The Art and Science of Crushing Grapes in Winemaking

The culture of wine dates back as far as 7000 BC when it was consumed for religious rituals and medicinal purposes. Its production and consumption became more widespread in the 15^th century during the European expansion. Eventually, wine made its way to the U.S. around 1562 by way of the French Huguenots who settled in Jacksonville, Florida. The settlers used native Muscadine grapes to produce Scuppernong wine.

History of the wine press

Much like the infamous grape stomping episode in “I Love Lucy,” treading grapes was the earliest form of extracting juice for winemaking. Winemakers would fill hollow logs with grapes, tread the fruit with their feet, then scoop the juice and crushed grape remnants into jars for fermentation.

Today, the process is less messy and less time consuming. Many wineries use wine presses like pressurized bladders to breakdown the fruit pulp and allow its juices to flow out. Here’s how it works: 

• Grapes are loaded into the cylindrical press chamber
• Compressed air enters the membrane and presses the grapes against the perforated half of the chamber’s surface
• A solenoid valve vents the membrane while a vacuum pump evacuates the remaining air, pulling the membrane back against the inside surface of the drum

Properly sizing a press comes down to three important questions: 

• How much do I have to press?
• How much can I press at the same time given the size of the press?
• How long will each press cycle take? 

Answering these questions will help determine the amount of time needed to set up/fill the wine presser, press the grapes and clean up. For more info on how compressed air and vacuum are used for winemaking, reach out to an Atlas Copco expert.