Introduction
Should we, as consumers, be concerned about buying wines from regions which have experienced wildfires? Why does smoke taint intensify as a wine ages? How can wineries mitigate the risk of producing smoke-tainted wine?
In this episode of the Unreserved Wine Talk podcast, I’m chatting with researcher Wes Zandberg.
You can find the wines we discussed here.
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Highlights
- Why does smoke taint show up differently in different wines despite the same level of exposure of the grapes?
- How can wineries mitigate the risk of producing smoke-tainted wine?
- Is there a health risk associated with wine made from smoke-exposed grapes?
- Why does smoke taint intensify with wine aging?
- Why does the perception of smoke taint become stronger with every sip?
- What are some similarities and differences between wildfire smoke exposure and the smoky aromas achieved with oak barrels?
- Are some grape varieties more susceptible to smoke taint than others?
- What are some of the main challenges in researching the effects of smoke exposure on wine?
- Were there differences between the wildfires in BC, California, and Australia wine country?
- Where is the current research focus for prevention and mitigation of smoke taint?
- How would routine testing of grapes in vineyards help researchers establish benchmarks for risk assessment?
- How could understanding more about the terroir of the air positively impact the wine industry?
Key Takeaways
- Should we, as consumers, be concerned about buying wines from regions which have experienced wildfires? As Wes observes, just because a wine region is experiencing wildfires or even smoke drift from fires farther away, it doesn’t mean that the wine will be tainted. Winery owners are not trying to pull a fast one over consumers by trying to sell tainted wine as it would ruin their brand. In fact, it’s the opposite in that a number of wineries have pulled their wines from the market upon discovering they were tainted.
- Why does smoke taint intensify as a wine ages? Wes explains that taint gets worse as wine ages because the wine develops new more subtle tertiary aroma compounds while some of the secondary aromas, and these may be bolder, diminish and these may have been masking the taint aromas, revealing what was already there.
- How can wineries mitigate the risk of producing smoke-tainted wine? Wes notes that Australia has pioneered these techniques such as making Rosé that’s not fermented on skins where the taint is. Smoke taint is less problematic for white wine because it too isn’t fermented on skins. He also says that winemakers can take it easy on the macerating enzymes to minimize the impact from grape skins on the juice.
- Fancy yeast may work, he adds, but it’s risky, as it’s difficult to predict how and why it works, and what may happen next time. Some winemakers have tried different fining agents or additives to absorb the smoke taint aromas with varying degrees of success.
- Picking by hand, rather than machine harvesting also helps since the grapes are more likely to arrive at the winery whole rather than crushed. It’s also gentler for even grapes not at risk of smoke taint so it often produces better wine. However, it’s more costly to harvest this way, so like most things in life, there are trade-offs.
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About Wes Zandberg
Before beginning his independent research career at The University of British Columbia (2015), Wes earned a PhD in chemistry at Simon Fraser University with Prof. B. Mario Pinto. Wes loved the rainy Fraser Valley so much that he remained at SFU, completing his post-doctoral research with Prof. David Vocadlo. This training instilled in Wes a fascination for glycoscience as well as a realization that the study of the structures/functions of carbohydrates (i.e. glycoscience) was—and still is—impeded by a dearth of suitable analytical tools and methods. Now, students in Wes’ lab at devise glyco-analytical methods that actually work for real samples rather than off-the-shelf model systems. Our research is highly applied and includes the analysis of milk/dairy products, mucus, fungi, seaweeds, placental tissues, and, of course, wine and grapes. Wes spends most of his “free time” shuttling his kids between sporting events and piano practices; he occasionally makes wine.
Resources
- Connect with Wes Zandberg
- Diary of a Book Launch: An Insider Peek from Idea to Publication
- Wine Witch on Fire Free Companion Guide for Book Clubs
- My Books:
- Unreserved Wine Talk | Episode 73: Women v Men Wine Tasting and Texture with Dr. Gary Pickering
- My new class The 5 Wine & Food Pairing Mistakes That Can Ruin Your Dinner And How To Fix Them Forever
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Transcript
Wes Zandberg (00:00:00) – Smoke taint intensifies with wine aging as you develop new tertiary aroma compounds and some secondary aroma compounds change. You remove masking aromas so concentration of everything else is changing to reveal what was already there.
Natalie MacLean (00:00:16) – I think you mentioned previously that once the wine is in our mouths, the perception of smoke taint can become stronger with every sip.
Wes Zandberg (00:00:24) – Correct. And smoke taint gets worse and worse and worse, and it dries out the back of your mouth. The bacteria in our mouth have enzymes that are like the yeast, enzymes that can chop the sugar off these phenols. And so we have our first sip and nothing much happens. But some of the bacteria go to work on the residual sugar bound forms. And then you have your second sip. And then they produce more. And by the third sip leads to an intensifying perception of the smokiness in the wine.
Natalie MacLean (00:00:57) – Do you have a thirst to learn about wine? Do you love stories about wonderfully obsessive people, hauntingly beautiful places, and amusingly awkward social situations? Well, that’s the blend here on the Unreserved Wine Talk podcast. I’m your host, Natalie MacLean. And each week I share with you unfiltered conversations with celebrities in the wine world, as well as confessions from my own tipsy journey as I write my third book on this subject. I’m so glad you’re here. Now pass me that bottle, please, and let’s get started.
