Thursday, February 10, 2011

Learning to formulate: The cool down phase

So we've taken a look at our heated water phase and the heated oil phase, so let's turn our attention to the cool down phase.

What do we put in the cool down phase? Pretty much anything that won't tolerate the heated and held phases of our water or oil, meaning anything that should be added at below 70˚C/158˚F. It doesn't matter if it's water or oil soluble - if it doesn't like heat, it goes into this phase. This generally includes extracts (hence the picture to the left), silicones, some cationic polymers (like honeyquat), most preservatives, Vitamin E, fragrance and essential oils, and fancy things like cosmeceuticals.

Most of our cool down phase ingredients call for 50˚C/140˚F or lower, so what should you do if you have something that calls for 60˚F/150˚F or 45˚C/122˚F? I like to consider my cool down phase to be 45˚C/122˚F, so I can add all the cool down ingredients together. You can add something that asks for 60˚C at 45˚C, but you don't want to do it the other way around. The key is not to add them at the higher heat and hold temperatures. (Click here for a post on when to include ingredients and what happens if you add things at higher temperatures.)

For instance, honeyquat wants to be added at 50˚C or lower, as does liquid Germall Plus. I can add those at 50˚C or 45˚C and see the same results. Don't go below 35˚C/95˚C as we'll start to see our ingredients become less soluble (the higher the heat, the greater the solubility of most of our ingredients, with a few exceptions). I generally use 45˚C/122˚F as the start of my cool down phase.

So there you have our three phases. Let's take a look at making a lotion base tomorrow.

6 comments:

Tara said...

Making a lotion base?!?! Hello! I have been waiting for this for quite some time! Yippee!!

MSC said...

Hi Susan,

What is the maximum percentage of ingredients, specifically oils, that I can add in my cool down phase? I recently read that it is better not to heat Argan oil, which I would like to use.

I am making a cream that is:
67% water
23% oils (not including my essential oils)
7% e-wax
2% essential oils
1% preservative

If I wanted 4% of my oil to be Argan could I add that during cool down, at the same time as my preservative and essential oils, or would that not work?

Thank you for your help!

Susan Barclay-Nichols said...

Hi MSC! I'm using your question in today's Weekday Wonderings. The short answer is that argan oil goes into the heated oil phase, not hte cool down phase. As a secondary question, why so much essential oil? Generally you're looking at 0.1% to 1%.

MSC said...

Thanks for responding Susan! The reason I want to use 2% essential oil is because I am using 3 different (essential) oils and I am concerned about getting enough of each one to get the benefits of each oil (geranium, lavender and rosemary). I have tried my recipe without the essential oils and loved it but I am going to try with those essentials this week, so it might still change and end up being a smaller percentage.

Samantha said...

hi, i've been making cream / lotion for a while..
i want to ask you about the cooling phase.. when i in cooling phase of the cream / lotion, usually i put my fragrance & preservative.. and mix them ( with stickblender) for about 1-2 minutes.. after that i leave them.. when it's already in room temperature, the cream is good, but i can see the fragrance & preservative not mix well, they like "mini bubble adhere to the base cream" that really look like the fragrance & preservative ( in cooling phase) not disolve to the base cream ( in hot phase) and make the finish product really awful..

is it because i mix it for short time ? how long we must mix the cooling phase ??
or is there anything else that can affect this ??

thank you,

Susan Barclay-Nichols said...

Hi Samantha! Can you please write up your complete recipe in percentages along with your procedure so we can take a look at it? I can't really help you without them.