How Is Olive Oil Made?

The culinary institute of america chef breaks down the process

By Jonny Lupsha, Wondrium Staff Writer

Olive oil is a staple ingredient in Mediterranean cuisine and found all over the world. Production of olive oil allegedly dates back more than 6,000 years. How does it get made?

Hand picking green and black olives on the branch tree
Olive oil is known as an ultra healthy alternative in recipes for replacing unhealthy fats from butter and margarine. Photo by William.Vaccaro / Shutterstock

It’s widely believed that olive oil was originally made either in the Middle East or the Mediterranean. Since then, it’s become one of the most popular cooking ingredients in the world, as trade from Greece and the spread of olive trees introduced new cultures to it. According to Statista, in the 2021-22 year, global production of olive oil reached 3.27 million metric tons.

Starbucks recently announced it would introduce olive oil as an optional additive to its coffees in Milan, sparking a mixed reaction among Italians. But how is olive oil produced? In the video series The Everyday Gourmet: The Joy of Mediterranean Cooking, before his untimely passing, Chef Bill Briwa, Professor of the Culinary Arts at The Culinary Institute of America, explained how olive oil gets made.

When Do Olives Get Plucked for Olive Oil?

Unsurprisingly, olive oil begins with olives.

“Olives ripen in the fall, sometime around October through the beginning of the year, at least in the northern hemisphere—in the southern hemisphere, subtract six months from that,” Chef Briwa said. “If you allow the olive to stay on the tree after it’s fully formed, so that it takes on first a blush of color, then it’s half-pink, and then it goes to blue, and now it’s three-quarters blue, and now completely blue and on its way to black by January of the following year, the oil that you get from there will change.”

The later the olive is plucked, the oil that comes from it changes from green and peppery to soft and buttery, and eventually greasy. The yield also increases as time passes.

How Is Olive Oil Made?

When an olive oil producer finds the proper balance between flavor and yield, they pluck the olives and separate them from the stems, seeds, twigs, and leaves. Then they crush the olives in a hammer mill, which Chef Briwa compared to a giant garbage disposal.

“You create a paste from everything that is the olive,” he said. “That paste is then mixed for a short amount of time, and that mixing allows the emulsion that may have formed in the crushing to break, so the oil begins to separate from the solids.

“Then, ultimately, we want to separate the oil from everything else, and that’s done by separating the paste—that sansa is what they call it—onto hemp mats, stack those mats up, press them, and the mat captures the solids.”

Meanwhile, the oil and the water flow out from the mats, and of course oil doesn’t mix with water. The two separate naturally and the oil can be decanted off the top, which is usually done in a centrifuge-like device.

Olive oil is also regulated and tested for defects, quick processing, and its percentage of free fatty acids. If the oil has less than 1% free fatty acids, no defects, and was processed quickly, it qualifies as extra virgin olive oil.

And it tastes great on fish.

The Everyday Gourmet: The Joy of Mediterranean Cooking is now available to stream on Wondrium.

Edited by Angela Shoemaker, Wondrium Daily