Welcome to episode 292. Should we as consumers be concerned about buying wines from regions that have experienced wildfires? Why does smoke taint intensify as wine ages? And how can wineries mitigate the risk of producing smoke tainted wine? In today’s episode, you’ll hear the stories and tips that answer those questions in Part Two of our chat with Doctor Wesley Zandberg, a professor at the University of British Columbia whose research focuses on these issues. You don’t need to have listened to Part One from last week first, but if you miss it, go back and have a listen after you finish this one.
As I mentioned last week, I recently finished recording the audiobook for Wine Witch on Fire: Rising from the Ashes of Divorce, Defamation and Drinking too Much. I’ve been waiting on tenterhooks to hear back from Tantor, my audiobook publisher, whether my recording was up to par since I recorded it from my home office rather than going to a studio in Toronto. So I was surprised to get an email the other day from another division of Tantor saying that my publication date is July 30th. Holy smokes. I hope that’s true, but I still haven’t heard back from the sound engineers that were actually good to go. This timeline seems lightning speed compared to the paperback version, which was about two years from contract signing to publication, and that’s industry standard. Regardless, we’ll still have to do pickups in a week or so. Pickups are the areas where I’ll need to redo the recording. It could be a sentence. It could be a paragraph. The engineers send the original clips, why they want them redone, and then I have to try to match the emotion, sound level and distance from my microphone as I had in the original, so that the replaced sentence doesn’t sound odd compared to, say, the one before it or the one after it. I know in the end, all of this effort will be worth it.
The magazine Writers Digest believes that audiobooks have a longer shelf life than paperbacks and ebooks because the listening audience values the audible format over the recency of publication. So for those of us seeking to make a small part of the world a better place rather than riches and fame, this gives me solace. The challenge in getting the word out about the new audiobook is that its launch comes about one year after the paperback and e-book, so it can’t ride on that momentum. Plus, those who are audiobook consumers like me, probably like you, may have checked for that format upon release and didn’t find it and then assume it wouldn’t ever be available. I’m going to try to share the news about the audiobook by being a guest on other podcasts and radio shows, so please let me know if there are any podcasts or radio shows that you suggest that I contact in any of the following categories. Wine. Food. Memoir. Writing. Women’s issues. Women in business. Entrepreneurship. Mental health. Recovery. Bullying. Self-care. Relationships. Divorce. Yep. Been through ’em all. Been there, done that.
If you have any other ideas on spreading the word about the audiobook, please let me know. Every little bit helps spread the message in this book of hope, justice, and resilience. I’ll put a link in the show notes to all retailers worldwide at nataliemaclean.com/292. Okay, on with the show.
Natalie MacLean (00:05:30) – And so sometimes then do I understand correctly sometimes these bad smoke molecules can get into the grape, and then it goes through fermentation and still doesn’t express itself like it could be okay as well.
Wes Zandberg (00:05:35) – Yes. So this is really quite fascinating to me. I just actually simply don’t have the student power to do this work. You know, if you look up some numbers, concentration of these, we’ll call them volatile phenols, this whole class of smoky aroma molecules. If you look at the concentrations that are found in some oaked wines, they can exceed that which is found in a tainted wine. We did this. So in 2019, we got about ten wines from the Okanagan region that were all tainted. That was a Washington State fire that blew up and tainted a bunch of southern vineyards. And they don’t believe any of those wines were ever marketed except two. And they were marketed as tainted wines. So one was called Fumé Frank and the other was Smoke Show or something. And actually they sold pretty well, but they were deliberately labeled smoke tainted.
But we got these wines that were varying degrees smoke tainted. We had a bunch of different labs test the concentration of these aroma molecules and we did sensory analysis. That was done with my very kind collaborators in Australia. So they did the sensory on that. So we compare the chemical data with the sensory data. What I can tell you is that the numbers that our labs were getting for the volatile phenols were below what you would find in a heavily oaked wine. So that tells you there’s something else going on with the story. And so just to add to that, in ’20, I can’t remember the year of one year we had fires. ’21 I think. There were two side by side vineyards that I’m aware of just an hour south of where I am in Kelowna, and both of them on the same side of the road, were socked in smoke for about two weeks. One of them I know very well produced a horrid product. It was a Rosé. We can talk about why they chose to produce a Rosé a little while, but it was not good. And the other one, I talked to the winemaker and he’s a consultant as well and he knew that there was going to be a problem.
And so he said, well, you know what? We’re going to try a fancy yeast. He said, fancy yeast. And that wine hit the shelves. I bought a bottle. It was good, and it was all right, but it wasn’t tainted. And so if we put these two things together: if we know a heavily oaked wine in some, not all, but in some instances high levels of volatile phenols. And we also know that sometimes winemaker can use fancy yeast and he can hide the taint. And that’s the point. It’s not so simple as saying, well, the concentration exceeds this limit. Therefore, the wine is tainted because wines have other aroma molecules that can either positively or negatively influence the perception of the taint. And I think that there’s an important story here. What happens when wine grapes are exposed to smoke is the plants not only take the volatile phenols in, but they also get stressed out and they’re not producing the same amount of volatiles and other things that they normally would. And so what you get is a combination between yes, the phenol is in there, but also you have a grape of less fruity character, and there’s less things that are just simply going to mask the taint. And so I think we need to add that into the equation. And that’s not an easy thing to do, but I think that will allow for better risk prediction.
