How would you summarize your findings on smoke taint thus far?

Interview with SC Labs CEO Josh Wurzer

Interview Highlights

In recent years, wildfires have arrived as a frighteningly frequent new threat to numerous pockets of the planet. From Australia to North America, blazes of unprecedented fury and prevalence have forced industries of all stripes to consider how a wildfire-heavy future could impact their operations.

For obvious reasons, this issue is one seen as especially urgent by cultivators of crops like grapes and cannabis. Beyond the risk of facing flames directly, producers from California, Oregon, Washington, and Western Canada must also grapple with the realities of smoke taint damaging or outright ruining their harvests. While the specifics of the distillation process make it possible to salvage damaged cannabis flower for use in concentrates, such options are unavailable to vintners, making the matter only more dire.

Without an accurate way to test for signs of smoke taint, grape growers are left to choose between tossing an entire crop or forging ahead and releasing a product of unacceptable quality. If it’s not yet at the point of being full-out existential crisis for the industry, the day isn’t far off. That’s where SC Labs comes in.

Originating in Santa Cruz, California, SC Labs is a licensed laboratory specializing in science-first cannabis testing for matters of accuracy, efficacy, safety, and compliance. That’s something co-founder and CEO Josh Wurzer takes seriously. Now operating in partnership with Agricor and Botanacor Laboratories, the trio have formed what they collectively bill as “the most trusted cannabis testing network in the U.S.”

It was that reputation that inspired a notable neighbor with wine industry connections to ask Wurzer what could be done to better understand how smoke taint affects grapes — and the best methods to test for it. Along the way, he also gained some notable insights into how smoke taint may affect cannabis as well.

The results were published in a new study, though there is still much work to be done. Speaking with AMMA, Wurzer detailed the new test SC Labs is launching to detect smoke taint in grapes, what his findings may mean for cannabis cultivators, and how saliva can be a game-changer.

Tell me about the study SC Labs recently participated in and what you learned from taking part in that?

Absolutely. There’s doom and gloom, of course, because wildfires are a regular thing now, but I don’t think it’s completely doom and gloom for the wine industry. We found that just because you’re near a fire, that doesn’t necessarily mean that your grapes are destroyed. There’s is some middle ground there. Coming into it, we were primarily a cannabis testing lab. Since 2017, when there was a big fire in Santa Rosa, a lot of the processors have had issues with cannabis showing up that smelled like smoke. Then, when it was extracted, it was even more pronounced.

The first place we looked was in the wine industry, because there’s at least some work that’s been done in that field. There is obviously no work that’s been done on cannabis, specifically, for us to look at, so we looked for the major, published, accepted markers for smoke taint in grapes. With cannabis, I don’t think it’s a one-to-one correlation. It makes more sense in extracts but not the flowers — I’m just setting-up how we came to get involved with these wineries — so we developed that first part, then let’s fast-forward to this summer.

At our first lab, in Santa Cruz, our next-door neighbor was Pelican Ranch Winery. Phil Crews owns that and he’s also a major chemistry professor at UCSC. We have a good relationship with Phil. This summer, I did a little tour of our lab for some summer school class he was teaching with kids from Cabrillo [College] and then he approached me and said, “I’m having a huge issue.” He explained to me that smoke taint compounds are found in very low amounts, because as soon as these compounds come into contact with the grapes, they’re incorporated into those grapes. Each of the smoke taint molecules binds with a sugar molecule, so it becomes a different chemical.

Essentially, while these smoke taint compounds may land on grapes and cause an ‘off’ smell, measuring them doesn’t necessarily give you a good indicator of smoke taint because very few of those original compounds remain in their original form. What we discovered, through the study, is that we didn’t have a clear picture of how those bond compounds survive. We needed to know how many of these compounds could survive the fermentation process and, of the ones that did, how long they could last in wine. I’ll get to that in a second, but the issue was that even though the smoke taint compounds might appear in very low amounts on account of binding to sugar compounds, when you consume those grapes or their juice or wine, your saliva frees that bond. When smoke taint compounds meet your saliva, the bond that attaches the smoke taint indicator compound, which causes the bad smell or taste, is released from the sugar and thus you taste it. So, you can’t smell it on the grapes, you can’t measure it by testing for smoke taint compounds, but your tongue can detect them because your saliva cleaves that bond.

