Questions and answers about shampoo bars: The master list (updated November 11, 2023)

I am writing this post to create a place where you can find all the questions you might have about shampoo bars! I’m making it a free post so those who bought the e-book or e-zine can read it, and I will update it as I answer more questions. I will only be answering those that were emailed to me or posted as a question on the blog in the comments or in this post, Shampoo Bar questions, share them here! I will not be answering anything sent by Facebook Messenger as it’s just too much annoying work to use that program and the app doesn’t work well on my iPad, so I have to use my tiny phone, which hurts my hands too much.

I’ll have a link to this post pinned to the right hand side of the blog where you see the other things are linked. 

Here are the types questions you’ll find in this post. Please note, if you aren’t a subscriber, most of the links won’t work for you. If you’re interested in becoming a subscriber for as little as $3 a month, click here! 

As a quick note, if you change the ingredients in the formulas I share, you will have different results. You can’t expect to remove, add, or substitute something and have the same results I might, so if you’re having trouble with a bar, go back to basics and follow the formula exactly as written. I encourage you to try different things, to customize it for your hair type and climate, but learning why we’re doing what we’re doing and why we’re using what we’re using is the only way to know whether something will work or not.

I’ve had so many people add a ton of concentrated Aloe Vera powder to their bars, then ask why the bar is so soft. (Read the answer to this below…) If you don’t know what it might do in the shampoo bar, please don’t use it.

Table of contents

Where to find formulas? Where to find e-books on making shampoo or conditioner bars?

An awesome visual tutorial for making bars kindly written by Jo-Anne? (subscribers only)

More Q&A about shampoo bars after the zoom workshop!

What kinds of shampoo bars can you make?

How big should we make our bars?

Questions about hardness & process

Why are you using water soluble rheology modifiers?

Don’t use 100x or 200x aloe vera in your shampoo bars

Please don’t add salts to your bars!

Oils & butters suppress foam!

Why are you using so much cetearyl alcohol?

When can you use them? How to use them?

How do you store your bars after using them?

Surfactants – Which can I use and how to use them?

What kind of bubbles, lather, and foam does SCI have?

Why you can’t use melt & pour as part of a shampoo bar

How to modify the formula to add other ingredients

Other ingredients we could add? Proteins, extracts, powders, cetyl alcohol, conditioning things

Why can we add cationic or positively charged things to an anionic or negatively charged shampoo bar with problems? (Updated November 2023)

Can we add clay?

Why don’t I press my shampoo bars? And how can I melt SCI well?

Lots about pH


Where to find formulas!

updated November 11, 2023

Where to find formulas for shampoo bars on this blog? If you’re a subscriber, please do a search for “shampoo bars”.

Or you can do a search in the new formula directory.

This is the second most recent series about shampoo bars I’ve written, and you can find all kinds of information about modifying them to suit your hair type and climate!

And this is the series I just finished on making “no more tears” type shampoo bars. (Link to part five with the links to the other parts in that post.)

If you’re not a subscriber, you can find my shampoo bars e-book or e-zine on the topic in the shop for the blog.

Where can you find conditioner bars on this blog? If you’re a subscriber, do a quick search for “conditioner bars”.

Or you can search in the new formula directory.

The most recent formula can be found by clicking here.

You can find the new Q&A about conditioner bars I started by clicking this link. (It includes links to formulas!) And another Q&A with all kinds of answers to questions I know you want to know!


Here are the e-books that contain information on shampoo bars…

Shampoo bars you will love: Creating pH balanced bars – This contains 41 different formulas for shampoo bars and loads of information on how to alter them. This is the most comprehensive resource I’ve written on shampoo bars with formulas that have been made since 2006 by thousands on my site, in my classes, and from my e-books.

One shampoo bar, four ways – This one is perfect if you want a ready-made formula. It contains no explanations on how to alter them.

My favourite class formulations: Hair care products

Goin’ on a holiday: Vital Vacation products

Hair Care Products e-book.

And my gorgeous chock full o’ rice shampoo bar for normal to dry hair you can find in Surfactants: Milder combinations for gentler products

Here are the e-books that contain information on conditioner bars…

Conditioner bars you will love! My latest with loads of formulas!

My favourite class formulations: Hair care products

Goin’ on a holiday: Vital Vacation products

Hair Care Products e-book. (All the proceeds go to fund our Rated T for Teen youth program in my hometown.)

Here are the e-books that contain information on both shampoo bars and conditioner bars…

My favourite class formulations: Hair care products

Hair Care Products e-book. (All the proceeds go to fund our Rated T for Teen youth program in my hometown.)

