Lately, we have been looking at how to make your own simple skin creams.
For the purpose of this article let’s look at the method of heating and mixing procedure.
Before you begin this process, it may be an idea to read yesterday’s article on formulating.
Heating and mixing stage
- once you have weighed all your water phase ingredients put them in a pyrex jug and place in the double boiler.
- repeat the same for your oil phase
- if there is one piece of advice I can give you whilst heating the different phases, it is to ensure that they are all at 70C. This will help with emulsification, preventing all those lovely ingredients from separating. If one phase is at 70C and the other higher, then the ingredients could separate! The same applies if one phase is below 70C
- next, hold the ingredients at this heat for around 20 to 30 minutes. This is an important part of the process, which will help to keep any unwanted microbes out of your formulas
- to ensure correct emulsification of your ingredients, ensure both phases are at 70C before combining them
- next put the phases together, add the water to the oil phase, which will help with emulsification and creating a nice stable formula
- using the stick blender mix well, mix the blend intermittently to ensure full emulsification until the temperature reaches around 45C
- finally decant your cream into the bottles, label, and date and you are ready to go
Things to avoid
- never crash cool your phases, this is something often amateur formulators will recommend, but it can cause separation.
- never put your bottles in the fridge, as this can create condensation in your jars.
- never leave it too long before you decant your lotion into bottles, I advise that once it reaches room temperature, decant into your bottles, otherwise you’re going to struggle.
- don’t forget about sterilization, this is such an important part of the formulating process and finally, remember to forget to keep a log of EVERYTHING in your recipe book.
The naked truth
Achieving stable emulsification is key, in order for everything to thoroughly emulsify, every ingredient needs to be oil-soluble and some ingredients just aren’t.
We know when an ingredient is put on the heat it becomes soluble, some ingredients start out as water-soluble, but when you turn up the heat they become oil-soluble, this helps us to create emulsification, known as phase inversion.
Earlier we discussed keeping the ingredients at the same temperature, for roughly around 20 to 30 minutes, this also adds stability to a formula, in chemistry, this is known as the Krafft temperature,
This process is often used when formulating surfactants, but it is also required during the emulsification process, once you understand these processes, you can be guaranteed a wonderful, stable product.