Friday, May 27, 2016

One ingredient, five products: Stearic acid - body scrub bars

Stearic acid is a great bar hardener, and I like to use as both a bar hardener and emollient in my body and foot scrub bars. Let's take a look at the body scrub bar today and the foot scrub bar on Monday.

What do I want in a body scrub bar? I want something that contains physical exfoliants that will exfoliate my skin and leave it feeling moisturized.

The first thing we want to think about is the butter you're using. Normally I use butters like cocoa butter, mango butter, or kokum butter to harden the bar, but I can substitut a little stearic acid in the mix to help as well. Stearic acid is not only less expensive than any butter you can find, but it's also a nice emollient. I think I'll use it at 10% in this recipe to make a really hard bar.

The down side of using so much stearic acid is that it can be a bit draggy on your skin, so consider using a greasier butter like shea butter or coconut oil as the secondary butter in this bar.

Do not use coconut oil as the primary butter in this bar as it will be very soft and fall apart in slightly warmer temperatures! 

For oils in this recipe, I definitely encourage you to use a liquid oil that will offer some greasiness. We want to get some glide and slip to this product! I generally use soy bean oil here as it has a nice long shelf life and offers all kinds of emolliency and phytosterols. You can use anything you want as an oil, but I do encourage you to use something inexpensive as it's not on our skin very long and we aren't getting all the benefits from the oil when it's being rinsed off.

I make mine emulsified so they will rinse cleaner than using all oils, so I definitely want something like Incroquat BTMS-50 or Polawax in the recipe to make sure it emulsifies well. You can use any emulsifier you like here.

Before you ask, yes, you can use any emulsifier you want. If it's an emulsifier, you can use it here. I suggest these ones as they tend to be less expensive and more readily available than some of the newer ones like Montanov 68 or Olivem 1000. You can use those, too, as you can use any emulsifier you wish in this recipe. 

What combination do I like? I generally go for cocoa butter with shea and soy bean oil for a greasier feeling product with Polawax or Ritamulse SCG. I really liked the black cocoa butter version I made as well. (No, I don't know where you can get it. The shop from which I bought it, Creations from Eden, doesn't carry it any more. If you're in Canada, check them out for other butters, like the golden shea butter, which is less greasy feeling and much stiffer than the refined stuff I normally buy!)

48% cocoa, mango, or kokum butter
25% shea butter, coconut oil, or babassu oil
5% Incroquat BTMS-25, Incroquat BTMS-50, Rita BTMS-225, Polawax
5% stearic acid
5% cetyl alcohol
10% oils

1% Phenonip
0.1% Vitamin E (anti-oxidant, optional)
1% fragrance or essential oil

Add physical exfoliating ingredients at up to 100% into the product. (See more below)

Melt everything except the the cool down phase in a heat proof container in a double boiler until all the ingredients are well melted. Remove from the heat and add the preservative, fragrance oil, and Vitamin E. Add your exfoliant and mix well. Then pour into a mold and put in the fridge or freezer until set. Let sit for 24 hours before using.

Add up to 100% sugar, salt, beads, seeds, loofah, baking soda, and so on. It really is your preference. If you are using sugar, you may need to add more than 100% because the sugar will melt into the warm oils - if you can stand the waiting, let it cool a bit before adding the sugar. You can add the salt right away into the hot oils. It will melt slightly, but not enough to be concering. Clay and jojoba beads will melt in the hot oils so you will need to let the mixture cool a lot - they really aren't a great choice here because you'll have to wait so long, the bar might actually solidify while you're waiting for the right temperature. Personally, I'd leave those for oil based or emulsified scrubs.

To forestall the question I always get asked about scrubs with exfoliants, I add them extra to the recipe. My base - the recipe above - should total 100%. Then I add exfoliants on top of that. That's because I like to use the base for a few different products, including foot scrub bars, and I use different levels of exfoliants for other products.

My personal preference as an exfoliant is sugar. It's inexpensive, it rinses off well, it melts away in the shower, and it feels great. You can combine exfoliants to make all kinds of combinations. You'll see on Monday that I like pumice and baking soda at 80/20 for a foot scrub bar.

Another question I'll get is about the preservative. I have chosen Phenonip because it can handle heat. I can't really use liquid Germall Plus here because it needs to be added at 50˚C or lower, and our bars will be getting quite solid by then. You can use any preservative that can handle heat in this recipe.

If you want to make a less greasy feeling product, use less greasy feeling ingredients like mango butter, babassu oil, any of the BTMS emulsifiers or Ritamulse SCG. If you want to make a greasier feeling product, go for cocoa butter, shea or coconut oil, and a greasier oil, like soy bean oil. It's up to you. I suggest you make a small batch to see if you like the combination you've chosen before making hundreds of these as gifts. (Because you will want to give them to everyone you know! I know I do!)

Related posts:
Back to Basics: Emulsified scrub bars
Black cocoa butter emulsified bars
Incroquat BTMS-50 in solid scrub bars
Formulating anhydrous scrub bars for different skin types
Road trip essentials: Solid scrub bars

Other posts in this series:
One ingredient, five products: Stearic acid
One ingredient, five products: Stearic acid - a hand lotion
One ingredient, five products: Stearic acid - foot cream

Join me Monday for foot scrub bars with stearic acid, and join me Saturday for another Weekend Wonderings!


CC Mirabella said...

Dr adorable on amazon carries the black cocoa butter :)
Thank you Susan

Baby Kat said...

Great recipe, thank you! I got stearic acid to harden my soap bars and it was very affordable, indeed.

Paige B said...

I was going to suggest Dr. Adorable too, but I tend to get it on eBay as it's generally cheaper and I can get free shipping, Ebates cash back, and use PayPal. That said, this is in the US, so I'm not sure how available it is in Canada.

Supriya said...

Hi Susan
I just made sugar scrub bar with stearic acid fron your recipe 5 days back and it's really good but my bar seem to be mushy like you can squiz in your palm and its relising water from sugar is it because of high humidity and our overall temp is around 28 degree pls guide me how to make bar hard coz I really like this bar
Thank you you are like angel for people like us who likes to make their product but don't know how

Susan Barclay-Nichols said...

Hi Supriya! Can you please post your exact recipe in percentages and process so I can help better? Did you put it in the fridge or freezer to set or did you leave it on a counter somewhere? Getting it into a cold place is very important!