Tuesday, March 17, 2015

Weekday Wonderings: Can you add glycerin to an anhydrous bar?

In this post, How to make a longer lasting lotion?, Susanna Originals asks: Can you use glycerine in an anhydrous recipe? For instance, if you were making a body bar could you replace 2 or 3% of the oil with glycerine?

The short answer is no. The long answer?

As I note in this post, we can mix water soluble things with water soluble things and oil soluble things with oil soluble things. We can only mix a water soluble thing with an oil soluble thing if we have an emulsifier. Glycerin is a water soluble ingredient and a body bar - which I'm guessing is a lotion bar of some kind - is anhydrous, so the two can't be used together without some kind of emulsifier. 

If you wanted to add glycerin to a lotion bar, you would need an emulsifier, like Polawax, Incroquat BTMS-50, Ritamulse SCG, and so on. You can see an example of a bar like this in my pumpkin seed oil body scrub bar. Because I have included Ritamulse SCG, I can include water soluble ingredients like a hydrolyzed protein or glycerin

You might see people adding water soluble ingredients to anhydrous products without an emulsifier. For instance, adding honey to a lip balm. I added sodium lactate to this lip balm a few years ago. How? I used lecithin, which can emulsify small amounts of water soluble ingredients into things like a lip balm or a lotion bar. 

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haya said...

does putting in a water soluble ingredient have the same implications as putting in actual water (ie: need preservative)? i see that you did include phenonip in your example

Susan Barclay-Nichols said...

I added a preservative to the scrub bar as it will be in contact with water while in the shower. A tiny bit of a water soluble ingredient probably doesn't need preserving because the water activity will be low. Would I include one? Probably, just to be safe!

Lise M Andersen said...

Oh yay! Thanks Susan - I missed that lip balm recipe - so glad you referred to it here. :)

Andy Lee said...

Hi Susan. I was very impressed with this post about how to include Glycerin in an anhydrous formulation using an emulsifiier. The post is what prompted me to purchase the Anhydrous ebook today (this makes my third of Susan's ebooks). I've been working with some anhydrous formulations and I just never knew you could do that. Clever!


Andy Lee

Susanna Originals said...

Thank you!

Gouri Padmaja said...

Hi Susan!
I am a big fan of your blog. Thank you for sharing so much valuable information. I am trying to make a anhydrous body butter for my baby. I want to add glycerin (like around 3%).can I use steric acid as an emulsifier?
Thanks in advance.

Susan Barclay-Nichols said...

Hi Gouri! Stearic acid isn't an emulsifier, so you can't use it to emulsify glycerin into your product. There are many emulsifiers you could try for this product, but if you're going to go to all that trouble, why not make a lotion?

Gouri Padmaja said...

I already made a product with shea abutter, oils, beeswax and 3 % glycerin. I melted everything and I blended with stick blender. It got emulsified!! I did not see any separation. I can make a lotion, but I don’t want to enter into the world of preservatives. Will I have to add preservative if there is a bit of glycerin in the formula?

And this is my inspiration for my recipe: http://www.lushusa.com/Lip-Service/03855,en_US,pd.html

Lip Service: Fair Trade Shea Butter (Butyrospermum parkii) , Apricot Kernel Oil (Prunus armeniaca) , Glycerine , Beeswax (Cera alba) , Fair Trade Organic Cocoa Butter (Theobroma Cacao) , Organic Extra Virgin Olive Oil (Olea europaea) , Tangerine Oil (Citrus reticulata) , Flavor , *Limonene , *Linalool . *Occurs naturally in essential oils

Unknown said...

Hi Susan Is it possible for me to add a preservative to a coffee and sheabutter body scrub its has oils, (glycerin included) Whats would the shelf life be for this type of scrub ? I wanted it have have a "frankbody" type of texture not creamy emulsified scrub! can i add a preservative (optiphen plus ) without having to add a emulsifier to it ?? like lecithin ?? would that change the texture ?

br.eyed_gurl said...

HI. I have been crafting lotion bars tailored to specific needs/conditons with great successs but want to add raw honey. I did this for the first time a few days ago and naturally it wouldnt even mix in. Most settled at the bottom before even poring into a mold. A small amount did however remain in the bars as you can see the brownish speckles from raw buckwheat honey. As an added bonus; it didnt make them seem sticky at all and are holding up well so far at room temp.I didnt add any preservative except vitamin E. Yes, i know, it wont last long. I'm hoping for a month. My question is, how can I get it to mix in? Lecithin? And since its all oils except for extremely thick, and NOT smooth honey, how and when do I add an emulsifier?And I really want to keep them "natural" yet make them last. Got any suggestions?