Definition - What does Wine Press mean?
A wine press is a tool used to extract juice from grapes. The press applies a certain amount of controlled force to release the juice from the grapes. Care is taken so as not to crush the seeds and release a heavy amount of tannins into the wine.
There are several different styles of wine presses but they all accomplish the same important task- releasing as much juice from the grapes as possible with the least time and effort.
WineFrog explains Wine Press
In the earliest records of wine making, grapes were crushed using human force. Grapes were placed in large tubs, and vineyard workers would stomp the grapes with their bare feet. The juice was then poured into vats for fermentation. This method worked well until wine makers needed larger quantities of wine to meet larger demand. Grape stomping proved too labor intensive, and the first mechanical wine press evolved from this need. The oldest wine press was discovered in Armenia, and it dates back approximately 6,000 years. The wine press is considered one of the pivotal innovations that revolutionized the art of wine making. Although all wine presses perform the same juice extraction, there are different methods employed by several types of wine presses.
Basket Press - One of the earliest wine presses, the basket press uses a large plate that is lowered into a basket full of grapes. The pressure of the heavy plate crushes the grapes and forces the juice through the basket slats into vessels for fermenting.
Horizontal Screw Press - Similar to the basket press, the horizontal screw press applies pressure to the grapes using large plates located on the sides of the container, instead of at the top. The plates are forced together horizontally, crushing the grapes and extracting the juice. This method produces more juice per press and is used when wine makers need to produce larger quantities of wine.
Bladder Press - The bladder press uses a large cylinder and a rotating bladder mechanism that inflates and crushes the grapes against the side of the cylinder. The extracted juice is then decanted through small openings in the cylinder.
Continuous Screw Press - When wine makers need a press that can handle the largest volume of grapes, they employ the continuous screw press. An Archimedes screw applies pressure and crushes grapes against the sides of the press, extracting the juice. The leftover pomace, or grape solids, is discarded while new grapes are continuously fed through the press. This process is repeated indefinitely and produces large amounts of juice to be fermented into wines. This press is not commonly used in the production of high quality wines.