rotofermenter or rotary fermenter, a horizontal fermentation vessel arranged so that the contents can be mixed mechanically either by rotating the vessel, or by rotating an inner shaft fitted with vanes in a stationary vessel. Designed to eliminate the need for punching down or pumping over, this equipment speeds the maceration phase of red winemaking. Some European wine producers, notably in Burgundy, have invested in them, as have a number of new world winemakers. Like most mechanical systems that promote skin–juice contact, they are expensive and require extensive and robust framing structures to mount and hold the horizontal tank. Rotofermenters are usually controlled by computers, with cycles of rotation chosen by the winemaker.
