Clark's Reductive Strength in Wine..(long/boring/geeky)

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Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby TomHill » Mon Oct 07, 2013 10:38 pm

I've been plowing my way thru ClarkSmith's "Post-Modern Winemaking". It's an absolutely fascinating
read and every wine geek should acquire this book. I must admit, being a simple little ole country
computational physicist (spoken in my best SamErvin drawl), the chemistry part is a bit difficult for
me to comrehend. But I try.
But the one chapter, "Redox Redux, Measuring Wine's Oxygen Uptake Capacity", has really caused me
to think (rare occurence, there). It talks in detail about a wines "reductive strength"...the ability
to absorb oxygen over the wines lifetime. Implicit in this "reductive strength" is the ability of a
wine to age over its lifetime. Greater "reductive strength"...the longer the wine will last.
He describes VernSingleton early-on work to measure a wines "specific oxygen uptake rate", using
the Warburg apparatus. VernonSingleton is probably the world's expert on wine phenolics. Way back
in the late '70's, I requested an appointment w/ Vern there at UCDavis for some discussions on
wine phenolics. Me...just a no-body wine geek (interesting how some things never change)...and Vern,
a busy/high-level enologist. The man was absolutely charming and chatted w/ me for almost 2 hrs,
patiently explaining stuff that I'm sure was pretty fundamental. Vern retired in 1991 and I believe
he's still alive.
Anyway, after decades of work on measuring the "reductive strength" in wine, Vern abandoned the work
because he couldn't inspire anyone to take advantage of his ideas. The Warburg apparatus that Clark came
upon in the early '80's at Davis raises the wines pH to a high level (the oxygen reaction rate at typical
wine pHs is terribly slow) and, using a manometer & stopwatch, measures the rate of oxygen uptake.
He further describes the work of Jean Ribereau-Gayon in Bdx in the early '30's to use the Warburg
apparatus to measure a wine's "total oxygen uptake potential"..which I gather is a measure of a wines
ability to age a long time....sort of the fragility of a wine to aging.
He then goes on to relate a discussion w/ RandallGrahm on a wines "qi", the Chinese life energy and
how it relates to a red wine's aging. A bit strange I thought for a scientist like Clark to go to
somebody like Randall.
He then goes on to describe how giving a wine extended hang time, as is wont in Napa Cabs, that 90%
of the wine's reductive strength is lost. He then describes Ducournau's discovery that oxygenated wines,
at first increase in reductive strength. As in MOx, I presume Clark's talking. He then admonishes us that
"oxygenation is not oxidation". Not sure I grasp that concept.
Anyway, the chapter is a fascinating read and I hope, one day, to fully understand what Clark's
talking about.
_____________________________________________
Which brings me to taday's pontifications and musings from TheBloodyPulpit:
1. So....we have the ability to measure, in the chem lab, a wine's ability to absorb oxygen over its
lifetime. It appears nobody gives a rat's a$$ about this ability. I gather this is a measurement that
LeoMcCloskey's Enoligix does not provide?? Is anybody using that measurement to predict ageibility.
______________
2. How, exactly, does a wine's "reductive strength" relate to its ability to age?? Preumably, you can dump
a $hitload of tannin into a wine at fermentation and dramatically increase its "reductive strength". Which,
I presume, means the wine can age for a very/very long time. Does that automatically mean the wine will
improve w/ age and be a better wine way down the road??
______________
3. We know that Gamay and Zinfandel can't age worth Jack$hit. And that Cabernet and Syrah and Nebbiolo can.
Can this "reductive strength" measurement tell us what's inherently in those grapes that allows/forbids
them to age??
______________
4. We know that Cabs like Harlan/Schrader/Colgin and other modern NapaVlly Cabs can't age for beans, because
of their long hang-times and alcohol levels. And that Ridge MonteBello can age forever. Would this
"reductive strength" measurement in the lab confirm what we already know anecdotally? We know that
RandyDunn leaves a long hang-time on his Cabernet and then RO's the alcohol down. Would the "reductive
strength" measurement, before and after the RO, confirm this practive as the right thing to do??

