Secrets of the Olive Harvest

Jonathan Harris | November 2018

Thanksgiving is almost upon us! This is one of my favorite holidays, when we gather to celebrate the harvest season and give thanks for the land’s bounty with family and friends. In North America we feast on foods recently gathered from the fields: squash and cranberries; sweet potatoes and brussels sprouts; and of course, pumpkin pie. A beautifully roasted turkey surrounded by the fruit of the harvest makes this the most American of holidays.

In Spain it is a little different – there are two important harvests of olives and grapes for wine: In October is the vendimia or wine festival where everyone in town celebrates the harvest of grapes for the next vintage.

Soon after, farmers across Spain head to the fields to gather that most essential crop, olives. Millions of tons of olives are shaken from olive trees every fall, most of them pressed and packaged as olive oil. In fact, Spain produces more olives and olive oil than any other country in the world.

It is impossible to imagine any meal in Spain without olive oil. This has been true for over 2,000 years, when the Romans introduced extensive olive farming to the Iberian Peninsula. It is hard to believe, but the archeologists discovered that one of the hills of Rome consisted of a huge mound of discarded terracotta amphoras which held olive oil that the Romans transported by ship from Spain. 

In much of Spain, breakfast often consists of toasted bread with olive oil (good luck finding any butter and jam!) and most Spanish recipes start with a splash of olive oil in a pan. Even my favorite cookies, crisp tortas de aceite from Sevilla, are made with flour, sugar, and extra virgin olive oil.

Olives are a pitted fruit, distantly related to peaches, plums and almonds. Actually, when you think about it, olive oil is nothing but pure fruit juice. There are hundreds of varieties of olives and a vast variety of flavors. You can enjoy all kinds of flavors --fruity, spicy, flowery, mild - just as you can savor all kinds of grape juice made into wine. 

Are olives naturally green, or brown or black? The answer is yes! In fact, all olives are green until they ripen late in the season. No matter what level of ripeness, never eat an olive directly off a tree. Raw olives are horribly bitter due to a compound called oleuropein. This chemical is intended to protect the fruit from pests and animals, humans included. Ironically, oleuropein contains antioxidants with health benefits, including anti-inflammatory characteristics. The spicy, mildly bitter notes in a quality extra virgin olive oil come from this compound.

Table olives are cured in a special brine that extracts the bitterness. Most table olives are green, though there are some dark brown ripe olives like the sweet Aragon variety. On another note, the typical pitted gray-black olives on your pizza are a California invention, basically green olives bombarded with chemicals to change their color and texture.

Fully ninety percent of olives harvested are pressed into olive oil. An olive tree takes about five years to mature at which point it produces from 15 to 20 kilos of olives, which amounts to between 2 and 5 liters of oil per year. This is where things get interesting.

Some compare olive oil to wine. in both cases the ‘terroir’-- the type of soil, and the variety of fruit contribute to the final flavor profile. Where this comparison falls apart is in ripeness and aging – fully ripe fruit and extended aging are essential for the finest wine but would be deadly for a good olive oil. The younger the better for olive juice/oil. Whereas usually the older the better with grape juice/wine.

The very best olive oils are pressed when the olives are still fairly green and not quite ripe. As olives ripen, the yield increases as the quality declines. A tree of fully ripe olives will yield twice the oil, but the taste will be both bitter and bland. As with most fruit, oxidation turns crisp, fresh fruit picked from an orchard tree (whether it be a peach, apricot or olive) into a soft, overripe one. The reason is oxidation, transforming a fresh olive into a soft, overripe one. After pressing, oxygen is also extra virgin olive oil’s enemy. This is why most oil is topped with a flush of nitrogen gas when it is bottled. A good bottle of extra virgin olive oil should be used within a couple of months of opening since it starts to oxidize the moment you open the bottle.

The olive harvest is still a surprisingly manual process. First, olives that naturally fall to the ground before harvest are often spoiled or dirty and are never used for olive oil. On the day of harvest, nets are spread below the trees and the branches are beaten with sticks or shaken with a special machine to drop the olives. The olives are collected from the nets and transported to an olive mill – the sooner the better! The very best oil is pressed within hours of harvest.

Our friends at Castillo de Canena in Jaén are fanatics about producing the very finest early harvest extra virgin olive oil. Every October the Vañó family monitors their olive trees carefully. They select a day when the olives have just started to ripen and harvest one batch to make their First Day of Harvest oil. The yield is spectacularly low, but the quality is phenomenal. I remember the first time I saw this oil poured into a white bowl. It was the color of antifreeze – literally glowing green. The aroma was impossibly fresh, smelling of artichokes and fresh grass. The price for a bottle of this amazing oil is not cheap (about $50 per bottle), but then again, how often can you get the very best of something for that price?

