A Pressing Matter Small-Scale Seed and Nut Oil Production

Plant-based oils, extracted from seeds, nuts, and occasionally fruits, have been a fundamental part of the human diet since as early as 6000 BCE. Archaeologists uncovered evidence of olive oil production in northern Israel ruins believed to be around 8,000 years old; in North America, archaeologists from Indiana University have found evidence of hickory nut oil extraction in the remnants of an ancient kitchen presumed to be more than 4,000 years old. These oils were vital to the health and well-being of their producers. The dietary fats found in seed and nut oils play a fundamental role in the body, assisting with the proper absorption of vitamins and with essential brain and nerve function.

In the 8,000 years since the first olive was squeezed to release its flavorful, golden essence, the use of oils in food, medicine, and religious ceremony hasn’t undergone many notable changes, but production methods have evolved dramatically. The earliest technique was the “wet extraction method.” In this method, the seeds or nuts are hulled, crushed, added to water, and then boiled. Oils float to the surface, where they’re skimmed off and reserved. This is a slow and low-yielding process. The first mechanical press was developed in India around 2000 BCE for the extraction of, resembled a large mortar and pestle and was typically powered by oxen; modern motor-powered models are still commercially available today, used most commonly across the Indian subcontinent.