Introduction
What are the main causes of wildfires in wine country? Which two weather-based factors are the strongest predictors of the severity of wildfires each season? What impact do wildfires have on the taste of your wine, and why is it difficult to predict whether smoke-exposed grapes will, in fact, produce 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
- What sparked Wes’ interest in winemaking and wine chemistry?
- Why are BC wineries at a disadvantage coming out of 2022 and 2023?
- What are the main causes of wildfires in British Columbia?
- How much damage was caused by the wildfires in late 2023 and why were they worse than in the past?
- Why did the wildfires start so early in 2024?
- Which two weather-based factors are the strongest predictors of the risk of wildfires each season?
- How does fire play an important role in the forest ecosystem?
- How do wildfires affect wine itself chemically?
- What is the economic impact of wildfires on the wine industry?
- Why is it challenging to predict smoke taint through analytical tools alone?
- How does yeast activity contribute to smoke taint in wine post-fermentation?
Key Takeaways
- What are the main causes of wildfires in wine country?
In 2021, Wes notes that the BC’s Okanagan Valley experienced severe wildfires due to arson. There was also some suspicion that some BC fires were ignited by train wheel sparks and logging operations so the latter closed down in the summer, especially because it was so dry. The vast majority, though, of wildfires are started by lightning and human causes, both errors and malevolence. - Which two weather-based factors are the strongest predictors of the severity of wildfires each season?
Wes observes that the quicker snow melts and evaporates, leaving drier conditions, the greater the risk of wildfires. This is exacerbated if seasonal rains are below average, especially in June and July. - What impact do wildfires have on the taste of your wine and why is it difficult to predict whether smoke-exposed grapes will in fact produce tainted wine?
Wes explains that there isn’t a chemical test to determine whether smoke-exposed grapes will actually produce smoke-tainted wines, and even if it does, it may be so mild as to be undetectable. Smoke taint also doesn’t express itself in unfermented grapes, making it even harder to predict its impact on the wine. He and fellow researchers are working on tools to make detection possible and mitigating its impact.
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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 54: What’s Minerality in Wine? Plus California Wildfires
- My new class The 5 Wine & Food Pairing Mistakes That Can Ruin Your Dinner And How To Fix Them Forever
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Thirsty for more?
- Sign up for my free online wine video class where I’ll walk you through The 5 Wine & Food Pairing Mistakes That Can Ruin Your Dinner (and how to fix them forever!)
- You’ll find my books here, including Unquenchable: A Tipsy Quest for the World’s Best Bargain Wines and Red, White and Drunk All Over: A Wine-Soaked Journey from Grape to Glass.
- The new audio edition of Red, White and Drunk All Over: A Wine-Soaked Journey from Grape to Glass is now available on Amazon.ca, Amazon.com and other country-specific Amazon sites; iTunes.ca, iTunes.com and other country-specific iTunes sites; Audible.ca and Audible.com.
Transcript
Natalie MacLean (00:00:00) – How do wildfires affect wine itself?
Wes Zandberg (00:00:03) – This is one that’s really hard to pin down because smoke exposure does not necessarily lead to a tainted wine. In fact, finding molecules responsible for smoky aromas in your wine or grapes does not necessarily mean that the wine is not a good wine. So there’s a lot of murkiness about this and perhaps misunderstanding. But yes, definitely it is very possible that smoke from wildfires, in some instances distant wildfires can drift into a vineyard and in that post veraison period, grapes are most susceptible to leading to tainted wine.
Natalie MacLean (00:00:49) – 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.
Natalie MacLean (00:01:31) – Welcome to episode 291. What are the main causes of wildfires in Wine Country? Which two weather based factors are the strongest predictors of the severity of wildfires each season? And what impact do wildfires have on the taste of your wine? And why is it so difficult to predict whether smoke exposed grapes will, in fact produce tainted wine? In today’s episode, you’ll hear the stories and tips that answer those questions in our chat with Doctor Wesley Sandberg, a professor at the University of British Columbia whose research focuses on these issues.
By the way, I still have two copies of Jennifer Williams terrific new book, Sharing a Glass, to give away. Jennifer was our guest last week and the previous week. All you have to do is email me at [email protected] and let me know that you’d like to win a copy. I’ll choose two people randomly from those who contact me. If you haven’t won a book yet, now’s your chance and keep listening, as my goal is to offer lots more books and other prizes with every episode.
Natalie MacLean (00:02:47) – In other book news, it’s taken me a month to finish recording the audio version for Wine Witch on Fire: Rising from the Ashes of Divorce, Defamation and Drinking too Much but I finally wrapped it up at the end of May. I booked off about two hours a day most days to record 2 to 3 chapters at a time. And you might be thinking, wait now that your audiobook is 60 hours long? No, relax, it’s only air quotes eight hours, which is actually pretty average for an audiobook. So was I drinking while recording? I mean, what took you so long that you might ask? Well in the audiobook industry they talk about finished hours, meaning the actual length of the final book as opposed to how long the recording took. The latter is always much longer because of mistakes, mispronouncing or swallowing words, accidentally skipping a sentence, coughing, sniffing, snivelling, and all kinds of other fumbles. In fact, it becomes a celebratory moment when you can make it through just one sentence without a retake.
