*Chaptalization is the process of adding sugar to must or juice before fermentation. This process is practiced in cool weather regions, where under ripeness are a problem and the sugar level of the grapes is too low to rich the desired alcohol level.

*Grapes with too much sugar mean a lot of alcohol will be produced and that can cause problems with the primary and secondary fermentations. High alcohol level is inhibitor for most yeast strains and malolactic bacteria and actually kills them which will cause a stuck or sluggish primary or secondary fermentation. To prevent that some water need to be added to lower the brix level, this will reduce the potential alcohol of the wine. However this practice could cause a dilution in flavors.