19/09/2021 05:45
How does winemaking influence an oxidative or reductive style? What is the affect on the final champagne and how does it influence its profile over time or ability to age? It takes a molecular sommelier to find out. Marcell Kustos, PhD, explains.
Champagne is home to a wide array of styles and wines. The distinct aromas and textures of each house are often attributed to the dominant grape variety of the blend, farming practices, time spent on lees, malolactic fermentation and dosage. While undoubtedly important, they come only second after the type of vessel used to ferment and store the base wine and reserves. As surprising as it might sound, this initial decision influences all consequential steps in winemaking. Broadly, the chosen vessel affects the level of exchange between wine and air, resulting in two basic styles: reductive and oxidative. How do these contrasting styles affect the aromas, flavours and texture of champagne wines?
Reductive champagne styles emerge from reducing oxygen exposure during winemaking. The purpose of this method is to preserve the fresh floral and pristine fruit aromas and produce a crisp, lighter-bodied and mineral style. Typically, the base wine is protected from oxygen, it ferments and matures in stainless steel vats instead of porous oak. In the absence of oxygen, sulfidic aromas arise, such as flint, gunpowder and struck match which are desired by many champagne lovers for the added layer of interest.
The reductive style lends itself to chardonnay-driven, linear champagnes with little or no malolactic fermentation as well as low dosage (0 – 6 g/L). To achieve the coveted vividness, they often contain less reserve wine. How do winemakers still achieve such complexity in reductive vintage champagnes? Interestingly, the praised toast and brioche aromas are formed by a particular type of reduction: yeast autolysis.
During extended aging on lees, the unique aromas and textures of champagne’s character develop through yeast autolysis in a reductive environment. The resulting champagnes are pure and layered with elegance and tension. However, when the reductive style is taken to the extreme, it can produce unpleasant aromas like rotten eggs, rubber, sewage and even skunk.
Oxidative styles introduce a controlled amount of oxygen at various stages of vinification. The most common form is fermenting and aging the base wine in oak barrels or vats to develop more decadent aromas, texture and interest. For the same motive, reserve wines are purposefully stored in wooden vats and blended with non-vintage champagne to add complexity. More often than not, oxidative styles also boast large percentages of reserves (sometimes up to 65 percent). Interestingly, each of the three main grape varieties is expressed differently by oxidative winemaking. Chardonnay develops aromas of toast, almonds and quince jelly, whereas pinot noir evolves toward hazelnut and tobacco. Meunier leans into field mushrooms and forest floor.
Hence the combination of vessel choice and grape variety is an indisputable cornerstone of house style.
Oxidative champagnes are typically medium to full-bodied, round and pinot noir-dominant. Full malolactic fermentation and higher dosage (8 – 12 g/L) tends to complement the inherently more winey character, although there are exceptions. On the downside, too much oxidative handling can accentuate aldehydic aroma compounds (think bruised apple, honey and sweat) at the expense of freshness. In some instances, malolactic fermentation can throw-up cream and yoghurt aromas but also turn into smelly cheese.
Are all champagnes either oxidative or reductive? The reality is hardly ever binary. Most champagne is made using the combination of both techniques to maximise complexity and retain freshness. Charles Heidsieck and Louis Roederer, for example, are considered great examples of blurring the line between reductive and oxidative practices in the pursuit of balance.
Does style affect aging potential and quality? Whether a champagne is oxidative or reductive doesn’t make a difference to its age-ability or quality. There is a consensus in that both styles can add complexity and interest, but the extremes of either side will dominate the fine details of champagne and kill the fizzy romance. High-quality, balanced champagne ages gracefully and the choice between reductive and oxidative comes down to preferences.
Without the sense of exclusivity, here are some recommendations from both sides of the style debate.
Reductive
Taittinger, Ruinart, Moët et Chandon, Billecart-Salmon, Salon, Egly-Ouriet, Pol Roger, Laurent-Perrier and Louis Roederer.
Oxidative
Bollinger, Krug, Vilmart & Cie, Jacques Selosse, Jacquesson and Bérèche et Fils.