Monday, March 30, 2009

Lotions: Emulsification - what's that then?

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.
EXAMPLE RECIPE
OIL PHASE
20 grams of oil
5 grams of emulsifier (I prefer Polawax)

WATER PHASE
75 grams of water

COOL DOWN PHASE
preservative
fragrance

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.

BUT WAIT!
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!

16 comments:

Anne-Marie said...

Susan,

This is SUCH a good tutorial. You did a great job on it. Big kudos to you for this.

SwiftCraftyMonkey said...

Wow! Thanks for the kind comment, Anne-Marie! You made my day!

chook88 said...

Thanks for an excellent tutorial

I've been searching for good quality info on HLB and this info is just the ticket

Hielscher Ultrasonics said...

Very good article, Susan. Found it, when browsing the internet. Thank you.

Alexandra said...

Susan, thank you, great article!
Very valuable info on HLB system….
By any chance, do you know where to find the HLB values for the oils such as raspberry seed, strawberry seed and blackberry seed oils? Seems like nobody has it on the web :-(

Anonymous said...

Have you worked with Glyceryl Stearate & PEG 100 Stearate?

Susan Barclay-Nichols said...

Hi anonymous. No, I haven't worked with those two emulsifiers together. Does it have a brand name or did you make up from the HLB system. I have worked with glycol distearate and ceteath-20 as my emulsifier, and I really liked it. (There's a post about that somewhere around here...)

Abby Farid said...

Susan,
Very informative, resourceful and you're very wonderful person. I love your articles very much for every effort you have done to benefits people like me....knowledge.

Thank you very much.

chemist said...

Hi
I have been formulation lotion bases and want to incorporate about 4% Schercodine C Amine into the lotion base, Im having problems keeping the emulsification together. The Cationic Schercodine is not compatible in a nonionic base, and in the cationic base the viscosity decreases dramatically to the point where i dont have a lotion. I have used a mixture of Incroquat TMS 50 and also Shea butter in my lotion bases but nothing seem to help with creating a uniform lotion let alone a stable one.... pls help!!!
thanks

kontakt said...

Hello Susan.

I have a vague idea that you somewhere mentioned an emulsifier that wouldn't need heating - not that you had used it, just mentioning. Do you remember something about anything like that?

Susan Barclay-Nichols said...

Hi kontakt. It finally came to me - Sucragel AOF! I'm writing a series about emulsifiers this week and next, and I'll include it in the series!

Gdaiva said...

Omg! I just stumbled on your site today, have a LOT of reading to do! Cant even imagine how much time did you put into it! Thank you so much!!
I just wanted to tell you, if you know about Thermomix? It supposed to be excellent machine for cosmetics too, but i can't find much info in English, so i'll try to figure out on my own... with your help it seems :)

Lisa Sigrist said...

Hi Susan,
You have taught me so much. Thanks for that! I have a recipe that I really really like but it is lacking in the emulsification area and I'm trying to fix it. I think I've got it figured out but before I make it again and waste more money, I was hoping to run it by you and see if you would give me some feedback?
Recipe was this:
Calendula Infused Olive Oil 3 oz
Almond Oil 2 oz
Grapeseed Oil 1oz
Coconut Oil 1/2 oz
Beeswax 1/2 oz
Rose Geranium Hydrosol 4 oz
4 oz Dist Water & 8 Drops Rose Concentrate
Aloe Vera Gel 4 oz
Vit E Oil 1/4 tsp
Lavender E.O. 5 drops
Rose E.O. 5 drops

Ok, First it had no Preservative and I figured out to use 25 drops of Germall+ or 2 grams. And I made my first batch based on the above. Their was no emulsifier though and I did indeed have trouble getting the water and oil to blend. I kept working on it and did get it pretty close but not perfect. I wanted to change the recipe to use Polawax and haven't modified a recipe before to do that. Per all the info I'm reading on your blog, I think I need to add 48 grams Polawax based on the total Oil Phase adding up to 193 grams x 25% = 48 grams. My waters add up to 339 grams. What do you think? Is it going to be successful? And do I leave the Beeswax just as it is in the recipe? I appreciate your feedback and thank you so much for all you do. You've been a tremendous teacher for me.

Susan Barclay-Nichols said...

Hi Lisa. Can I be completely honest? There's nothing unique about this recipe that you couldn't do with another recipe. For instance, figure out how much water you have here, then choose one of my basic recipes and put the ingredients you like in there. It'll save you having to do all kinds of work to make this work.

If you want to keep this recipe the way it is, then figure out the percentages then add Polawax at 25% the oil phase (as you've already done). You'll want to use 0.5% liquid Germall Plus, which is about 2.85 grams (round to 3) if you're using these amounts. (Are these liquid or weighed ounces? This is why I prefer grams!)

Two points of interest: Don't make a huge batch of this. You're looking at making almost 600 grams of this product, which is waaaaaay too much for a tester batch. I'd try making 4 to 8 ounces at the most, so getting your product into percentages is a better idea for making smaller batches. Why waste ingredients when you are trying something out for the first time?

I'm sure you know this, but beeswax is not an emulsifier, so you can choose to keep it in or not. Figure out how much you have in there by percentage. It looks like something like 5%, which is quite a lot in my opinion. What does it bring to the product that you like? A few things that beeswax can do is thicken the product, offer a feeling of waxiness, offer a feeling of occlusion, a bit of moisturizing, and so on. If you want those things, leave it in...

Anonymous said...

I loved the way you directed every technique, I am practicing these mixtures since 6 years, as a result of excitement, and collection of effects of herbs and stuff and i have made a moisturizer which has a very less oil in it and is a pre-used recpie by me, I want to be advised by someone(I obviously mean you)to give this mixture a lotion like look
This is my favourite concortion as it soothes, softens and glosses the skin,
Coconut oil -1gm
Almond Oil-1gm
Olive Oil- 1g
Basil Distilate-2.5-g
Rose Distilate-2.5g
Aloe Vera-10g
Honey-2g
Glycerene-5g
Papaya Pulp ext.-10g
Petroleum jelly(side application)
Mint ext.-3g
Vitamin E-3g
Lemon ext -4g
Please help me I am dying to see it as a lotion...the petroleum jelly is used along with the mixture i want to use it too in with the mixture..

Susan Barclay-Nichols said...

Hi Anonymous. Please edit your comment to include your name, or I will have to delete it.

What emulsifier are you using?