Harvest Date vs. Best-By Date: The Trick to Spot Stale Oil

Here is a small trick of the trade worth knowing. The “best by” date on an olive oil bottle is not measured from the harvest. It is typically set from the day of bottling — and bulk oil can sit in tanks, ships, and warehouses for a long stretch before that day ever comes. A bottle can carry a reassuring date far in the future while holding oil that is already well past its prime.

The date that cannot be gamed is the harvest date: the season the olives actually came off the trees. Producers who are proud of their freshness print it. Producers whose oil has an uncertain past tend to leave it off, and the omission is its own answer.

So flip the bottle over and look. Olive oil is not wine; it does not improve with age. It is at its most alive in the months after pressing, which is why Posterino mills within hours of harvest, stores the oil under nitrogen, and bottles it on the estate. When freshness is the whole point, you date the harvest — and stand behind it, as our family has for six generations.