Natalie MacLean (00:03:54) – Woohoo! Try talking out loud for two hours straight, and you’ll start to get a feeling for what I mean. Your mouth and your throat dry out and tighten. The text starts dancing on the screens, kind of zooming in and out. Your legs feel like they’re going to buckle underneath you. I recorded the book while standing up, just as I do for this podcast, so that I have higher energy and my wild hand gestures don’t knock over my tea, the microphone, and anything else in my orbit. Plus, you’re not simply reading your book out loud in a normal voice. You are performing it for an audiobook as if you’re on stage for a live audience. So this intense process feels a bit hallucinatory at times, especially when you’re not a professional audiobook narrator. I used all the pro tools I could muster from sliced green apples and mint gum to make me salivate, but not too much to my favourite cool, smooth stone to hold when I thought I was losing it. I avoided dairy, too drying. Did some deep knee bends before starting to get my blood flowing. Fortunately, I had already read or mumbled aloud my book three times during the editing process. That was so painful. But that’s how you catch typos, overused words, and long winded sentences that leave the reader gasping mentally.
It’s also how you learn to vary the rhythm and tempo of your text by mixing short and long sentences. So that not only prepped me for the audiobook recording, it also saved me from the ghastly experience of discovering many typos when the book was already in print. There are industry horror stories out there of writers finding, yes, hundreds of typos that somehow slipped by the writers and their editors. That’s actually easier than you think, because our minds naturally fill in gaps when something’s missing, so that we can understand quickly what’s been written. Anyhow, I’ll have another update for you next week as we get closer to the end of this process.
Speaking of Wine Witch, have you read the paperback or e-book? If yes, well then have you bought a copy for a friend or family member? Please consider doing that if you’d like to support this podcast that I do on a volunteer basis to ensure continues, you can order it for yourself or someone else from any online book retailer now no matter where you live. It usually arrives in a day or two. And of course, the e-book is instant. It’s a fast read and every little bit helps spread the message in this book of hope, justice, and resilience. You can send a copy directly to a friend or family member via the online retailers, and I’ll put a link in the show notes to them at nataliemaclean.com/291.
Okay, on with the show.
Before beginning his independent research career at the University of British Columbia, Wes Zandberg earned a PhD in chemistry at Simon Fraser University. He says he loved the rainy weather so much in the Fraser Valley that he remained at SFU, completing his postdoctoral research. Wes is fascinated with glycol science, which will ask him about. As far as I can understand it, the molecular analysis of sugars and carbohydrates. And he has developed both analytical tools and methods for their study. His research includes the analysis of milk and dairy products, mucus, fungi, seaweeds, placental tissues and wine and grapes, which is what we’re going to focus on.Wes spends his free time shuttling his kids between sporting events and piano practices. He occasionally makes wine, and he joins us now from his office at UBC in Kelowna. Welcome, Wes. We’re so glad you’re here.
Wes Zandberg (00:07:53) – Thank you, Natalie, for having me. It’s a pleasure to be here.
Natalie MacLean (00:07:56) – Awesome. Great. Okay, before we dive into wine and wildfires, tell us a little bit about making wine. Was this in your home or at a winemaking facility? Just curious.
Wes Zandberg (00:08:08) – Yeah. Viewers are probably going to gasp when I say this, but I started making wine in graduate school.
Natalie MacLean (00:08:17) – With air quotes for those who are listening.
Wes Zandberg (00:08:20) – Because in the Fraser Valley, actually there’s ample blackberries, and I picked those and made wine out of that. So it’s debatable if anything fermented that’s not grape is technically wine. However, this actually did sort of spark in me a real interest in wine chemistry because quite obviously a berry or a plum or an apple or whatever is not a grape. And so this becomes an instance of chemical reverse engineering. What is missing in these other things that is present in a grape? And how can I tweak the conditions to make something like a blackberry Bordeaux or something like that? So honestly, that is how I got into making wine. I didn’t actually make wine from grapes until I started my smoke taint research. And then I’ve been making wine, of course, in the lab.
Natalie MacLean (00:09:08) – That is fascinating. Is anything unusual ever happened when you were making either the blackberry wine or the wine in your lab?
Wes Zandberg (00:09:15) – Oh, yeah lots of unusual things. I would say one of the most life threatening things happened to me while I was picking berries. I found that the cleanest berries and the ripest would be growing along irrigation or drainage ditches, along farmer’s fields. And I was happily picking next to a herd of dairy cattle one day, and failed to realize there was a rather irate bull in the field. I sprinted to safely actually and saved about three gallons of berries. So I think I have a record for fastest sprint through blackberry thorns carrying berries.
Natalie MacLean (00:09:48) – That’s something. That’s great.
