Ξ September 4th, 2009 | → 4 Comments | ∇ A Day at a Time, Interviews, Technology, Wine News |
A few days ago I had the pleasure of speaking with Professor Bob Kreisher, president of Mavrik North America (MNA). After having written a piece on smoke taint some days earlier, it soon became apparent proper explanations of key elements were absent. It has been my good fortune to have been contacted by Dr. Kreisher, an ernest student of the subject. He offered very valuable clarifications. Indeed, he offered much more, as you may read below.
However, a proper word of caution. Mavrik is a private company. Much of the interview revolves around successful results implied by the use of a proprietary technology on unknown wines from unnamed producers. Further, I have not personally tasted any of the wines, either before or after MNA’s smoke taint removal process. Therefore this interview is in no way designed to give a competitive advantage to one of a number of companies associated with this general tech.
That said, the writer in me takes a particular delight in Dr. Kreisher’s charming thumbnail bio:
“Bob was born and raised in Indianapolis. He graduated from Purdue University the year it started its Enology and Viticulture program, completely unaware of this development. After many years in university administration, teaching, and consulting, Bob moved to California to help with the organizational design of an emerging winery. Meanwhile, Bob developed a keen interest in developing technologies of winemaking that are gentle and cost-effective to allow cutting edge cellar techniques that enhance the expression of terroir and winemaking, rather than reducing wines to similarity. After intensive research into available and emerging technologies, Bob formed MNA with Mariana Brown. In his spare time, he enjoys cooking, film, hiking, gardening, travel, and spending time with his family and friends.”
Still, questions remain. Most importantly, in my view, is that of a wine’s aging arc. Inasmuch as a given wine is purged of offending compounds involved in smoke taint only to the sensory level of a given set of tasters, might it be possible that the ‘bad’ molecules remaining will reassemble over time, and at some point cross the sensory threshold? And could this possibility hinge on the kind of smoke released or the grape variety? Since the research into smoke taint is still developing, dating largely from 2003, it must remain uncertain, as a practical scientific matter, whether long-aging wines will show smoke taint or some other as yet unrecognized gustatory artifact in later years. After all, a comprehensive explanation of a wine’s chemistry has yet to be written. How is it that residual smoke taint molecules would not deserve a chapter? But this is a matter of pure speculation on my part.
Here is a relevant doc from MNA. MNA Smoke Taint Standard Operating ProceduresMB090715
On to the conversation. I spoke with Dr. Kreisher the morning of August 31st.
Admin Good morning. I understand you’ll soon be on your way to UC Davis. What is the purpose of your visit?
Dr. Bob Kreisher It’s a, I don’t know if conference is the right word, a symposium, let’s say. The Trellis Alliance is bringing Kristen Kennison from the Australian Wine Research Institute (AWRI) to speak and to share some of her research.
Yes. That would make sense. Since the first smoke taint post my blog has been visited by a series of Australian universities.
BK Curtin and the University of Adelaide, I would assume.
Yes. And I’ve interviewed Andrew Yap about his company, Cavitas, and Forensics specialist John Watling, for example, both on unrelated matters. A few others.
BK Great. They’re certainly years ahead of us when it comes to smoke taint. I’ve told a lot of customers this. I’m sure that the Australians wouldn’t feel the same way about this, but we’re really fortunate that they got to endure a lot of the really bad taint, and then figuring out just what the heck was going on and what to do about it.
Just out of curiosity, why do you think it is that the Australians are so far ahead of the US when it comes to research in these kinds of matters? It’s not simply smoke taint; it’s all kinds of wine related subjects.
BK Well, that’s true. But the big thing with regard to smoke taint is simply that they started to experience serious problems with widespread brush fires near vineyards. I’d say probably 2003 is generally considered to be the first year. Certainly the Australian Wine Research Institute is doing much of it, though it’s not only them. I think it’s that there’s a lot more money that’s being provided, for whatever reason.
