Did you ever look at the label of an oil that you were buying and see the term “expeller-pressed”? First things first, if you see that term, it means it’s a good oil to buy. But why?
Expeller-pressed is the way the oil is made. The way it is extracted from the nut or seed. Basically, it means that it gets literally squeezed out of the item in one single step through the use of an intense force.
Think of like…putting an almond in a vice and what squeezes out is the oil. You could never make it at home with tools like that, obviously, but that’s the general idea.
Basically it’s a mechanical process that uses a giant screw that continually squeezes the oil out of the nut or seed and in the process can create a lot of friction and heat.
Running the dry, cake-y material through the press a second or third time results in better capture of the oil from the material, but often with quality sacrifice.
The expeller pressing method generally captures around 65% of the oil. Not a great yield, admittedly. Creates a lot of waste.
When you see the term “first cold press” or something similar, it means that it was obtained on the first press of the material (olives, nuts, etc) and that it wasn’t warmed up too much, sometimes even cooled at the same time so that it doesn’t get warmed up on purpose.
Keeping it cold is supposed to be good for the oil because it doesn’t alter the product chemically with too high of a heat (flavor, etc).
However, the actual temperature isn’t regulated here in the US, so what you buy could still have been warmed a lot, possibly making this “cold press” distinction useless.
Expeller Press video on YouTube
This is a really weird video from China, I presume, with a completely weird choice of music that is totally distracting lol. But it does a good (albeit grainy, poor resolution) job of demonstrating how an expeller press works. I suggest watching it on mute and fast forward. Ha!
What If My Oil Doesn’t Say “Expeller-Pressed”?
The important thing to note is that if an oil doesn’t say “expeller pressed” it almost certainly means that the oil was extracted using a chemical method…most often using one called hexane.
According to the Environmental Protection Agency (EPA) website:
Hexane is used to extract edible oils from seeds and vegetables, as a special-use solvent, and as a cleaning agent. Acute (short-term) inhalation exposure of humans to high levels of hexane causes mild central nervous system (CNS) effects, including dizziness, giddiness, slight nausea, and headache. Chronic (long-term) exposure to hexane in air is associated with polyneuropathy in humans, with numbness in the extremities, muscular weakness, blurred vision, headache, and fatigue observed. Neurotoxic effects have also been exhibited in rats. No information is available on the carcinogenic effects of hexane in humans or animals.
I don’t write this information on this website in order to scare anyone about anything, and obviously expeller-pressed oil is more expensive than chemically-derived oil. Companies use hexane because it is a cheaper method of production and leads to much greater yields (99%!) and less waste. ($$ Cha-ching! $$)
In order to get rid of the hexane used for processing, the oil is then heated. This can definitely alter the makeup of the original oil, so it doesn’t seem like a great option overall, for production or quality of the finished product.
I buy regular oil occasionally but know that it’s probably better to buy expeller-pressed everything. I have no idea how much hexane is leftover or is harmful in that type of oil, so I can’t make definitive judgments on it, especially not publicly on my website. I’m no scientist!
BUT! If you’re anything like me, you know it’s important to at least know how the food we eat gets from nature or lab to our bellies. The more we know, the better choices we can make. Amirite or amirite??
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Want to stock up on some expeller pressed oil? Get a (high heat) sunflower oil and a cold press olive oil (low-medium heat) to start:
(These are Amazon affiliate links.)
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