That’s what Phil brought to us: he wanted to find a way to get an accurate indication of smoke taint. He said, “The only place in the world that can do this test that looks for the bond compounds is in Australia.” The Australian Wine Research Institute (AWRI) has done pretty much all of the research to date, before we came along, on wine and smoke taint, because they’ve obviously had huge wildfire problems there and they have a big wine industry.

They’ve done their research but they’re the only lab in the world that can measure the bond compounds and Phil was complaining about how difficult the whole situation is for him. He can’t send raw grapes because of agricultural import rules, and it takes months for him to get his results back. He asked us if we could develop a test for these compounds because it’s very similar to the techniques we already use to measure pesticides and toxins in cannabis. So, we developed a test for him to be able to measure the results and we actually got it accredited.

Then Phil went out and collected all these samples over multiple years, so you’ve got samples from before and after fermentation in there. He’s got samples that were geographically centered around several different wildfires in the Sierra region. That gave us all these different types of samples and answers to all these different questions. He was collecting samples and giving us direction, and we developed the assay to do the testing, and then we did all the testing for that paper.

Like I said: we’re a cannabis lab. We didn’t necessarily intend to 100% offer this as a paid testing service, but since that paper came out, there’s been so much interest that we’ll probably get into the wine testing business a little bit here too.

The research on cannabis, meanwhile, remains ongoing because we don’t have anything to build upon and there are a lot of differences with the free smoke taint compounds. First, we don’t have all the sugars, so the compounds aren’t immediately getting incorporated. With grapes, they immediately get incorporated because their thin skin gets bound to the sugars and the grapes suck these compounds up, whereas if you measure the grape leaves, there’s very few of the compounds and that’s probably closer to cannabis.

These compounds may be landing on cannabis, which is a very sticky and resinous plant, and trying to stick to it. We have detected some of these smoke taint compounds in cannabis that’s been close to smoke, but is it a major quality issue at the same level? Probably not. But when you extract that cannabis and it’s going into an extract which will presumably be vaporized, well, now you’re getting a smoky flavor in that extract and it’s much more noticeable.

I think we’ve still yet to find the compounds to look for in cannabis and I think where we’re going to start focusing our research, going forward, is in measuring sulfur as an element in cannabis because a lot of the sulfur compounds cause that ‘off’ smell and, on top of that, a lot of people use sulfur vaporizers in greenhouse grows to keep molds and mildews away. They’ll vaporize elemental sulfur right into the atmosphere and that is a major issue for extractors. If you talk to extractors, they’ll tell you that the sulfur can come through in the extract and cause bad tastes and flavors. It could potentially even be a safety issue.

If people are vaporizing a good amount of sulfur, that’s not good. It will cause sulfur dioxide or sulfuric acid to form in people’s lungs. You don’t want to be breathing in a lot of sulfur. Anyways, that’s how this all came to be and how we how we ended up participating in this project.

SC Labs Seeks to Quantify Danger Wildfire Smoke Poses to Cannabis, Grapes

We established a normal background level for some of these compounds where there shouldn’t be an effect and some presence of these compounds is not necessarily indicative of contamination. We also established different levels of contamination with these smoke taint compounds. We reestablished levels for uncontaminated, lightly contaminated, moderately contaminated, and heavily contaminated, which allows the wine industry to have a bit more nuance in deciding which grapes are good and which are bad.

We also established that just because you have close proximity to a fire, that doesn’t necessarily mean you’re going to have gross contamination. We had several samples that came from nearby, moderately sized fires, and they only had small to moderate contamination. Then we have some samples that were near larger fires, and they had pretty bad contamination.

