Grapes


“From (a) chemical point of view, wine is an acidic aqueous ethanol solution with aroma compounds.” Gosh, that sort of takes the glass_012.jpgthrill out of your $12-glass of Sonoma-Cutrer Les Pierres Chardonnay 2005. Might as well define Uma Thurman as a carbon-based, water-logged uma_011.jpgmammalian sack of DNA.

The truth is — ready? — all material things are composed of chemicals, and a bottle of great wine, about which we might rhapsodize so lyrically and which we may elevate to sensual, cultural and economic pedestals, is naught but a glass container filled with about 85 percent water (more or less), 12 or 13 percent alcohol (more nowadays) and 2 or 3 percent highly complex chemical compounds. It’s those minute traces of chemicals that give wines their most desirable characteristics. Well, we need the alcohol for the buzz.

I know, you’re thinking, “Jeeze, this killjoy is fixin’ to take all the fun and magic and romance outta wine.”

I wouldn’t do that, being a firm believer in the fun and magic and romance of wine, but I also think that we who love wine — consuming it and writing about it — ought to know more about what wine really is, whence its attributes derive and how it makes them known.

To this end I have been reading — well, reading isn’t the correct word because much of this book is impenetrable to the normal person with an advanced degree — reading at a collection of papers called The Chemistry of Wine Flavor, edited by Andrew L. Waterhouse and Susan E. Ebeler, published by the American Chemical Society Symposium Series in 1998 and distributed by Oxford University Press ($35).

We learn, for example — and there will be a test — that when we swirl a glass of wine and unleash its inimitable aromas into the air and into our noses, our sensing agents are being stimulated by 600 to 800 distinct volatile compounds, the primary source of which is the fermentation process. These compounds may be divided into five groups: alcohols; esters; carbonyl compounds (aldehydes and ketones); sulfur-containing compounds; and organic acids.

The particular flavor of a varietal wine — and don’t forget that most of what we describe as flavor is actually aroma — whether sauvignon blanc or chardonnay, cabernet sauvignon or pinot noir, is the result of a very complicated series of transformations that begin at root-level in the vineyard, continue through the maturing and ripening of the grapes and speed up exponentially during the relatively violent and energy-releasing processes of crushing, maceration and fermentation. I mean, imagine if you were an innocent little grape that came to the big city and all that happened to you; you would probably turn out to be a cheap, scuzzy muscatel, living in the gutter, and blame it on your childhood.

The hint of herbaceousness that sometimes characterizes cabernet sauvignon and merlot wines? That derives from the volatile short chain aldehyde called 3-Methyl-1-butanal, other wise known as isovaleraldehyde, which I guess is the name-brand version. The cocoa or coffee-like undertones we sometimes detect in red wines? That’s 2-Methyl-1-butanal. What a difference a molecule makes! The more pronounced herbaceous elements of sauvignon blanc, that bell pepper, green bean, gooseberry quality, comes from methoxypyrazines, actually from three methoxypyrazines, but we won’t go into that except to say that one of them, the most abundant, of course, is responsible for the canned asparagus nature of sauvignon blancs that have crossed over to the dark side. This is why canopy 24683-00-92.gifmanagement is so important in the farming of sauvignon blanc vineyards. Look, there’s an isobutal-methoxypyrazine now! Cute l’il fella. Simple and elegant.

The previous paragraphs merely skim the surface of a fount of knowledge that grows ever deeper as more research is done into the physical mechanics of wine. We haven’t mentioned color, the result of a range of anthocyanin pigments and pigmented tannins (created by the interaction of anthocyanins with catechins, proanthocyanidins and ellagitannins), nor have we touched on the chemistry of tannin itself, the proanthocyanidins, while the bitterness and astringency associated with large amounts of tannin derive from flavonoid polyphenolic compounds. And those polyphenolic compounds, oh my god, what a rich stew of influences they bring to the color and texture of wine! And I haven’t mentioned the broad range of glycosides, a two-molecule linkage of which one molecule is a sugar and the other, well, isn’t, but may be our old friend the anthocyanin. The point is that in their many combinations “grape glycosides are of fundamental importance to wine flavor,” as one of the essays in Chemistry of Wine Flavor states, affecting such elements as apple, floral notes, honey, dried fig, chocolate and tobacco.

