For centuries, for millennium, olives were picked the same way: grasp a branch and lightly running your fingers downward, gently pluck and pull the olive away from the branch. Let the olives drop into a basket or a well placed net. At the end of the day, your hands feel soft and supple from handling the fruit, and your arms are a little stiff from reaching for the next branch. Picking olives is fun and romantic when it’s a hobby, but far more serious when it’s your life’s work.
Continuing our conversation with olive oil producer Nicola Bovoli, of Vicopisanolio in Tuscany, he tends about a thousand trees, and each tree yields on average 10 kilos of olives, but it can range up to 25 kilos per tree. Last year’s harvest was about 12-13% oil. If you hang around an oil mill at pressing time, yield is a big topic. Many factors will affect the fruit yield and the oil yield. Sometimes the olives have more water in them, so even though you deliver more fruit, you won’t necessarily get more oil. And you pay the mill by weight, so having water heavy olives, or processing fruit filled with branches and leaves is a drag because you pay by the bulk weight of the olives delivered, not by the oil yield. Olive trees tend to produce abundant olives in an every other year cycle so once again you have to yield to Mother Nature’s capricious rules.
After you’ve harvested your olives, it’s time to press them, and historically at Vicopisano, the olives were crushed between two large stones that were turned by animals. However, Signor Bovoli was intent on getting the best yield and the best oil so two years ago he upgraded the system. He explained some of the problems with the stone method. Let’s say, your neighbor accidentally delivered moldy fruit and his olives were crushed before yours. The stones are now contaminated and even though they are washed, your oil will pick up some of the muffa or mold. Now that’s going to be a real bummer after all the work that went into the growing and harvest of your oil. There is also a degradation of the flavor and quality of the oil the longer it is exposed to air and light. Oxidation is the enemy of olive oil.
Vicopisano upgraded to the Pieralisi system about two years ago, and it was a difficult process. The problem wasn’t the installation of the high tech Pieralisi machinery, but convincing the customers of his mill that this machine was better than the traditional stone method of crushing the olives. Have you ever tried to change an Italian’s mind about something?? The system used at Vicopisano is a little different than this post, because he uses a vertical centrifuge, but the basic idea is the same. Within 45 minutes, the olives are processed into oil without ever exceeding 24C and without any oxidation. A pure expression of the fruit.
Once the oil is produced, Nicola stores his olive oil in stainless steel tanks, maintained at a constant temperature of 18C. Oil that is stored this way will remain at its optimal quality and can be sold for up to 18 months after the harvest. But, Nicola’s oil never lasts that long!
What this means for those of us who don’t have our own olive groves is: store your olive in a dark colored bottle, away from light, away from heat. I buy olive oil in bulk 3 or 5 liter tins and decant it into a bottle. In our case, we’ve found an old whiskey bottle works superbly, however you should label it or you wind up with strange salad dressing and even stranger cocktails. Properly stored, an open bottle of olive oil will last from 2 to 4 months, but be aware that the flavor degrades and fades as it ages. Use it or lose it.
A general rule of thumb is to buy what you can use in a two month period. Use industrial grade extra virgin olive oil for cooking and save the good quality artisinal olive oil for finishing or for when you want to truly experience the unique flavor of that oil. For the good stuff, I only use it for finishing, never with heat.
Vicopisanolio is available at Gustiamo.com and is part of the Pantry Basket that provides essential ingredients for the recipes in Cooking Simply: The Italian Way! Buon’appetito.