Friday, January 30, 2015

Can we substitute one ingredient for another in a product? Lotion bars

If you're wondering if you can substitute one ingredient for another, check out first what the ingredients do in the product. What exactly does the ingredient do? Is it a surfactant, an emollient, a conditioning agent, an emulsifier, and so on? What does it bring to the product? What is its skin feel? Does it thin or thicken the product? Is it essential for the success of the product - for instance, is is the bubbly and lathery thing in a body wash or an emulsifier in a lotion - or is it a nice addition - for instance, a film former or humectant? Why exactly is the original ingredient in the recipe and what will substituting it for the one you have do to the end result?

Yep, it all comes back to knowing your ingredients! I know, I know, right? There's just no way to get around it! Learning about the ingredients you have - learning what they do, how they do it, what they feel like, and what they bring to the product - is the only way to get to the point where you can make substitutions or create your own recipes from scratch!

Let's say you want to substitute one oil for another in a lotion bar recipe.

33% beeswax
33% mango butter
33% soy bean oil
1% fragrance oil

If you wanted to use kukui nut oil instead, you might take a look at why the soy bean oil is in the recipe in the first place. A liquid oil is necessary in a lotion bar to keep it from being too hard. It will also contribute to the skin feel and greasiness level. Soy bean oil is a light and greasy feeling oil with a lot of Vitamin E and phytosterols. It will make the lotion bar feel medium to heavy greasiness. Kukui nut oil is a light and non-greasy feeling oil that has a very silky after feel with an unknown (to me) amount of Vitamin E and phytosterols. If I used this in the product, it means my product would feel less greasy and more silky. Can I substitute one for the other? Yes! We can almost always substitute one liquid oil for another liquid oil in our products!

The exception? If you're working with castor oil and beeswax together, there is a neat effect they have when they are together in something like a mock Vaseline or lipstick. The beeswax becomes more plastic when combined with castor oil. Don't make changes in these two products! 

Related posts:
Can we substitute one oil for another?

Let's say you want to substitute the mango butter for another hard butter, like coconut oil. Could we? What does the mango butter bring to the product? It has a high melting point, which means the product will stay solid, and it offers a dry, powdery feeling instead of a greasy one. Coconut oil has a low melting point, which means the product won't be solid any more when it reaches 24˚C or 76˚F, and it has a greasy skin feel. Can we substitute the coconut oil for the mango butter?

No. The mango butter has an important role here, to keep the bar more solid, so we can't substitute something that might melt at slightly above room temperature for it.

Could we substitute another high melting point butter for the mango butter? Yes! We could use cocoa, shea, kokum, and so on for it because they will maintain the shape of the lotion bar.

What about substituting one wax for another? Beeswax is a plasticizer and hardener, helping the bar keep its shape and stiffness. Could we use something like carnauba or candellia wax? Yes, but we would have to modify the amount we use as these other waxes make lotion bars much much harder. In general, we divide the amount of beeswax in half for the wax, then make up the rest with the butter and liquid oil. So we might use 16% candellia wax and 40% oil, 39% butter instead of 1/3 of each.

When we alter something, we will change the skin feel. Your bar with candellia wax, kukui nut oil, and shea butter will not feel even remotely like my bar with mango butter, beeswax, and soy bean oil, but we aren't altering the chemistry of anything when we make these substitutions. When we're making anhydrous products, changing the ingredients is about changing the viscosity, skin feel, stiffness, and so on, changes in physical sensations. When we make changes in things like lotions, we could be changing the chemistry of the product, so we have to give it a little more thought.*

*This isn't to say that you can't alter the type of oils or butters in a lotion. I can't think of a situation in which a lotion using an all-in-one emulsifier like Polawax, e-wax, Incroquat BTMS-50, or Ritamulse SCG couldn't have the oils changed as long as the concentrations stayed the same. (So, not going over 25% oils for something like Ritamulse SCG.) What I mean is doing things like not including an emulsifier. We'll take a look at substituting things in a lotion next week! 

Related posts:
Substituting cetyl alcohol in a recipe
How do you know what to substitute?
Substitutions: Playing around with a recipe
Substituting one ingredient for another
Can we substitute one oil for another?
Substituting: Figuring out what's important in a conditioner. 
Substituting: Learning INCI names
Substituting: How to tweak that amazing sounding recipe!
Substitutions: Modifying a lotion with what you have (part one)
Substitutions: Modifying a lotion with what you have (part two)
Substitutions: What to do when you can't wait to create! 

Formulating on a budget: An introduction
Formulating on a budget: Buying ingredients
Formulating on a budget: A test recipe


shahn said...

Can you use cetyl alcohol/ester or btms as a substitute for beeswax?

Susan Barclay-Nichols said...

As I mention in the post above, to know if you can subtitute something, you have to know the ingredients. In what product are you substituting one for the other? What does the beeswax do in the recipe? What does cetyl alcohol do in a recipe? What would it do in this recipe? What does BTMS do in a recipe? What will it do in this recipe? If you can answer those questions, then you'll know you have a substitution possibility.

Robin said...

I have dome sera bellina wax but have not yet used it. Would I need less than bees wax? Thank you

Robin said...

Oops I have some

Maria said...

This looks like it might make the start of a deodorant bar--with zinc oxide added, maybe some cyclomethicone for glide (Haven't figured that part out yet) and some deodorant additive (bramble berry carries this product and I think it is probably a necessary addition to really make a deodorant work.) I don't think mango would be good--might stain. Perhaps cocoa butter and less beeswax. Oh, the possibilities!