Milling and pressing olives is now a high-tech hygienic process, with stainless steel grinders for pulping the olives and modern centrifuges to separate the oil from water and impurities. This was not the case until fairly recently. A few years ago, we traveled to Catalunya with our friend Hans de Roos to visit one of the last traditional mills in Spain. Hans presses his Can Solivera Wild extra virgin olive oil in the old way. 

The traditional method is to grind the olives under a cylindrical granite millstone. Then the pulp is spread onto round esparto grass mats that are stacked on top of each other. This tower of mats is pressed until the oil streams out, pouring into a stone channel that runs into holding tanks. The oil then decants naturally, with the organic material settling on the bottom of the tank. This labor-intensive process is expensive and requires experienced millers to ensure a clean, pure olive oil – a tradition that is almost lost. These traditional mills used to dot the landscape in Spain, but there are only a half dozen of these mills still following this process. Our Can Solivera oil is one of the few produced this way, and is served at the world famous El Celler de Can Roca restaurant in Girona.

Romance aside, the modern process usually produces a much higher quality extra virgin olive oil because of the precise controls. Stainless steel equipment and an automated process ensure that no impurities are introduced. The pressed oil is stored in refrigerated stainless-steel containers that are flushed with nitrogen, blocking oxidation and allowing for stable long-term storage.

Now, not all olive oil is extra virgin. After the oil is pressed, the used pulp is often carted off to a factory where it is chemically treated to extract every last drop of oil that remains. This is called pomace oil and is fine for deep frying or industrial uses but lacks most of the flavor and health benefits of extra virgin olive oil. Beware of oils that are called “light” or “extra light.” These are usually pomace oil with a splash of extra virgin for color and a bit of flavor.

With such a vast production of such a valuable oil, there are bound to be vendors who seek to confuse or cheat customers. Much of Italy’s extra virgin olive oil originates in Spain and is then transported in tankers to be packaged in Italy – not illegal, but very confusing. Worse are companies that fraudulently mix cheaper oils with extra virgin oil to optimize their profits, which is illegal but hard to detect. 

The best way to ensure you purchase authentic quality extra virgin olive oil is to buy from a trusted source. We regularly visit olive fields and mills in Spain, meeting with the producers, many of whom have become personal friends of our family. We directly import most of our extra virgin oils, ensuring that they are packaged and transported carefully to preserve their quality.

How an oil is packaged and handled is very important. Extra virgin olive oil should be thought of as fresh pressed fruit juice – which it is! All the healthful compounds and antioxidants need to be protected. The enemies of great olive oil are heat, light, oxygen and time. Opaque bottles or cans can block damaging light. Always store your olive oil in a cool area, never close to a cooking surface. You can also store olive oil in the refrigerator, though it may solidify in the cold. Simply allow it to warm to room temperature before serving.

Time and oxygen are the final factors. I remember giving a friend a nice bottle of olive oil by Castillo de Canena. A year later, I visited his house and noticed the same bottle on his countertop, only half finished. He told me that he only used it on special occasions because he liked it so much. I explained that this was like opening nice bottle of wine and then pouring a glass every couple of weeks and corking it again. 

What he didn’t understand was that once you open a bottle, the clock starts ticking on everything that makes extra virgin olive oil so special. All the subtle flavors and amazing healthful compounds begin to fade, slowly transitioning into a bland, unremarkable oil within a matter of months. Freshness definitely matters.

Spain’s bounty of olives is the cornerstone of the Mediterranean diet, a way of eating that is proven to lead to a long, healthy life. In fact, Spain is projected to have the longest lifespan in the world by 2030. I have a friend in Spain who tells me her parents drink a shot of extra virgin olive oil every morning for the health benefits alone!

You don’t have to go to this extreme to enjoy the benefits of extra virgin olive oil. My family has replaced margarine and butter with extra virgin olive oil for use on toast or rice or potatoes. And fresh salads and vegetables are natural partners with a good oil. Just a few teaspoons a day will add flavor and health to your home.

As you plan your Thanksgiving feast, I encourage you to make olives and extra virgin olive oil an important part of your meal. And a bottle or two of Rioja wine is not a bad idea either! 

¡Buen Provecho!
Jonathan Harris