But back to where power is not a problem, let s look at rotary fermenters and heating the grapes. Similar to a cement truck, rotary fermenters are vats with paddles in them. Turning the fermenter in one direction uses the paddles to mix the juice and grape skins, and turning in the other direction empties the fermenter of its contents. These kinds of fermenters tend to be very good with difficult grapes, such as Pinot Noir, that have relatively smaller amounts of colour pigments found in their skin. It is easy, however, to handle the grapes too roughly, which results in astringent flavours in the wine, so an experienced person is required to run the machine.
Less time is required to extract the various components.
The resulting wine often has a soupy character to it. Finally, carbonic maceration produces light and fruity wines that are best drunk early, within a few months of the harvest. The most famous example of wine made using this method is Beaujolais Nouveau, released in the second half of November every year. For this reason, whole grape bunches are needed to be able to do carbonic maceration. The grapes are placed in a vat that will have been flushed with CO2 gas to prevent oxidation, and without any oxygen, the grapes start to die.