If you want to learn more about surfactants, I encourage you to check out this e-zine – Surfactants: A reference guide – as I have charts and information on every surfactant I’ve used in the last 12 years.

All of my materials are e-books, so they don’t come in hard copy form (yet?). You can print them if you like, and I’ve met so many people who do this!

An awesome visual tutorial for making bars kindly written by Jo-Anne

subscribers only

Yep, thanks to the kindness of Jo-Anne Emery, the mod for Syndet Shampoo Bars on Facebook, there’s a new visual tutorial for those who want to make shampoo bars for my subscribers! Click the link to see it! Woo hoo!

More Q&A about shampoo bars after the zoom workshop!

created June 29, 2020

As a note, we had a great Zoom workshop in June 2020 on shampoo bars – free to all levels of subscribers- and I wrote a six part series answering questions that were asked, which you can find here!

In part one, we took a look at how to substitute surfactants.

In part two, we looked at pH, pH testing, and pH meters.

In part three, we looked conditioners we might add to create conditioning shampoo bars.

Side post about creating volumizing hair care products…

In part four, we took a look at emollients we might add, like fatty alcohols, solid oils, and butter.

In part five, we looked a few other ingredients we might add, like botanical extracts and violet no 2 to make purple bars.

In part six, we looked a few different questions about chelating ingredients, melting cold process formulas, how to use the bars, and more. 

What kinds of shampoo bars can you make?

created February 11, 2020

I’ve shared this on the blog, e-books, and in-person classes, but I thought it was a good idea to share the summary here. As a note, I teach you how to make all these variations in my e-books and on the blog

In general…

Clarifying bars have no conditioners.

Conditioning bars contain conditioners. You can something like Incroquat BTMS-50, polyquaternium 7, or STEPANQUAT Helia. 

Moisturizing bars contain emollients. You can add emollients, like a liquid oil, solid oil, butter, fatty alcohol, or solid ester. I don’t recommend stearic acid as it’s super draggy and suppresses foam and lather.  

Hydrating bars contain humectants. You can add hygroscopic ingredients – those that draw water from the atmosphere to your hair – or those that form films to trap water in or prevent transepidermal water loss (TEWL).

As a note, beeswax is not a humectant. I don’t know why anyone would say this, but it isn’t. It’s an occlusive that can film form and reduce TEWL, but no one wants this in a shampoo bar as beeswax is heavy, waxy, and draggy.

You can combine these as you wish to make conditioning, moisturizing, and conditioning bars for all kinds of hair types. 

For curly hair, emollients aren’t always better. I have wavy/lightly curly hair with an oily scalp, and adding emollients makes my hair limp and greasy. If you want to add emolliency, I suggest doing that in the conditioner.

How big should we make our bars?

updated June 13, 2019
I make my smaller bars 120 grams, my larger ones 180 to 210 grams. I find anything smaller than 120 grams is used far too quickly. I like to have my bars around for months. I make a batch of 6 large bars  and a few smaller ones every 6 to 8 months, and they last that long for my family as well as handing them out to people who might want to use them.

Questions about hardness & process

updated June 12, 2020

Your bars should be hard enough to be dropped and remain solid. If they aren’t, here are a few ideas on what to do…

For all my formulas, please put your shampoo bars in the freezer, especially in the summer. I give this instruction for all my formulas, and it’s essential to ensuring you’re creating a harder bar.

I can remove my 120 gram (4 ounces by weight) bars in about an hour, but you can leave them in as long as you wish. They should be solid when you pop them out of the molds.

No matter what, leave the shampoo bars to sit on a counter for 24 to 48 hours to allow the water from the liquid ingredients to evaporate.

As you can see in the picture, my bar was soft enough to allow me to press a thumbprint into it after removing from the freezer, but the next day, after letting it sit for 24 hours, it is solid as heck!

Room temperature is 20˚C or around 70˚F. If it’s warmer than that in your home, the bars may not be completely solid for a while. Leave them out for the water to evaporate as I mention above, or store them in a cool place for a bit.

Humidity will affect your bars, especially if you’ve been using glycerin, sodium lactate, or another humectant. If you can, get your bars into a room with a dehumidifier or air conditioner or into the fridge or freezer for a bit.

The sodium lactate in the formula is not optional. This hardens the bars. You can go as high as 5% with this ingredient. If you have the powdered version, please dissolve it in the liquid surfactant.

You can add stearic acid or a butter to harden the bar, but this will reduce the lather, foam, and bubbles. Take a look at a formula for dry hair that adds stearic acid at 3%.

If you’re a $5 subscriber or higher, visit the October Q&A as there’s a great conversation going on over there between Sima and Charlette about experiments they’re doing with stearic acid and shampoo bars.


You can reduce the liquid surfactant by up to 10% and replace it with more SCI. (I mention this a few times in the e-books.) This means you’d subtract 10 from the amount of liquid surfactant – so if it’s 20%, reduce it to 10% – and increase the SCI by 10% – so if you have 30% SCI, you’d now have 40% SCI. The downside of this is that the bar may be more draggy on your skin or hair, so make a small batch and keep very good notes about what works.


You want the bars to bounce when they hit the floor, not shatter, so you don’t want to have the hardest bars in the world. Try small batches of the formulas I suggest and let them sit out for 24 to 48 hours. Then try them.

Also, why are you using water soluble rheology modifiers?

NEW, June 12, 2020

I’ve noticed lately people are using sodium alginate to harden their bars. One, a gelling, water soluble thickener isn’t appropriate for shampoo bars that will be used in water or stored in a shower because it’s water soluble and can dissolve easily. Two, it needs to be gelled by adding a cationic ion in the form of calcium, which we rarely find in shampoo bar, so it’s not working at its best in your bar without it.

Why are you using carrageenan in your bars? To make it gel, you need to wet and disperse it in water, then hydrate by mixing while heating to 60˚C. As it cools, it gels. Just putting it in a bar and hoping it’ll gel when it gets wet is doing nothing except adding something that attracts contamination pretty easily. Please don’t do it. The carrageenan is adding nothing to the shampoo bar.

Related posts

Carageenan, iota– natural gum, anionic

Carageenan, kappa – natural gum, anionic (used as Genugel® CG-130)

Don’t use 100x or 200x aloe vera powder in your shampoo bars!

A woman wrote to me the other day to say her shampoo bars were soft and sticky. I asked her to tell me her exact formula, and it was identical to one of mine with one huge exception – she added 1% concentrated aloe vera powder, either 100x or 200x. Since then, I’ve read of a few people doing this and having soft bars. This is a profoundly bad idea for a few reasons…

This is an enormous amount of aloe vera. 1 gram of 100x aloe vera powder is equal to 100 grams of aloe vera. 1 gram of 200x aloe vera powder is equal to 200 grams aloe vera. So adding 1 gram of 100x aloe vera powder to 100 grams of shampoo bar means you have added the equivalent of 100 grams of aloe vera to 100 grams of shampoo bar. Adding 1 gram 200x aloe vera powder to 100 grams of shampoo bar means you have added 200 grams of aloe vera to 100 grams of shampoo bar. This is a serious problem, and will result in your bars being incredibly soft.

Aloe vera contains a lot of electrolytes, which can interfere with the electrical charges of the surfactants. Add a bit too much and a thick liquid surfactant will fall apart quite easily. Imagine what adding the equivalent of 100 or 200 grams to 100 grams of shampoo bar will do.

If you’re a subscriber, I’ve written a longer post about this topic, which you can find here

Please don’t add salts to your bars!

added July 3, 2020

Remember the bit we just did about not using Aloe vera because it has electrolytes, which can ruin a shampoo bar? This applies to salts, which are also electrolytes. No matter the type of salt – table, fine, sea salt, Epsom, Dead Sea, or other – it will make your bar soft and mushy. Leave it out. It does nothing for your hair and makes the bar fail.

If someone made this suggestion to add these to your shampoo bar, please go tell them it’s a bad idea, that the product failed, and you’re unhappy. They will probably dismiss you by saying, “well, it worked for me,” but it’s worth a try. At least other people won’t waste their time and supplies making something that doesn’t work. 

Related posts:

What’s a salt? 

Chemistry Thursday: Ionic bonding and salts! (updated)

A few ideas for gifts you can give this year: Bath salts!

From my classes: Handmade Christmas – bath salts

Q&A quickies: Formulas for Dead Sea Salts?

Oils & butters suppress foam

updated June 12, 2020

If you’re adding oils and butters to your bars, it will suppress the foam. The combination I use the most – SCI and SLSa – is super foamy, bubbly, and lathery, but adding a bunch of oils and butters or other oil soluble things, like cetyl alcohol, will suppress all of that.

If you add cetearyl alcohol to a bar, it will suppress the foam.

If you add stearic acid to the bar, it will suppress the foam and makes it feel draggy.

