Co-fermentation
Encyclopedia
Co-fermentation is the practice in winemaking
of fermenting
two or more grape varieties at the same time when producing a wine. This differs from the more common practice of blending separate wine components into a cuvée
after fermentation. While co-fermentation in principle could be practiced for any mixture of grape varieties, it is today more common for red wines produced from a mixture of red grape varieties and a smaller proportion of white grape varieties.
Co-fermentation is an old practice going back to the now uncommon practice of having field blends (mixed plantations of varieties) in vineyard
s, and the previous practice in some regions (such as Rioja
and Tuscany) of using a small proportion of white grapes to "soften" some red wines which tended to have harsh tannins when produced with the winemaking methods of the time. It is believed that the practice may also have been adopted because it was found empirically to give deeper and better colour to wines, which is due to improved co-pigmentation resulting from some components in white grapes.
appellation of northern Rhône
, while the use of white varieties in red Rioja and Tuscany wine has more or less disappeared. In Côte-Rôtie, the red variety Syrah and the aromatic white variety Viognier
(up to 20% is allowed, but 5-10% is more common) must be cofermented, if Viognier is used. The reason why Viognier has been kept in Côte-Rôtie (while for example the white grapes Marsanne and Roussanne
are hardly found any more in red Hermitage
or other red Rhône wines where they are allowed) is that it adds signature floral aromas to the wines. The popularity of Côte-Rôtie has led to New World
interpretations of this blend, most notably Australian
Shiraz-Viognier blends, which are also produced by co-fermentation.
The reason why co-fermentation is not more widely practiced, is that it "locks in" a certain blend already at the start of the fermentation, which gives the winemaker less possibility to adjust the blend after fermentation.
Winemaking
Winemaking, or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from other fruit or non-toxic plant material...
of fermenting
Fermentation (wine)
The process of fermentation in wine turns grape juice into an alcoholic beverage. During fermentation, yeast interact with sugars in the juice to create ethanol, commonly known as ethyl alcohol, and carbon dioxide...
two or more grape varieties at the same time when producing a wine. This differs from the more common practice of blending separate wine components into a cuvée
Cuvee
Cuvée is a French wine term derived from cuve, meaning vat or tank. The term cuvée is used with several different meanings, more or less based on the concept of a tank of wine put to some purpose:...
after fermentation. While co-fermentation in principle could be practiced for any mixture of grape varieties, it is today more common for red wines produced from a mixture of red grape varieties and a smaller proportion of white grape varieties.
Co-fermentation is an old practice going back to the now uncommon practice of having field blends (mixed plantations of varieties) in vineyard
Vineyard
A vineyard is a plantation of grape-bearing vines, grown mainly for winemaking, but also raisins, table grapes and non-alcoholic grape juice...
s, and the previous practice in some regions (such as Rioja
Rioja (wine)
Rioja is a wine, with Denominación de Origen Calificada named after La Rioja, in Spain. Rioja is made from grapes grown not only in the Autonomous Community of La Rioja, but also in parts of Navarre and the Basque province of Álava. Rioja is further subdivided into three zones: Rioja Alta, Rioja...
and Tuscany) of using a small proportion of white grapes to "soften" some red wines which tended to have harsh tannins when produced with the winemaking methods of the time. It is believed that the practice may also have been adopted because it was found empirically to give deeper and better colour to wines, which is due to improved co-pigmentation resulting from some components in white grapes.
Use today
The only classical Old World wine region where co-fermentation is still widely practiced is now the Côte-RôtieCôte-Rôtie AOC
Côte-Rôtie is a French wine Appellation d'Origine Contrôlée in the northern Rhône wine region of France. The vineyards are located just south of Vienne in the communes of Saint-Cyr-sur-le-Rhône, Ampuis, and Tupin-et-Semons. The vineyards are unique because of their vertical slopes and their stone...
appellation of northern Rhône
Rhône (wine region)
The Rhône wine region in Southern France is situated in the Rhône river valley and produces numerous wines under various Appellation d'origine contrôlée designations...
, while the use of white varieties in red Rioja and Tuscany wine has more or less disappeared. In Côte-Rôtie, the red variety Syrah and the aromatic white variety Viognier
Viognier
Viognier is a white wine grape. It is the only permitted grape for the French wine Condrieu in the Rhone valley.-History:The origin of the Viognier grape is unknown. Viognier is presumed to be an ancient grape, possibly originating in Dalmatia and then brought to Rhône by the Romans. One legend...
(up to 20% is allowed, but 5-10% is more common) must be cofermented, if Viognier is used. The reason why Viognier has been kept in Côte-Rôtie (while for example the white grapes Marsanne and Roussanne
Roussanne
Roussanne is a white wine grape grown originally in the Rhône wine region in France, where it is often blended with Marsanne. It is the only other white variety, besides Marsanne, allowed in the northern Rhône appellations of Crozes-Hermitage AOC, Hermitage AOC and Saint-Joseph AOC...
are hardly found any more in red Hermitage
Hermitage AOC
Hermitage is a French wine Appellation d'Origine Contrôlée in the northern Rhône wine region of France south of Lyon. It produces mostly red wine from the Syrah grape; however, small quantities of white wine are also produced from Roussane and Marsanne grapes...
or other red Rhône wines where they are allowed) is that it adds signature floral aromas to the wines. The popularity of Côte-Rôtie has led to New World
New World wine
New World wines are those wines produced outside the traditional wine-growing areas of Europe, in particular from Argentina, Australia, Canada, Chile, New Zealand, South Africa and the United States.-Early wines in the Americas:...
interpretations of this blend, most notably Australian
Australian wine
The Australian Wine Industry is the fourth largest exporter of wine around the world, with 760 million litres a year to a large international export market and contributes $5.5 billion per annum to the nation's economy...
Shiraz-Viognier blends, which are also produced by co-fermentation.
The reason why co-fermentation is not more widely practiced, is that it "locks in" a certain blend already at the start of the fermentation, which gives the winemaker less possibility to adjust the blend after fermentation.