Reproduced from Year 4, Issue #18 of Spirito di Vino Asia...
This series of article has taken the view that style, or the personality of the wine, and quality, its degree of excellence are two fundamentally different issues when it comes to scoring wines. This is why it is imperative to understand how key production methods affect style so that quality can be fairly evaluated.
For the sparkling wines category, three main factors fundamentally influence the style of the final wine not only in terms of effervescence, but also in terms of body, aromatic profile and texture. The first relates to how the bubbles, also called the “mousse”, are obtained. The second is the choice of grape varieties for the base wine and the third concerns the sweetening of the final wine.
Most sparkling wines today, with a few exceptions, are the result of a second fermentation in a pressurized container to trap the CO2, a by-product of fermentation with yeasts, and give the wine its fizz. Of the two most common methods, the most traditional consist of encouraging the bubbles to develop in a bottle while the other is to trigger the development of the mousse inside a stainless steel tank. In both methods, once the second fermentation has run it course, lees from the spent yeasts remain into the wine for a period. Key is that each method allows for very different winemaking techniques and thus results in completely different styles.
It is common in the traditional method to leave the lees undisturbed for several months, sometimes years, in order to encourage the development of an “autolytic” character reminiscent of biscuit, pastry-like or fresh bread. Autolysis also contributes to increase body and enhance the voluptuousness of texture. As the second fermentation occurs in a bottle at cellars temperatures around 10-12C, the process can be very slow and the resulting style emphasizes complexity of the autolytic character and the subtlety of fruit aromas as well as the velvety aspect of its texture.
In contrast, in the tank method, the lees tend to naturally settle at the bottom of the tank and this in turn minimizes the autolytic character and helps preserve the freshness of the grape aromas. In addition, the temperature can be easily maintained at around 18C during the second fermentation and maturation so that secondary aromas from various esters can be produced to further emphasize freshness of fruit and a perfumed character to the wine. The resulting style is a wine that is fresh, vibrant, and refreshing in many ways.
Some grapes are selected for their aromatic character while others are selected for their neutrality and/or ability to age for long periods. Key to style is the blend of the grapes used for the final wines, as each variety will react very differently to various winemaking techniques and provide varied characteristic to the final wine. For example, Pinot Noir contributes flesh and muscle and the resulting wines using it in high proportion are mostly be great partners to food. Chardonnay on the other hand provides a lemony mineral character as well as finesse and elegance and the wines are the ones with the longest ageing ability. Aromatic grapes like Moscato Bianco, used to produce the wonderful Moscato d’Asti, are handled in a specific way to emphasize its delicate notes of spring blossom and stone fruit aromas while the grape of Glera, used to make Prosecco, benefits from fermentation at cool temperatures and minimal autolytic character to yield wines of beautiful perfume and vibrancy of texture.
Most sparkling wines are from cold to cool climate origins and therefore are naturally high in acidity. In most cases, the second fermentation which adds body, the use of lees and other techniques such as oak ageing and artful blending do not soften the hardness of the acidity to the extent required. In such case, balance in the final wine is obtained through the addition of a sweet solution, called “liqueur de dosage”, to the final wine just before shipping. Depending on the final its sweetness, it is labeled as Brut (below 12 g/l of residual sugar), Extra-Dry (12-17 g/l), or Dry (17-32 g/l). For very low sweetness, the wines are labeled as Brut Nature (0-2 g/l) or Extra-Brut (0-6 g/l).
The method of production, the grapes, and the final sweetness greatly influence the final style of sparkling wines and all must be taken into consideration in a fair comparative evaluation of quality.
In the next issue, we will look at the effects of vintage variation on quality.