Expeller-Pressed vs. Cold-Pressed Oils
Definition
Mechanical, non-chemical methods of extracting cooking oils from seeds, nuts, and fruits using physical pressure rather than toxic chemical petroleum solvents (hexane).
Why It Matters
Over 90% of commercial vegetable oils (canola, soybean, corn) are extracted by bathing crushed seeds in petroleum-derived hexane solvent, followed by bleaching and chemical deodorization at temperatures exceeding 450°F (232°C). 'Expeller-Pressed' uses a mechanical screw press that squeezes oil out without chemical solvents, though friction can generate moderate heat (150°F–200°F). 'Cold-Pressed' is the gold standard: the physical pressing is temperature-controlled to never exceed 120°F (49°C), preventing delicate monounsaturated and polyunsaturated fats from oxidizing into toxic lipid peroxides and preserving heat-sensitive polyphenols.