What is Expeller Pressed Oil and Why Does it Matter?

Ingredient list aficionados (OK, geeks) like us come across interesting phrases and wordings in product packages. In some cases, the fancy words mask a simple ingredient, trying to create an aura of sophistication or health (100% pure evaporated cane sugar syrup is basically…sugar). But sometimes they do have meaning.

We wanted to know in which camp to place “expeller pressed” oil.

What you need to know:

The three most popular methods of oil extraction from vegetables, nuts and seeds are :

  • Chemical solvents
  • Centrifuge
  • Screw press (expeller)

Often, more than one method is used, this in order to squeeze the most oil out. The process usually begins with cracking the hull of the nut and then applying one of the aforementioned methods, followed by another.

The solvent extraction method is very popular, and uses hexane, which is a poisonous chemical. The process is very effective and usually recovers 99% of the oil. However, in order to get rid of the hexane, the oil is heated to a high temperature. This changes the flavor profile and for some delicate oils like olive oil, may ruin the flavor altogether.

Mechanical extraction is how things were done for centuries. Applying heavy pressure to olives or seeds until oil starts seeping out. An expeller is a big screw that is tightened until it crushes the nut/seed and causes the oil to run. This method provides yields of only 65-70% of the oil. Many companies then try to extract the rest of the oil using the chemical solvent.

Mechanical pressing may create high temperatures, especially when squeezing hard nuts. This usually happens when working with automatic machinery in high volume. The issue with high temperatures, as we mentioned before, is that they change the flavor of the oil.

Which brings us to the term “cold pressed”. Some companies go to great efforts to maintain a temperature below 90 degrees Fahrenheit when pressing the oil. In Europe the term “cold pressed” is regulated and oils cannot exceed that temperature. But in the US, there is no such regulation. Cold pressed could mean anything under 400 degrees…

What to do at the supermarket:

Well, now you know what expeller pressed oil and cold pressed oil mean. Compare labels, compare prices, and most importantly compare the taste. Then decide which oil works best for you.

Get Fooducated: iPhone App RSS Subscription or Email Subscription

Follow us on twitter: twitter.com/fooducate on facebook: facebook.com/fooducate

Get Fooducated

  • http://www.awakenedwellness.com Rachel Assuncao

    Thanks for the information. It’s great to see such a clear and easy description. I usually opt for cold pressed unfiltered oils first. I find they have the best flavor (though often a shorter shelf life). What guarantee is there that all the hexane is removed from the chemically processed oils?

  • http://foodtrainers.blogspot.com Lauren Slayton

    Other than looking for expeller (which I did and have to admit didn’t know what the expeller looked like) how do we no no hexane used? can you tweet me the answer?

  • Niki

    Awesome information. Thank you!!

  • http://www.thetableofpromise.blogspot.com The Table of Promise

    Isn’t it ironic that fats that require more aggressive extraction (like soybean, corn and cottenseed) come from what we consider relatively low-fat food sources and are all POLYunsaturated oils. Where as olive, peanut and sunflower oils come from fatty food sources,can be made with expeller pressing and are MONOunsaturated. What do you think that says about which fats we should be eating? I think that by choosing only expeller pressed oils we will also be more likely to choose oils that are more natural, more traditional, and better for our health.

  • Bill McNye

    I only use expeller pressed (ie the good stuff) when the end product wont get cooked. Usually, I dip some good whole grain bread in extra virgin olive oil while I cook. By the time dinner is ready, I am full.

  • chris

    Good article, but I don’t think the most important thing is taste for me.  When plants and nuts reaches over 118 degrees F, the enzymes will start to get killed.   That’s including the good ones.  Plus, depending on the plant or nut, fat will start to become more saturated and can even become rancid.  Different oil has different boiling point.  For me, keeping the most nutrients in the food in its raw or lightly cooked state is the best.  Otherwise, I am eating high calories (fat) without much benefits.

    • SS

      Good point!!!

  • Joe

    I bought a can of Spectrum  brand expeller pressed coconut oil from supermarket.  It does not have the nice coconut smell and flavor. 

  • http://www.facebook.com/people/Sandy-McGarity-Darrell/1469754405 Sandy McGarity Darrell

    Should cold-pressed olive oil be refrigerated or is there shorter shelf life?

  • Angela Maldonado

    Thank you for this article. This really explains why hydrogenated oils give me migraines that last several days… there is nothing good about chemically processed food.

  • lindylu

    Your definition of sugar is simplistic. The idea behind “evaporated cane sugar syrup” is that the (however few) nutrients in the cane remains rather that being processed out.