One of the great varietals in the world is undoubtedly Sauvignon Blanc. With a history dating back centuries, wines made from this very special grape have played major roles in establishing some of the world’s finest wine regions. When fermented dry, Sauvignon makes some of the easiest-to-appreciate, crisp, expressions of green apple, wild grasses, and citrus. Sweet wines made from the grape are typically profound expressions of honey and spice. However, making memorable Sauvignon is not a process lacking in challenges.
From the vineyard to the winery, Sauvignon requires a very definite structure in order to deliver a true expression of the varietal. In the vineyard, Sauvignon is overtly vigorous and needs constant attention in order to harvest fruit that is not aggressively herbaceous, affected by powdery mildew or black rot. It naturally flowers late and ripens early – even in the coolest of climates. Depending on its intended use, it is either picked in early September or late in the fall before frost can damage the sweetly shriveled clusters of grapes.
For Sauvignon meant to be fermented dry, a slightly sweet, high acid harvest schedule applies. The grapes are normally gathered over several weeks, beginning in early September, in order to maximize both the declining acidity and rising sweetness.
For Sauvignon grapes that are meant for sweet wines such as Sauternes – made in the Graves district of Bordeaux France – an appropriate amount of Noble Rot (Botrytis cinerea) has to have affected the clusters of grapes and concentrated the sugars. Botrytized grapes must be conscientiously picked in order to achieve premium results during the winemaking process.
All winemaking styles aside –there are significant variations between New and Old World dry and sweet wines made from Sauvignon– it is the snappish, aromatic qualities of the dry white wine that have gained global prominence as a result of experiments in vineyards and winemaking.
After decades spent experimenting with vineyard yields and winemaking influences –including fermenting Sauvignon musts in oak and stainless steel, variations in yeast selection, and the use of corks or screw caps– wineries around the world have come to their own meticulous means by which to feature the particular attributes of Sauvignon.
It is felt by many that a low yield (0.6 tons/acre in the Loire Valley – this is extreme compared to an average of about three tons per acre in America), plus low temperature fermentations (< 60º F) in stainless steel, plus the use of various yeasts to impart a multitude of flavors in the wine, plus the subtle influence of neutral oak ageing, produces the best expression of dry Sauvignon possible.
For sweet Botrytized wines of Sauvignon, the grapes mature as they normally would on the vine, but eventually (Botrytis is naturally infrequent but for certain parts of the world) retain a shriveling rot that concentrates the sugars within each grape. Wines made from these grapes often see only new oak and are typically blended with Semillon.
For many producers, the last remaining issue in preserving the character of Sauvignon is whether to bottle it with a screw top or a cork. Depending on whom you ask, there are benefits to each choice/option. In my experience, screw caps are easiest to open and re-close. They epitomize the modern quest for a quick and trouble-free quaffable wine drinking experience. Corks are a bit more involved in the opening, but offer just as good a closure.
The only major difference that I (and my colleagues at Bernardus Winery) have noticed is the tendency for Sauvignon (and other white wines) to retain a particular reductive quality in the bouquet when it has been sealed with a screw cap. This is largely due to the “perfect” seal a screw cap delivers. It is airtight and therefore does not permit the natural ageing potential imparted by oxygen that naturally passes through a cork closure. Although no significant palatial variations seem to be evident in a bottle that’s been sealed with a screw cap, a lackluster aroma on a Sauvignon (or any wine for that matter) is no one’s friend.
With corks, Sauvignon – and all wines – will undergo an extended micro oxygenation as oxygen within the cork and outside the bottle effects the wine slowly over time, ageing it, drawing flavors and aromas together until they are in union and the wine, instead of being an amalgam of nuance and flavor, evolves into a singular quality.
Granted, dry Sauvignon is not a subtle age-worthy wine, but one that should be enjoyed as soon as possible after harvest and fermentation are complete. It is not meant to be cellared and therefore it does not require the effects of a cork to aid its development.
One issue with the use of corks is the potential for “cork taint.” This is especially prevalent among white wines, which are more delicate than red wines. Cork taint, as described by Jancis Robinson in The Oxford Companion to Wine, is defined thusly: “Although research results vary, around 5 percent of all wines sealed under cork display a musty taint. This is caused by a number of potent organic compounds the most significant of which is 2,4,6-trochloroanisole, or TCA … These taint compounds are metabolic products of funghi [sic] naturally present in cork, or which have grown in the cork at various processing stages….”
Cork taint has been a major catalyst in the winemaking industry’s move toward screw caps.
Sweet wines made from Sauvignon, including but not limited to Sauternes, are most definitely age-worthy and therefore do require a cork for maximum expression of the wine’s nuances when Botrytized. For it is only through ageing sweet Sauvignon that the majesty of this wine style is achieved. Wines from Sauternes can be cellared for decades because of their sweetness and acidity.
What it comes down to is being aware of what you are buying, how and where it was produced, and why you might be elated or bummed when you open the bottle. A simple search online or at your local bookstore can make all the difference between buying a rising star or a real stinker.