How is vegetable oil grown?

Vegetable oil isn't grown; rather, it is extracted from plants. The plants that the oil comes from are grown.

Here's a breakdown of how vegetable oil is made, including information about the plants involved:

The process of obtaining vegetable oil involves several steps after the oilseed crop (like soybeans, sunflowers, rapeseed/canola, or corn) is grown and harvested. The specific extraction method can vary, but generally follows this pattern:

1. Growing the Crop: The plant source is cultivated using standard agricultural practices (planting, irrigation, fertilization, pest control, etc.). Common oilseed crops include:

   • Soybeans: A major source of vegetable oil, particularly in the United States.
   • Rapeseed/Canola: Widely cultivated, especially in Canada and Europe. "Canola" is a specific variety of rapeseed bred to have low levels of erucic acid.
   • Sunflower seeds: Popular in many regions and produce a light, flavorful oil.
   • Corn (maize): Corn oil is extracted from the germ of the corn kernel.
   • Other oilseeds: Cottonseed, peanuts, olives (for olive oil, which is typically cold-pressed), palm fruit (for palm oil), and coconuts (for coconut oil).

2. Harvesting: The oilseed crop is harvested when the seeds are mature.

3. Cleaning: The harvested seeds are cleaned to remove impurities like dirt, stems, and leaves.

4. Crushing/Pressing: The seeds are mechanically crushed or pressed to extract the oil. There are two primary methods:

   • Expeller Pressing (Cold Pressing): This method uses mechanical pressure to squeeze the oil out of the seeds. It's often favored by smaller, specialty companies, as mentioned in the provided reference.
   • Solvent Extraction: This method, more common among large vegetable oil producers, uses solvents (typically hexane) to dissolve the oil from the seeds. This is more efficient and extracts a higher percentage of oil. The solvent is then evaporated, recovered, and reused.

5. Refining: The crude oil extracted contains impurities that affect its color, flavor, and stability. Refining removes these impurities through processes like:

   • Degumming: Removes gums and phospholipids.
   • Neutralization: Removes free fatty acids.
   • Bleaching: Removes color pigments.
   • Deodorization: Removes volatile compounds that cause undesirable odors and flavors.

6. Packaging: The refined oil is then packaged for distribution and sale.

In summary, while the plants that provide vegetable oil are grown, the oil itself is extracted from the plant matter (usually seeds) through mechanical pressing or solvent extraction, followed by refining.