Wes Zandberg (00:09:51) – So my work is on smoke taint, and we’ll talk about that in a little bit. But obviously one thing we do is we make wine from smoke exposed berries and hopefully controls. And we did that one year and then got a bunch of experts, some people that are better at tasting wines than me. And interestingly, this panel preferred the smoked wine to the non-smoked wine, which might actually say something about our skill and making wine, I’m not sure. But they could certainly tell the difference, but the preference was for the smoky one.
Natalie MacLean (00:10:19) – Wow, that is fascinating. And if you ever came up with a wine label or brand, maybe you have, but if you haven’t and wanted to create one, do you have any ideas of what you’d name your wine?
Wes Zandberg (00:10:30) – Oh yeah, I’m partial to BlackBerry Bordeaux. I’m sorry.
Natalie MacLean (00:10:34) – Oh that’s great. That is good. BlackBerry Bordeaux with a little wildfire on the finish. Cool. All right, so before we dive into wildfires, we should note just as a way of preface that this year is 2024. Well, 2023 going into 2024, in the winter was a really dry winter and the warmest winter on record in Canada. This encouraged an early bud break on the vines in British Columbia. Then the region experienced a severe frost in January up to -27 Celsius degrees, which really sadly killed the buds and 97% of the crop. While wineries are selling stock from previous vintages, this is going to have a ripple effect not just for this year’s vintage but for several years to come, since vines don’t recover from frost damage in just one year. So BC wineries are already behind the eight ball before the wildfire season has started. Do you have any observations on that aspect, or shall we just move right to the wildfires?
Wes Zandberg (00:11:31) – Yeah, actually, one thing I should mention is what you say is correct about the January frost killing a lot of buds. Actually, in the 2022-23 season, we had an extremely warm Fall. And then in December of that year, about less than 24 hours, the temperature changed, I don’t know, almost 20 degrees. And the vines weren’t ready. And so we had actually lots of vines actually killed. The whole plant was dead, rootstocks were cracked and things like that.
In this growing year, we were already planning a big replant in B.C.. What I should say about last year’s vintage, though. So we had this really big cold snap at December of 2022. The surviving grapes in 2023 were fantastic until the smoke came. That’s what we’re going to talk about. But the grapes that made it were good, so people were optimistic. And then this last winter, like you mentioned, we had this January cold snap that killed a lot of bud. So yeah, the industry here, it’s going to be lean. That is for sure that there are two interesting things about that. This is a little bit outside my expertise, but I am aware that there are hybrid varietals that are very, very frost hardy. And so actually there may be some wineries or vineyards that actually get reasonable crop from those. And the second thing I would point out is that there is research that I’m aware of going on in Canada on frost resistant rootstock and things like that, and I think there’s some promising leads there, although this isn’t my main area of work.
Natalie MacLean (00:13:02) – Sure, I understand that. And for anyone who’s curious or doesn’t know, hybrids are usually a cross. They’re not the traditional or classic vitis vinifera grapes like your Chardonnay or Cabernet and so on. They can still make good wines, but they tend to be like – Baco Noir is one. Vidal is another. Seyval Blanc. Those are examples of hybrid grapes that they are, as you say, more winter resistant, winter hardy, the vine stalk. Great. Okay, so apart from human error and lightning, how do a lot of these wildfires start or is that the majority cause.
Wes Zandberg (00:13:33) – That is of course the vast majority. In 2021 we had some pretty serious fires in the Kelowna region. Kelowna is in the middle of BC’s Okanagan Valley. And so the entire Okanagan, particularly the south, is where the majority of BC grapes are. So that 2021 fire really affected the Okanagan Valley because it was local. That was arson. So I wouldn’t call arson human error because like, it’s human malevolence or I don’t know. Yeah, those are the main ones. There has been some suspicion that some BC fires were sparked by trains so that we all sparks and of course logging operations can spark. But because of those concerns, of course, many logging outfits closed down in the summer, especially when it’s very, very dry. They just won’t work. But yeah, the vast majority is lightning and human caused.
Natalie MacLean (00:14:24) – Wow, wow. Oh my gosh. I can’t imagine why someone would want to do arson that’s beyond the pale. Oh my God, so much destruction. Oof! Okay, so let’s set the stage. What happened with wildfires last year? Like, kind of give us a high level scope of how much burned and how that related to wine country in terms of the damage.
Wes Zandberg (00:14:46) – Oh, wildfires just was horrid across Canada. I think the Canadian I think the numbers were like 16 million hectares or something like that. I don’t know how many acres that is. It’s just enormous. I mean, we obliterated the 1989 record, which was the last record, and I think it was just a dry early spring across the country. We had fires out east in Quebec, Ontario. And your viewers may remember that smoke drifted all the way down to New York City and other US states, even Pennsylvania. And that was very early. And Alberta and BC got involved with some massive fires. The numbers in BC were in the millions of hectares burned again due to, in part, hot, dry conditions. I should say it’s obvious that the hotter and the drier the forest is, the more combustible the fuel is and the faster the fire takes off. But also, as forest industry has developed in BC and also the United States, and also as areas have become more populated, it’s been imperative for industrial and safety reasons, especially for the past 120 years or so, to really rapidly put out forest fires. And before that would happen, forest fires would frequently just blow through our old growth forest. They’d clean the underbrush and the fuel, but they would never get into the crowns of the trees. And this was really good, because it kept the density of the forests from getting too thick.
