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Pressurized bladder crushes grapes

Pressurized bladder crushes grapes

Villagers don’t dance barefoot in the vats to crush the grape harvest anymore. The burgeoning worldwide wine industry demands higher volume and greater consistency. French manufacturer Fabbri SA, a winemaking-equipment specialist in Entraigues, offers its Optimal line of wine presses to provide just those factors.

Fabbri's Optimal line of crushers features a gentle pressing action — powered by pneumatics — suitable for all types of grapes, fresh or fermented. Stainless-steel construction eliminates the danger of contamination from grease, metal chips, or other substances. A range of press sizes can handle juice volumes from 132 to 9,000 gal.

Getting it done

About half of the cylindrical press chamber’s surface is perforated with laser-cut slots that allow the juice to pass through easily and exit. The other half of the cylinder surface is unbroken, except for doors to load the grapes and unload the press cake at the end of a cycle. A flexible food-grade synthetic membrane separates the two halves of the press chamber. An electric motor rotates the cylinder on its longitudinal axis to position it for loading and unloading, to tumble the grapes, and to break up the press cake for easier removal.

Grape crusher applies compressed air to one side of a bladder to squeeze juice out of grapes. Vacuum is then used to pull the bladder back to its fully retracted position.

After grapes are loaded into the press, compressed air slowly inflates the membrane so it presses the grapes against the perforated surface. After the pressing cycle is complete, a solenoid valve vents the membrane to atmosphere while a vacuum pump evacuates the remaining air — pulling the membrane back against the inside surface of the drum.

Fabbri delivers the Optimal presses with one or two high-quality, industrial air compressors and a vacuum pump. (A two-way valve permits connecting an external air supply.) Users can choose manual operation or automatic cycling managed by a PLC for more consistency. Typical cycles gradually build pressure to a maximum of 2 bar and hold it between 2 and 20 minutes.

Harv Tomlinson, of Oklahoma Export Co., the US agent for Fabbri, provided information for this article.