Yes. It also appears the Australian research model is quite different from the American model. The Australian university system actively hires entrepreneurial outfits doing primary research, and provided they teach, assume a certain teaching load within the a given university, they could continue doing proprietary research on university grounds.
BK Yeah. I don’t know the model real well but I’ve been to the AWRI. One thing they’ve made very clear is that, although I think they were established with some public funds, they are completely self-sustaining. And AWRI operates a lab that charges for services.
So about the issue of smoke taint itself. First of all, what can you say about the varieties of combustible material. I’m thinking of eucalyptus forests as opposed to manzanita brush, a pine tree forest… are the chemical signatures of smoke substantially different with respect to the smoke taint of grapes?
BK Well, I don’t know that anyone knows the answer to that question definitively. But I can tell you this, I’ve had the opportunity to taste smoke tainted wines both in Australia and here. Obviously in Australia there’s a predominance of various eucalypts that are burning in most of the regions. And here there was probably some minor participation by eucalyptus; it was mostly manzanita, pine and redwood presumedly from of the fire up north. So the taste is pretty much the same. My cross-section here in the US is much broader than my cross-section in Australia, but I don’t notice any substantial differences. And I don’t see anything in the sensory literature that suggests that there are significant differences.
Early on some people were saying ‘Oh, it’s not going to be a big deal here because we don’t have eucalyptus.’ The truth of the matter is that eucalyptus next to a vineyard can and will impart eucalyptus oil to the skin of the grapes. And we’ve actually done some work removing that as well. But that’s a direct entry. Well, it’s not even an entry. It’s something that gets on the skins rather than something that’s in the skins.
So that’s a broad way of saying I don’t really see any reason to believe that there are significant differences. Which is not to say that there are not fine distinctions. It probably even matters what temperature a fire is burning at, how much moisture is in the wood, things like that. But when it gets right down to how the wine tastes, how you get the taint out of the wine, it doesn’t seem to me that there are any significant differences.
I’m wondering about the variety of grape and how it evolves in the bottle, that there might be different expressions from different smoke sources over time inasmuch as the chemistry in a bottle of wine is on-going, especially in an unfiltered wine.
BK There’s not. There’s both a good reason to assume that there wouldn’t be and also observational evidence that there’s not. I’ll talk about the first one first. The reason one would assume that would not happen is that, first of all, due to the very nature of their origins these compounds are the most simple form that is available. So what that means is that they’re not likely to be spontaneously generated from precursors say the way ethyl acetate is an oxidation product of ethanol. They’re not likely to react chemically speaking.
I do think there are important chemical interactions, but they are not likely to react with other components in the wine and evolve in that sense. We do know fairly well that they simply do not respond the way other phenols do in terms condensation or polymerization. Micro-oxygenation, oak chips, you name it, these phenols do not seem to take part in those processes, polymerization or condensation.
So the process of removing the offending elements from wine is not time sensitive? It can be done at any point in the vinification process? Or afterwards, even if its been sitting in tanks?
BK Almost! Not quite. Chemically speaking, from about the third or fourth day of primary fermentation the level of the taint is going to remain at least very similar. I’m not saying that it won’t change at all but that it’s not going to change dramatically. The sensory qualities, though, and no one has a good explanation for this at this point, but the sensory qualities do not seem to stabilize until after malolactic fermentation. There just seems to be this magic number of six weeks after ML completion that just seems to do it. And everybody I’ve talked to, I mean people are just blown away when they start to say ‘Oh, I thought the wine was fine, and then it started to show some character’. And I say ‘Six weeks after ML?’ They’re like, ‘Yeah! How’d you know?’ It just seems to be extremely consistent in that regard.
The reason I’m focussing on ’sensory’ is that you can remove the compounds no matter what stage of the wine’s life it’s in. The only reliable means, at this point, of determining the end point of processing is sensory. So if you were trying to do that before the completion of ML you’re shooting in the dark. You really don’t have anything to go on.
