Emulsification

Before we begin talking about anything, the first thing we need to know about is emulsification. What is it? Emulsification is when we take oil and water, two things that do not naturally mix, and bring them together in one homogeneous mixture. This is achieved by using an emulsifier, such as Polawax. There is a vast number of emulsifiers to choose from. We can use a self-emulsifying agent by itself, or using the HLB system you can make your own emulsifier by using 2 ingredients, one with a high HLB value, and one with a low HLB. An emulsifier is an ingredient with a hydrophilic head, which means water loving, and a lipophilic tail, which means oil loving. By using these ingredients, we are able to uniformly hold water and oil together in an emulsion. 

Lotions, creams, conditioners, even some body washes and scrubs are emulsions. When oils and water based ingredients are brought together and mixed, it turns white and creamy. That's what gives lotion its opaque look. All emulsions are made in different phases. We have the water phase, which would be your water, water based ingredients, and ingredients that are soluble in water. The oil phase, which is any oils, butters, fats, lipids, emulsifiers, and other oil soluble ingredients. Both of these phases are heated separately, to about 170F and held for 20 minutes. Then, the magic happens. After heating & holding both phases, they are mixed together, resulting in emulsification of both phases. After mixing and letting cool a bit, any ingredients that are heat sensitive are added and mixed in. This is called the cool down phase.

There are a few different keys to making a successful emulsion.

Most importantly, an emulsifying agent is needed to bring the water and oil phase together.

Second, we need heat for everything to mix together.

Lastly, we need plenty of mixing to ensure the phases stay together and don't separate over time.

Without these important factors, we get a failed emulsion. The water and oil will separate, sometimes with just some oil leaking out, sometimes we get complete separation, with the creamy oil layer on top and a watery layer on the bottom. It can happen right away, after a few days, or it can happen after a while. There is always something to be learned from a lotion fail, and we can usually figure out what we did wrong so we know what not to do next time!

Now that we've learned about emulsification, we can begin learning about how to make products and emulsions of our own!