I think another takeaway is that, with this type of testing, wineries were able throw away fewer grapes. It allows wine producers to avoid disposing of grapes that aren’t contaminated but may have been near a fire. It leads to a lot less waste of the grape crop. Right now, you either take the risk of making bad wine and ruining the reputation of your winery, or you have to throw away grapes that may or may not be contaminated because the proper test isn’t out there and you can’t tell just from smelling the grapes. I can’t necessarily even tell from seeing them, in grape form, 100% of the time — especially if it’s only moderately or lightly contaminated.

This will help the industry and it will also help the insurance industry to know which claims to pay out on. It’ll help winemakers and the people producing grapes to collect on insurance claims in crop loss cases as well. It’ll help the industry to at least put some parameters in place for a phenomenon that’s going to be affecting us more and more every year. That’s why we’ve decided to make a test, commercially, because there’s so much interest.

We’re launching that this week, commercially, and then clients won’t have to send samples to Australia. I also imagine some of the more dedicated wine testing labs aren’t too far behind us. With cannabis testing, we’re still highly regulated. I think cannabis is a tough crop to test because it’s so resinous and that can lead to a lot of background noise in terms of the results.

Can you talk a bit more about why extracts are more susceptible to smoke taint than flower when it comes to cannabis?

We don’t have a ton of data on all the angles with smoke taint in cannabis. There’s a lot more work to be done and we’re going to continue that work. One thing we do know for sure is that some of the odors and compounds that we do see, that are traditionally associated with smoke taint, do make their way into the concentrates but there are things people can do. Since cannabis can be distilled down into just THC for a lot of purposes, there are ways to get those compounds out. If you do distillation, or if you run it through flash chromatography, it’s easier to chemically clean those extracts up after the fact. There are options for these manufacturers that aren’t there for grape producers or winemakers.

I can also only imagine that more accurate testing for smoke taint opens the door to better testing for other pollutants etc. that may become more prevalent in the years to come as well.

Absolutely. We’ve come across a bunch of interesting stories regarding the unintended consequences of environmental pollutants that have come into contact with cannabis plants. We are in California, Oregon, and we have lab space in Colorado too, and we’re testing at every facility for numerous environmental contaminants in cannabis. Every batch that comes through for the day is tested much more strictly and at a much higher level than pretty much any other agricultural crop I can think of. As a result, we see all these weird contaminants.

For instance, we had an issue with lip balms and anything like them where they kept coming up, for a long period of time, causative for a pesticide called coumaphos. Specifically, it was any balm etc. that had beeswax. We basically tracked the contamination back to the beeswax, not the cannabis, because people came to us right away and said they’d tested the distillate that went into the product, it came back clean, then after they’d diluted it into their product, it tested positive. The first thing we say is, “Let’s test everything else in your product.”

Good organic beeswax shouldn’t have any pesticides in it, right? The problem is that you can’t really control where the little guys choose to fly, so coumaphos is used. It’s a pesticide that’s applied directly to beehives, though it shouldn’t be applied to organic bees. It’s also applied to livestock. Different types of livestock will be sprayed down with coumaphos to keep the insects off them but what happened is that bees from beehives that were within 50 miles of any type of livestock would go pick it up.

Now all those producers are fine because when they source organic beeswax, they do a lot of questioning of the producer to make sure they’re sourcing it from bees that are more than 50 miles away from a livestock operation. I would also bet that if you were to go and pull any other lip balm or anything else that has beeswax in it — Burt’s Bees, whatever — and test it, there’s going to be a ton of coumaphos in it because they’re not required to test their products at the same standard cannabis products are tested at. The thresholds are different. There are allowable limits for environmental contamination and such that don’t exist in cannabis.

I’ve got a million more stories like that. Pretty much all types of cocoa come from volcanic soils and volcanic soils are very high in cadmium. That means a lot of chocolate products, especially if they have a high cacao content, don’t pass the threshold for cadmium contamination in California. It’s kind of my favorite part of the job: playing contamination detective and trying to source back some of these contaminations to the source. But a lot of this stuff has come to light thanks to cannabis because no other products are tested to this level.