Carbonic Maceration - History

History

The process of carbonic maceration occurs naturally in a partial state without deliberate intervention and has occurred in some form throughout history. If grapes are stored in a closed container, the force of gravity will crush the grapes on the bottom, releasing grape juice. Ambient yeasts present on the grape skins will interact with the sugars in the grape juice to start conventional ethanol fermentation. Carbon dioxide is released as a by product and, being denser than oxygen, will push out the oxygen through any permeable surface (such as slight gaps between wood planks) creating a mostly anaerobic environment for the uncrushed grape clusters to go through carbonic maceration. Some of the earliest documented studies on the process were conducted by the French scientist Louis Pasteur who noted in 1872 that grapes contained in an oxygen rich environment prior to crushing and fermentation produced wines of different flavors than grapes produced in a carbon dioxide rich environment. This was because the fermentation process had already started within the individual grape clusters prior to the introduction of yeasts during conventional fermentation.