To make sure the ancient vessels once held olive oil, the researchers compared the chemical residues left on the ancient clay to those from a modern-day clay sample with 1-year-old olive oil inside. The analyses of the two were remarkably similar, they found.
Of the nearly two dozen pottery containers found at the site, two dated to around 5,800 BCE, says the Times of Israel.
Finding olive oil in ceramic containers from Ein Zippori, together with the ﬁnds from Kfar Samir at least, teaches us that the storage of vegetable oil and especially olive oil was a routine custom and had a major role in the diet of the pre-Ghassulian population.
According to the Times of Israel, the find may mark the earliest known case of olive oil production in the Mediterranean basin.