Monday Wonderings, eeting asks this question: I need help with troubleshooting an oil-free moisturizer (modified from Susan's) and was hoping someone can enlighten me.
HEATED WATER PHASE
Aloe Juice 50%,
Sodium lactate 2%,
Green tea extract 5%,
Hydrolysed Oats 2%,
Sea Kelp Bioferment 5% (Preserved with: Phenoxyethanol, Chlorphenesin, Sodium Dehydroacetate).
HEATED OIL PHASE
BTMS conditioning emulsifier 3%,
Cetyl alcohol 2%.
COOL DOWN PHASE
none...(because the lotion curdled...Susan's note)
I heated and held each phase separately at 70˚C for 20 minutes, then added the water phase to the oil phase slowly with constant mixing. However, when about half of the water phase was added, I got a really weird solidified/curdling (a layer made up of small, off-white eraser rubbing lookalike solids floating on top). I can't figure out what the problem is (though I suspect the kelp bioferment but don't know why!). Any help or comments will be greatly appreciated! Thank you!
this recipe for an oil-free moisturizer?
Did it look at a bit like this? This is from my epic lotion fail using Ritamulse SCG. In this case, I used more oil than the emulsifier could handle. This is a process called coalescence. If you take a peek at this post, When lotions go wrong!, you'll see there are a few different ways lotions can go wrong, but I have a feeling that the issue here was too much aloe vera, which isn't just a water replacer, it's an electrolyte.
Electrolytes are ions that can conduct electricity, but more importantly, they're those ions we call anionic, cationic, and non-ionic. Something that is anionic is something that is negatively charged. Something that is cationic is positively charged. And something non-ionic has a neutral charge.
Incroquat BTMS-50 is positively charged, so we call it a cationic emulsifier. If we add something like aloe vera that can be an electrolyte, we are introducing some negatively charged or anonic ions into the mix. (We're also adding some cationic ions or cations, but that isn't causing problems here.) The more we add, the more negatively charged the lotion will be. When a positively charged thing meets a negatively charged thing, we can get some problems in the product, like curdling.
My suggestion is to take the aloe vera down to 10% or even none at all at first - after all, water's a good ingredient, not a filler - and see if the recipe works for you. (I make it all the time, my version, but your mileage may vary.)
I also think you might be using BTMS-25 instead of BTMS-50. That can cause some problems with emulsification as you have 25% emulsifier not 50%, but that's more about lotions or conditioners that contain a lot of oil. You have 2% oil in the form of cetyl alcohol in ths product, here, which should be emulsified But I don't think that is what happened here...)
How to know whether you have BTMS-25 or BTMS-50?
Check this post on the INCI names.
Check this post on how to substitute one for the other.
When lotions go wrong - an example!
Here's a checklist I've written about figuring out what might have gone wrong with a lotion (short version), or check out this troubleshooting post on how to figure out what might have happened and what we can do next time.