Wine Press Troubleshooting: Causes & Fixes

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Problems on this page:

Press cycle taking too long Juice yield lower than expected Juice too high in solids or phenolics Membrane leaking or torn Air or vacuum system faults Oxidation of the juice Cleaning problems Loading and emptying slow

Press cycle taking too long

Hits OEE: Performance

Symptoms: Pressing a load takes longer than usual, and the receiving bins back up.

Drainage channels or screens blocked

Clean the drainage channels and screens between loads.

Membrane pressure steps set too high too early

Check the pressing program; a gentle start keeps the cake draining.

Grapes not crushed or destemmed as planned

Check the destemmer and crusher settings for the variety.

Press loaded above its capacity

Check the load weight against the press capacity.

Prevention: Cycle time and load weight recorded per press.

Juice yield lower than expected

Hits OEE: Quality

Symptoms: Less juice per tonne of grapes than planned.

Pressing program too gentle for the target yield

Review the program steps with the winemaker.

Cake not crumbled between steps

Check the rotation steps between pressure steps.

Membrane not reaching pressure

Check the membrane and air supply for leaks.

Juice lost through leaks

Check the door seals and drains.

Prevention: Yield recorded per load.

Juice too high in solids or phenolics

Hits OEE: Quality

Symptoms: The press juice is too cloudy or harsh for the wine style.

Pressure too high in the late fractions

Separate the press fractions and stop at the pressure the winemaker sets.

Too many rotations breaking the skins

Reduce the number of rotations.

Screens damaged

Inspect the screens.

Grapes macerated longer than planned

Check the time from harvest to pressing.

Prevention: Press fractions tasted and measured per load.

Membrane leaking or torn

Hits OEE: Availability

Symptoms: The membrane loses air, or juice gets behind it into the air side.

Membrane worn or punctured

Inspect the membrane and replace it if it is cracked or punctured.

Sharp objects in the grapes

Check the sorting table and destemmer for stones, metal and wire.

Membrane clamping loose

Check the clamping bars and their bolts.

Pressure set above the membrane limit

Check the maximum pressure in the program against the maker limit.

Prevention: Membrane inspected before every harvest and after any leak.

Air or vacuum system faults

Hits OEE: Availability

Symptoms: The press cannot build pressure, or it cannot pull the membrane back.

Compressor or blower fault

Check the compressor or blower output and its alarms.

Air valve sticking

Service the air and vacuum valves.

Hose or fitting leaking

Replace leaking hoses and fittings.

Pressure sensor or controller fault

Check the pressure sensor against a gauge.

Prevention: Air system checked and serviced before harvest.

Oxidation of the juice

Hits OEE: Quality

Symptoms: The press juice browns or loses fresh aroma.

Inert gas protection not used or not working

Check the inert gas supply to the press and the juice tray.

Pressing cycle longer than needed

Shorten the cycle where the program allows.

Grapes arriving warm

Harvest or cool grapes so they arrive at the temperature the winemaker sets.

Juice tray open to the air

Cover the juice tray and pump juice away promptly.

Prevention: Juice colour checked per load.

Cleaning problems

Hits OEE: Availability

Symptoms: Grape residue remains between loads or at the end of the day.

Screens and drainage channels not cleaned

Clean the screens and channels with the press isolated.

Built-in spray system blocked

Check the spray nozzles and water pressure.

Cleaning water too cold

Check the water temperature for cleaning.

No written cleaning method

Write the daily and end-of-harvest cleaning sequence.

Prevention: Cleaning checked at the end of each day.

Loading and emptying slow

Hits OEE: Performance

Symptoms: The time between loads is long because filling and emptying are slow.

Must pump too small or worn

Check the must pump output.

Door jammed or slow to open

Check the door mechanism and seals.

Pomace cake not discharging

Check the rotation program for emptying.

Pomace conveyor stopped or full

Check the conveyor and the pomace bin change.

Prevention: Turnaround time between loads recorded.

Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.

Related equipment guides: decanter centrifuge · centrifugal pump · compressed air system · CIP system · fermentation tank

Stop the same fault coming back

Recurring wine press stops usually trace to a cause you cannot see by hand. The partner we recommend is Fabrico: it tracks OEE and downtime live from PLCs, IoT sensors or AI cameras; where cameras are fitted, the video of a stop sits next to its machine data so the cause can be reviewed; and a technician opens the work order from the stop in the same system. Data is hosted in the AWS EU region, and Fabrico and the company behind it hold ISO/IEC 27001, ISO/IEC 20000-1 and ISO 9001.

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Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover