Between the olive harvest and the oil in the bottle there is one step that decides almost everything: milling. This is where a good olive becomes a good oil, or loses much of its potential. At Frantoio Cesare Battisti, in Vetralla, it is the stage we pay the most attention to, because it is where the work of a whole year is played out in the space of a few hours.
What milling actually is
Milling does not just mean pressing: it is a sequence of steps that turn the olive into oil.
- Crushing: breaking the fruit, flesh and stone, to release the droplets of oil from the cells;
- malaxing: the olive paste is slowly stirred, so the tiny droplets merge into larger ones;
- extraction: the oil is separated from the solids (the pomace) and from the vegetation water;
- final separation: the oil comes out clean, ready to rest.
Each phase leaves its mark on aroma, taste and stability: small shifts in time or temperature are enough to change the result. Today most mills work in a continuous cycle, with a mechanical crusher and a centrifugal decanter, a system that reduces contact time with the air compared with the old presses and helps to limit oxidation.
The time between harvest and milling
The most underestimated aspect is how much time passes between harvest and processing. Olives should be milled within a few hours: leaving them to wait too long, perhaps heaped up in sacks, starts fermentation, raises the acidity and dulls the aromas. It is the “fusty” defect you recognise at once on tasting, and no machine can put it right afterwards.
In Tuscia the harvest falls between October and November, and on the warmer or wetter days managing the timing well becomes decisive. That is why olives should be kept in ventilated crates, not in sacks, and brought to the mill as soon as possible. If you bring us your olives, we arrange the delivery together: write or call us to organise the milling.
Temperature: what “cold” really means
People often talk about cold extraction, but it is worth understanding. The temperature during malaxing affects the yield, but also the aromas and polyphenols: heating the paste too much helps to draw out more oil, but it drives off the aromas and makes the oil less stable over time. The wording “cold extracted” means precisely that the paste was worked below a defined temperature threshold, generally around 27 °C, so as not to sacrifice quality on the altar of quantity.
We work at controlled temperature because we prefer quality to yield. A difference of a few degrees cannot be seen by eye, but it can be tasted in the glass and, above all, in how the oil holds up months later.
Technology and healthy olives: you need both
Not even the best plant can make up for badly harvested or bruised olives: milling amplifies whatever the olive brings with it. Healthy olives, ripe at the right point, respond well to gentle processing; stressed olives, attacked by the fruit fly or left to ferment, give more difficult oils even with modern machinery. That is why milling is part of a journey that begins in the field, with pruning and harvesting, and does not end at the mill.
After extraction one last choice remains: to filter or not. Freshly pressed oil is often cloudy, because it contains residues of flesh and water; a light filtration makes it more stable and extends its life, while unfiltered oil is more intense but should be consumed sooner. They are different paths, both legitimate, as long as the buyer knows what is in the glass.
Why it matters even if you only buy oil
Careful milling is what allows an oil to hold up over time, without losing its balance after a few months. When you taste an extra virgin oil that is clean, fragrant and free of defects, there is almost always this care behind it: healthy olives, quick timing, controlled temperature, clean equipment. Our Caninese oil is born this way: you can find it in our shop.
Frequently asked questions
How soon should olives be milled? Ideally within a few hours of harvest: the sooner they are processed, the better the oil.
What does cold extraction mean? Working the paste below a certain temperature threshold, generally around 27 °C, to preserve aromas and polyphenols.
Filtered or unfiltered oil? Filtered oil is more stable and lasts longer; unfiltered is more intense but should be used sooner. It depends on how and when you will use it.
Would you like to mill your olives in Vetralla? Contact Frantoio Cesare Battisti.