Your olive oil is being milled: what is actually happening?
The milling season is an incredibly intense period for the good people we work with – they tend to work an 18 hour day, seven days per week and for at least two months, ensuring the fruit is flawless, is taken quickly to the mill, and then transformed in to our favourite juice. There are pitfalls all the way, and they have to be extremely careful at every stage.
In the groves so far the focus has been on the agriculture, but now it’s on the picking. Our producers all pick green olives to guarantee the highest quality oil, but the phenolic ripeness needs to be there and this is a fine point, the optimum picking window is a matter of days. Producers need to consider the weather carefully: you can’t pick if it’s raining (currently a big problem in the North of Italy), conversely warmer weather at this point in the year encourages the dreaded fly that damages the fruit. If the latter happens top quality producers will not use that fruit, because it makes rancid olive oil – all reasons why you need to know where your oil comes from. Lastly they need to consider the time it takes for olives to be picked and taken to the frantoio to be milled – ideally within 4 hours, never more than 8 hours, because otherwise the fruit starts to oxidise. Considering a medium sized producer might have ten thousand trees, this is a very complex operation in terms of timing and health of the fruit, because what is actually happening in the mill is also crucial.
Before picking starts all machinery in the frantoio in checked, cleaned and tested to ensured it is ready to go. When the olives arrive they are passed through the following processes, each of which has a different machine:
- De-leafing and washing
- Milling: This when olives (stones and skins and all) are actually crushed making a pulp.
- Malaxing: The paste is passed through a machine which slowly turns the pulp continuously coaxing out droplets of oil from the cell membranes of the olives.
- Separating the various parts of the pulp: oil, water and solids.
- Filtering the oil.
During all these steps the miller can intervene to adjust the heat, pace and different filters, thus showing their skills and adding their magic to the final product.
As the various stages of processing are going on, new olives arrive from the groves, and the pickers start on new trees, and so it goes for about 2 to 3 months with only a few hours to rest each day.
We wish everyone we work with masses of strength, fine weather and good fortune for the exciting weeks ahead.