The Internet is a wonderful place to find information. It really is. But some of the time, the information is incorrect. And it pisses me off.
What prompted this post: a page I follow on Facebook shared this page about making “Rosemary Essential Oil”. It was shared numerous times before and even after another lady and I corrected it in the comments, thereby spreading the misinformation even further. The instructions tell how to make Rosemary-infused oil. While I have nothing against infused oils (I use them a lot), it’s totally different than Rosemary essential oil.
“Essential oil” (EO) is the volatile oil component of a plant. It’s what gives the plant its smell. For most plants, it is extracted by steam distillation*. There are some plants, though, where the oils are pressed out (as in citrus from the peel). Yet others don’t have enough oil to press out and the heat of distillation would evaporate any volatile oil so those are extracted by using a solvent.
Motivated by that post, I started perusing the Internet to see what was out there on making essential oils. There are a bunch of sites that tell you how to do it at home, some even giving instructions on how to build your own still. There’s a problem even with that: I found very little discussion of how much plant material you’re going to need to obtain a decent quantity of essential oil.
Some plants have more oil than others. This is why, when you buy pure essential oils, the prices vary widely. If you’re looking at a shelf of EO bottles and Rose is the same price as Lavender, walk away. It takes approximately 60,000 Rose blossoms to yield just one ounce (by weight -a little less than an ounce by volume) of Rose essential oil. Conversely, only 220 pounds of Lavender flowers will produce about 7 pounds of oil. The more oil in the plant, the easier it is to get in quantity & the cheaper it’s going to be**.
One of the sites I saw suggested drying your herb before putting it into the still. That way you can get more material crammed in there. All well & fine if you’re using something like Lavender with a lot of volatile oil in it. But what about, say, Lemon Balm? That has so little volatile oil that nearly all of it evaporates in the drying process. You’d be lucky to get just a few drops of EO off a pound of dried leaves.
I make a lot of my own hydrosols (flower water) on top of my stove, using a method described in James Green’s book, The Herbal Medicine Maker’s Handbook. (Which, by the way, I highly recommend.) When I’m using strong-smelling plants, like Rosemary, I’ll get a few drops of essential oil floating on top of the hydrosol, which I draw off with a pipette. I’d probably get a little more if I actually used an alembic & distilled it. But even with my large Rosemary plants & a bountiful harvest, I still wouldn’t get enough oil to fill multiple bottles.
If you want to try distilling your own essential oils at home, by all means, do so. Just don’t expect to have 50 bottles of Rose essential oil to sell, unless you have a field of nothing but aromatic Rose bushes and a lot of time.
Please don’t believe everything you read on the ‘Net. It ain’t all correct.
* The process is very much like making moonshine and the equipment is nearly identical. When I mused about buying an alembic, hubby said OK if he could “borrow” it for his own use. I haven’t yet purchased one but if I do, I think I’ll have to guard it…
**The most expensive essential oil I’ve found thus far is Lotus Blossom. Last I saw, it was selling for £400 ($665) for five milliliters.