Wine Style vs. Terroir:
A Viticultural Perspective
We can manipulate wine style in the vineyard but how much should we do so?
Mark Greenspan Wine Business Monthly October 2016
(Dr. Mark Greenspan has more than a quarter century of scientific viticulture research and viticultural field experience. He specializes in irrigation and nutrition management,
yield and canopy management, vineyard climate and microclimate, vineyard design and vineyard technology. He is the founder of Advanced Viticulture, Inc. based in Windsor, California (www.advancedvit. com), providing consulting, technology, vineyard management and vineyard development for wineries, winemakers and wine growers devoted to producing premium wines. Please direct queries to email@example.com or 707-838-3805.)
I H A D A CON V ER SAT ION the other day with a client who is a winemaker for a premium Central Coast vineyard. I won’t give out this winemaker’s name because these thoughts are to be taken as my opinion, not my colleague’s. But I found the conversation very stimulating in that the ideas being conveyed to me by my counterpart very much matched my own feelings. And it fired me up because, like anyone in the wine industry, I have ideas about wine—at least premium wines. I respect the fact that there are other opinions, and that they are just as valid as mine, even if they’re, well, not quite correct!
The conversation was about the push for wine style over that of expression of the individual terroir of the vineyard. The movement towards the “California style” of in-your-face, “fruit bomb,” thick as syrup, super-ripe wines seems to be taking a bit of a break. But that idea has not. Some regions, including the Paso Robles region, are known for their jammy, ripe, big-bodied, highly structured wines. That has become their identity and has served them well in the market, creating a regional style that defines not only their wines but fits right into their wild-west type of history and personality. Paso Robles is a great wine region and has continued to mature, such that more recently created brands are being accepted into the mix and are developing their own identities. It’s a really good example of a developing younger region but also seems to illustrate the difference between leaders and followers.
Have you heard the expression “wine is made in the vineyard?” Of course you have! Everyone says it, but it seems not everyone believes it or practices it. It comes down to ripeness, when fruit is picked relative to ripeness, and the viticultural practices that affect fruit maturation and ripening. The safest way to decide when to harvest is to overshoot the ripeness mark. That way, flavors are concentrated, off-flavors (like veggie-ness) are minimized, seeds are more likely to be hardened and, to the detriment of the grower, yield is reduced. Dehydration can be legally offset by adding water at the crush pad to facilitate fermentation. But there is more than simply a loss of water when fruit is picked with extended hang time. The flavor changes, from delicate and complex to simple and jammy to possibly cooked and raisiny. Once overripe, flavor cannot be brought back. In my opinion, the overripe style overwhelms and dominates the site character: its terroir (however you define it). Ripe wines reflect the complex flavors that the soils and climate contribute to the fruit and wine. Wines of terroir cannot be overripe. Overripe wines are not terroir-driven wines.
That non-flattering description of the very-ripe style sounds counter to what wine marketers like to tout, but that was the style many wineries had adopted in the first decade of the 2000s and into the second decade. The style continues to be produced, but many wineries have backed off of that superripe style and have created more and more wines with finesse and restraint. But not everyone. Paso Robles is a region where jammy ripeness seems to continue to rule the roost. It’s quite possible to produce more restrained, terroir-driven wines in that region, but those tend to be outliers, drawing less favor from wine critics, who seemingly expect a singular regional style. Yet, both styles are possible in Paso Robles (there aren’t really only two styles, but I’m oversimplifying on purpose). And that’s where I’ll stop the discussion about Paso Robles, lest anyone think I’m picking on them, because I’m not. Paso Robles is a true premium wine-growing region, and I simply don’t think it’s living up to its full potential yet. I’d like to see more wines of terroir made there, just as I’d like to see them made in all premium wine regions. As a consumer, it would make things so much more interesting and enjoyable.
But How Do We Get Terroir-driven Wines Viticulturally?
I’ll suggest that it is viticulturally lazy to allow fruit to become overripe before harvest. The practice of extending hang time masks a lot of bad practices. Shall I name them all? Well, it’s really all of them, from pruning to thinning to even harvesting. Pruning too many or too few buds creates an imbalance between the amount of fruit to vegetative growth and could also compromise the canopy structure vegetative/fruit balance. Suckering and shoot-thinning also affect this balance, as well as affecting the micro-environment of the fruit zone. Timing and quality of that practice are critical viticultural steps. Leaf- and lateral-pulling in the cluster zone also has a direct effect on fruit development and acclimation to the environment. Again, timing and quality are critical for that practice. Fruit-thinning has an effect on fruit development and uniformity of maturation. Once again, timing and quality are critical. Fertilization? It has a direct effect on canopy health, photosynthesis and fruit composition. And yes, timing and precision are critical. I could keep on going, but you get the idea. Viticultural practices affect fruit quality and thereby wine quality. And extended hang time can reduce the ill-effects of falling short on one or more of the above list of practices. But there is the cost paid by loss of site expression and a dull, flabby, overly-jammy wine style.
