grapepress

A grape press is a device used to extract juice from crushed grapes by applying pressure to the grape mash. It is used in winemaking and in the production of grape juice. The term historically referred to wooden basket presses, but modern grape presses include hydraulic, pneumatic (bladder), and continuous systems.

There are several types. Basket presses use a screw mechanism to press pulp against a perforated inner cage. Bladder or pneumatic presses use air pressure to gently squeeze the pulp, reducing harsh extraction; continuous screw presses push grapes through a series of rollers and pressure plates for high throughput.

Operation: Grapes are crushed or destemmed; the resulting mash is loaded into the press. Under pressure, juice is expelled while the pomace remains in the basket or chamber. Juice is often collected, clarified, and may be settled or fermented; the course of pressing influences color, tannin extraction, and aroma.

Applications and byproducts: In winemaking, pressing is timed to balance juice yield with desired phenolic extraction. In grape juice production, pressing yields clear juice with minimal skins contact. The solid residue, or pomace, can be used for distillation (grappa), animal feed, or compost.

History and design: Press technology evolved from heavy wooden structures to stainless steel with sanitary design, automation, and temperature control. Modern presses emphasize gentle, uniform pressing to preserve quality while maximizing yield.