Anyway, I'm sorta interested if Clark's onto something here related to a wine's ageibility. Personally,
I will probably put more reliance in PaulDraper's palate than some lab measurement. But I find this to
be a fascinating topic. Talk amongst yourselves and enlighten me.
Tom
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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby John Treder » Mon Oct 07, 2013 11:15 pm

>> 3. We know that Gamay and Zinfandel can't age worth Jack$hit. And that Cabernet and Syrah and Nebbiolo can.

Which sort of argues why "field blend" Zins such as Geyserville or Coffaro's Block 4 age better than straight zins, right?
John in the wine county
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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby Mark Lipton » Tue Oct 08, 2013 12:07 am

Tom,
I think that you are right to question the linkage between oxidation/oxygen uptake and aging in wine. Years ago, I got into a discussion about this with Michael Pronay, an Austrian wine critic. He pointed out that wines recovered from sunken ships that had spent decades on the bottom of the ocean usually had aged magnificently, presumably with minimal oxygen ingress all the while. Looked at another way, the most immortal of wines, Madeira, has next to no "reductive strength" I'd be willing to bet. And on another note, if I wanted to measure the reduction potential of wine, I wouldn't use oxygen and a manometer to measure it. I'd use a nicely measured, soluble oxidant like hypochlorite (Clorox) or sodium periodate and just do a simple titration. Iodometric titration is a traditional variant of that.

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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby Craig Winchell » Tue Oct 08, 2013 12:55 am

Clark and I were classmates in many of our classes, having transferred in from parts east at the same time, he from MIT and me, in a roundabout way, from Haverford. Clark is Clark. He's a good winemaker, a good technologist and a good technician. He's a smart guy. However, in this I feel he has missed the mark. A proof is that there are white wines which are tasty at release, yet which can age well, and there are reds, presumably with phenolic material including anthocyanins which exhibit a marked antioxidant effect, which will not age as long, though tasty in their youth. I have often found acidity to be a good predictor of aging ability, all other things being equal. Certainly, tannins and other phenolics contribute, but are part of a spectrum of factors which contribute to aging. I tend to believe that chemical reactions other than oxidation are partially responsible for aging. If the wine is considered perfect at the commencement of the period, then the oxygen permeability of the closure will contribute to oxidative reactions which will change the wine, often for the worse. If the wine is not perfect to begin the period, then the oxidative reactions will certainly contribute to a change in the wine, for better or worse. But there are other concurrent reactions, due simply to proximity of different chemical moities and enough energy present to allow initiation of these reactions between them. Some of these are oxidative as well. The difference between redox reactions and others are in absorbing/contributing electron pairs, and such reactions need not require oxygen, which is what Clark means by "Oxygenation is not oxidation", I believe. And as far as Clark's penchant for going mystical a la Randall Graham, well, he's human, and follows success.
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Probably....

Postby TomHill » Tue Oct 08, 2013 10:02 am

John Treder wrote:>> 3. We know that Gamay and Zinfandel can't age worth Jack$hit. And that Cabernet and Syrah and Nebbiolo can.

Which sort of argues why "field blend" Zins such as Geyserville or Coffaro's Block 4 age better than straight zins, right?


Probably, John. That's not the raison d'etre for mixed plantings, but you could have a point.
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Well....

Postby TomHill » Tue Oct 08, 2013 10:10 am

Craig Winchell wrote:Clark and I were classmates in many of our classes, having transferred in from parts east at the same time, he from MIT and me, in a roundabout way, from Haverford. Clark is Clark. He's a good winemaker, a good technologist and a good technician. He's a smart guy. However, in this I feel he has missed the mark. A proof is that there are white wines which are tasty at release, yet which can age well, and there are reds, presumably with phenolic material including anthocyanins which exhibit a marked antioxidant effect, which will not age as long, though tasty in their youth. I have often found acidity to be a good predictor of aging ability, all other things being equal. Certainly, tannins and other phenolics contribute, but are part of a spectrum of factors which contribute to aging. I tend to believe that chemical reactions other than oxidation are partially responsible for aging. If the wine is considered perfect at the commencement of the period, then the oxygen permeability of the closure will contribute to oxidative reactions which will change the wine, often for the worse. If the wine is not perfect to begin the period, then the oxidative reactions will certainly contribute to a change in the wine, for better or worse. But there are other concurrent reactions, due simply to proximity of different chemical moities and enough energy present to allow initiation of these reactions between them. Some of these are oxidative as well. The difference between redox reactions and others are in absorbing/contributing electron pairs, and such reactions need not require oxygen, which is what Clark means by "Oxygenation is not oxidation", I believe. And as far as Clark's penchant for going mystical a la Randall Graham, well, he's human, and follows success.