Natalie MacLean (00:08:50) – That’s a complicated but fascinating number of factors that are interacting here. So could it be in the future that if you use a fancy yeast and maybe plant more Syrah which tends to be smokier in nature anyway, and do a full bodied with oak aging you could help mitigate even when there are wildfires.
Wes Zandberg – Yes,
Natalie MacLean (00:09:09) – Like make it sellable at least I don’t know.
Wes Zandberg (00:09:12) – Yes. So Syrah I wouldn’t recommend here. It’s the least frost tolerant or Shiraz. So unfortunately all our Shiraz is dead now because it can’t handle the frost. But, I mean, now if we’re getting to mitigating, there’s some obvious things that wineries can do. And Australia has really kind of pioneered lists of tricks and things like that, but some are quite obvious. So for instance, we know that the majority of these phenols, however, they’re trapped in grapes. If they’re combined with other sugars or whatever, we know that the majority of them, over 50%, are stuck on the skins. All right. So first of all, if you can make a Rosé don’t ferment on skins. And that means also smoke taint is less problematic for white. It’s not absent but it’s less problematic for white wine which isn’t fermented on skins. You can also simply just take it easy on the macerated enzymes. Just minimize what you’re doing to the skin. And if you can, don’t machine harvest. Pick by hand and try not to bust things up too much.
Natalie MacLean (00:10:14) – Right. Because that’d be releasing them into the flesh of the grape if you’re heavy handling.
Wes Zandberg (00:10:19) – Yeah. So there are some things that can be done. Fancy yeast. I think it’s a great idea, but it’s risky. It’s not quite clear why that worked. And this instance it did, but it’s not something that you can easily extrapolate. And the wineries in the Okanagan here just talk occasionally to some people. They’re very, very inventive and have come up with, in some cases, some good solutions. How applicable they are to other settings yet, I don’t know. But some people tried different fining agents or additives that hopefully absorb the aromas. People in both sides of the border have tried reverse osmosis or tangential filtration or other attempts to mitigate and to varying degrees of success. So it would be quite interesting, I think, to get these people together and start to organize a little bit, because a lot of the stuff isn’t shared that widely.
Natalie MacLean (00:11:15) – Get more methodical about it. Can you actually wash the grapes, or would that be just to manhandling it or I don’t know.
Wes Zandberg (00:11:22) – Oh, have you been reading my grant proposals or…
Natalie MacLean (00:11:25) – Yes. Secretly I do a lot of preparation for these interviews, Wes.
Wes Zandberg (00:11:31) – So this is really interesting. So I have done some work on this and so has Australia where we deliberately smoked grapes in the field. We have some very kind, very generous vineyards that are willing to let irresponsible academics burn stuff on their vineyards in the middle of bad forest fire season. And so we deliberately bagged some grapes. We smoke them, we have control and things like that. And so we’ve done experiments where we smoked grapes and then cut them off the vine immediately and wash them. You can’t wash the phenols off. Australia has done similar things. They’ve even tried combinations of like water and alcohol to see if that works. And the best that I can see combing through Australian literature is you can’t wash it off. But that would be an obvious solution. I do believe you can – my students are working on this right now – so come back in a year or so and maybe we’ll have some answers. We’re working on this. I do believe you can. But the one thing is ideally where you would want to wash it off is in the vineyard before you actually pick it. So that’s the trick, because if you’re a really, really big vineyard, right, you’ve got grapes coming in on like 18 wheel semi trucks. They’re getting squashed on the truck. There’s no washing that. It’s just going straight into the crusher or the de-stemmer right. So you know things are a little smaller and more polite in Canada. And maybe you could wash things as things are coming off the field. But a big solution would be can we wash it right there in the vineyard? Can we wash it off?
Natalie MacLean (00:13:00) – Right. Just before I keep going here, I’m wondering though, let’s say we get a wine that is technically tainted with smoke, but we like the taste of it. Is there any health impact to drinking something like that or it’s okay. It’s still in that family of volatile phenols, like as if the wine had been oak aged. It’s all the same. Don’t worry about smoke taint, healthwise.
Wes Zandberg (00:13:22) – No, I don’t think. I mean these things like. Yes, we can perceive them, yes, but that’s just because we have an ability to perceive by smell something at such an incredibly low concentration. I don’t believe there’s a health risk there. We have also done some fermentation studies. So you could say, well, if these things are toxic, do they affect the yeast? Then you would expect to have the fermentation rate changed and things like that. That’s something we’ve never noticed. So it doesn’t look like it’s toxic to the yeast. And I don’t believe it’s toxic to us either. And besides, we get it from oak and tomatoes and ketchup and other things.
Natalie MacLean (00:13:59) – So really interesting. And you said fancy yeast. So the other question, of course, would be if that winemaker’s vineyard had not been exposed to wildfire and he used the fancy yeast, you wouldn’t know what it still have, would it turn the wine really weird. The reverse if it wasn’t being affected by smoke, wildfire smoke?
