Hemp Therapies Wiki / Hemp Oil & Hemp Seed Oil

How Hemp Oil Is Made

Hemp seed oil is produced by mechanically pressing hemp seed, most commonly with a cold-press oilseed machine that compresses the seed under pressure without added heat.

The Pressing Process

Hemp seed is commonly cleaned to a 99.99% purity level before pressing. Hempseed is reported to be roughly 49% oil by weight. Trace cannabinoid residue can appear on the outer surface of pressed hemp oil due to plant matter adhering to the seed hull during harvesting and processing, even though the interior of the seed itself does not produce meaningful cannabinoid content. Production can also involve cleaning seed of foreign matter, conditioning it for moisture content, and then processing it by mechanical pressing, solvent extraction, or both; hexane is commonly cited as a solvent used in solvent-extraction processing. Crude hemp seed oil can go through multiple refining stages, chosen according to the oil’s intended end use.

Refined vs. Unrefined Oil

Unrefined, cold-pressed hemp oil retains a green color ranging from light to dark, a nutty flavor, and naturally occurring chlorophyll from the seed; darker unrefined oil is described as having a grassier flavor. “Virgin” hemp seed oil refers to this unrefined form. It is described by suppliers as more sensitive to degradation from light and temperature than processed oils, and is generally recommended for cold use rather than heated applications. Refined hemp seed oil, by contrast, is clear and colorless with little flavor. Reported physical measurements: crude hemp seed oil has a specific gravity of 0.9200, refined hemp seed oil has a specific gravity of 0.8927, and the refractive index of refined hemp seed oil is 1.4570 at 40°C under the stated measurement conditions.

Summary

Hemp seed oil starts as a cold-pressed extract of the cleaned seed, then may go through further refining depending on its intended use — a distinction that shows up directly in the oil’s color, flavor, and measured physical properties.