In fact, many species of trees we have in B.C. at least don’t even release their seeds unless a fire goes through. They need that heat and that’s just part of how they reproduce. And so that was sort of the normal state of things. But as we suppress fires, the fuel burden increases. And in B.C. starting I think in the early 90s, I think maybe even earlier than that but we had several insect infestations. The worst was the Mountain Pine beetle and it destroyed millions of hectares of trees. So now the trees are dead and young trees are growing up. So what all this means is, yes last year was early heat and dry, but the fuel load is enormous. And so when you combine those things, it’s a recipe for a perfect storm.
Natalie MacLean (00:16:51) – Absolutely. And I love the term Fuel Load. Like all the dry brush, the dead trees that just builds up. And as you say, usually Mother Nature would take care of this naturally in the past. But humans have intervened. And fire suppression is not letting these fires burn where perhaps they should. And so it just it’s like a pent up demand. So when something goes, there’s so much dry shrubbery, so many dead trees, like it’s like an explosion.
Wes Zandberg (00:17:17) – Yeah, precisely. And I would say, having fire naturally go through and thin a forest was the norm. I think now the fire load just makes that untenable. You can’t even try to do it that way anymore.
Natalie MacLean (00:17:29) – Okay. Wow.
Wes Zandberg (00:17:32) – Now, what is required? And this would be something a forester would be more able to talk to. But I think we have to go into some of these areas where there’s just a lot of dead trees and use machines to get them out of there, because the issue is and this is what happened across Canada and also in the Okanagan near Kelowna where I am is when you get that much fuel on the ground, that fire gets so hot, then it leaps up into the crowns.
Natalie MacLean (00:17:56) – Are the tops of the trees.?
Wes Zandberg (00:17:58) – Yes, and in B.C., very similar to California in the conifer forests, you have all these conifer trees, and the crowns have got all these needles with all these oils. It’s like gasoline and the trees literally explode. And you get these massive fires that leap from crown to crown and they’re intense enough that these fires even create their own weather events. But that happens when the fire gets up in the crown instead of just stays on the ground and burns through.
Natalie MacLean (00:18:25) – They create their own weather events, that is they change the weather like they create smog and so on.
Wes Zandberg (00:18:31) – Well, that too, but I mean, I think they suck the oxygen into the fire at such a rate that it creates things like tornadoes and things like that. So we have in B.C., I know that we have instances where crown fires are so vicious that entire burning trees are yanked out of the ground roots and they’re flung across an entire valley.
Natalie MacLean (00:18:50) – Oh my gosh, by nature, just by force of the…
Wes Zandberg (00:18:53) – It’s just like the tornado. The whirlwind just pulls them out. We didn’t have something quite so serious here last year. But this is the real risk, right. Because when the fire gets that high in the trees, then you get embers and things that are launched miles. And that’s exactly what happened last year in August. Like I mentioned, we had a 2022 vine kill from frost. The surviving grapes were fantastic from all that I’ve heard. And then on August 15th, I think, on the west side of Okanagan Lake. So it’s about 140km long like that just runs right up the valley. And Kelowna is kind of straddled on both sides of that lake, right in the middle of wine region. We had a fire start on the west side. It just raced down the hill, burned a whole resort of about 75 structures or something like that. Just race down and on the east side of the lake. I mean, that’s a three kilometer, maybe a little bit more jump. Everybody was watching there and they were like, yikes, that looks bad. And then suddenly sparks just fly kilometers across the lake and it starts again. And so at the peak of that fire, I think we had 35,000 people evacuated, over 100 structures burned, and it was right next to some reasonably large vineyards. Of course, there was some vine damage, not a lot but some. But the big risk, of course, is we just had weeks and weeks during which the surviving grapes sucked in fresh local smoke. And that’s the big risk.
Natalie MacLean (00:20:22) – Yeah, and that’s where we’re heading to our discussion. Oh that’s incredible. Wow. It’s so visual. It’s like the special effects you would expect in a movie except this is real life. You know, fire, tornadoes and trees ripped out of their roots by oxygen getting sucked in. Oh my goodness. Okay, so although there were several small wildfires in April of this year near Oliver, which is also the Okanagan Valley. They have since been contained. The current wildfires near Fort Nelson are about 1400 kilometers away and this is as of June 5th, 2024. However, those in wine country are bracing for wildfires that could be worse than last year. Why did the wildfires start so early this year, Wes?
Wes Zandberg (00:21:04) – Well, the ones up north, mainly because we had an unusually mild and dry winter and this was predicted. We knew heading into this winter that it was an El Nino year.
Natalie MacLean (00:21:17) – And El Nino is what it’s the warm ocean currents that come up from South America.
