Making Lotion: What is an emulsifier and how does it work in cosmetics?
Emulsifiers in action– when oil and water do mix!
Typically creating a lotion or cream takes three phases: a water phase, an oil phase and a finishing phase that occurs after your emulsion has cooled. But oil and water don’t mix. Or do they?
Since water and oil do not mix but stay separated, an additional agent (emulsifier) is necessary to form a homogenous mixture keeping water and oil together. Without an emulsifier, you can ‘aggitate’ the water and oil together but as soon as you stop, they fall out and separate back to oil floating on water. In cosmetic chemistry– and in kitchen chemistry, we use ’emulsions’ to blend two immiscible (unblendable) liquids together.
An emulsifier (also known as an “emulgent”) is a substance that stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as “surface active agents”, or surfactants. Emulsifiers work because their molecules have two parts: one part loves water and one part loves oil.
There are two types of emulsions: Water in Oil W/O and Oil in Water O/W.
Water in Oil W/O – in this emulsion the oil surrounds the water and the oil touches the skin first. The level of greasiness depends on the formula – all of which will be absorbed into the skin. The emulsion is often made with your choice of oil, beeswax, borax and water. If done correctly you will have little to no greasiness.
Oil in Water O/W – this emulsion has the oil being surrounded by water. This method creates cream and lotions that feel moist, less greasy. When absorbed into the skin there is very little to no oily residue. You will likely use an emulsifying wax for this emulsion.
Emulsifiers come in a variety of forms. For cooking we often use eggs as emulsifiers. In cosmetics, you can use from emulsifying wax, lecitin, or stearic acid, a stabilizing agent found in vegetable fats. Beeswax and borax work, too. As do cetyl alcohol and polysorbate 20. (Beeswax isn’t vegan, so stay away from that if you’re looking to create products for the vegan market.) We have a number of emulsifiers on our website.
Making lotion? Experiment!
Now that you have a basic understanding of how and why an emulsifier works, you can start figuring out what you want to create. As you experiment, keep in mind the basic ratios for making lotion:
- Emulsifiers 5-8% – beeswax, candelilla wax, lecithin, stearic acid, etc.
- Oils 12-20% – avocado, almond, olive oil
- Water, Additives, and Botanicals to 100 %. – organic tea, rose water, plain water, infusions
Experiment with different carrier oils and emulsifiers to find the perfect balance for your ideal product. You can add botanicals to the oils by infusing them before adding with water, or you can drop in a few essential oils and mix into your basic lotion once it’s cooled.
Hand crafted lotions are popular holiday and anytime gifts, Once you get comfortable making lotion, you can branch out in many different directions.
Do you have a favorite lotion or creme recipe you’d like to share?