The different characteristics of Sauvignon Blanc and their sensory quality

Myth and Reality

David Allen, Master of Wine, recently wrote a very interesting post about the different styles of Sauvignon Blanc. In his introduction, he emphasizes that when we talk about wine, we often find in front of a big divide between what the general public wants and what experts think you should drink. And that, according to Allen, is particularly the case when it comes to Sauvignon Blanc. One conclusion could be that is because it is perhaps one of the grape varieties that allows the greatest versatility in terms of its style. But let’s not get ahead of ourselves.

As it happens, I was a guest at a notable event shortly before said article was published. At the end of May, the Sauvignon Experience took place for the fourth time in South Tyrol, with two days focusing on one of the most important grape varieties in this small region, which produces so many high-quality wines. Once again, the wines of the 2020 vintage, which had participated in the national Sauvignon competition, could be tasted during the public tasting as well as a selection of other Sauvignons from all over the world as part of the event. In addition, Helena Lindberg reported on the guest wine country New Zealand and its Sauvignon Blanc in an extensive master class. Even more remarkable, however, was a meeting of various oenologists and cellar masters, academics, journalists and experts brought together by the organizers on the day before the official opening of the Sauvignon Experience 2022. The topic of this round table was the qualitative interpretation of the different characteristics that can be found in a Sauvignon Blanc such as the various aromas and flavors as well as the different styles the wines is made in.

It was remarkable as well as ambitious, because here a number of wine personalities came together to exchange points of view, to explain perspectives, to discover similarities, and perhaps to define a vision about what the road ahead may be for one of the most popular grape varieties in the world.

A global success story

The story of Sauvignon Blanc in itself is an astonishing one. Starting from its French motherland, it has triumphed around the world and is now at home in almost all wine-producing countries. Well over one hundred thousand hectares of Sauvignon Blanc worldwide and growing are an expression of its success.

With such a geographical distribution, the development of different styles is inevitable. That and the particular aroma profile of the grape variety.

Peter Dipoli, South Tyrolean winegrower and one of the initiators of the meeting, a few years ago published the book “The Sauvignon Blanc in South Tyrol”. In addition to lots of other valuable information about this grape variety and the styles of wine that are made from it, he also describes precisely the background of the aromatic range and the two extremes that define the boundaries between which Sauvignon Blanc operates: green-vegetative notes on one hand; ripe and with aromas reminiscent of tropical fruits on the other hand. These expressions are based on two different chemical compounds: first, the methoxypyrazines, which are responsible for notes of green peppers, freshly cut grass, tomato leaves, nettles, boiled potatoes or fresh asparagus. Second, thiols produce impressions of grapefruit, passion fruit, blackcurrant, gooseberry, broom and boxwood, among others.

In order to fully understand the underlying tensions that this discussion is based on, it is imperative to remember that thiols are only released by yeasts during fermentation from their odorless precursors, cysteine and glutathione. Therefore, neither the Sauvignon Blanc grapes themselves nor the must obtained from them show thiol notes, but become apparent only during and after fermentation. Lastly and to present the minimum possible of necessary facts, we need to understand that the stage of maturity is also responsible for the total amount of these raw materials, which means that the time of harvest is particularly relevant, too.

It is often presented in a simplified way that grapes harvested earlier can therefore be attributed to a sensory result that is characterized by methoxypyrazines, whereas riper grapes are the basis of thiol notes. In fact, it is this basic understanding that forms the foundation for contemplating the different styles. After all, the tradition of Sauvignon Blanc may be rooted in the famous varietal wines of the Loire or as a blending partner for dry or sweet Bordeaux wines; the great success in terms of trade and reputation in the recent history of the grape variety, however, clearly belongs to those specimend that have their origin in New Zealand, but have also found more or less recognition in other wine-growing regions. This success, Allen writes, is largely due to the combination of aromas that come from grapes of different maturity and harvested at different stages: on the one hand, green notes dominated by methoxypyrazines, and exotic aromas stemming from riper grapes – each with different characteristics depending on the taste as well of the respective winemaker as the climatic and economic conditions they are working in.

Yet, one has to add that in reality it is not that simple and as maturity in itself is a term that is not entirely black or white but can be defined in different ways. For Sauvignon Blanc, for instance, we need to recall that although during the ripening process methoxypyrazines degrade over time, the precursors to the thiols, cysteine and glutathione, need sufficient time to develop. Maturity in terms of grape ripeness therefore might be something entirely different as compared to the maturity of its aromatic compounds.

To give you another example, it can be compared to other great grape varieties such as Riesling, in which similar chemical processes take place and only a sufficient maturation period, which is usually between at least 100 and 120 days, means that it can achieve its typical elegance. Heat, which causes the must weight to rise, is not necessarily conducive to qualitative development, since the grapes ripen more quickly but do not have the required time to complete other important processes such as aroma development.

As demonstrated by researchers from the University of Florence, the same applies to Sauvignon Blanc, based on the development of the grapes in Bolgheri. In their study, they showed that premature ripening in a warm area led to a reduction in aroma potential. This led the researchers to conclude two things: firstly, that this could be caused by already established climatic events; secondly, that this is the proof that climate change has a direct influence on the phenological development stages of the grape. In turn, this leads to premature aging and thus affects the qualitative characteristics of the grapes.