Wes Zandberg (00:21:21) – I believe so, that the technical definition we would have to look at. But I believe if the ocean surface temperature stays above average for a certain length of time, it’s considered an El Nino. And that predictably affects the climate is especially on the West Coast. And it means it’s going to be milder. It actually in some parts of the West Coast, particularly California and southern B.C., it means we’re wetter and the normally dry parts got drier. And that was particularly pronounced up north where we had these early. And on top of that, the two big ones that I’m aware of, there was one in Fort Nelson and one in Fort McMurray, which is in Alberta, and the Fort Nelson one was sparked by power poles going down and sparking a fire. So we had sort of a dry condition and then a human caused fire. I guess you could say the Fort McMurray one, interestingly, was a forest fire that had been burning all winter.
Natalie MacLean (00:22:19) – Is that what they call a zombie fire or a hold over fire?
Wes Zandberg (00:22:22) – Yeah, actually I hadn’t haven’t heard the term before, but yes, that makes sense.
Natalie MacLean (00:22:27) – Zombie, the Walking Dead, they come alive again and as soon as the season returns.
Wes Zandberg (00:22:31) – So what happens is these fires are so hot that they can kind of follow stumps and roots under the ground, or they can get into peat, and then it just sort of smolders under a blanket of snow.
Natalie MacLean (00:22:42) – So it’s even without a lot of oxygen, they can stay alive. Well sort of.
Wes Zandberg (00:22:48) – There’s so little oxygen that it doesn’t flame, but it stays hot enough. But it stays hot. When the snow disappears, you get a fire pop up. And so yes, this is frequent, I think. And that was what happened in the Fort Murray fire.
Natalie MacLean (00:23:01) – Wow. Okay. And as well, like we’re saying, drier winter, I’ve seen sort of more technical terms like there was significantly less snowpack. So there was not a lot of snow had built up over the winter. And that can help mitigate some conditions, you know, especially that dry ground fuel. But that didn’t even help.
Wes Zandberg (00:23:20) – Yeah. So a wetter winter would be helpful. Drier winter increases the risk. What’s really, really quite important, though, is independent of whether it’s a wet or dry winter. What’s quite critical for this part of Canada in particular is how late spring is. So how quickly does the snow we have, whether it’s normal or not, evaporate or run off? And the second thing is, is do we actually get adequate seasonal rains? So actually in this part of the world it is naturally dry. But we actually have a bit of a rainy period in June trailing into July.
Natalie MacLean (00:23:55) – Right. And that’s peak fire season too isn’t it.
Wes Zandberg (00:23:58) – Well that’s just before it.
Natalie MacLean (00:24:01) – Oh just before it. Okay.
Wes Zandberg (00:24:02) – I think so. But that’s really critical because you could have a dry winter and then have adequate rains. So this is sort of the situation we’ve had in the Okanagan at least this year. We did have a dry winter, but we had a really, really cool wet spring. So that’s good. Now we could flip that and go into really hot, dry summer. But we’ve got some moisture in the ground now. That is not the case up north. And that is I believe, the influence of El Nino. So we have to keep two things in mind. Is the winter wet and is there moisture in the ground, but also do we just get the normal amount of seasonal rains, which does. Well, basically it doesn’t stop fire risk, but it kind of creates a more normal fire season.
Natalie MacLean (00:24:45) – Sure. Now again I know you’ve already mentioned forestry isn’t your expertise, but still it’s really helpful to really put this in a good framework. One of the things, if I understand correctly, is that the forestry service has satellites and drones that monitor these hotspots or zombie fires or hold over fires or whatever. And you can put them out. The best time of the year is January, when it’s cold and damp, I guess. But is that part of the ongoing kind of monitoring and has that been effective? What are your thoughts on that?
Wes Zandberg (00:25:19) – I don’t know, that’s a really good question. I mean, we do have technology, some of it’s satellite based where we can get a pretty good infrared picture of things. I don’t know if it’s just not possible to dig those fires out in the winter. It may not be, but I doubt that. I do also think that a lot of the fire service is disbanded in the winter because there’s less risk. So I think maybe because they’re not a 12 month year round organization, they just don’t have the resources. I don’t know.
Natalie MacLean (00:25:49) – Sure. Okay. Cool. So one of the strongest predictors of how intense the wildfire season will be is the late spring early summer rainfall season, which you’ve mentioned. This sets the stage for the critical peak wildfire season. Again, it’s okay if it’s outside your area of expertise, but do you have an idea of how much precipitation has to fall or to make a sizable, literally a dampening effect on wildfire season?
Wes Zandberg (00:26:15) – It depends. If you’re in a valley, I think in this part of the southern interior of B.C. – I can’t comment too much else – but I think about 30mm would be reasonable in the valleys and then a bit higher up. But like the high elevation plateaus, maybe 50mm would be a normal season and that would be mostly precipitation coming in June ish July. That would just create a normal risk, like a more usual. Yeah.
Natalie MacLean (00:26:42) – Right. According to one forester that I did communicate with him, thanks to you. He was saying that rainfall is harder to predict than other weather conditions, so that makes predicting wildfire season so difficult. It’s just harder for them to predict average rainfall, which can change. All right. So what do people misunderstand about the control burning of old forests. So we touched on it a little bit that it actually has to happen. But why do people resist that. Some people not everybody.
