Many presses have a variable speed drive. This may be an electronically variable speed drive, a variable pitch drive, or another type of drive that allows the
pressing screw to be driven at different speeds.
Turning the screw(s) faster will put more feedstock through the press in a set amount of time and increase the oil production rate (gallon or liters per hour). This sounds like a great idea, but there are downsides to running the machine faster. As the screws turn faster, more material is moving through the press and this provides less time for the oil to migrate out and be separated from the meal. As a result, the slow-er the press is run the higher the extraction rate for oil; the less oil is left in the meal. If cold pressing of the oil is a requirement, then a slow-er speed is often necessary because as screw speed increases, the temperature of the oil and meal moving through the machine also increases. Temperature and efficiency of oil extraction need to be balanced against overall oil production to decide on a screw speed.
