What Is an Emulsifier?
Oil and water don’t mix. We all know that.
Yet open a tub of face cream or pump out some body lotion and you’ll find oil- and water-based ingredients sitting together in one smooth, creamy product.
So, what’s keeping them together?
Meet the emulsifier.
If you’re learning to formulate your own cosmetic or personal-care products, emulsifiers are one ingredient category worth understanding. They play an important role in products such as creams, lotions, moisturisers, conditioners, sunscreens and cleansing milks.
That’s why we’re starting Emulsifiers Explained, a five-part BrightPack series created with technical input from our in-house chemist to help small businesses, start-ups and aspiring formulators better understand the ingredients they’re working with.
Because better formulating starts with understanding what’s actually happening inside the bottle.
So, What Exactly Is an Emulsifier?
In simple terms, an emulsifier is an ingredient that helps oil and water mix and prevents them from separating again.
More technically, an emulsifier reduces the interfacial tension between the oil and water phases, helping to create a stable emulsion.
An emulsion is a mixture of two liquids that wouldn’t ordinarily remain mixed – most commonly oil and water.
Without an appropriate emulsification system, the smooth lotion you formulated could eventually separate into visible layers of oil and water.
And nobody wants their carefully developed cream doing that on a customer’s bathroom shelf.
Why Are Emulsifiers Important?
Keeping oil and water together is their main job, but emulsifiers can influence much more than separation.
Your emulsification system can also affect the texture, viscosity, appearance and performance of your finished product.
The right system can help:
- Create a stable formulation
- Prevent oil and water from separating
- Improve stability during storage
- Improve spreadability and skin feel
- Improve manufacturing consistency
- Improve the appearance of the finished product
So, when you’re choosing an emulsifier, you aren’t only asking:
“Will this keep my oil and water together?”
You should also be asking:
“Will this help me create the product I actually want?”
How Do You Choose the Right Emulsifier?
Unfortunately, there isn’t one emulsifier that works for everything.
A lightweight lotion may need something different from a rich cream or hair conditioner.
Before choosing an emulsifier, consider:
What are you making?
A lotion, cream, conditioner, body butter or sunscreen will each have different formulation requirements.
What does your formulation contain?
Your oil-phase percentage, water-phase composition and other ingredients can influence which emulsification system is suitable.
What do you want the finished product to be like?
Think light, rich, silky or thick – and consider whether you want a matte, velvety, rich or fast-absorbing skin feel.
How are you manufacturing it?
Whether the formulation uses a hot or cold process also needs to be considered.
Ingredient compatibility, active ingredients, packaging, cost and stability requirements can all play a part too.
It might sound like a lot to consider, but that’s exactly why we’re breaking emulsifiers down into a series.
We're Here to Help You Understand What You're Formulating
At BrightPack, we don’t want to simply supply an ingredient and leave you wondering what to do with it.
We work with many small businesses and start-ups that are learning, experimenting and developing their own products. Along with supplying raw materials, we want to make the technical side of formulation easier to understand, with educational guidance supported by our in-house chemist.
As this series continues, we’ll introduce ingredients available from BrightPack and help explain where they fit into the bigger emulsification picture.
Because an emulsifier is rarely just an emulsifier.
There are different types, classifications and functions – and understanding those differences is where things start getting interesting.
Coming next: Emulsifiers Explained Part 2 — Not All Emulsifiers Are the Same
If emulsifiers all help bring oil and water together, why are there so many different types? Next week, we’ll look at how emulsifiers are classified and why those differences matter when you’re formulating.