Wes Zandberg (00:27:14) – I don’t know. I mean it did naturally happen. And like I mentioned, this is really quite amazing to me. Some trees just simply won’t release their seeds unless they have the heat from the fire. Interestingly, burning plants create classes of compounds. They’re called corrections that are also like plant hormones that trigger plant growth. So fire is actually naturally sort of built into the ecosystem here. So I don’t think people would resist that, except now that is no longer tenable given just the density of fuel and the proximity of urban centers and things like that. So what I think might be a little bit more controversial though is, okay, well, we can’t maybe have frequent fires as part of the landscape management, but we can carefully log it or we can sometimes get machines in there and then thin things out and things like that. And I think there you’ll find more resistance. I do think that actually careful, well managed logging industry mimics many of the beneficial impacts of fire. So yes, you’re cutting down trees, but you’re thinning the forest out the remaining trees get more of the water and there’s less shade and less fuel and things like that for young seedlings. And the fire risk is lower.
Natalie MacLean (00:28:33) – Absolutely. Yeah. And I think this is just things that I’ve been reading in the news. But I do think that some people misunderstand just how much fire is integral to the circle of life in nature, and that some advocate just we have to save all trees, including especially old trees. But sometimes that’s not the case. It actually will sacrifice more of the forest if you don’t either let Mother Nature do what it’s supposed to do or control it in some way with strategic logging or whatever.
Wes Zandberg (00:29:04) – Yeah, I mean, this is a little off topic, but why not? I mean, if you think about it from a carbon perspective too, right. Old trees get sick. They’re no longer sequestering carbon from carbon dioxide. Young trees that are growing rapidly, they’re taking a lot of CO2 out of the air actually. So we like the idea, the mystique of old growth forest. But really, if you think of what we call old growth forest now is old growth, because we didn’t have those frequent fires coming through and cleaning things up. You didn’t necessarily have such dense old growth forests a hundred years ago, because fire comes through and cleans it up all the time. So there’s a lot of different facets to these questions of management and fire risk, that’s for sure.
Natalie MacLean (00:29:47) – Absolutely. All right. So I’ll finally get to your area of expertise. You’ve been a very good sport about this whole because I wanted to have the larger picture first. So beyond the actual fires themselves, either destroying vines or wineries or the infrastructure like vine posts and so on, how do wildfires affect wine itself?
Wes Zandberg (00:30:07) – Yes. So it’s the smoke from the wildfire that’s a big risk. And this is one that’s really kind of thorny and hard to pin down, because smoke exposure does not necessarily lead to a tainted wine. In fact, finding molecules responsible for smoky aromas in your wine or grapes does not necessarily mean that the wine is not a good wine. So there’s a lot of murkiness about this and perhaps misunderstanding. But yes, definitely it is very possible that smoke from wildfires, in some instances distant wildfires, can drift into a vineyard. And we’ve had it here where that smoke just settles in for 2 or 3 weeks at a row. And if that happens when the wine grapes are usually they have to be post veraison a few weeks.
Natalie MacLean (00:30:57) – So where they turn from that green to red or whatever colour they’re going to be when they mature.
Wes Zandberg (00:31:03) – Yeah. This is research that’s been done out of the Australian Wine Research Institute. They’re pioneers in this, not me, I have to confess, but they’ve shown that in the post veraison period grapes are most susceptible to leading to tainted wine. So I would say the biggest risk. And it’s also the hardest one to calculate because, you know, I can do some digging in the numbers. I do this if I’m applying for funding, right.
Everybody wants to see the bad news. And then I give them the solution. So I can tell you that mega fire event in California 2020, I believe, costed the industry about 600 million USD. Now that includes in California obvious loss of grapes and like the vines burned, it also factors in loss of tourist revenue and somehow, somewhere in there people try to put in smoke taint or smoke impact. But how do you calculate that, right? Like any decent winery in the States or Canada, if they find that they got smoky wine sitting in the winery, they’re not going to put it on the shelf. They’re not going to say oh well maybe my consumers aren’t going to notice. They’re not going to risk it. They’re just going to dump the wine and then there’s no insurance available. And so they don’t report it. And so how you put a number value on that, that’s quite difficult. But I would say hundreds of millions probably is lost due to wine that’s just simply not sellable because it doesn’t taste good.
Natalie MacLean (00:32:27) – My goodness. So what happens when smoke taint does affect the wine permeating the grape skin? It’s going in after veraison, after it’s turned a variation, after it’s turned colour. What is it actually doing? What happens and when does it express itself and what sort of you said it wasn’t detectable at first, but what’s happening?
