Glycerine vs Propanediol for Fresh Food Extracts - Which is Best?


Pictured: the beginning of an extract-making experiment with fresh strawberries.

Because the industry offers herbal extracts in propanediol as well as glycerine, I recently decided to do my own little test to see how they compare.


Let's Start with the Berries

This experiment came about immediately after bringing home a case of fresh organic strawberries. They were on special and it was a generous portion – much more than we could eat. As I had recently received an order of propanediol, it was a bit of a no brainer for me to take some berries for my test.

My husband (a big fan of strawberries), couldn't help but notice me removing the most perfect looking strawberries from the box. He mumbled something about that being far more than I needed for a face mask, so I explained I was going to use them for an extract.

"I'm going to do a comparative test of glycerine vs propanediol" I told him.

Note: I have forever pronounced propanediol: 'pro-pan-eh-dee-ol'
I know it's not correct, but unfortunately, I can't seem to shake this pronunciation.

His expression changed to one of surprise as he asked me 'Profanity oil? What's that?"

(insert an hour of giggling)

Now, of course, this ingredient will forever be called profanity oil around here.

A Bit About Propanediol

Like glycerine, propanediol is

  • plant-based and considered natural (produced via corn sugar fermentation)
  • a humectant
  • a preservative booster
  • a solvent
  • water soluble
  • an emollient
  • commonly used in cosmetics

One could be tempted to wonder if there is any difference at all, wouldn't one? Hence the test.

The Experiment

I prepared both batches as I normally do for a fresh food glycerite and left them to infuse for my normal amount of time.

The first difference showed up a few minutes after starting the brews. The propanediol (on the right) seemed to get straight to work. Notice how the liquid is pinkish in the jar on the right?

This continued over the days until they were ready to strain. Here's what they looked like when I took off the lids. (Propanediol is on the right)

And here's what they looked like after straining. The berries that were in glycerine are noticeably darker while the ones that were in propanediol look like they've had the very life sucked out of them.

Strangely, that didn't result in a darker liquid. The propanediol produced a lighter colored liquid.


Another noticeable difference is viscosity. The propanediol extract is runnier (although that isn't very visible in the photo, there is a pretty big difference).

Next Time

As for scent: I'll get into that one next post, as I had to pass the two around for some nose tests. I'll also be doing a few side by side tests of these 2 extracts in different products in coming posts. 

Want to make your own glycerine extracts? This book might be just what you're looking for.






Do Tell

Do you make extracts using propanediol? Please leave a comment below!

Comments

Sal said…
Interesting!
It looks to me as if the propanediol was more dehydrating for the strawbs - hence their shrivelled-up-ness and the runnier liquid? So - if water is life, then it did suck the very life out of them : )
Will look forward to the sniff test results!
Thanks,
Sarah
LisaLise said…
Hi Sal - I agree!
Eleftheria Iliadi said…
Hello! I have your The Art of Making Glycerites Book and i was wondering if i can apply the glycerin extration methods you are giving to extract in propanediol, or it s just a different story ?
LisaLise said…
Hello Eleftheria Iliadi - As a starting point you can apply the same methods. HOWEVER: there will be differences in added water amount, infusion time and straining process with quite a few materials. Start with a few small side by side infusions to get a feel for the differences in the 2 materials - and have fun with it! :)
Eleftheria Iliadi said…
Thank you Lisa!! :)
suki-san said…
Hi Lise!I was wondering if you had an opinion on the correct required •minimum• percentage of either of the above solvents, when working with fresh materials, in order to make it 'self-preserving'?
For example, from my experience in herbal practice, I've learned that when preserving a fresh succus, one must use 20%, or 25% 190proof ethanol (depending on who you ask/read). I was about 2seconds from adding 40gms of ethanol to my 160gm fresh plantain leaf succus, when I suddenly remembered a blog post of yours regarding making glycerites with fresh material..I'd love for this to be something that could be used comfortably(topically), without the drying of the skin that alcohol can cause. Especially as this is to be part of a healing wound lotion.
Thank you for any response you choose to share with me. I hope you are well.
Muchlove, suki
LisaLise said…
Hi Suki-san - Great to hear from you!

Your questions are answered in my book The Art of Making Glycerites for Cosmetics in details. There are calculation charts for working with both self-preserving glycerites and glycerites with added preservative. Check the shop at LisaLise.com for more detailed info on what the book contains.