“Prise de mousse” with a shortened 1-step yeast starter preparation
Presented by
Description
The “prise de mousse (PDM)” or secondary fermentation is the step that allows a base wine to become sparkling or effervescent. It requires the preparation of a yeast starter also know as “pied de cuve (PDC)” made of yeasts capable of consuming all the fermentable sugars and transforming them into alcohol and carbon dioxide, the gas that drives the effervescence. The quality of the PDC is therefore essential to a successful PDM. Traditionally the PDC is prepared in three days but this study showed that the preparation time can be reduced by half (36h) and to a single step. This work is based on the optimization of the existing protocol by adjusting the contents of sugars and assimilable nitrogen. It allows us to propose a new technical solution for the yeast starter preparation able to perform a PDM in a time equivalent to the protocol traditionally used (72 hours). This study was performed with three "Champagne" yeast strains and two PDM temperatures (14 and 18°C). Twelve months after the start of the PDM the bottles were riddled and disgorged. The tasting showed no sensorial differences between the sparkling wines made from the two yeast preparation methods. This technical progress in the preparation of the PDC allows for a 50% reduction in the downtime of the yeast tanks, as well as a reduction in the associated energy costs (electricity).