Wes Zandberg (00:14:20) – I don’t know about that.
Natalie MacLean (00:14:21) – Yeah, I don’t know. Have to do controlled experiments.
Wes Zandberg (00:14:25) – Yes, and also. Actually you have to do a lot of experiments because obviously these fancy yeasts are creating potentially masking aromas. This, by the way, is I believe a potential reason why smoke taint intensifies with wine aging. So it used to be thought, well, okay, so you have a pool of these volatile phenols in a great some of them are free. They’re just hanging out just like they arrived from smoke. But this is a minority. The bulk of the iceberg, you have a phenol that’s chemically linked to one or more sugars of various combinations, right. And so not all of that gets broken down by the yeast during fermentation. So even in the wine you have some free phenol, probably more than you had in the grape. And that’s what you perceive. But you have still a large pool of stuff that’s tied up with sugars. And so the thinking was, well, these can just slowly break down with aging. And then the taint gets worse and worse and worse in the cellar. The taint does get worse and worse in the cellar.
But Australian research has shown quite clearly, I think, that the actual concentration of the phenol in the wine isn’t changing. So that’s what Australia showed. We actually deliberately put these sugar linked forms in wine, corked it and then stored it for a while and then I measured it again. And I can tell you they’re rock solid. They’re really stable. So we get a gradual intensification with aging. What I think is happening is as you develop new tertiary aroma compounds and some secondary aroma compounds change and so forth, again, you remove masking aromas. So concentration of everything else is changing to reveal what was already there, just like fancy yeast could produce maybe some esters or something. We don’t know at this point. Maybe two phenyl ethanol or something like that. And then you just got enough that masks it or something. Right. So I think the same phenomenon happens during aging. And so, you know, again, this is kind of a tricky question. On the mitigation side. Is yeast always going to be the solution I doubt it.
Natalie MacLean (00:16:31) – Different factors at different points of the wine’s life. Just wow. And I think you mentioned previously that also, once the wine is in our mouths, the perception of smoke taint can become stronger with every sip. What’s happening there?
Wes Zandberg (00:16:46) – That is correct. And this is really why one of the obnoxious things about smoke taint. Like sometimes we like smoky aromas and it just smoky and it just sort of hangs out. But smoke taint gets worse and worse and worse, and it dries out the back of your mouth. And I think it’s called a retro nasal perception. You kind of smell it up the back of the nose there. And what has been shown I think reasonably well is that the bacteria in our mouth have enzymes that are like the yeast enzymes that can chop the sugar off these phenols. And so we have our first sip and nothing much happens. But some of the bacteria go to work on the residual sugar bound forms. and then you have your second sip, and then they produce more. And by the third sip, now you’re getting this big production of free phenol from stuff that was initially not really perceptible. And it just slowly leads to an intensifying perception of the smokiness in the wine.
Natalie MacLean (00:17:41) – Wow. Wow. Wow. Okay. And so then just to come back to the oak barrels in which wine is aged. They’re toasted in that they’re open at both ends and then they’re sort of sat over a sort of campfire, small little fire, so that they get toasted or charred on the inside to the degree that the winemaker wants them charred. Are these the same family of phenols as the wildfire smoke?
Wes Zandberg (00:18:08) – Yes, they are. And in some instances, the concentrations released from the oak into the wine may exceed that which is found in tainted wine. But there are also some differences. So okay, again one difference that I already mentioned was I think smoke exposure just generally reduces the fruity character of a grape and means that the grape can mask it less. Whereas if you have a really nice wine and it goes into oak, it’s even nicer. The other thing is I should mention that different kind of plant produce different relative concentrations of these phenols. So hardwoods don’t produce the same kind of phenols as soft woods which don’t produce the same kind as grasses and other shrubs that would burn. And this, of course, you know, people who like smoked meat or they like the old fashioned barbecues, right. So you would use mesquite or hickory or cherry.
Natalie MacLean (00:19:01) – Right. And they give different smoky tastes. Yeah. The source fuel. Yeah.
Wes Zandberg (00:19:05) – Yeah. Exactly. Because they have different combinations of phenols being produced. So hardwood is very different than soft wood. You wouldn’t ever use pine the soft wood to make a barrel.
Natalie MacLean (00:19:15) – Right. Is it because of the resin. Yeah.
Wes Zandberg (00:19:17) – First of all it’s resin. It’s softer. It’s not as waterproof. But even if you could find a really, really hard, waterproof, dense, soft wood, it would not produce the same suite of volatile phenols as oak wood. It’s unlikely that it would be the same desirable combination. And so if I look through the literature on what phenols are produced from oak and what phenols are produced from smoke tainted grapes, particularly from British Columbia where I am, there is some overlap, like maybe 40% of the phenols are the same, but there’s some really outstanding unique things. And those are a group of volatile phenols which contains a lot of crystals in them that’s responsible.
Natalie MacLean (00:19:58) – They coat the wood, timber, and you get that sort of acrid, tarry smell when you go past like a construction site.
