Processing EVOO
Commencing mid autumn the olive fruit is monitored for ripeness. This is initially done by slicing some olives to see how far the colour of the olive skin has penetrated into the flesh or simply by hand crushing to feel how firm the olive is and how oily the flesh is. Sample batches of olives may also be sent to a laboratory to be analysed for oil content. In Australia, just using the olive's skin colour is not a good indication of ripeness as our stronger sunlight tends to darken the skin well before they are ready to harvest.
Harvesting early tends to produce a lower yield but a more pungent robust oil, harvesting later tends to produce a higher yield and a lighter softer oil. The oil aroma, pungency and taste also depend on the cultivar and local soil and climatic conditions - our terroir. As we have several cultivars planted and we aim to produce only the highest quality extra virgin olive oil, the actual harvesting can extend over a six to ten week period.
We use our own tree shaker is used to harvest the olives. This ensures sufficient fruit is available each afternoon to immediately process in one batch. Our daily batch run is typically 4 to 5 ton - about 10 crates. This ensures that the olives are not left sitting in bins or crates waiting for a sufficient quantity to be harvested prior to processing (typically the case for hand-picked olives) where they can overheat & commence to oxidise.
The tree shaker clamps rubber jaws around the tree trunk, then extends an inverted umbrella catching net around the tree. The jaws vibrate in a small cyclic motion, first in one direction and then in the other. Olives are quickly shaken from the tree into a bin located beneath the jaws. Typically it only take about one minute to shake a tree & move to the next. When the bin is full the olives are emptied into large crates and when the creates are full they are transported to the on-site processing facility.
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A fork-lift fitted with a tipping unit empties the crates into a large intake hopper where a conveyor feeds them past a leaf extraction fan and into a special olive washing facility.
After washing a modern hammer mill uses stainless steel hammers rotating at a high speed to crush the olives into a paste.
The paste is fed into a malaxing unit (like a big horizontal kneading machine) where it is gently stirred/mixed. Both the duration & temperature of the malaxing process are closely monitored to ensure true ‘cold processing’ is achieved. |
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After the malaxing process, the olive paste is transferred to a horizontal decanter which is used to remove the solids from the liquids. The solids (pomace) are conveyed to an external pit & later composted to be spread back onto the grove. The liquid, (primarily olive oil & bit of water) is pumped to a high-speed vertical separator which spins at around 7,000 rpm to remove any remaining water.
The cold processed EVOO finally flows out of the separator into a holding tank.
It is then transferred and stored in 1,000L air-tight foil lined containers or in large 5,000L stainless steel storage tanks where it is covered with a nitrogen blanket. After the oil has been allowed to settle for a few weeks all bottling, labelling and packaging is done on-site inside an air-conditioned stainless steel shipping container.
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