If you add butters to the bar, they will suppress the foam and make them feel draggy.

If you add liquid oils, it will make the bar softer as they aren’t solid at room temperature and it will suppress the foam.

I can’t stress enough that if you add oil soluble ingredients, you are suppressing the foam, bubbles, and lather. My SCI and SLSa bars are so foamy, I’m embarrassed by the suds generated in the shower at the gym that takes over all the space. If you aren’t getting the same results, you’re probably suppressing the foam with too many oil soluble ingredients. This would include conditioners like Varisoft EQ 65, Incroquat BTMS-50, or Rita BTMS-225, as well as non-ionic emulsifiers like emulsifying wax NF, Polawax, Olivem 1000, glyceryl stearate, and more.

That picture is what my sink looks like just rinsing out the containers in which I’ve made shampoo bars, that’s how foamy my formulas will be. If yours doesn’t look like that, definitely ease up on the oil soluble ingredients.

If your bars aren’t like that and you have hard water, you can add up to 0.2% tetrasodium EDTA, disodium EDTA, or sodium phytate to help chelate the metals.

Why are you using so much cetearyl alcohol?

new for June 12, 2020

Why is everyone suddenly using loads of cetearyl alcohol to the point where my friends who run shops are selling out? Yes, it’s a fatty alcohol that will help boost the conditioning, but as you saw in the previous section, it also suppresses the lather and foam. It also feels waxy on hair and will weigh down fine hair, which is why I don’t recommend it.

If you really want to use a fatty alcohol, why not use cetyl alcohol, which has much nicer slip and glide, is much cheaper, and is much easier to find? You’ll find you have less drag, and you’re saving a whack of money.

When can you use them? How to use them?

You can use them the moment they come out of the freezer, but they won’t last as long as those that sit for a bit.

With my bars, I get my hair wet, swipe the bar over my hair, lather it up – it’s super bubbly and lathery – rinse, and repeat. (I have oily hair, so I need two washes.) Don’t lather it up in your hands then apply that to your hair as you’re losing out on the creamy goodness!

How do you store your bars after using them?

In the October Q&A, Sima asked: Hey everyone, just a question on Shampoo and Conditioning Bars. Was wondering what you do after you have used a your shampoo or conditioning bar on your hair? What do you place in on, do you wipe it dry, do you air dry on a soap dish, how do you store them after use?

Charlette suggested: Actually I just have it in a small ramekin container. The important thing is to drain any water from shower out of it, stand it vertically in the ramekin, remove it from the shower and set on vanity to dry out until my next shower.

I just leave mine in the soap dish or the place where I’d put soap in the shower. I don’t do anything special, I just leave it there because I’m a slob who can’t be bothered to make the effort at times, I admit. For my travelling or gym bag, I have one of those portable soap dishes. I try to leave it open when I get home or when I’m done with them, but sometimes I forget and they get a bit squishy.

Surfactants – Which can I use and how to use them?

updated June 12, 2020

Please read the directions on how to melt the SCI with the liquid surfactants and follow that process to melt these together. This works to melt the ingredients very quickly. I know other bloggers make other suggestions, but this is the method that’s worked for me since I started making these in 2006.

If you’re using powdered SCI, you don’t need to heat it as it’s easy to mix it with other things.

In this post, Olenka asked: “I can’t neither find SLSA nor other powdered surfactants except SCI. Is it ok to substitute SLSA with SCI? Would a shampoo bar still work with basically 2 surfactants (SCI + Coco Betaine)?”

It will still work, and it would be quite nice for someone with very dry hair as this version would be very mild.

If you want to use sodium coco sulfate (SCS) instead of SCI, please read the section below on pH or read the section in the e-book about that.

My bars are already sulfate free as I don’t use sodium lauryl sulfate (SLS), sodium coco sulfate (SCS), or sodium laureth sulfate (SLeS)

The reason for using more than one or two surfactants is all about creating a milder bar. You can read more about this in the surfactants series I wrote on mildness, the summary for which you can find here.

Don’t forget I have an enormous surfactants section of the blog, which you can always find under ingredients in the resource tab of the menu. 

What kind of bubbles, lather, and foam does SCI have?

updated June 2019

As a note, SCI doesn’t have lacy glove foam: It has elegant, fluffy foam. (This is known.) It’s one of the reasons we love it so much. Lacy glove foam comes from ingredients like foaming proteins – silk, oat, soy, etc. – where the bubbles are small and not as numerous, so they look like a lacy glove on your hand.

