Bleeding is a corrective practice that balances the marc/juice ratio in a vat. It is used when a plot has produced much more than expected or if the berries are very large. The objective is to concentrate the must in order to obtain a more balanced wine. The must drawn off during bleeding is used to make rosé.
For it to be effective, it is necessary to bleed the must immediately following vatting so as not to lose anthocyanins unnecessarily. Moreover, a minimum juice volume of 15% must be removed for the effect to be significant. More substantial bleeding may be carried out depending on the average berry volume. Note that in the case of an under-ripe harvest, bleeding can lead to an over-expression of herbaceous aromas.