In the third part of our series on the art of blending, Westgarth Wines wine specialist Maurizio Broggi looks at the specifics of two of the most key white wine blends.

In the fine wine world there are as many white blends as there are red, but few that command such renown as those of Bordeaux, whose Grand Vins seek to balance body and freshness to create a captivating drinking experience, and of course Champagne where blending is used for both consistency and expressiveness.

Among the world-class white wines, Bordeaux whites hold a well-deserved place, especially those from Graves and particularly Pessac-Léognan – the finest dry whites in Bordeaux. These wines are typically barrel-fermented and matured, blending Sauvignon Blanc and Sémillon, sometimes with small proportions of Muscadelle and/or Sauvignon Gris.

While Sémillon was once considered to be Bordeaux’s primary white blending grape, Sauvignon Blanc takes a more central focus today, with some white Bordeaux wines even comprising 100% Sauvignon Blanc. Sauvignon Blanc contributes crisp acidity and fruity, aromatic character, while Sémillon adds weight and body, softening the sharp acidity of Sauvignon Blanc. Muscadelle provides grapey and floral aromas, Sauvignon Gris imparts perfume and body.

The actual blend is very flexible and depends on the house style of each château. Celebrated classed growth Smith Haut Lafitte typically crafts its white Pessac-Léognan with 90% Sauvignon Blanc, 5% Sémillon, and 5% Sauvignon Gris. By contrast, the historic Château Pape Clément adopts varying proportions depending on the vintage, with approximately 50-70% Sauvignon Blanc with 20-40% Sémillon, 1-5% Muscadelle, and 0-7% Sauvignon Gris.

Not surprisingly, Bordeaux’s exceptional sweet wines – Sauternes and Barsac – also rely on the same grape varieties. However, in these luscious, long-lived sweet blends, Sémillon usually takes the lead as the dominant grape. Sémillon contributes richness, texture, weight, and aging potential, while Sauvignon Blanc plays a crucial role by providing fresh acidity that balances Sémillon’s opulence.

Any discussion on blending would be incomplete without considering Champagne. Blending is a pivotal step in Champagne production. Each champagne producer has developed a distinctive house style through assemblage, ensuring consistency year after year despite significant vintage variations.

The three primary grape varieties – Chardonnay, Pinot Noir, and Pinot Meunier – play crucial roles. Chardonnay contributes steely acidity, aging potential, and linear structure. Pinot Noir provides body and structure, while Pinot Meunier adds floral and fruity notes. These grapes may originate from diverse vineyards, soils, climates, and villages, offering many nuanced possibilities for blending.

In total, there are eight permitted Champagne varietals, including Pinot Gris and Petit Meslier. Some varietals feature in blends to add subtle nuances like florality and herbaceousness, and other newer varietals have been developed to include more fungus-resistant fruit.

After alcoholic fermentation, the base wines or vins clairs are tasted to understand quality and characteristics. As the year progresses, decisions are made based on these tastings and the character of the base wines. Some lots of Chardonnay may provide acidity, while others have floral or citrus and green fruit notes. Some lots of Pinot Noir may offer more body and structure, while other attractive red fruit notes. During the assemblage, all these features are carefully considered as the final blends take shape.

Current vintage base wines aren’t the sole blending components in the assemblage as reserve wines play a crucial role in Champagne. Reserve wines consist of base wines from previous vintages, stored in various vessels such as stainless-steel tanks, oak casks, and sometimes even magnums. In Champagne, reserve wines are indispensable, especially for non-vintage cuvées, as they help maintain the house style and ensure that the wines are approachable at a younger age. Additionally, they contribute to the complexity, balance, and character of the top cuvées.

Blending Champagne base wines presents unique challenges. These wines inherently lack balance and only achieve their correct equilibrium after the second fermentation and aging on lees. Furthermore, they lack the balance provided by dosage (liqueur d'expédition) – the mixture of wine and sugar that counterbalances Champagne’s racy acidity.

While non-vintage blends already showcase the wines’ character, top cuvées like Cristal, Krug, or Dom Pérignon are meticulously blended to achieve structure and complexity for long aging, allowing them to develop character during extended bottle aging.

Creating a successful Champagne base wine blend is no easy task. These wines are acidic, lean, neutral, and dry. Achieving a blend that will develop into a balanced, complex wine that maintains the house style or assembling a top luxury cuvée that will go through extended bottle maturation requires remarkable skill. Master blenders in Champagne must possess not only a keen nose and palate but also intuition and an excellent memory. Recalling previous vintages and wines is essential for maintaining the house style and understanding how these components will marry together in a top cuvée destined for long aging.

Want to read more? Take a look at some of our other blogs:

• • The art of timing the harvest
  • How winemakers measure grape ripeness
  • The harvest dilemma – navigating environmental and practical constraints