Wes Zandberg (00:20:05) – Yeah, exactly. So when I look at my tainted wines, I have extremely small concentrations of crystals, but three different ones. Really really really low concentrations. These are not found in oak. I cannot see them in the literature and what we did. The few sort of correlative studies between sensory and chemical analysis showed very, very clearly that those crystals, which are really hard to nail down because they’re so low concentration, but those accurately are predicting the perception of taintedness. I should say so to sum up the whole idea about, oh yes, there’s some overlap. And so we know the story is not simply about absolute concentration, because otherwise barrel would taste like smoke and it doesn’t. So there are some mitigation due to the synergy with other desirable compounds. But at the same time, there are some very subtle differences right on the bottom end of the concentration range that I think might be responsible for the taint.
Natalie MacLean (00:21:03) – Right. And another mind blowing comparison or, I don’t know, not a statistic. Something you used before is that you keep saying low concentrations, but it’s the equivalent of one teaspoon of this smoke taint molecule in an Olympic sized swimming pool. And you’d pick it up like that’s incredible. Wow. Are there certain grapes that are more susceptible to smoke taint than others?
Wes Zandberg (00:21:29) – Again, you may have been reading my grant proposals.
Natalie MacLean (00:21:32) – You didn’t leave your door locked [laughter] last night [laughter].
Wes Zandberg (00:21:37) – This is a really good question. As far as I know, there’s really one paper that sort of looked into it in Australia, but they kind of smoked everything at the same time and then looked at the taint by some sensory studies and chemical. But I mean an obvious answer is white grapes are sensitive simply because we don’t ferment them on skins. Full stop. You would think that potentially thinner skinned grapes would be more sensitive. That is a reason why most of my work to date has been on Pinot Noir. The other reason being that it’s a more cold tolerant red variety. So it’s closer to where I am. I don’t have to travel three hours to do fieldwork.
But if we go back to the observation that there are differences in risk depending on what stage in the ripening process you are. And so to really answer that question, we would have to take different varietals of grapes and expose them to the same smoke at the same time in the ripening period, which is really, really hard to do experimentally, right. Like if you want to do this, you either have to wait for a fire to happen and then just sort of choose the different varieties without adequate controls or you’d have to take off some grapes and smoke them. If you do everything all at the same time, you might be able to keep the smoke the same. But now you have differences in the grape and if you want to get the grapes at the same time in the ripening cycle, then the smoke is going to be different. So this is a really, really tricky question to pin down, but I would love to give you an answer. We are hoping to do a little bit of this work. We think we can do it experimentally. More simply, I guess we could say that might let us keep the smoke more constant and then still address that question.
Natalie MacLean (00:23:20) – Sure. Well, all of these answers would go a long way toward mitigation if you can isolate these different variables. Let’s see, was there a big difference or not really between the wildfires in BC wine country versus California wine country versus Australia wine country? Maybe source fuel, I guess, but anything else?
Wes Zandberg (00:23:41) – Absolutely. Between BC and Australia and both in the fuels. So in Australia, you know you have these big eucalyptus forests and a lot of brush. And so the predominant fuel source is hardwood, which produces – we’ve done this; we know very well – it produces a drastically different suite of volatile phenols than the conifers that the pine and stuff that we have in BC and California. On top of that, a major issue in Australia is actually prescribed burns, where farmers that grow flax or barley and things like that, these agriculture residuals, they don’t compost very well at all. And so the farmers can’t just plow them back under the field. So like the leftover flax stalks and barley, it just burned up. It’s put into and they burn it. And if that smoke then blows into a nearby vineyard, then you get smoke taint. So obviously a solution there is to carefully coordinate when you do these prescribed burns. But my point is that the fuel source is different. And therefore chemically, what we see in the grape is quite different.
We know this. And also we know that if you talk to Australian experts, they will say the Australian taint presents itself differently than the kind of taints we see in North America. If you compare California to BC, again I am aware of some chemical differences. For instance, we never really see very high concentrations of these sugar bound forms. The literature is almost unanimously in agreement that this is how they’re trapped. We never see really high concentrations of those. California usually does. In BC, we have high concentrations of something that’s not free, but it looks like these compounds might be tangled up with other things that aren’t simply sugars. That’s not from what I can see the case in California, although the fuel sources I think are somewhat similar.
Natalie MacLean (00:25:35) – Right. In California, would they be more apt to be bound to sugar molecules? Because on average, California’s warmer. Therefore, the grapes are riper and have more sugars naturally. Sure could be. Just hypothesizing.
Wes Zandberg (00:25:50) – Yeah. No, it could be. I mean, I can think of that’s a perfectly reasonable hypothesis. You’re right. Yeah, it could be cool.
Natalie MacLean (00:25:57) – Okay. I want to join your lab. So you’ve mentioned some costs here. I was reading somewhere the cost to the Australian wine industry – I don’t know if this has been total aggregate over the years – has been 300 million due to bushfires. Or if that’s one year or. And then I think I’ve read or you mentioned the cost to the California industry, not just from one year, but over the years could be in the billions, which is just devastating. And I mean, Canada must be in between there somewhere, but it really warrants a lot more research and a lot more you should be getting your funding for all of this.
Wes Zandberg (00:26:31) – I think I have some, so I’m accelerating now. I have hired several excellent students and so we’re tackling some of these things now in mitigation I think is critical. And then second is prevention right.
Natalie MacLean (00:26:45) – Yeah. So mitigation you’ve mentioned a number of things. But go ahead.