I didn’t list one item in the above diatribe on vineyard practices: water management. That’s not because it’s not important. It’s that it’s perhaps the most important. Water management, sometimes called irrigation management, is of key importance in growing wines of terroir. Some may say that dry-farmed vineyards produce the ultimate in terroir-driven wines, and I won’t disagree, but most California vineyards, especially those in arid regions, cannot be practically or commercially dry-farmed. In regions with dry summers, like California, irrigation can be manipulated so as to influence vine and fruit physiological responses to influence fruit maturation and ripening. So perhaps there is an advantage for irrigated vineyards as long as it is not abused. And it often is abused.
We can argue over alternative vineyard practices, but those who excessively irrigate have little upon which to stand. I’m not referring to producers of value-level wines. They definitely need to irrigate more than premium winegrowers as they are not focusing on terroir or finesse. But excessive irrigation leads to all kinds of evils: excessive vigor, shading in the fruit zone, elevated pyrazine levels, disease and lack of flavor development, not to mention a waste of a scarce resource. Water management is both a science and an art, so there are different approaches that are all legitimate in the sense that there is room for different approaches.
But I feel that there is a “best way” that plays into vine and fruit physiological responses, and that allows the vineyard to be harvested when it best reflects the site’s terroir. That is, fruit develops flavor maturity before it collapses. I’ve described it before, many times before, in fact, but perhaps not always in the context of terroir or production of more finessed wines.
Working Backward from Fruit Ripening
Let’s discuss ripening in a very general sense. I like to separate the sugar-accumulation portion of ripening from all the other parts of ripening: malic acid metabolism and production of secondary metabolites. Sugar accumulation occurs due to photosynthesis in the leaves. The sugar produced in leaves is loaded into the phloem vessels at the source end, which draws in water from the apoplast (extracellular space), creating pressure that drives sap flow away from the leaves. At the berry end, sugar is actively unloaded from the phloem into the berry’s apoplast, which causes water to flow out of the phloem. This process drives water and sugars into the berry. Most of that water is lost from the berry via transpiration through the berry skin. This perfect system is how the berry accumulates sugar. It is affected by water stress in some ways: increase or decrease in photosynthesis and ease of water movement from apoplast into the phloem’s symplast (intracellular space). But that is not the really interesting part.
The so-called secondary metabolism of the grape—the metabolism of malic acid inside the berry—serves as an energy source for a multitude of enzyme-catalyzed reactions that form the majority of organoleptic components in the fruit: tannins, anthocyanins, aromatics, co-pigmentation constituents, etc. This is the stuff that makes wine interesting, different from one another, and, well, flavorful. The cascades of biochemical reactions are mediated by numerous enzymes. The enzymes are coded in the DNA of the grape berry and are transcribed into messenger RNA that directs the translation of the codes into proteins, of which enzymes are a subset. These enzymes are formed within the cells of the berry independently of the mother vine. Work that has been done in the last several years has shown rather definitively that water stress, through stimulation of stress hormones (namely abscisic acid), and suppression of growth hormones (namely gibberellins, cytokinins and auxins) stimulate the production of these enzymes. In practice, this has the effect of promoting the flavor ripening process in the fruit.
But timing is critical. The majority of these changes occur just before and during veraison. There is an additional effect after veraison, but the most critical time appears to occur about the time of veraison. So it is critical to manage water such that the vine is stressed (mildly) just before, during and a bit after veraison. Maintaining a mild stress after veraison has some effect on continued stimulation of ripening, but a more severe stress may be detrimental towards harvest, as a loss of photosynthesis could stop sugar (and water) loading of the fruit, leading to early berry dehydration.
What does this have to do with terroir and finessed wines? In California, we seem to have an abundance of sunlight (too much of a good thing). Rain and even clouds are rare in most of the state during grape-growing season. So, we have little trouble getting fruit to sugar up. But that can be problematic as we don’t always have the same ease of flavor maturation. I have found that the careful and precise application of vine stress, during critical phenological stages, allows flavor maturation to proceed more rapidly. This provides the winemaker with the ability to call the harvest when flavor is at its peak and before the sugar content gets out of hand. Another thing to add here is that sugar accumulation occurs only up to some point. It varies, but around 24° Brix, sugar accumulation ceases, and further increases in Brix are due mainly to loss of water from the berries. Accelerating the flavor ripening process, through controlled water stress management, allows fruit to reach optimal flavor maturity without having fruit collapse on itself, causing flavors to become overly jammy and cooked, reducing yield and all of that.
I feel that this leads to more options for timing of harvest by the winemaker, selecting the picking time to reflect the flavors they want in their wines, and not having to wait for the bad stuff to go away.
I continue to witness what I feel are detrimental approaches to water management, not only detrimental but almost 180 degrees away from what is ideal. The practice of giving vineyards an irrigation at the onset of veraison, purportedly to hasten and even up veraison, may indeed have some short-term benefit but in the long-term does not benefit the fruit maturation process. More and more, I am finding growers and wineries that followed this practice but have turned away from it with my guidance and with beneficial results.
The water management strategy is not really intended to be a “big drink” versus “small drink” argument, nor is it really an “early deficit” versus “late deficit” comparison, but it is more about vine stress management. How one dials in the vine stress depends on many factors, such as soil types, precipitation patterns, hot weather, rootstock, variety and a few other factors. But one cannot ignore what science has shown us. We can influence fruit ripening in a beneficial way and allow the site to express itself and wines to be distinct and special rather than waiting until the fruit collapses and creating wines that taste like all the other pruny-jammy types in the neighborhood. WBM