Thanks for your inside comments on Clark, Craig. I don't think of Clark as a snake-oil salesman or fraud, by any stretch. But I just wish I had the background
to understand some of his pronouncements. Certainly, that link between reductive strength and ageibility seems a bit tenuous. As for example in white wines
and in Madeiras, as Mark cites. I think the acidity is also a very critical element.
Jeez...it's all so complicated...can't we just have a simple ole integro-differential equation to solve?? :-)
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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby Craig Winchell » Tue Oct 08, 2013 12:12 pm

When we started the Davis Enology and Viticulture Organization (DEVO, named after the musical group of the time, which I believe may also have been a Clark Smith contribution), he was unanimously elected the group's first president, the reason being not only that he was quite well respected, but also that he wanted the job, and didn't mind devoting some time to it. But it certainly did not look bad on his resume, and maybe ambition had something to do with it. He is not a theoretician, he's a problem solver(in the engineering genre), whose greatest contribution (in my opinion) has probably been to identify how small, quality oriented winemakers can embrace technology to improve the quality of their products, and providing a mechanism to achieve that (Vinovation and other), at a time when most of the winemaking world was falling back into the dark ages of anti-science, traditionalism and biodynamics. He's made many contributions over the years, but there has also been a fair amount of shameless self-promotion. Why not? He deserves to benefit. I would typically classify his writings as the latter. Nothing like a writing gig or book to solidify one's credentials.

So I agree with you, Tom, that the link seems tenuous, because it is. And I ask why you believe understanding Clark's pronouncments is a worthwhile endeavor? With your background, you can join the ASEV as an associate, and have the archives of the American Journal of Enology and Viticulture at your disposal, to do a literature search of the research and its data, and come to your own conclusions.
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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby Steve Slatcher » Wed Oct 09, 2013 3:16 am

Craig Winchell wrote:He's made many contributions over the years, but there has also been a fair amount of shameless self-promotion. Why not? He deserves to benefit. I would typically classify his writings as the latter. Nothing like a writing gig or book to solidify one's credentials.

No reason not for him to self-promote, but many reasons not to spend money and time reading the self-promotion. However smart he is, and whether or not his methods work, I would not recommend the book (though I seem to be in a minority): http://www.winenous.co.uk/wp/archives/4581
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Hmmmm....

Postby TomHill » Wed Oct 09, 2013 10:21 am

Steve Slatcher wrote:
Craig Winchell wrote:He's made many contributions over the years, but there has also been a fair amount of shameless self-promotion. Why not? He deserves to benefit. I would typically classify his writings as the latter. Nothing like a writing gig or book to solidify one's credentials.

No reason not for him to self-promote, but many reasons not to spend money and time reading the self-promotion. However smart he is, and whether or not his methods work, I would not recommend the book (though I seem to be in a minority): http://www.winenous.co.uk/wp/archives/4581


Hmmmm......good review, Steve. And some of your points I agree with. I've noted the occasional (endless?? Not sure I'd call it that) repetition of points.
I agree that the book could have used a stronger editing hand. There are times I'll read a paragraph and scratch my head.."What'd I just read"?
Sure...Clark is a (shameless?) self-promoter. But that sort of thing one can (hopefully) filter out. But, all in all, I'm learning a lot from the book and it's
causing me to think a lot. I'll have to go back & reread it to try to understand much of it, I think. Which I will do.
What I would really like to see is have PaulDraper and Clark sit down together on a panel and talk about (post?) modern vs traditional (post-industrial
as Paul calls it) winemaking. Paul is the consumate gentleman and there would be no sparks flying...but it would be a very spirited discussion.
As for "great visionaries like Rudolf Steiner".....hmmmm...that kind of caught my attention. If you wanted to use the sobriquet "self-promoter", then
Steiner would be the one, IMHO.
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Re: Hmmmm....

