Episode 196: How Essential Oils Are Extracted

doTERRA: People have been distilling essential oils in one way or another for thousands of years. And today we're going to talk about the most up-to-date methods of distilling the most pure essential oils.

Welcome back to Essential Oils Solutions with doTERRA, the podcast where you'll hear exciting, useful, and simple everyday uses for essential oils from experts in the field.

Today's episode is brought to you by the On Guard Protective Blend. A powerful blend of essential oils, On Guard provides a natural and effective alternative for immune support when used internally. Your body does a lot for you, so why not get your guard up?

Today, we're excited to talk to Dr. Scott Johnson—author of multiple books and hundreds of articles about health, wellness, and essential oils—about the different methods of essential oil distillation and how they're used today. Scott, thank you so much for being here with us today.

Dr. Scott Johnson: It's my pleasure! Always glad to share more about essential oils.

doTERRA: Yes, this is a topic that I am very excited about because I feel like it doesn't get talked about enough. So my first question for you is how long have people been extracting essential oils from plants?

Scott: Well, crude aromatic extracts have been used as far back as recorded history. Historical records and even archaeological evidence suggests that ancient cultures extracted volatile aromatic extracts for rituals and for food and religious purposes, health, and even economic reasons. But true essential oils weren't really extracted until around the late 10th to early 11th century.

The Persians are usually credited with being the first to extract true essential oils using like distillation methods. And then it snowballed from there in other European countries where they started to adopt that.

doTERRA: Right. Now, you mentioned this has been going on basically since recorded history. What are some of those earlier methods that they were using to extract those crude essential oils?

Scott: Yeah, early aromatic extracts were likely extracted in animal or vegetable fats. This method is called maceration, and it's not really creating true essential oils or what we would call an essential oil today.

doTERRA: Right.

Scott: Basically, the fats were used as solvents to extract the volatile aromatic compounds from various different plant materials. The plant and fats, that mixture goes through a process of straining and filtration until an aromatic extract is created.

Interestingly, one of the benefits of this method is that more of the plant's true aroma or authentic to the original plant materials is captured in this type of oil because this method extracts some heavier, larger plant molecules with it.

Another older method is called enfleurage, which is still occasionally used today, although pretty rarely now. This method is primarily used for delicate flower oils like rose. Just like maceration, this process uses fats as the solvent, and these fats can be hot or cold during the process. Flower petals are pressed into the fats and then you replace those every few days and you continue this process for a couple of weeks, which causes the aromatic compounds in the fat or in the petals or the plant materials, whatever you're using at the time to seep into the fat. Then once you have that fat and aromatic compound mixture at the end, you actually take alcohol and wash that mixture, which helps to separate the plant extract from the fat.

doTERRA: Wow. So a little bit more labor intensive than some of the ones we use today.

Scott: Right, where it's taking weeks of process instead of maybe several hours.

doTERRA: Right. That is incredible. So looking at our improved technology for extracting these essential oils, what would you say the most common method is for extraction today and how does it work?

Scott: Today steam distillation is by far the most commonly used method, but hydro distillation and cold pressing are also used.

Steam distillation uses a pressurized system, and the steam passes through plant material that's inside of a big vat called a still. The steam causes small glands in the plant material to rupture and that releases aromatic compounds. And then these compounds travel through piping that goes into a condenser that converts them back into liquid form, leaving a mixture of the essential oil and steam, which is then later separated in a in a separator. Because oils are usually lighter than water, the oil rises to the top and the water sinks to the bottom.

A few exceptions to this are Clove and Cinnamon and Wintergreen. They're more dense than water. And so they'll actually sink to the bottom of this separator with the water floating on top.

doTERRA: Wow. And those are those really kind of thick oils you can notice when you pour them out of the bottle.

Scott: Yeah, they can be.

doTERRA: So you mentioned a few there, the really heavy ones. What are some of the other common essential oils that are extracted through steam distillation?

Scott: Well, the bulk of essential oils are extracted this way, and that would include things like that most people are familiar with, like Lavender and Peppermint and Oregano, Eucalyptus, Clove and lots, lots more. I mean, most of your oils are actually going to be extracted this way.