Wes Zandberg (00:26:48) – Yeah. So I mean some things I can’t talk about right now because the work’s ongoing and it’s competitive. I’m sure absolutely.
Natalie MacLean (00:26:55) – I’ll sneak into your office tomorrow night. No I’m kidding.
Wes Zandberg (00:26:58) – I mean, I’m not the only one in the world working on this. And so but, we have some ideas on mitigation that we’re really excited about.
Natalie MacLean (00:27:07) – Like the targeted removal of volatile phenols and that sort of thing.
Wes Zandberg (00:27:11) – Yeah, yeah. So far, people are kind of hoping for the best, right. We try reverse osmosis. We try tangential filtration. Some people have tried ozone. That just destroys everything. That’s not going to work.
Natalie MacLean (00:27:22) – What is that? Ozone. What are you doing in that case or what are they doing?
Wes Zandberg (00:27:26) – I suspect they exposed the grapes to ozone before fermentation, but I can’t remember exactly. But I mean, it destroyed the actual smoky aromas but it destroyed everything else in the process. And that’s kind of the problem with a lot of these thing is you remove too much.
Natalie MacLean (00:27:40) – And so the remedy is worse than the disease or whatever that thing is.
Wes Zandberg (00:27:45) – Yeah. There has been some stuff published that uses something called molecularly imprinted polymers. That’s the technical term. Just think about this like a filter. The pores and the filter are exactly the shape of the molecule that you’re interested in removing. Then you can force it through. The issue is these are tremendously expensive and not reusable. But I like the idea. I mean, I think this is the way we need to go. And so we’ve got a few things on the go there as far as prevention goes. Obviously washing might be a part of that and we’re also very interested in potentially exploring agriculture sprays. So we kind of put a product on a grape that either blocks the phenol full stop or makes it more washable, right. Because right now we know that you just can’t wash it. It’s not going to remove it. But is there something already approved? There’s lots of products approved for use in vineyards. Can we find one that sort of protects the grape? And the flip side of that coin is if we don’t find any of that, protect the grape, at least we have some idea about products that make it worse. So this is work that we’re very interested in accelerating throughout the summer.
Natalie MacLean (00:28:53) – Well and then prevention is sort of upstream or three steps back. I’ve heard that wineries are cutting back dry shrubbery, making sure barbecues and other flammable materials are just secured and not giving that instance of sparking. And of course, we can do that too. As wine lovers, I mean, let’s not make our human error deliberate, like campfires and so on. Make sure they’re out. What else can either wineries do that’s preventative or we as wine drinkers?
Wes Zandberg (00:29:24) – Well, I mean, obviously a lot of the big problem fires are not actually close to the vineyard. You know, they’re caused by carelessness or sometimes maliciousness and a fire distant blows smoke in. But of course, I live in Kelowna, B.C. It’s hot and dry here, kind of like California. And you still drive around and you see people throwing their cigarettes out the window. And I was like, really, really people. This is so just that kind of behaviour change needs to happen. That’s bigger than just the wine industry. Interestingly, the idea about removing brush, like when we have these interface fires like we had last year.
Natalie MacLean (00:29:59) – What does an interface fire mean?
Wes Zandberg (00:30:02) – It just means there’s forest is so close to the city that it burns into towns. And what the big risk again is the ash. So ash will get flung and then somebody has a really nice cedar hedge right beside their house, and the patio is shaded. But that’s just like gasoline, right. Spark hits that and the cedar tree burns. And then the siding of your house is on fire. So there are things there that wineries are obviously doing as well, but more on the side of things where I’m working as an analytical chemist. This is actually how I was brought into this project. I should mention there is a company in Kelowna. They’re a for profit analytical company called Super Research and Development that was interested in making smoking tests that they could use for insurance purposes. So they said, hey, we want to help fund the PhD student, can you make a test? And so we got started on this on the analytical side of things. And I think at the time we probably made the best test in the world. I think we can improve on it. But at the time I think we made the best there was.
And I’ve already sort of explained all this about sugars, right? There’s some sugar that goes on. Sugar goes off. I’m a sugar guy. That’s my training. So this was an interesting merger of academic interest as well as sort of an economic one. But as a result of that, what we came to the realization was, was that nobody bothered testing their crop. If it wasn’t smoking, why would you why would you pay 100 bucks for a test if there was no smoke?
Natalie MacLean (00:31:26) – Oh, that’s right, until you have the problem.
Wes Zandberg (00:31:28) – Yeah, but these things are naturally present in some grapes. I already mentioned high levels in Shiraz. But other grapes have some of them too. So here we are. We made a test. We worked and worked and worked on it. And yet nobody knows what normal is. Who knows, right? And so you’re always comparing something to who knows what, right. And so you say, oh that’s high. Well compared to what? And so one thing I think vineyards can do is we can actually start to do more routine testing. So we can sort of establish that benchmark that I think is very important. And then internally, once we have a bit of a pile of data, now you can start tasting things and you can try to internally at least correlate with the objective chemical test is telling you about your subjective perception. So one other thing we’re really interested in is obviously if it’s a $100 or $200 analytical test, that’s going to handcuff how much willingness there is to do widespread testing across your vineyards. So another thing we’re very interested in doing is making these tests simpler. You can actually use your smartphone and a little probe and you can go to different spots in your vineyard and actually get some of the same benchmark information. This I think would be really, really useful to helping grape producers assess risk.