Postby Steve Slatcher » Wed Oct 09, 2013 1:40 pm

TomHill wrote:As for "great visionaries like Rudolf Steiner".....hmmmm...that kind of caught my attention. If you wanted to use the sobriquet "self-promoter", then Steiner would be the one, IMHO.

It probably didn't come across clearly enough, but "great visionaries like Rudolf Steiner" was meant to be heavy with irony. Many people are probably thoroughly fed up of hearing me rail against Steiner and Biodynamics, but if you want to know what I think please feel free to light the blue touchpaper ;)
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Sorry....

Postby TomHill » Wed Oct 09, 2013 2:05 pm

Steve Slatcher wrote:
TomHill wrote:As for "great visionaries like Rudolf Steiner".....hmmmm...that kind of caught my attention. If you wanted to use the sobriquet "self-promoter", then Steiner would be the one, IMHO.

It probably didn't come across clearly enough, but "great visionaries like Rudolf Steiner" was meant to be heavy with irony. Many people are probably thoroughly fed up of hearing me rail against Steiner and Biodynamics, but if you want to know what I think please feel free to light the blue touchpaper ;)


Sorry, Steve....I'd forgotten your views on Steiner/Bio. I get it, now.
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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby Steve Slatcher » Thu Oct 10, 2013 3:10 am

The fault is all mine, Tom.
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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby Clark Smith » Tue Oct 15, 2013 1:28 pm

TomHill wrote:
But the one chapter, "Redox Redux, Measuring Wine's Oxygen Uptake Capacity", has really caused me
to think (rare occurence, there). It talks in detail about a wines "reductive strength"...the ability
to absorb oxygen over the wines lifetime. Implicit in this "reductive strength" is the ability of a
wine to age over its lifetime. Greater "reductive strength"...the longer the wine will last.
He describes VernSingleton early-on work to measure a wines "specific oxygen uptake rate", using
the Warburg apparatus. VernonSingleton is probably the world's expert on wine phenolics. Way back
in the late '70's, I requested an appointment w/ Vern there at UCDavis for some discussions on
wine phenolics. Me...just a no-body wine geek (interesting how some things never change)...and Vern,
a busy/high-level enologist. The man was absolutely charming and chatted w/ me for almost 2 hrs,
patiently explaining stuff that I'm sure was pretty fundamental. Vern retired in 1991 and I believe
he's still alive.
Anyway, after decades of work on measuring the "reductive strength" in wine, Vern abandoned the work
because he couldn't inspire anyone to take advantage of his ideas. The Warburg apparatus that Clark came
upon in the early '80's at Davis raises the wines pH to a high level (the oxygen reaction rate at typical
wine pHs is terribly slow) and, using a manometer & stopwatch, measures the rate of oxygen uptake.
He further describes the work of Jean Ribereau-Gayon in Bdx in the early '30's to use the Warburg
apparatus to measure a wine's "total oxygen uptake potential"..which I gather is a measure of a wines
ability to age a long time....sort of the fragility of a wine to aging.
Tom

Tom,

When I talk about reductive strength, I am speaking generally of any source of anti-oxidative power, many of which remain mysterious. The Warburg flask, with its pH shift strategy to accelerate uptake, is likely not a complete measure, but probably does give us a handle (though not a true quantitative measure) on the oxidative diphenol component of reductive strength. It’s more properly called a phenolic oxygen uptake assay.

Acidity is not to be ignored, but its influence is poorly understood. To begin with, it seems pretty clear that titratable acidity (the taste of acidity) has nothing to do with aging. pH is certainly the gas pedal of both phenolic oxidation and microbial activity, as I have been teaching for decades. But this does not mean that low pH wines age particularly well since, for example, their phenolic reactivity to oxygen is suppressed.

The uptake of lees as a result of bâtonage seems to impart substantial reductive strength unrelated to phenolic reactivity. The buzz in the finish I refer to as “minerality” seems also related to reductive strength, though we don’t even know what it is, let alone how to measure it.