Now, the function of your technology is, of course, to remove the offending molecules, whatever they may be. Smoke is a very complex mixture. But if the analysis in the end is fundamentally sensory, then have you done experiments to determine in fact how much is removed? Are they, the tainting compounds, completely removed? Partially removed? Is your target exclusively sensory level analysis and not a molecular level analysis?
BK The target is sensory at this point. There’s simply no means in existence of making a molecular or chemical determination of the end of processing. Guaiacol and 4-methyl guaiacol are merely marker compounds. After processing they’re pretty useless. In fact, it’s one of our goals not to remove wholesale quantities of guaiacol and 4-methyl guaiacol because these are desirable compounds, especially at this stage, a year after harvest. A lot of people have intentionally put them into their wines through barrel aging, chips or whatever. And so, one of our goals in terms of the characteristics of our adsorptive media, is to not remove those compounds in significant quantities.
There is simply no means of determining that [making a molecular or chemical determination of the end of processing]. That said, we have been suppling samples to Davis. So far as I know, I don’t know it they are doing much with them yet. They’ve been looking for funds to get them on the HPLC [high performance liquid chromatography] because that costs them some time. It’s not owned by the department, I don’t believe. They have to essentially rent it from whatever unit of the university owns it. Anyway, we’ve been providing them with samples after processing with no markers as to where they came from; providing them with samples to analyze, to try to determine and identify some of these compounds. That’s an on-going struggle. I know that the various entities in Australia have tried the same thing. It’s not an area I know a lot about. I may know more about it this afternoon after meeting Kristen Kennison! I don’t really know the state of the art at this point.
With respect to your technology, Mavrik’s technology, how was the tricky matter of the molecular weights of the associated chemical compounds resolved? I know many of them are quite close. So it seems the adsorptive technology would remove all kinds of compounds in addition to the targeted compounds.
BK Well, that’s not entirely true. The first thing you said is true; that relatively speaking they are very close in molecular weight. That presents a challenge. But it also presents an opportunity in that we don’t have to take a huge broad sections of the wine for treatment. We can take a very narrow cross-section of the wine for treatment. That said, different compounds adsorb at different rates on different media. Even carbon, which is one of the less discriminating media, just won’t adsorb some things at all. And even when you’re talking about carbon, there are many different kinds of carbon with different sized macro-pores, different surface electrical qualities; there are ways of modifying any kind of absorptive media, chemically, electrically, etc. to make them behave in different ways. And so, is it a perfect process where you can hone in on something excruciatingly specific? No. But there are ways of figuring out what is in this permeate that we want to keep and don’t want to remove, and trying to find ways to leave that relatively unmolested.
About the only thing we’ve never been able to completely exclude is carbon dioxide. We feel pretty fortunate about that because carbon dioxide, of course, in the early age of a wine, removing carbon dioxide can be very desirable; and in the later stages, like now, we can remove too much carbon dioxide. But the beauty of it is that it’s both easy and legal to add back, and is considered to be a completely inert process, adjusting CO2. Almost everybody does it before bottling.
From a marketing point of view, is it your experience that wineries are reluctant to have their names associated with a smoke taint removal process?
BK Oh, sure! From a marketing standpoint my experience has been that wineries are reluctant to have their name associated with anything that doesn’t seem sexy and natural and hands-off, and so on. That’s a much broader spectrum but, yeah, sure. Wineries don’t have flaws! Wineries make perfect wine, vintage after vintage, and that is all the consumer needs to know!
It’s the nectar of the gods, after all. (laughs)
BK Exactly. Exactly. (laughs)
Just out of curiosity, what would you say (I suppose this is a political question), but what would you say to those who are biodynamically inclined or hardcore organically inclined, those with a spiritual ‘dog in the fight’; how would you characterize your process with respect to ideas of ‘naturalness’?
BK Sure. I would say, all in all, all of our… well, several things. First of all, the process is CCOF approved. Any organic winery can use it. Yes. And in fact, many have. I don’t know how Demeter would look at the process. I really have no clue. But I can tell you that biodynamic wines have been through our process. Those wineries, it did matter to them. When we did the wine, and I think it probably had to do something with lunar cycles and things they map out, certain days for certain things; I don’t know a lot about that so I’m not going to say exactly how that influenced it, but I do know it was important to them when we did the work. So, with that regard, it’s something that’s already pretty straightforward.