Natalie MacLean (00:32:44) – Sure. Oh, that sounds great. Wow. And I’m tied always to a happy ending. I know there’s been a lot of sad news between wildfires and frost, but I’m just wondering if there’s anything good that can come from wildfires. I mean, the thing that comes to me is that perhaps vintners and winemakers get to rethink what they plant and how they plant. Like if they had legacy vines that maybe now have to be uprooted, they really can think more widely, creatively perhaps I don’t know in terms of how they want to start from scratch. Is there anything else that might be positive about this?
Wes Zandberg (00:33:21) – Yeah. Two things. The first thing is really smoke specific, and that is we have shown that really it’s the freshness of the smoke that’s problematic. So in 2020, for instance, when California had its trial by fire, literally, we got all that smoke for a whole month maybe more right near the end, right at the beginning of harvest in B.C. and it helped the crop a lot. So we were all smoke all over the place. But what it did was it dropped the temperature and so it delayed ripening. And actually that was good because if it gets too hot your sugar concentration, your brix is actually high before the rest of the grape is mature. And so your grape quality isn’t that good. And we put a cap on it in late August and had fantastic grapes because the smoke cooled the climate and…
Natalie MacLean (00:34:09) – Without tainting the grapes.
Wes Zandberg (00:34:11) – Without tainting the grapes whatsoever. And again, that’s why I say we should say smoke impact. We could see that the phenols were there, but there was no taint. And the grape quality was fantastic. It was hidden beautifully. So this is one thing. So fire not necessarily always bad. Really, really close fire is probably going to be problematic. The other thing I would just want to leave your viewers is just this wild idea of mine. At some point, I’d love to pursue this. We’ve shown that airborne aromas can transfer sometimes over great distances, to grape and influenced the perception the quality of the resulting wine.
And in the case of smoke negatively. But it doesn’t have to be negatively. Can we think about the positive side of this? Are there things in the air that we can smell that are unique to a certain region or actually just pleasant that can transfer to a grape and then have an impact in the quality and the perception of the resulting wine. I think there is a positive side to all of this fundamental work that we’re doing. And you could call that terroir of the air.
Natalie MacLean (00:35:16) – Yeah or airroir.
Wes Zandberg (00:35:18) – Yeah, yeah. That’s great. So for instance, there has been some evidence that eucalyptus, the main aroma compound from eucalyptus tree, can be transferred to grapes in Australia. Now that’s debatable because it might be the case that grape can actually naturally make that. We need to dig into that a little bit. But think about other aromas, like in California, especially in B.C.where I am, all the grapes are produced in this really, really long, narrow valley surrounded by lovely conifer forests that all on a hot August day are putting out these aerosols that are all pine derived aerosol. Alpha and beta piney. And it smells like an air freshener, right?
Natalie MacLean (00:36:01) – Yeah. But naturally so. And it could be a greater signature.
Wes Zandberg (00:36:05) – What does that do to a grape? I don’t know. It might be there’s a positive airfoil here. And that would be really fun to tackle something.
Natalie MacLean (00:36:13) – It would be and it would make the place more placey, more there-ness because it’s coming from the natural environment. Just like wild yeast can settle on and then a lot of believers in wild yeast say it expresses more of the place because the yeast is from there. These air water molecules might make a wine more itself.
Wes Zandberg (00:36:32) – Yeah. And on that note, too, I mean vineyards are always playing around with cover crops and things like that. Like there’s a lot of actual manipulation you could think of if we could pursue this. So anyways, right now the economic concern is the taint. But I don’t think this story needs to stop at taint. I think there’s a positive side to that coin.
Natalie MacLean (00:36:53) – Oh that’s great. I love a happy ending. Thank you for doing that. It’s like I thought, oh, this is just going to be such a downer. But it’s fascinating. Good things can come from it. Oh my gosh, Wes, I love this conversation. Having gotten to all the questions I had for you, but is there anything we haven’t covered that you want to mention?
Wes Zandberg (00:37:12) – I think that’s about it. I can’t remember what I wanted to cover. I think it’s important again to leave your viewers with the idea that, yes, we can measure something. Yes, smoke does have an impact on grapes and wine that doesn’t necessarily always mean a taint. At the end of the day, you have to taste it and then you have a taint. And I think people should know that vineyards and wineries across the continent are not interested in permanently ruining their brand, so they’re not going to try to pull a fast one on consumers and say well maybe they won’t notice.
And so I don’t think people should worry that much that people are going to deliberately put tainted products on the shelf they’re not interested in a suicidal market move like that. So just because it’s smoky in BC doesn’t mean a BC wine is going to be tainted, because there are ways and I’ve tasted them – in fact, I’ve done the chemistry on the wines that I tasted made with fancy yeast. And I can tell you that the phenols are there and they’re not at all apparent by taste.
Natalie MacLean (00:38:17) – Yeah, I love that whole give the wine a second chance. So even if it is tainted, don’t assume this winery doesn’t make good wines. The taint may not have expressed itself when the wine left the winery. So I think that’s really important. Everyone deserves a second chance. So does a wine. But also, if you’re hearing about wildfires, check as to where those are, because often the wine country, if they are distant, you can still visit and they need your support more than ever from tourism, you know, especially after all the impacts this year. So don’t rule out visiting wine country just because it had wildfires in the past or you’re hearing about them now. They may not even be affected in that area. This is great, Wes. Where can we find you and your research online?
