A few times I've mentioned using polysorbate 20 or 80 to mix your oils into water. But what are these ingredients? They are emulsifiers. (If it's in bold, you know it's important!)
Normally, oil and water don't like to mix. Water is polar, oil is non-polar, so the oil just floats on top of the water, not mixing and being all oppositional to each other. If we add an emulsifier - an ingredient that is both hydrophilic and lipophilic (water loving and oil loving) -- it will bring the two together in a stable mixture.
Why does this matter? Because bringing together water, oil, emulsifier, and other goodies makes a creamy concoction that will be your skin's best friend. Learning how to emulsify is the key to making your first lotion.
If you made the water soluble make-up remover or the water based fragrance spray, you've already used an emulsifier (polysorbate 20). If you made the conditioner, you've actually made a lotion using BTMS as the emulsifier to bring together the water and silicones, oils, and fragrance or essential oils!
We need three things to emulsify our lotion properly.
- Chemical emulsification - choosing a good emulsifier will save you heartache in the end. If you want to learn more about emulsifiers, the HLB (hydrophilic-lipophilic balance chart) is a great place to start, but I generally choose emulsifying wax as it is a good all around emulsifier for basic lotions. (Polawax, emulsifying wax, and BTMS-50 are all-around emulsification systems, so they're easy to use).
- Heat emulsification - we have to heat our ingredients up to a place where they are happy to emulsify.
- Mechanical emulsification - we have to blend our ingredients together using a hand or stand mixer or stick blender.
I like to make oil in water lotions, meaning the droplets of oil are suspended in a water base, so there is far more water in the recipe than oils. (Water in oil recipes are thicker, like cold cream, and require different emulsifiers to work well.)
WHAT DOES AN EMULSIFIER LOOK LIKE?
The three emulsifiers I've mentioned above come in "pellet form", so they need to be melted. Non-Polawax emulsifying wax can be in flake format as well. So they need to melt before they are useful. Other emulsifiers come in other forms - polysorbate 20 and 80 are liquid.
HOW TO MAKE LOTION
In the recipe below, you'll see 3 "phases" or categories of ingredients.
Oil phase: These are the ingredients you'll weigh in your Pyrex jug then heat to 70C in your double boiler. This contains all the ingredients that play well together as oils and need to be heated. In your oil phase you will put your oils, butters, emulsifiers, co-emulsifiers, thickeners, and oil soluble goodies.
Water phase: These are the ingredients you'll weigh into your Pyrex jug then heat to 70C in your double boiler. This contains all the ingredients that are water based and need to be heated. In your water phase you'll put your water, hydrosols, aloe vera, witch hazel, sodium lactate, and other water soluble goodies.
Cool down phase: These are the ingredients you will add to your emulsified mixture when it has cooled below 45 - 50C. This phase will include your hydrolyzed proteins, panthenol, fragrance or essential oils, preservative, silicones, and other heat sensitive ingredients.
SUPPLIES YOU'LL NEED FOR GENERAL LOTION MAKING
- A scale - you can get a decent one from London Drugs or a kitchen supply shop or Voyageur for $40 or so. (You will see recipes in volume format, but weighing is far more accurate, especially for smaller quantities like preservatives or fragrance oils).
- Pyrex jugs or other heat proof jugs or stainless steel pots. At a minimum, have 2 - 2 cup jugs (but you'll want more!)
- Spoons - Metal spoons you only use for making things. Go to a restaurant supply store and get 50 for $5.00.
- Stick blender or mixer with beater attachments (for lotion) or whisk attachments (for mousses)
- Candy thermometer - inexpensive, accurate, and good for testing temperatures
- A funnel to pour the lotions into bottles
- A bottle (new and clean). Get these from the dollar store or from your local supplier.
20 grams of oil
5 grams of emulsifier (I prefer Polawax)
75 grams of water
COOL DOWN PHASE
Use 25% of your oil amount in emulsifier. So for 20 grams of oil, we'll want 5 grams of emulsifying wax.
1. Weigh your oil and emulsifier in a heat proof container. Put into the double boiler.
2. Weigh your water in a heat proof container. Put into the double boiler.
3. Heat the oil and water until they reach a temperature of 70C and hold for 20 minutes. This ensures any badness (bacteria, etc.) will be heated out of your mixture. (This is called the heat and hold method.)
4. After 20 minutes, you will want to pour the oil phase and water phase into a heatproof container and mix with an electric mixer for 3 to 5 minutes. The mixture will be hot. (You can pour your water phase into your oil phase if you don't have many Pyrex jugs lying around!)
(This is the point of emulsification - watch! The water and oil come together in a creamy white mixture the moment you pour the oil and water phases together. You've got lotion. We still need to work on the mechanical emulsion - using the mixer - but right now you're seeing the moment the water and oil stop hating each other and learn to live together!)
5. I leave the lotion in a safe place to cool for about 10 minutes, then I check the temperature. I mix it again.
6. I like to leave it for a few minutes, then mix again. (I think I'm obsessed with mixing, to be honest.)
7. When the temperature is below 45 to 50C, add the heat sensitive ingredients like fragrance or essential oils, preservatives, silicones, and hydrolyzed proteins.
This is not actually a recipe I want you to follow. This is a sample recipe so you can see the basics of lotion making. This doesn't have a preservative (ESSENTIAL FOR LOTION MAKING) or any goodies for your skin.
WHY CAN'T I USE POLYSORBATE 20 OR 80?
You said it was an emulsifier, and I have tons of it lying around from other projects!
This is what is called a high HLB emulsifier - it has a value of 16.7. If you want to use it, you would have to pair it with another emulsifier, a low HLB emulsifier like glycol distearate (1) and do all kinds of math and create the perfect balance between the low HLB emulsifier and the high HLB emulsifier. Once you've mastered using Emulsifying Wax NF, Polawax, or BTMS, and you want a challenge, you'll probably want to learn more about how to make your own emulsifiers.
If you find this all very interesting, then check out the great post at Lotioncrafter.com on the HLB System (created by the most amazing cosmetic chemist, Maurice, whose work has inspired me to learn more!)
Remember, the recipe above is only an example. It doesn't contain all kinds of wonderful skin loving ingredients or preservatives we want to include in a lovely lotion...so visit us tomorrow!