Not only in climatic terms, but in other areas, too, has the wine sector seen a sea of change over the last couple of decades, be it in the vineyard or in the cellar. Technologization of cellar management has created a multitude of possibilities and the influence of harvesting methods and fermentation processes on the aromatic and phenolic attributes can also be demonstrated in Sauvignon Blanc. Ultimately, however – and research has shown this as well – it is the thiols that play a central role in the flavor profile favored by tasters due to the low threshold for the perception of such flavors.

At the same time, and this has also been shown by the various tastings over the past few years, the aromas created by methoxypyrazines give Sauvignon Blanc a recognition value that gives it a distinctive advantage.

Sauvignon and sensory analysis

Against the background of the different characteristics of the Sauvignon Blanc, this though takes us back to the initial question: how should the sensory properties of a Sauvignon Blanc be evaluated from a qualitative point of view.

The New Zealand model already mentioned is undoubtedly a Sauvignon success story. On the other side of the globe in California, Robert Mondavi laid the foundation for the success of his Fumé Blanc at the end of the 1960s by aging Sauvignon in oak barrels, which also found many imitators. Still, as MaryAnn Worobiec, Senior Editor of the Wine Spectator wrote a few years ago, one can only wonder whether Mondavi has had the same success elsewhere the world would have had given that many of these wines were basically unimpressive compared to the best French wines. Ultimately, this nothing but speculation , although terroir in this case certainly was not a huge part in the equation of Mondavi’s formula for success.

Worobiec also writes that while the success of New Zealand Sauvignon may be due to the combination of different aromas (i.e., presumably the combination of grapes from different harvest dates, which subsequently contain different amounts of methoxypyrazines and thiols), one should still give praise to the local winemakers since, in addition to the focus on better viticulture, the selection of the right locations also played a not inconsiderable role.

It is this aspect that Peter Dipoli pointed out in the discussion as the focus on the respective terroir, is also a solution in order to avoid competition and interchangeability with products from other regions. Thus, only the appropriate terroir would make the corresponding wine unique. He and Hans Terzer, cellar master of the renowned St. Michael Eppan cooperative winery, emphasized that eventually trying to copy other areas such as New Zealand or the Loire would be pointless. Instead, one should rightly be proud of one’s own style, such as the one created in a small region such as South Tyrol.

Aromatic differences in quality

But can this be used to draw conclusions about the variations in quality between the different styles based on their aromatic profile?

Picking up the baton during the conversation, Gianni Fabrizio said in his opinon wines made from unripe grapes are fundamentally just as flawed as wines made from grapes that are beyond ripe. It is certainly a justified statement, even if I am not an oenologist and therefore would not permit myself a judgement as to where exactly the limitations of ripeness are. Ultimately, however, it seems to me that far from being an incontestable question but rather another grey area that cannot be conclusively established and a diverging opinion on the subject may not entirely be out of place.

Yet, that what can be said is that it needs perfect grape material with regard to the longevity of wines. Therefore, since the aging ability of a wine is also often presented as a quality feature, ripeness as discussed above could well be a determinant in terms of overall quality in respect of aromatic profiles.

Returning thus to the aspect of terroir, it is interesting to see how much the differences in location, inclination, orientation and geological structure, which all form part of the concept that is terroir, can have an impact even in a relatively small region like South Tyrol with just 5,500 hectares. This was recently demonstrated through a study that extensively examined the geological and climatic differences within the region based on different locations. Among other things, the study highlighted that a varietal Sauvignon Blanc could only be produced in vineyards located at 450 meters above sea level or higher.

The comparison of the wine quality between the different geographical zones has revealed some characteristic qualitative traits that express the varietal typicality caused by the thiols. In turn, these are the direct result from the longer and slower ripening in certain locations that have a more suitable exposure or altitude.

Consequently, the importance of the right location – which is an essential factor for all grape varieties, it should be said – plays an important role in Sauvignon Blanc in particular, since the perceived sensory properties can be an expression of its origin. This extends naturally to the correct selection of the vineyard positioning as well with and only through proper work in vineyard and cellar.

Returning to the question raised at the very beginning though and seeking to provide an answer, I have to admit that, ultimately, I am not entirely sure whether it is necessarily the right approach to try and work out a divide between different group of consumers, as the question in the introduction suggests. Mario Pojer, the well-known winemaker from Trentino, casually expressed his point of view that was echoed many when he said that during his early days, he probably enjoyed just as much drinking Novello and wines with a strong barrique character as he does Nebbiolo today or most of the Sauvignons tasted during the discussion. Thus, everything is an evolution of taste and with growing experience one eventually enjoys things of higher quality.

Lastly, and for the sake of completeness, the event produces another interesting aspect with regard to the perception of aromatic quality and preferred styles. Each year the organizers don’t limit themselves to have the participating wines tased by the local jury; instead, the same wines are tested by a different set of experts from other locations such  as Friuli, the Loire, or Styria. This is particularly interesting because since the results tend to differ significantly in some regions while they produce similar results in others. That, in turn, leads to the conclusion that the perception of what makes a great Sauvignon differs fundamentally depending on the origin and background of the audience.

Hence, this last point together with the arguments presented above makes me believe that it may actually be more important to communicate and explain where the differences lie, why the styles are the way they are, and what’s essentially in the bottle. After all, this is an aspect that is becoming increasingly relevant, especially with regard to the sustainability of viticulture. And that’s all the more important when it comes to such a versatile grape variety such as Sauvignon Blanc.

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