News from the Vineyard
September 15, 2021
By Edouard Bourgeois
After seeing a recent post from the always informative and beautiful Instagram account of Domaine Lafarge, I wanted to share a few thoughts on the magic of fermentation. In the social post, Clothilde Lafarge shows pictures describing the making of “a pied de cuve”. The French expression translates to “foot of tank” and is basically the winemaking equivalent of a sourdough starter to make bread. The idea is to cultivate local yeasts also referred to as indigenous yeasts, naturally present in the environment of the winery and the vineyard. Without yeasts, the alcoholic fermentation cannot occur and wine cannot be made. It is then essential to pay attention to the quality of these yeasts and their origin. Terroir? Did you say terroir?
The process aims to build a population of viable (alive yeast) and vital (strong) elements in the wild yeast culture in a small volume of wine. This helps the winemaker to complete a clean fermentation (low volatility and reduction, without spoilage yeast or bacteria) that successfully consumes all of the sugars leaving a dry wine.
The process involves picking a small amount of grapes a few days to a week before all of the grapes are going to be picked. The grapes are crushed and allowed to start fermenting. This builds the population of the native yeasts that were present on the grapes. This culture is then added to the rest of the grapes when they are picked.
Using a Pied de Cuve helps start a fermentation quickly, and, through its production of carbon dioxide, to protect the wine or bunches from oxygen exposure and potential production of volatility.
The Pied de Cuve is often built up by adding more fresh juice/grapes to double the volume when the yeast needs more food. This may be undertaken several times. Doing this increases the population of yeast to ensure there are enough to complete the fermentation of the main wine.
Like all things wine, there are thousands of different options for preparing a Pied de Cuve. Using whole bunches, just berries, starting the Pied de Cuve in the winery or in the vineyard, or even adding wild flowers to introduce the native yeast present on those flowers into the Pied de Cuve.ing of Pied de Cuve
Must in fermentation. The CO2 is a byproduct of alcoholic fermentation and forms this foam