What’s actually important about this dizzying array of chemical compounds and their almost infinite sway of interactions and transformations is that the more that scientists delve into the inner workings of grapes and the fermentation process the more tools they acquire for learning how to analyze and gauge the potential to influence through chemistry the quality of the wine while the grape is still on the vine. Already the “glycosyl-glucose assay,” introduced in the late 1990s, is being used in vineyards and wineries to test such theories and practices.

So, keep all of this information in mind the next time you tiptoe down the winding stair to your cellar, extract a dusty bottle of Cheval-Blanc ’49 from its niche and guide it, like Orpheus tenderly leading Eurydice, back to the light. Whatever people have said or written about the wine, it’s just a bottle filled with water, alcohol and more seething chemical compounds than you could shake a stick at or even want to think about. Forget about drinking the stuff and send it to me instead. I’ll run a few tests for you, have a sip or two, let you know how it works out. Oh, and tell Uma.

The image of isobutylmethoxypyrazine is from flavornet.org.
The image of the glass of white wine is from cleehouse.com.
And the image of Uma Thurman is from — and I’ll provide the link here; many of you will thank me — venus.provocateuse.com.

We were having dinner last night — cod, potato and chorizo stew — and drinking a bottle of the Silverado Vineyards “Vineburg” Chardonnay 2005, Carneros (about $30), an absolutely lovely, pure and eloquent expression of the grape. As we often do when we spend an hour or so with a bottle of wine, we talked about it, how it evolved in the glass, its virtues and defects (this had no defects) and about, in this case, how the chardonnays we love — balancing spicy fruity richness with minerally and acidic elegance — aren’t the ones that win top scores and prizes.

Then LL said, “As far as I’m concerned, this is white wine. This is what white wine should be. Chardonnay is the stake in the ground.”

I was stunned, not only because I wished I had thought of that phrase but because of the boldness of the assertion. Chardonnay is the stake in the ground! chard_01.jpg
“But what,” I said, “about riesling and sauvignon blanc and chenin blanc? They can make great wines.”

“Yes,” she said, “I know that. But there’s a greatness in the best chardonnays that’s better than anything else in other white wines. And it’s the same thing for cabernet sauvignon. Cabernet is the stake in the ground for red wine.”

“But — pinot noir! Isn’t pinot noir the Holy Grail of red wines? We love pinot noir!”

“How many pinots do we try that are really great, I mean, intense and pure and classic? Maybe one out of 20. And two out of three of those come from Burgundy. And they’re still pretty light. Why should we celebrate pinot noir just because it’s so finicky that making a great wine from it is some sort of miracle. Wait, I know, you’re going to mention syrah and merlot, yes, those are capable of being made into great wine. But the most consistently great red wine, the most dependably great red wines are based on cabernet sauvignon. It’s the — ”

“Right, I know, the stake in the ground.” cab_01.jpg
I thought all day about what LL said last night. Could it be true that chardonnay and cabernet sauvignon grapes possess a deeper, more dimensional quality of power and potential than other grapes? When I think of the greatest white and red wines I have tasted in my career as a wine-writer, I have to admit that most of them have been chardonnays and cabernets, or at least blends that contain cabernet sauvignon.

Yes, of course I can think of instances of wines made from other grapes that were sublime:a barrel-sample of Chateau Petrus 1998 (which will be immortal) in December 1999; it’s 100 percent merlot, the greatest merlot wine in the world. And on that same trip to France, in Burgundy now, standing in the cold damp cellar at Domaine Roumier tasting Chambolle-Musigny “Les Amoureuses” 1998 out of the barrel, a pinot noir that seemed lifted directly from the dirt and soil and sub-strata of the vineyard. A Barbaresco 1961 made by Angelo Gaja’s father, tasted at 30 years old. The Savennnieres-Coulee de Serrant 2000 of Nicholas Joly. A Hermitage La Chapelle 1949 tasted in 1989. But those are special instances and special wines.
So, I wonder, is there not dignity and nobility about the greatest wines made from chardonnay and cabernet sauvignon grapes, not merely dignity and nobility but consistent dignity and nobility, a consistently historical living up to potential that other grapes and wines, however fine they may frequently (or rarely) be, cannot match with such an awe-inspiring combination of insouciance and confidence?
Perhaps so. Perhaps I’m waffling on this issue.
Let me know about where you would drive that stake in the ground.

The image of chardonnay grapes is copyright Vivai Cooperativi Rauscedo, Italy.

The image of cabernet sauvignon grapes is from http://www.winegeeks.com.