I mentioned hydro distillation earlier, which is a little bit different than steam distillation. Sometimes people use those terms synonymously, but hydro distillation, the plant material actually comes in contact with the water rather than the steam just passing through.

And so some essential oils are better extracted this way. That would be plant materials like Frankincense resins. So resins are a good type of plant material that’s better with hydro distillation, and sometimes like Ginger too. And we do that because more of the precious essential oil and the bioactive compounds are preserved and extracted using that method with those plant materials.

doTERRA: Now, I notice you didn't mention any citrus fruits in those lists. How are citrus fruit essential oils extracted?

Scott: Yeah, citrus oils are a little bit of an anomaly when it comes to essential oils. Although they can be distilled like traditional Lavender or Peppermint in the same process, they are often extracted through a mechanical process which is called cold pressing or expression.

Unlike distillation, this method doesn't require any heat. Instead, fruit is placed in a machine, and it's passed across some rasping cylinders that pierce the surface of the peel. And this causes small sacs in the peel to rupture and release essential oil.

You've probably experienced this yourself, or at least seen it if you've ever peeled an orange, because as you peel an orange, you see sometimes a burst of just like a liquid that flies out of it. And that's you rupturing those sacs and that's releasing that essential oil when you're doing that.

Next the water is sprayed over the fruit, which creates a mixture of both water and essential oils, and this mixture is centrifuged and filtered to isolate the essential oil.

doTERRA: So you mentioned that it's mostly from the peel that we're getting this essential oil. What is then done with all the leftover fruit?

Scott: Yeah, that's a good question. And it really depends on which fruit is being distilled as well as the grower that produced it. Some use the spent—we call it biomass—the biomass or the leftover plant material as mulch or a fertilizer. Others actually can use it to burn as fuel for boilers.

doTERRA: Oh, interesting.

Scott: Some will actually sell that as a byproduct for other people to use in different industrial applications.

And in some cases, it's discarded. But keep in mind that some fruits like Green Mandarin were already destined to be discarded anyway because they're removed from the tree as part of the thinning process to make the fruit grow to the right size and maturity. And so it would have been discarded anyway.

doTERRA: Right. Now what about some of those more delicate plants, the ones who wouldn't make it through a steam distillation process or cold pressing? How are those essential oils extracted?

Scott: Yeah, delicate plants, they may be extracted via a solvent, like alcohol. And they produce what's called an absolute and not a true essential oil.

Another, more modern and emerging method is to use supercritical carbon dioxide because of its unique properties that allow it to be both a gas and a liquid. It's also a really clean extraction method. It produces extracts—aromatic extracts that have an aroma very authentic to the plant material, and it has an ability to selectively extract specific constituents if that's what you were trying to do.

An example of this is our Madagascar Vanilla, which leverages this technology to produce an absolute from the vanilla beans.

doTERRA: Right. And it's amazing to see how this technology for essential oil extraction is still progressing. There are still new inventions and discoveries being made to make sure that we're getting that super high-quality, pure essential oil.

Scott: Yeah, they're always adapting and coming up with new ways, or just maybe refining the existing processes to produce high-quality essential oils that are pure and natural.

doTERRA: Scott, I have learned so much today, but before we end, I have to ask you, what resources do you recommend if people want to learn more about how essential oils are extracted?

Scott: I think that a great place to start is the Essential Oils Specialist Certification Program. So this explains a lot more about extraction methods and some of both their pros and their cons in greater detail. So just visit training.doterra.com to look up this course and go ahead and jump in, dive in, and start taking it.

doTERRA: Absolutely. It has been wonderful to talk to you today. We always appreciate when you come down and teach us a little bit more about essential oils.

Scott: My pleasure. Glad to be here.

doTERRA: Thanks for joining us and congratulations on living a healthier lifestyle with essential oils. If you want to try any of the products you learned about, click on the link in the episode description or find a Wellness Advocate near you to place an order today. And remember, if you liked what you heard today, rate, review, and subscribe wherever you listen.