Using both science and anecdote, Patricia B. O’Hara has squeezed new stories out of the humble olive.
O’Hara, the Amanda and Lisa Cross Professor of Chemistry, recently published The Chemical Story of Olive Oil (The Royal Society of Chemistry), written with two other chemists: her husband, Richard Blatchly of Keene State College, and Zeynep Delen of Bogazici University in Istanbul.
A book launch party will take place on May 13 from 2 to 5 p.m. at the College’s Alumni House. The event will feature a talk, reception, tasting and book signing.
The book is about chemistry, but it’s also about olive oil and the people who make it. “Each chapter,” O’Hara said, “has a different chemical story that connects to the life of the olive.”
Since 2010, O’Hara has taught as part of an interdisciplinary summer workshop in Turkey devoted to the science of olives. During a sabbatical in 2015-16 she and Blatchly embarked on an international tour of key olive oil producers. Making stops in Turkey, Spain, Italy, Greece, South Africa and Australia, the couple observed the olive harvest and met people who grow olives and process the oil.
Their book covers the planting and care of olive trees, the harvesting of the fruit (yes, it’s fruit) and the processing of the oil. It also considers, among other topics, quality control, health benefits and sustainability issues.
“We start out with olive origin stories,” O’Hara said, “and then we talk about oil and water. We get into the electronic structure of the atoms and the bonds and polarity, and that's chapter one. Chapter two is planting, and then we get into the soil, the olive press, enzyme activity and so on.”
“It's a total liberal arts curriculum, right in that simple agricultural product.”
Olive oil cultivation is probably as old as human civilization itself. According to O’Hara, genetic analysis traces the olive’s forbears to bushes in ancient Asia Minor that produced small, oily fruit.
“If you're starved for food, as you have to imagine early humans were, and you notice that there's some oil coming out of this bush, you're going to start to harvest the berries, squeeze the berries and collect the oil,” she said. “The oil was a caloric commodity,” and perhaps as a result, numerous traditions developed involving oil as a sacred gift or sacrament.
While the oil may be divine, the olive itself protects the seed by having an unpleasantly bitter flavor. It’s only by curing olives into submission that they become palatable, O’Hara said.
And while much of the cultivation of olive oil involves the actual growing of the olive, the proof is in its crushing.
“An olive by itself is so, so, so bitter, but as you crush it and then break open the cell walls, the enzymes from the inside of the cell mix with the oil. Enzymatic breakdown of the fatty acids leads to smaller carbon chains that smell like green apple, and grass, and fruity flavors..”
The book profiles people whose life's work is in a good bottle of olive oil. “They're men, they're women, they're from Spain, Turkey, South Africa, New Zealand, Australia,” O’Hara said. “And they're passionate about what they do.”
As a result of her research, O’Hara has developed a palate for olive oil. It’s made her more picky about the oil she uses in the kitchen, but it’s also expanded her use of olive oil as a replacement for butter. The couple now have certificates as olive oil tasters from the University of California Davis Mondavi Center. Still, she considers herself a novice, as oil experts train for years.
“It's not different than wine tasting. Some of it tastes like apples, and some of it tastes like bananas, some of it tastes like artichoke, and tomatoes.”