Tuesday, December 12, 2017

Question from Patreon: Why did this lotion fail? Part two - fragrance or essential oils and mixing

Yesterday, we took a look at how changes in oils and preservatives might impact a lotion. What else could be an issue here?

Fragrance and essential oils aren’t inert ingredients: We know vanilla can make things brown, but it can also thin out a product thanks to the vanillin. This is why we may have problems working with vanilla with polymeric emulsifiers (ones we can use cold) that contain a polymer, like Aristoflex AVC, or a gelling agent, like Sepimax ZEN or Ultrez 10, and surfactants. I used vanilla fragrance oil in this formula, and it remained stable, which is a good thing.

More information on this topic:
Understanding the Vanillin Villian (my article from Handmade Magazine
Did vanilla turn my lovely lotion brown?

Is anyone interested in learning more about the chemistry of how vanilla messes with gels? I think it’s really interesting, but I also wear molecular earrings and read chemistry texts in bed, so I can accept my opinion might be in the minority. :-)

What’s in myrrh essential oil? “The main chemical components of myrrh oil are a-pinene, cadinene, limonene, cuminaldehyde, eugenol, m-cresol, heerabolene, acetic acid, formic acid and other sesquiterpenes and acids.” (Reference) I’m not seeing anything here that should destabilize a lotion, so this is probably not the issue, but I can’t be completely sure as I haven’t used it in this formula.

More information on the chemistry of myrrh essential oil:
Compound Interest, chemistry of myrrh
Chemical Composition of the Essential Oil and Supercritical CO2 Extract of Commiphora myrrha (Nees) Engl. and of Acorus calamus L.

The way we make the product can have a huge impact on how it turns out. For instance, Olivem 1000 needs to be stick blended, Simulgreen 18-2 needs to be stick blended then mixed with a hand mixer, and Varisoft EQ 65 needs to be stick blended only. It’s all about shear. Stick or immersion blenders are high shear, beaters on a hand mixer are low shear.

I have a drink mixer on my Kitchenaid mixer, and it’s considered a propeller mixer, which is why I bought it. It would be considered low shear. For this product, it shouldn’t make a difference, but I haven’t tried it with that attachment.

Having said this, Simulsol 165/Lotionpro™ 165 doesn’t have an issue with mixing with a hand mixer, stick blender, or propeller mixer, so I don’t think it’s that.

For more information on mixers:
Gift ideas for crafters - mixers!

After analyzing all of this, I don't think the essential oil, oil choice, or mixer is an issue. I think it's all about the interaction with the preservative.

Looking at all of this, what suggestions do I have for working with Simulsol 165/Lotionpro™ 165? I really don’t have much to suggest as it’s a fairly easy to use emulsifier that isn’t picky about how we mix it. It’s one of the ones I consider fairly foolproof in that we can alter the oil phase easily, switching out any oil for any oil, any butter for any butter, any oil for butter, butter for oil, and all of those things for esters or other oil soluble ingredients.

However, if you're using one of the harder to use preservatives, as we discussed yesterday, alter any formula with this emulsifier to below 30% oil phase.

What does this mean? The oil phase is everything that has to be emulsified by the emulsifier, meaning everything that's oil soluble in the formula, including oils, butters, esters, fatty alcohols, fatty acids, fragrance oils, essential oils, and other oil soluble ingredients, like vitamins, anti-oxidants, cosmeceuticals, and more.

In this formula, the coffee butter, oil of choice, cetyl alcohol, and fragrance or essential oil make up the oil phase. If my limit is 30%, I like to keep things below 29% to compensate for hand slips and such, which I did in the modification in yesterday's post.

If you were to use something like Ritamulse SCG with a maximum oil phase of 25% and you wanted to use this preservative, you want to make sure you're using no more than 24% to be on the safe side.

Related posts:
When lotions go wrong!
Why did my lotion fail? Loads of links here!
Why did my lotion fail? Emulsifiers
Why did my lotion fail? Emulsifiers continued…
Why did my lotion fail? Heating and holding
Why did my lotion fail? Optiphen
Why did my lotion fail? Water in oil emulsions
How to make a successful lotion

This post appeared on November 27, 2017, on my Patreon feed. If you'd like to see these posts three to four weeks earlier, click here for more information on my Patreon feed. $10 subscribers get an e-zine as well as discounts from awesome shops, like Lotioncrafterbut you can subscribe at as little as $1 a month to gain access to the feed.

Why sign up for Patreon? Because this is my full time job now, and your subscription helps me write more and experiment with more ingredients and equipment for the blog!


karina said...

I love it when you offer chemistry lessons, I find them fascinating. Do you have any favorite chemistry books I can read? Thank you.

Frit said...

I agree with Karina! I'm fascinated by the chemistry, and yes, Kevin Dunn's book "Scientific Soapmaking" is on my wish list, since you recommend it so highly. ;)


Unknown said...

I'm definitely interested in posts about the chemical constituents of essential oils and how you think they work in formulations. Thanks!

carolyn said...

(Blogger is listing me as unknown though I entered my email address and name. Carolyn here. i said I was interested in EO chemical constituents.)

Bridget Clancy said...

Lotionpro is one of my favorite emulsifiers. I find it has a nicer, less waxy skin feel than emulsifying wax(Polysorbate 60 and cetearyl alcohol), it’s inexpensive, and like Susan says it’s not picky. I have found though that it’s more important to mix it thoroughly than with e wax. I’ve made emulsions with e wax that I have gotten away with just stirring up with a whisk(lazy I know), but I find I have to mix Lotionpro with a stick blender or it separates/doesn’t emulsify. I had problems with it not emulsifying when I tried to mix it with an egg beater instead of a stick blender. But others here may have had a different experience.