This is doubtless an incomplete list. I only devoted such considerable space to Singleton’s diphenol cascade because we understand so much about it compared to the other sources. This lavish coverage should not be construed to equate phenolic content with reductive strength. Certainly, high tannin does not guarantee long life as most phenols are rather unreactive with oxygen, andconversely, skinny little Mosels with none at all often age amazingly well.

I’m currently testing an alternative method to measure reductive strength which employs the Nomasense optical O2 sensor, an optical system that communicates through the glass with an oxygen-sensitive dot placed inside a bottle containing a wine sample. If we place the bottle in an argon atmosphere at a controlled temperature, we can nondestructively observe dissolved oxygen decline over the course of weeks and months.

Unlike the Warburg, which probably measures total uptake potential for phenolics only, this is a direct measure of the wine’s collective O2 appetite. While Warburg looks at the integral under the curve for the whole wine’s life, this measures the rate of the current uptake. I’m hopeful this will prove a useful tool to guide blending and bottling choices.

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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby Clark Smith » Tue Oct 15, 2013 1:33 pm

TomHill wrote: He then describes Ducournau's discovery that oxygenated wines,
at first increase in reductive strength. As in MOx, I presume Clark's talking. He then admonishes us that
"oxygenation is not oxidation". Not sure I grasp that concept.
Tom


I think it’s important to distinguish between oxygenation treatments and oxidation, which they often seek to prevent.

There are many ways to use oxygen enologically which do not oxidize the wine. For example, the German practice of browning musts to remove phenolics prior to fermentation, bizarre as it seems, gives us more delicate, fresh, and aromatic wines post fermentation because they are not subject to peroxide generation, a byproduct of phenolic oxidative polymerization. These wines age very well because there’s little left in them to oxidize.

In Micro-oxygenation, which occurs post fermentation, usually on big reds, we introduce oxygen at a rate lower than the wine’s capacity to consume it. This is to put 100% of the reaction into polymerization, particularly with the goal to incorporate anthocyanins into polymeric pigments, where they are more stable and also act as “bookends” on polymerization, thus minimizing chain length.

If we do these treatments correctly, we not only prevent oxygen from being available for oxidative reactions such as aromatic degradation, microbial activity and furfural generation, but we also increase the wine’s oxygen uptake capacity for a time, because the dimers initially formed are more reactive than the monomers we start with.

It's counter-intuitive, but early micro-oxygenation can double or triple the required time in barrel. I just released my 2006 Lodi Cab and the 2005 "Crucible" Cab Sauv has only been out for a year. These wines are still very much on the uphill side of maturity.
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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby Mark Lipton » Wed Oct 16, 2013 3:25 pm

Clark Smith wrote:In Micro-oxygenation, which occurs post fermentation, usually on big reds, we introduce oxygen at a rate lower than the wine’s capacity to consume it. This is to put 100% of the reaction into polymerization, particularly with the goal to incorporate anthocyanins into polymeric pigments, where they are more stable and also act as “bookends” on polymerization, thus minimizing chain length.


Can you explain to this organic chemist how anthocyanins serve as chain terminators for tannin polymerization? I'm assuming here that you're referring to the polymerization of condensed tannins such as the procyanidins.

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Re: Clark's Reductive Strength in Wine..(long/boring/geeky)

Postby Ben Rotter » Mon Oct 21, 2013 4:22 am

I have yet to receive my ordered book (the next consignment from the publisher seems delayed), so I can't comment on the book or its content at this point, but I found this an interesting thread. I also appreciate Clark chiming in. Although it might be said he has a vested interest in doing so, not every author would (or does) respond to such a thread.
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Yup...

Postby TomHill » Mon Oct 21, 2013 10:03 am

Ben Rotter wrote:I have yet to receive my ordered book (the next consignment from the publisher seems delayed), so I can't comment on the book or its content at this point, but I found this an interesting thread. I also appreciate Clark chiming in. Although it might be said he has a vested interest in doing so, not every author would (or does) respond to such a thread.


I appreciate Clark's coming here to comment as well, Ben.
Supposedly, the 2'nd printing is due out towards the end of this month.
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