Monday, February 5, 2018

Frontier Psychophysics: The Prequel


Image ©Avery Gilbert

 When I moved to Colorado in mid-2015, it occurred to me that there were two local olfactory opportunities that might be commercialized. One was cow manure, the other was pot.

When the wind is right, the unmistakable scent of manure wafts over Fort Collins from large-scale cattle feedlots many miles to the east and south of town. Having grown up in California’s Central Valley, the smell of manure is, to me, familiar and not particularly disagreeable. But immediately downwind of feedlots it can be pretty intense, and the cattle industry is interested in cost-effective ways to reduce it. I did a literature search and concluded that the problem has not been adequately attacked from my point of view, i.e., as a the fragrance industry would tackle a new malodor issue. I think a combined chemical and psychophysical approach could yield commercial innovations.

But the more alluring opportunity proved to be pot, newly legal in Colorado for recreational use and an industry that is growing at an exponential rate. I sniffed my way through the wares of local dispensaries and was amazed at the enormous olfactory range on display. Some strains reeked of grapefruit, others were dense and funky. Some were almost cheesy, others mildly hay-like or even piney. From a fragrance standpoint, there is at least as much going on in weed as there is in wine, beer, coffee, or tea.

But there’s a big difference. Those other agricultural products have a long history of aesthetic appreciation. They have fully developed olfactory lexicons (think, for example, of the U.C. Davis Wine Aroma Wheel). And they have chemical standards and training programs.

Cannabis, on the other hand, maintains an outdated, underground feel. Sure, there are aficionados who can be eloquent in describing the aroma of a given strain. But there is no organized, empirically-based, agreed-upon basis for describing the scent of weed. For example, in the various “Cannabis Cup” competitions, smell is one of many dimensions on which a strain is judged, but as far as I can tell there are no specific criteria for evaluating a sample’s smell. If sheep or chickens were judged that subjectively at the county fair, there would be a riot in the livestock pavilion.

I made some inquiries at the local campus, Colorado State University. I had excellent discussions about possible collaborations with faculty in the psychology and chemistry departments. The conclusion was always the same: cannabis research was impossible. Or to be more precise, a university that takes even one dollar of federal funding is obliged to play by federal rules. That means that in order to do cannabis research, one needs a DEA license to hold and handle the drug. One can use only federal money (NIH, NSF, etc.) to carry out the research—no private or corporate funding. And finally, and most disheartening, one can only use cannabis grown at the officially approved federal plantation in Mississippi. (This product is frequently lampooned as being a throwback to 1970s era weed—the low potency, twiggy, seedy, stuff that one “cleaned” on an LP cover before rolling into a doobie.)

By this point I had landed on a simple idea—to treat locally available cannabis strains as a just another consumer product. I would do routine sensory research to characterize the relevant odor descriptors, and see whether consumers could tell one strain from another based on smell.

That was my original idea. To make it happen, I had to blaze my own trail. I found an angel investor and created a new company: Headspace Sensory LLC. I wrote an entire research plan and got it approved by an independent institutional review board. I found an excellent collaborator in Joseph DiVerdi, a Colorado State chemistry professor with an interest in cannabis and his own private lab. With his help I found a genial landlord willing to rent me a couple of rooms perfect for sniff testing.

All the elements were in place. But I still needed to find volunteer sniffers. That would prove harder than I had imagined.

“A Very Distinct Smell”


“Marijawana’s bad, and it also has a very distinct smell, okay? I’m gonna pass around just a little tiny bit. Now, I want you all to take a smell, so you know when someone is smoking marijawana near you.”
Mr. Mackey
South Park S2E3

I published a new smell study today in the scientific journal PLOS ONE: Consumer perceptions of strain differences in Cannabis aroma. You can download a free copy here. Sure, there’s some statistics and chemistry, but anyone interested in smell—or weed—can read it and understand the results.

In the spirit of Hollywood prequels, I will describe in a subsequent post how the study came about.