What is bâtonnage?
During the fermentation process, yeast transfers the sugar to alcohol and when its work is done, the yeast cells die and drop to the bottom of the tank or barrel forming a fine deposit. Over time, the yeast cells break down and release a number of different compounds back into the wine (amino acids, mannoproteins, fatty acids). These compounds give complexity to the wine. They contribute to the ‘mouthfeel’ of the wine and to its aromas and flavour.
Bâttonage is the French word for stirring the ‘lees’ (the name given to the deposit). As you can see from the picture before the wine is stirred it’s perfectly clear and after bâtonnage has taken place it becomes cloudy. This is because the deposit is stirred up using a special tool that can reach even the most inaccessible parts of the barrel and in doing so it redistributes the sediment among the wine, maximising contact with the dead yeast cells.
The amount of time that a wine stays in barrel (or tank) on its lees will depend according to the vintage year. Not all wines are stirred – this will be a decision taken by the winemaker according to the style of wine he or she is making.
These pictures were taken at Chateau de Fesles in Anjou when winemaker Gilles Bigot was stirring all the barrels of Chenin Blanc during our visit.