Pressing Business at the Olive Mill
Nothing prepares you for the aroma of freshly pressed olives. Maybe you’ve smelled extra virgin olive oil from the bottle before you pour it on a salad or dip a piece of bread into it. It’s lovely: fruity, grassy and full of possibility. But step into an olive mill and you’re subsumed by the intensity, surrounded by a symphony of flavor notes swirling through the atmosphere.
After a full day of harvesting in the olive grove, we delivered our olives to our nearby frantoio or olive mill. As tired as we were, the excitement of the mill and its intoxicating aroma revitalize us. We joined friends and neighbors to wait for our turn, guarding out bounty until our olives were emptied into numbered bins assigned to us for the press. We checked out everyone else’s raccolta, sneaking glances to see if we had embarrassed ourselves with an inadequate leaf and twig removal process.
As we waited, we pondered the numbers. One quintale of olives is equal to 100 kilograms. You’ve probably never heard of a quintale; we certainly hadn’t. It seems it has a long history here as a measurement of mass, rooted in the classical Latin centenarius, which means “hundredlike.” It moved through late Greek, Arabic, medieval Latin and Old French, resting firmly in the modern Italian farmers’ lexicon. One hundred kilograms of olives can be expected to produce 15 liters of extra virgin olive oil. The big bins you see in the photos hold about two quintali, so all those olives will only produce about 30 liters of olive oil if all goes well. We started to feel particularly possessive about our olives and their yield, not wanting to relinquish a single drop during the pressing process.
Much like the different olive harvesting methods used across Italy, there are firmly held schools of thought about the right way to press olives to obtain the highest quality extra virgin olive oil. From the ancient method of using granite millstones to today’s high tech centrifuge or linea continua machines, each process is staunchly defended by its advocates. To meet rigid organic extra virgin olive oil certification requirements in the European Union, organic olives must be pressed using machinery that is never used to mill non-organically grown olives. Presses are inspected regularly to ensure that this standard is observed rigorously, so we were pretty confident about our olive mill choice. Our closest organic mill uses a certified organic linea continua, so we’ve chosen to use two distinctly different approaches for Pascarosa olive oil. For our extra virgin olive oil, we opted for a traditional stone-ground, cold-press process at the mill down the road and we’ll use the linea continua or automated centrifuge for our organic oil.
The initial steps for both methods are pretty similar. The olives are prepared for pressing by separating any stems and leaves. Leaves don’t create much of a problem and can actually add flavor in small quantities, but twigs and dirt can lead to defective oil. when they’re clean, the next step, called the frangitura, is where the olives, pits and all, are crushed until they form a dark brown paste. During the crushing, this paste is kneaded and generally heated ever so slightly so the oils will begin to be released. The exact temperature of heating is a topic of great debate and often varies from one mill to the next, but the heat will never rise over 80ºF (27ºC)—the maximum temperature allowed during extraction to still consider the oil “cold pressed.” Some mills turn up the temperature during this process to shorten the processing time or increase the oil yield, but the resulting oil will lose flavor, polyphenols and its coveted low rate of acidity. In the traditional stone ground method, large granite wheels slowly crush the olives as they rotate. In the linea continua, the olives are sliced with sharp blades instead of being crushed. This is the moment when the aromatic olive-y fragrance is released, permeating the skin of the mill workers and escaping out the doors and into the surrounding countryside.
Once crushed, the next step is called the gramolatura, where the olive paste is spread out onto many circular mats made of a woven material, which are then stacked on top of one another and placed in a hydraulic press. This spreading process looks like icing a cake and is accomplished by practiced hands that don’t miss a beat. As the olive paste is very slowly pressed, a reddish brown mixture of oil and water emerges. This liquid produced from the estrazione (extraction) still doesn’t look like the luscious green and gold olive oils you would expect. To make the final product, this liquid is put in a centrifuge that separates the oil from the water. Watching the freshly pressed oil drip out of the centrifuge in vivid shades of greens and golds provides a moment of intense satisfaction. We dipped our fingers into the stream of oil—the prima spremitura—that flowed from the press and the sensation was extraordinary. Every net we spread, every branch shaken and every bin hauled on our shoulders to the waiting truck suddenly made sense.
Today many olive mills often use an entirely mechanical method, which can combine most of these steps into one continual cycle from washing to the final product. This new process isn’t remotely as romantic as the stone mill we used for our Pascarosa extra virgin olive oil, but the linea continua mechanical pressing offers many advantages. Each step takes place in a temperature-controlled environment and the stainless steel machines allow for easy sterilization and cleaning. And it’s fast . . . about an hour from start to finish. The traditional method takes a few hours, which has the decided advantage of offering plenty of time to catch up on local gossip with farmers who are waiting for their turn at the press. It’s this moment of interaction, the irreplaceable link to the past, that we hope to help preserve by importing olive oil from our own trees and those of our neighbors. Farmers and wealthy landowners alike still stand side by side at the mill, united in their satisfaction with their raccolta, secure for another year in the knowledge that their olive oil will brighten their meals and sustain their families.