Wes Zandberg (00:39:03) – The easiest place to go to my employer’s webpage. I work at University of British Columbia, and then you’ll find me there and my email and other contact information. And that would be the best way.
Natalie MacLean (00:39:16) – That would be great. So fascinating conversation. I know we could keep going for another couple hours, but I guess you have some research to do. So there you go. Yeah, she gets it. Anyway, thank you so much for your time today, Wes. I really appreciate it.
Wes Zandberg (00:39:30) – You’re welcome.
Natalie MacLean (00:39:31) – Okay. Bye for now.
Natalie MacLean (00:39:34) – Well, there you have it. I hope you enjoyed our chat with Wes. Here are my takeaways. Number one, should we as consumers be concerned about buying wines from regions that have experienced wildfires? Well, as Wes observes, just because a wine region is experiencing wildfires or even smoke drift from fires farther away, it doesn’t mean that the wine will be tainted. Winery owners are not trying to pull a fast one over us as consumers by trying to sell tainted wine, as it would just ruin their brand. In fact, the opposite is true in that a number of wineries have pulled their wines from the market upon discovering they were tainted, even though it cost them thousands of dollars and the industry millions of dollars.
Number two, why does smoke taint intensify as wine ages? Wes explains that the tank gets worse as wine ages because the wine develops new, more subtle tertiary aroma compounds, while some of the secondary aromas, which can be bolder, diminish and these may have been masking the taint aromas, revealing what was already there.
And number three, how can wineries mitigate the risk of producing smoke tainted wine? West notes that Australia has pioneered many techniques, such as making rosé that’s not fermented on the skins where the taint is. Smoke taint is less problematic for white wine because it too isn’t fermented on its skins. He also says that winemakers can take it easy on the macerated enzymes to minimize the impact from grape skins on the juice. Fancy yeast may work, he adds, but it’s risky as it’s difficult to predict how and why it works and what could happen next time. Some winemakers have tried different fining agents or additives to absorb the smoke taint aromas with varying degrees of success. Picking by hand rather than machine harvesting also helps, since the grapes are more likely to arrive at the winery whole rather than crushed. It’s also gentler for even grapes that are not at risk of smoke taint, so it produces better wine. However, it’s more costly to harvest this way, so like most things in life, there are trade offs.
In the show notes, you’ll find the full transcript of my conversation with Wes, links to his website, and research the video versions of these conversations on Facebook and YouTube live, and where you can order my book online now no matter where you live. You’ll also find a link to take the free online food and wine pairing class with me called the Five Wine and Food Pairing Mistakes That Can Ruin Your Dinner and How to Fix Them Forever at nataliemaclean.com/class. That’s all in the show notes at natalie maclean.com/292.
Email me if you have a tip or question. I’d also love to hear from you if you’ve read my book or are in the process of reading it at [email protected].
If you missed episode 73, go back and take a listen. I chat with Doctor Gary Pickering, a professor at Brock University’s Cool Climate Enology and Viticulture Institute in Niagara, about tasting wine and his mouth feel wheel and super tasting kit. I’ll share a short clip with you now to whet your appetite.
Gary Pickering (00:43:00) – You are more likely to be a super taster if you’re a woman. It may be as high as twice as likely. Women have other advantages too. They tend to be better discriminators to be able to use words and vocabulary better to describe what they’re sensing than wine. We’re basically a lost cause us men, Natalie.
Natalie MacLean (00:43:17) – Well, that’s what I was getting at and I’m so glad you’ve joined us to help prove the point. This is really grossly generalizing, but if we think of men being more right brained spatially, math and women being more left brain logic, putting words to aromas, what you said really picks up on those generalizations. What do you mean by women tend to be more discriminating?
Gary Pickering (00:43:37) – The work suggests that when you have an odorant, an aroma compound at a particular concentration in wine, you don’t need to add as much before women will pick the two samples as being different, whereas you need a high concentration of that odour for men to be able to discriminate between those two smells. A woman can put more accurate and consistent labels on what they smell.
Natalie MacLean (00:44:05) – You won’t want to miss next week. When we chat with Sophie Menin, whose writing focuses on the myriad ways that wine connects us with our senses and the rhythms of the natural world. She and Bob Chaplin are co-authors of the splendid new book A Year In The Vineyard and she’ll join us from her home in New York.
If you liked this episode or learned even one thing from it, please email or tell one friend about the podcast this week, especially someone you know who’d be interested in learning more about wildfires and their impact on both the wines you drink and the environment. It’s easy to find my podcast. Just tell them to search for Natalie MacLean Wine on their favourite podcast app, or they can listen to the show on my website. Thank you for taking the time to join me here. I hope something great is in your glass this week, perhaps a vibrant Pinot Noir from British Columbia.
You don’t want to miss one juicy episode of this podcast, especially the secret full bodied bonus episodes that I don’t announce on social media. So subscribe for free now at nataliemacLean.com/subscribe. Meet me here next week. Cheers.