The question of ‘naturalness’… there are people that are going to find the notion distasteful no matter what. But when you get right down to it, every material, everything used here is excruciatingly inert. The machines are made out of stainless steel, and I don’t think anybody has issues with stainless steel these days. Or completely natural, like coming from natural materials. At the end of the day people don’t find the process very sexy but there is nothing here that is bizarre or out of this world, or that gets left behind in the wine when the process is finished.
Many of the concerns revolve around the politically charged notion of manipulation, with a capital M.
And that is one of a suite of cultural terms that ‘interferes’ with a number of technologies, for good and for ill.
In your email to me you mentioned that blending is never… rather, it’s a long shot…
BK Let me interrupt. Sorry about that, Ken. I just want to go back and say one thing just to be sure it’s clear, because the CCOF asked me to be very clear about this. The process is CCOF approved. You can’t use the phrase CCOF certified. It means something completely different. I don’t know what it is but they asked me to be clear about that in my language. So if I’m going to get quoted somewhere I’m going to ask you to use the word ‘approved’ and not ‘certified’. Sorry to interrupt! I just wanted to be clear about that.
No worries. It’s quite alright. I’m going to change the subject actually, from blending to something else. The process, is it different for white wines?
BK No, not really, except for the fact that it tends to go more quickly, take much less time with white wines. It generally depends on exactly how the wine is made. It’s generally only heavy press fractions that actually express some smoke character. And generally speaking the levels are much, much lower in white wines. Other than that it is exactly the same process.
What the hell, I’ll ask the question about blending. You had said it was a long shot. A ratio of 50 to 1 would be required to dilute smoke tainted wine. But has it ever occurred over the course of your process that the wine might be too tainted, or that there might be some other wine addition protocol that you observe? In other words, during your process I understand that things are taken away but are things ever added?
BK As far as the work we do, no. I do know that people have looked at various tannin adjuncts and fining agents, things like that to kinda fine tune. But that’s not something we’ve been involved in. In general, I think people, I know people have definitely been disappointed with fining. Our recommendation is if you’re going to fine anyway, do it and see what it gets you. But be careful because what people who have tried it have found they will just fine out all of the character out of the wine except for the smoke taint! (laughs)
As far as covering it up, people have found that they may be able to smooth it out a little bit with out tannin adjuncts and things like that. But in general, I don’t think anybody really found that it’s useful for anything more than fine tuning.
Can you give me some idea of how widespread is this problem of smoke taint? It is not necessarily the core of your business, or is it?
BK No. Not really.
Is it in the tens of thousands of gallons? Can you give me a ballpark figure of how much tainted wine is out there requiring treatment? This would involve not only you’re company but others associated with this technology.
BK I’m sure that the volume of wine at this point runs into the millions of gallons.
This would include Australia, of course.
BK I’m just talking about California in 2008.
Millions of gallons?
BK Oh, definitely. What I know that has definitely been treated. That’s safe to say. How many millions? I wouldn’t want to venture a guess. But it is safe to say millions.
And this would all be related to smoke taint?
Now, there are other companies out there. Do they use similar technology?
BK Well, it depends on what you mean by similar. When you boil it down to its simplest form which is making a separation, to separate the offensive compounds from the desirable compounds, and then doing something to try and remove those offensive compounds from the permeate essentially, then, yeah, they’re pretty similar. That said, the devil is in the details when it comes to this, most definitely. Because we’re right on the threshold here of passing and not passing the offensive compounds, and then removing the offensive compounds but not the desirable compounds. Broadly speaking, yes, and no, not in the details.
Thank you, professor. Thank you for your time. You’ve certainly done me a great service, and that of my readers.
BK Any time, Ken. I look forward to meeting you some day.
Take care and enjoy the UC Davis meeting.