In the second part of our series on the art of blending, Westgarth Wines wine specialist Maurizio Broggi looks at the specifics of blending red wines.

Bordeaux, Rioja, and Southern Rhône red wines are examples of prestigious red blends. Where single-varietal red wines, such as Burgundy, look to express the nuance of a sole grape variety in its totality, red blends look to balance the strengths of several grape varieties to create an intricate mosaic of expression.

In Bordeaux, assemblage is the process of selecting the lots that will make up the final blend. Many châteaux produce their grand vin by choosing and combining only the finest lots. The lots that don’t make the cut may be used to produce a second wine (and sometimes even a third wine). Alternatively, the château may decide to sell these wines to negotiants to produce commune- or regional-level wines.

The process is typically carried out within the first few months after fermentation. During this phase, decisions are made regarding which wine lots will be blended to create the primary grand vin for that vintage. The blends are primarily based on Cabernet Sauvignon, Merlot, and Cabernet Franc along with smaller proportions of other auxiliary grapes such as Petit Verdot and Malbec.

Typically, the wines of the Left Bank (such as Médoc and Graves) tend to be based on Cabernet Sauvignon, with Merlot and Cabernet Franc playing supporting roles. The wines of the Right Bank (such as Saint-Émilion and Pomerol) tend to be predominantly based on Merlot, often with Cabernet Franc as the second main blending partner alongside, but to a lesser extent, Cabernet Sauvignon.

The château’s choice regarding the proportion of each specific grape variety in the blend is based on their objectives of style, balance, and quality. However, this decision is significantly influenced by the vintage and the performance of each grape variety in that specific year.

Frequently, supporting grape varieties such as Cabernet Franc play a crucial role in shaping the wine’s character. In Pomerol, during dry and ripe vintages such as 2015, 2016, or 2018, the vibrancy and freshness provided by Cabernet Franc have been pivotal in balancing the opulence of the dominant Merlot.

In Saint-Julien, Château Léoville-Las Cases’ grand vin is largely based on Cabernet Sauvignon, which accounts for 75-80% of the blend, along with a small proportion of Merlot and Cabernet Franc. While Cabernet Sauvignon contributes structure, power, and concentration, and Merlot adds softness and body, Cabernet Franc truly harmonizes the blend by providing it with complexity, elegance, and refinement.

Historically, the red wines of Southern Rhône have been crafted as blends, combining several grape varieties. Particularly, Grenache typically takes center stage, accompanied by Mourvèdre and Syrah. Carignan and Cinsault will occasionally play a role in the blend also.

While Southern Rhône blends can seem convoluted by the number of varietals used, each plays a very specific part in the structure of the wine. Among them:

• Grenache contributes red fruit flavors, along with spicy and garrigue notes, while providing a soft body and alcohol;
• Syrah adds structure, fruitiness, acidity, and color; and
• Mourvèdre enhances the wine’s color, along with black fruit and tannins.

While all Southern Rhône appellations require a certain proportion of grape varieties (with Grenache as the dominant grape), Châteauneuf-du-Pape – the region’s most prestigious and powerful wine – permits the use of up to thirteen grape varieties without specifying any minimum requirement. This flexibility empowers producers to choose grape varieties freely for their blends. Notably, the renowned estate Château de Beaucastel makes its distinguished Châteauneuf-du-Pape ‘Hommage à Jacques Perrin’ primarily from Mourvèdre.

Rioja, Spain’s most famous wine region, is known for its traditional red blends primarily based on Tempranillo. These blends often incorporate Garnacha (Grenache) and smaller proportions of Mazuelo (Carignan) and Graciano.

Tempranillo forms the backbone of the blend, imparting flavors of raspberry and strawberry. Garnacha adds body, while Mazuelo and Graciano enhance the blend with fresh acidity.

Historically, Rioja wines were shaped by extended maturation in American oak barrels, resulting in a savory character with aromas of dried fruit, cured meats, and dill, alongside sweet spice notes of coconut and vanilla. However, today many producers produce more modern and less traditional styles. Maturation periods are shorter and French oak has become prevalent, although some still adopt American oak or a combination of both. This flexibility allows for creative blending combinations based on the type of oak adopted and the length of aging in barrel.

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

• • The art of blending: the fundamentals
  • Alcoholic fermentation: yeasts
  • Oak and barrel maturation: types of wood