I recommend you to start simple and add one ingredient per batch. I usually make 10~16g per batch so it is not too expensive. Also use the less expensive oil before the real fine-tunning, when you have a great formula that requires very few tweaks.
I would start with only:
Batch 1 (Please make small batches! like <20g!)
SCI - 70%
Cheap oil (coconut. I usually use sunflower) - 4%
Butter - 5%
Cetyl Alcohol - 13%
SCI - 52%
Cheap oil - 4%
Butter - 5%
Cetyl Alcohol - 31%
In previous tests (using starches and cetearyl alcohol) I couldn’t see any difference comparing the version with ~50% and ~70% surfactants. So please try it yourself and see if your formula can be cheaper and still do the same job!
It should take less than 30 minutes in freezer for each formula to be good enough to test.
If you use starches (corn or tapioca) instead of some of the Cetyl/Stearic (like ~20% starches and ~5% stearic + cetyl) it becomes “ok” faster but can look rough (not well-finished).
Then you can go adding 1 or 2 ingredients for each batch.
Remove from the cheaper oil or butter to add oils and from SCI to add solids.
BTMS is mostly cetearyl alcohol so you can change some of the Cetyl alcohol for it.
> Oils and butters will only fight with the oils in your hair for the surfactants attention, that’s true. But this is a solid product and the *feeling* is important. About ~5% butters and ~5% oils usually give me a bar that is quite hard but not a piece of stone lol. If I try to regulate the softness with glycerin, water or capb bad things may happen. More on that below.
> Jojoba oil is VERY expensive. I recommend you to do at least the first tests with another cheaper oil and later try to incorporate jojoba.
>more than 15% CAPB can make the bar quite sticky. This is much less important if you have quite some hardeners (cetyl/cetearyl alcohols or stearic acid total >20%).
> I’ve seen bars with polyquat 7 (not mine though) so I know it is possible.
> Glycerin can mush bars very easily (I see you didn’t use it but still a good info).
In my tests there is also very little (not noticeable) difference in performance and final appearance substituting cetearyl for tapioca starch or corn starch in order to add up to 100%.
> Too sticky? Reduce glycerin or CAPB or Water
> Too soft? Reduce oils and/or butters
> Lacks foam? Reduce oils and butters, increase surfactant
> Try one conditioning agent at time. Make one batch with BTMS, one with Polyquat 7 and one with both. Then compare.
> Reduce fragrance. I usually see it <1.5%.
By the way, what kind is your SCI? The powder version? There is a commercial version that is ~60% SCI and ~40% stearic acid.
Here some formulas I found and saved for myself. Good luck!
Handmade style shampoo bar (with starch) (Colonial Chem)
Hor Pour shampoo bar (Colonial Chem)
The file shampoo bar melt: I did it myself and hate it to this day because it is really sticky. It has a lot of glycerin. Polyquat 10 at only 0.2% (I didn’t use it because I don’t have it 😐 ).
>>>>The file from Ajinomoto: There is a formula in page 25. Also each ingredient comes with a function that can help you to compare to your formulation. Guar quat at 0.8%.
Many of the internet formulas just feel “meh”. Some are quite sticky and crumble easily. Some also can be very different because the location where the maker was is another one! I’ve seen bars that looked quite good because the person lived in places where the temperature is like ~20ºC. I livre in Brazil. We got up to 35ºC easily. Keep that in mind please.
Feel free to discuss it more if you can manage to understand my terrible english ::wink: