Shampoo bars: My foolproof way to melt SCI!

I shared this on my SwiftCraftyMonkey Facebook page and in our Syndet Shampoo Bar Facebook group, and thought you might be interested too…

Before we start…

Learn more about the main ingredient I use in shampoo bars, sodium cocoyl isethionate (SCI).

Sodium cocoyl isethionate (SCI) – Fatty acid isethionates – also see A few notes on SCI and click here to see more about how to melt it for shampoo bars. 

Also take a look at this updated post where I have gathered together all kinds of information on this surfactants.

Also check out this post on the suggested usage and “safe as used” rates for this surfactant!

Finally, check out this post on the low water solubility of SCI, 0.01% in 25˚C water. 

Here’s my foolproof way of melting SCI! 

There are always questions about how to melt SCI, and my suggestion is always to fill your double boiler as high as it will go and have it as hot as possible without having it spitting into your container.

I use this large container to make it easier to mix and so the ingredients have more contact with the heated jug. (Ingredients above the water line will be harder to melt.) This 1 kilogram batch took less than 20 minutes to melt.

Don’t do any of this “low simmer with a scant 1 inch of water” stuff. You’ll be here forever, if the SCI melts at all. I’m not kidding. I’ve been following this method of 17 years, and I never have an issue.

As I’ve demonstrated here time and time again, that’s pointless. Heating your ingredients to 70˚C (158˚F) or higher – like we need to do with SCI as contains fatty acids that melt at 69˚C (156.2˚F) – is to heat it well with boiling water as high up the container as it can be done without bubbling into the container.

Related post: Making shampoo bars: A (kinda) visual tutorial full of hints, tips, and techniques! (Updated for 2023)

Related post: A “How to make syndet shampoo bars” visual tutorial!

Related post: Demythifying the myths: A super simple method to melt BTMS in a double boiler!

This is my trick: Have the water hot as possible, as high as possible.

It works for every kind of SCI. No need to grind it – just heat it high! 😁

As a note, in the photo at the top, I’m using powdered SCI, but this applies to all versions of SCI as they all contain fatty acids. The more solid, the more fatty acids they likely contain. 

Why melt your bar?

Melting any form of SCI is melting down the fatty acids, which cool in the freezer to create a harder, more pliant bar that doesn’t crumble after a bit of use.

Not melting the SCI means the fatty acids won’t melt and re-form to harden your bar. I suggest melting all kinds of SCI – powder, prills, needles, noodles, and flakes – as they all contain fatty acids that can be melted.

These bars last for freakin’ ever, you can use them right down to a sliver because the fatty acids – which aren’t water soluble, they’re oil soluble – don’t melt in the shower, keeping the bar together. 

Getting a shiny bar like this one means you have to melt all those fatty acids well, then pop them into the freezer or at least a fridge as soon as possible so they’ll cool quickly and we’ll get those lovely beta formation crystals that’ll keep a product stable and solid. If you don’t melt them properly or let them cool on the counter, you can get grains or dull shampoo that isn’t shiny.

In short, melting your shampoo bar will produce a harder, less crumbly, more bouncy, shinier bar than one that’s been made at room temperature by mixing and moulding or pressing.

Related posts:

Triglycerides: Why coconut oil & shea butter don’t mix! Part one!

Triglycerides: Why coconut oil & shea butter don’t mix! Part two!

Check out my instructions for making a shampoo bar! 

You can find them in this post! 

I have these instructions with eery formula I’ve shared on the site, in my classes, and in my e-books. The key is to heat the SCI and liquid surfactant on its own until the SCI has melted properly. Then you can add the other heated ingredients. This is important because the more you add, the longer it’ll take to melt. So start with just the SCI and surfactant, then add more when it’s reached temperature.

Want to learn more about shampoo bars?

Learn more about shampoo bars in the giant shampoo bar post or buy my e-book – the one, the only, the original – Shampoo bars you will love: Creating pH balanced bars!

One shampoo bar, four ways (a shorter e-book with only formulas, no formulating advice)

Also check out these solid bar e-books! 

Body cleansing bars you will love – contains all kinds of formulas for body cleansing bars with all new, updated information on making all kinds of solid bars, including shampoo bars, with a profile on SCMI

Conditioner bars you will love – chock full of information and formulas for conditioner bars!

My favourite class formulations: Hair products

Hair care products: Shampoos & conditioners – my larger e-book with loads of information on making all kinds of hair care products, both solid and liquid