Wes Zandberg (00:32:46) – Okay, so there’s a few things here. You may have to ask the question again if I don’t get to it. We talk about smoke taint, but I would like to propose a different word just to clarify things a little bit and that it would be smoke impact. So smoke is produced when biomass wood plants, among other things, burns and plants the major structural material and plant biochemist would call lignin cellulose right. So it’s basically lignin that’s like the stuff that makes plants waterproof. And the cellulose in other things is what makes it rigid. It’s kind of like the rebar of a plant. It makes it strong. And when those materials burn, particularly the stuff called lignin, it creates a whole bunch of different molecules. And these are called phenols. The simplest phenol is the phenol. And this is the antiseptic used in some hospitals. So that’s sort of sick sweet smell you smell in a hospital sometimes that’s the simplest phenol.
Natalie MacLean (00:33:42) – Its a molecule, is it?
Wes Zandberg (00:33:43) – It’s a molecule. Yeah. And then we have different chemical variations of a phenol. So different tweaks to the molecule a little bit. And they all smell a little bit different but they’re all incredibly pungent. And so we have things like Guayaquil. This is a very famous one. It smells smoky. And then we have chrysophanol. They smell ashy and things like that’s medicinal. And for ethyl phenol this is an interesting one. It’s produced by burning fuel. It’s also produced by spoilage yeasts like brettanomyces. And it’s responsible for wet taint, which is like the barnyard smell you get in some wines. So all of these are related molecules, and they can be produced when wood or plants and things like that burn. They can also be produced from oak barrels, which is maybe something we can discuss a little bit later. But these compounds, we’ll just call them volatile phenols because they’re volatile. They boil at low temperatures and because it can exist as gases at low temperatures, we can perceive them by our sense of smell very easily. They’re completely different than the other phenolic like tannins and the pigments that we have in one. Those aren’t volatile at all, okay?
Natalie MacLean (00:34:54) – They’re not airborne or they don’t boil at low temperatures, as you say.
Wes Zandberg (00:34:57) – So they’re somewhat related chemically because they share obviously the same kind of chemical groups. But there are differences that make one class volatile and therefore perceptible by smell. And another class is just not so. It influences the colour and the astringency of the wine, but not really your perception by smell. So these phenols, interestingly, some of them are naturally produced by plants, including grapes. So some grapes naturally have reasonable levels of these volatile phenols that are also found in smoke.
Natalie MacLean (00:35:33) – What would be an example of that? Which grapes naturally have a smoky kind of character?
Wes Zandberg (00:35:38) – Well, a very, very famous example would be Shiraz or Syrah has extremely high levels of a volatile phenol called single or some people say single, but single is very, very high levels in Shiraz they also have some glycol. And if you go to your wine textbook and look it up, if it’s an old enough book, they’ll say well that’s responsible for the spicy or the peppery smell of those wine. So it’s not necessarily unattractive. So these compounds can be naturally produced. Some of them anyways at some levels in grapes they also originate in wine from contact with oak, which is something we can talk about more in a little bit. But my point is that they exist in high concentrations in smoke, particularly fresh smoke, which then gets transported to a vineyard, and then those phenols responsible for the aroma of smoke are absorbed into the grape tissue, and we can sometimes detect them, which means the smoke impacted the grape. But its simple presence does not necessarily mean that that grape or that wine will be tainted because, like I’ve already mentioned, these can enter wines through oak and they can exist naturally at very high levels in some varieties, like Shiraz for example. So smoke taint, I would say we should be careful to use smoke taint for actually a glass of wine that you drank that is not good.
Natalie MacLean (00:37:04) – Smells and tastes like an ashtray maybe.
Wes Zandberg (00:37:07) – Yeah. But you can’t just do a chemical test and say, well, that is smoke tainted. Smoke taint I would keep for a subjective personal sensory assessment of the wine, because we can always show we have very good analytical instruments. That’s my job. So I can almost always detect things. But that doesn’t mean it’s going to influence negatively how you perceive your glass of wine. But this then gets to the really, really tricky bit about prediction. So I mentioned these phenols. There’s about 10 to 12 common ones that we look for with our analytical tests. And we know they’re in smoke. And we know that these things are responsible for the aroma of smoky whiskies, like a whisky or smoked meat, or even they naturally occur in plants like tomato and basil, right. One of the main things that gives basil its taste are volatile phenols that are also found in smoke. So they’re naturally there. One of the tricky things is when we have these exogenous phenols come to a grape, they’re absorbed. How they’re absorbed into the grape tissue is still under debate. But we know that they get in, they get into the grape. So you could say, well, this is very easy. I mean, I just test the grape. And if that volatile phenol concentration is high enough, then it’s tainted. But the grape just won’t leave those phenols alone. What the grape will do is a grape, especially if it’s ripening, is full of sugar, right? And it’s full of enzymes. And grapes will take the enzymes in the grape and the sugar and the grape, and they’ll basically put a sugar onto the volatile phenol.
They will make a new molecule. They will take a sugar and combine it with the phenol to make a new thing that has sugar chemically linked to it. And that’s not going to break down at all. And this is very, very similar actually, to how our body’s an animal for that matter, would detoxify drugs, right? If you take an aspirin or whatever you take and you eat that and your body will metabolize that by linking it to sugars, and then it’s usually excreted from the body, usually in your urine or something like that. And plants do the same thing to make things less toxic. This is a plant’s way of taking things that are somewhat dangerous to the plant, and making them not really offensive is very, very common biochemically, even, like I said in people. But what happens then is two things. One is you can take a single volatile phenol, just take quiet call. That’s one of the most pungent, okay. And just so you take glycol, but you can put many different combinations of sugar on there.
Not just one product is formed. So it’s really difficult to know what you’re looking for first of all. And second of all, if you take a phenol and put a sugar on it, the whole new thing that the plant produced is basically sugar, like, in other words, you can’t smell it. It’s not volatile, it’s just hanging out in the grape. Well behaved. You can eat that grape and it tastes perfectly fine, right. So you don’t actually normally have exceedingly high concentrations of these volatile phenols in smoked exposed grapes. It’s a really, really difficult analytical chemistry question. What happens then is you have grapes that taste fine. They smell fine. You don’t really have high levels detectable by the testing labs. So the winery goes to harvest those grapes and then they macerate and squash and they do all kinds of fun things in the winery. And then they add the yeast and the yeast has enzymes that are dedicated to breaking sugars off of things. That is kind of a requirement for fermentation, breakdown of sugars and things like that. And so yeast take these phenols that you can’t smell because they’re behaving more like the sugars to which they are attached. And the yeast breaks that sugar off. And now that free molecule is free again. And so what the big risk is grapes that smell fine, that then five months later, we’ve got 20,000 litres of tainted wine.
Natalie MacLean (00:41:07) – Right. Because the yeast has resurrected those smoke taint molecules and now it’s expressing itself, but only post fermentation. And as you say, they’ve already spent the money on harvesting the grapes, making it. And then they’re left with all this unsellable wine. Holy. Wow.
Wes Zandberg (00:41:23) – Yeah. And also, of course, wine is no longer a crop. So if you’ve picked it and fermented it…
Natalie MacLean (00:41:30) – Why is that? It’s not a crop?
Wes Zandberg (00:41:31) – Well, no. Grape is a crop. So if it’s on the vine in the vineyard, it’s considered a crop. So crop insurance applies. Once you’ve picked it, I can’t technically call it a crop anymore because you did something to it. So then you’re not eligible for crop insurance. Maybe there’s some other insurance. So insurers. If you suspect your grape is tainted but again you might not because it tastes fine and it smells fine and the testing lab comes back and says, your numbers look good. And a vineyard in my part of Canada, we’re not as hot consistently as California. We can’t produce the yields that the southern vineyards can. So vineyards here, wineries, they need every grape they can get. They might just harvest at risk anyways. But the point is, is that once you’ve picked it, there’s no real possibility of crop insurance anymore.
Natalie MacLean (00:42:17) – Wow. Okay. My goodness, that’s really painting them into a box.
Natalie MacLean (00:42:18) – Well, there you have it. I hope you enjoyed our chat with Wes. Here are my takeaways. Number one, what are the main causes of wildfires in wine country? In 2021, Wes notes that the BC’s Okanagan Valley experienced severe wildfires due to arson. That is almost unbelievable. There was also some suspicion that BC fires were ignited by train wheel sparks and logging operations, so the latter closed down in the summer, especially because it was so dry. The vast majority, though, of wildfires, are started by lightning and human causes, both errors and, as Wes says, malevolence.
Number two. Which two weather based factors are the strongest predictors of the severity of wildfires each season? Wes observes that the quicker snow melts and evaporates, leaving drier conditions, the greater the risk of wildfires, and this, of course, is exacerbated if seasonal rains are below average, especially in that critical June-July period.
And number three, what impact do wildfires have on the taste of your wine? And why is it so difficult to predict whether smoke exposed grapes will in fact produce tainted wine? Wes explains that there isn’t a chemical test to determine whether smoke exposed grapes will actually produce tainted wines, and even if the smoke does taint them, it may be so mild as to be undetectable. Smoke also doesn’t express itself in unfermented grapes, making it even harder to predict its impact on the wine. He and fellow researchers are working on tools to make detection possible, as well as mitigating smoke impact.
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 can 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 nataliemaclean.com/ 291.
Email me if you have a sip, tip, question or would like to win one of two copies remaining of Jennifer Wilhelm’s terrific new book, Sharing a Glass. I’d also love to hear from you if you’ve read my book or are in the process of reading it at natalie@natalie maclean.com
If you missed episode 54, go back and take a listen. I chat about wildfires in California. I’ll share a short clip with you now to whet your appetite.
Natalie MacLean – What is minerality when it comes to wine? Is it a taste, a feeling, or some bogus concept meant to keep wine? Mysterious? What’s the latest with the devastating wildfires in Sonoma wine country? And how will that impact the wines we drink? Why are winemakers wary of cannabis producers? It’s not what you might think. And what is a new wine group doing to help with a balanced life? That’s exactly what we’d be learning on today’s episode of the Unreserved Wine Talk podcast.
You won’t want to miss next week when we continue our chat with Wes. 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 the podcast. Just tell them to search for Natalie MacLean Wine on their favorite 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 BC Riesling.
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