolates can be like… well, a box of chocolates: You never know what you’re going to get.

That’s the premise of recent findings from Bay Area scientists, who found that fats in chocolate are producing THC potency that’s different than what the products claim.

When you buy a weed-infused chocolate bar at a dispensary, it’s usually labeled at 100 milligrams of pot potency. That number is determined by mandatory California lab testing that all infused chocolate batches must go through.

But those lab numbers may be a little bit baked, according to Dr. David Dawson, research principal at Oakland’s CW Analytical. At one of the Bay Area’s longest-operating cannabis testing labs, Dawson has done quality assurance and testing for plenty of infused products. But he’s found something about chocolate that’s just nuts.

“You would not assume a phenomenon like this where the more you put in the vial, the more off your values are going to be,” Dawson tells SF Weekly. “That goes against basic statistical representation.”

Dawson presented his findings last month at the prestigious American Chemical Society conference in San Diego, detailing how larger volumes of chocolate in testing would show lower THC results, even when using the same chocolate.

“The more chocolate you put in the vial for testing — the more sample we are actually testing — the lower the calculated potency values,” he says.

This particular lab started testing more than 10 years ago back in the medical marijuana days, and mostly just tested buds for potency and pesticides. But new varieties of oils, tinctures, dabs, and the like present an advanced set of testing problems.

“Some products don’t follow the logic of analytical testing that everything else follows,” says CW Analytical CEO Dr. Robert Martin. “When the cookies and brownies and all of these other things started coming in, we saw a lot of variability.”

To make matters tougher, California has far more rigorous standards for cannabis products than for other items that require testing.

“The food industry allows 20 percent variability in any claim you make on a label,” he tells us. “You get a plus or minus 20 percent on a food label for all the vitamins, sugars, proteins, fats, and everything else in a product.

“In cannabis, we get a plus or minus 10 percent. That 10 percent is hard to hit. Whether it be Kraft or General Foods or Nestlé or any of them, none of them could hit a 10 percent in their production lines.”

The problem with mixing the psychoactive ingredients in marijuana with chocolate is that it causes what chemists call “matrix interference,” a change in the results based on the behavior of one of the factors in the mix. Labs are seeing more and more of this with exotic new infused products like essential oils, emollients,and lotions that create unpredictable results.

“They’re interfering with our machines and interfering with our chromatograms,” Martin says. “In a state that requires so little variability in the finished products, we’re concerned that some of the matrices are creating more variability than the state understands.”

These variations could have big implications for the producer of the chocolate, who might be forced to destroy their whole batch. Everyday cannabis buyers, though, don’t have much to worry about.

“This is not a public health crisis or anything,” Dr. Dawson tells us. “Maybe it is up to five to six percent discrepancies, where that chocolate might be five percent stronger than what was tested.”

That ten percent variance range means your “100 milligram” chocolate could have as much as 109 milligrams of THC, or as little as, say, 93 milligrams. But the additional X factor of chocolate variance adds new uncertainty to these numbers.

“Because of this phenomenon, if you have that five percent difference, the actual 93 milligrams might read as an 88 milligrams,” he says. “And that falls out of the range, so the producer would then have the batch fail.”

Sure, it’s a first-world problem to have to worry whether the labels are right on you marijuana chocolate bar. But it’s a sign that we could have more unknown flaws in letting the consumer know what they’re buying.

“If this is a phenomenon out there, who knows what other similar type of issues might be facing cannabinoid testing,” Dawson says. “In order for this industry to really take off and thrive, it needs to be built on a foundation of sound science.”