Part of the traditional process of red winemaking involves a maceration step, allowing the skins and seeds of the grapes to “steep” together for a certain period of time in order to extract the desired compounds that make up a quality wine. If one just leaves the skins and seeds sitting in the wine and leave it alone completely, eventually all the skins will rise to the top, forming a hard, virtually impenetrable cap resulting in poor extraction, and poor yeast performance, just to name a couple examples.
What winemakers and cellar workers have to do to improve performance and optimize phenolic and other compound extraction from the skins and seeds to the wine, they must “stir up” the solution, punching down the skin/seed cap at the top and reintegrating it into the wine. More extraction can occur, and then over time, the skins and seeds float back up to the top. You can see then, this becomes a cycle of punching down and mixing, which depending upon how it is done can be time consuming and relatively difficult.
One of the more recent technological advances to help improve maceration techniques is the Ganimede fermentation method, and is the focus of the study presented to you today. Very briefly, the Ganimede fermenter consists of an inverted cone inside and toward the top of the device, allowing carbon dioxide to become trapped in the space between the cone and the side of the fermenter. As fermentation goes along, the CO2 continues to build up until the pressure is high enough to be released through an external pipe that connects back to the top of the fermenter, effectively pushing the skin and seed cap back down into the must. This is apparently a much more gentle method than physically punching down the cap with more traditional materials and equipment.
How does the Ganimede fermentation method compare with traditional fermentation and maceration methods in terms of the phenolic profile of finished wines before and after aging? Is the Ganimede fermenter as successful as traditional maceration in extracting phenolic compounds from the must? How does a wine fermented in a Ganimede fermenter fare with aging compared with traditional methods?