Using melt & pour as part of a shampoo bar

Before July 2018, I’d never heard of anyone using melt & pour soap to make shampoo bars, but now they’re everywhere, like this soap that has these solid SCS or SCI noodles. I don’t recommend this method as the bars you make this way with either have an alkaline pH or they won’t harden properly.

This isn’t a product I made. I was sent this picture by someone asking a question about these products.  

If you see a recipe that contains melt & pour soap, you will be making a bar with a final pH that’s above pH 7. Almost every melt & pour soap I’ve ever encountered – including the SFIC shea butter base on Amazon that’s being recommended by some groups – is a soap, meaning it contains saponified oils, which means it’s alkaline. It cannot be not alkaline as it stops being soap when the pH drops to 7.5-ish or lower. This is why it is gooey and mushy and won’t harden if you throw some citric acid into it: This cannot exist at an acidic pH.

If someone claims they can make a pH balanced melt & pour shampoo bar – ask for this information and ask for pictures of each step with exact measurements.

  1. What was the pH when they started? How did they measure it?
  2. How did they test the pH? Ask for a picture of the pH meter or pH strips with at least 3 testing areas on it.
  3. How did they alter the pH? Ask for exact measurements in grams or percent, and ask exactly what they used – for instance, 50/50 citric acid/distilled water.
  4. What was the final pH? Again, ask for pictures of the pH meter.

Please check out this discussion on Chemist’s Corner about using M&P soap and reducing the pH, and check out this SDS which shows the pH level of 8.5 in section 9.

There is a melt & pour shampoo bar base from Stephenson called Crystal SS that they say can be used as a shampoo bar base. Click here to see the data bulletin, including pH and such.

You can add things to this base to make it more hair friendly, like conditioning agents like polyquaternium 7, panthenol, hydrolyzed proteins, and up to 5% oils or butters. I haven’t used it and it will still have an alkaline pH, but you can increase the mildness of the product by adding a few things to it. Check out this post on the Chemistry Store for more information.

How to modify the formula to add other ingredients

As a general rule, when adding something to a shampoo bar….

If it’s a solid ingredient, compensate by taking that much from a solid surfactant. So if you add 3% stearic acid, you’d remove 3% total from either the SLSa or SCI.

If it’s a liquid ingredient, compensate by taking that much from a liquid ingredient, like the surfactant. If you add 2% more liquid hydrolyzed protein, remove 2% from the liquid surfactant.

Other ingredients we could add?

In this post, Donna asked: “No cetearyl alcohol or other alcohol in this recipe?”

No, it’s not necessary. You could add a fatty alcohol – cetyl alcohol, cetearyl alcohol, or behenyl alcohol – if you wished as it can act as an oil free emollient, bar hardener, and conditioning booster, but it can suppress foam, lather, and bubbles. Try it at up to 3%. Remove 3% from the liquid surfactant if you’re trying to make the bar harder or remove 3% from the SCI if you’re just adding it because you like it.

In this post, Allison asked: “I’m wondering if it’s possible to use behentrimonium chloride in place of the BTMS-50 in shampoo bars? I have a bit more of that on hand than I do the BTMS-50 and am curious.”

Yes, you can totally use any other waxy type conditioner in place of the BTMS-50, including behentrimonium chloride or BTMS-25.

As a note, if you have fine hair, you can easily replace the Incroquat BTMS-50 with some of the positively charged or cationic polymers you find in this post. like Honeyquat or polyquaternium 7. Just replace the Incroquat BTMS with one of these liquids, then reduce the liquid surfactant by the same amount. If you use 3% polyquaternium 7, then remove 3% liquid surfactant.

In this post, SiriusPotty asked: “Also what is the maximum % you would recommend for including hydrolysed proteins in a recipe? My hair loves protein like crazy and was wondering how far I could push it. Say theoretically you had a 2% limit, could you split this say between 3 different proteins as long as it amounted to 2% of the recipe?”

As for hydrolyzed proteins, you could divide it up in a few different kinds, or you could add more and reduce some of the liquid surfactant by the amount you add. So if you add 2% more liquid protein to the bar, remove 2% from the liquid surfactant. If you really like them, use two or three. So you could use 2% hydrolyzed oat protein, 2% silk amino acids, and 2% hydrolyzed baobab protein. This means you have 6% total, so you’d have to remove 4% from the liquid surfactant.

In this post, I was asked a few times about using Ayurvedic powders. I have never tried these ingredients, so all I can suggest is that you follow the guidelines I’ve shared in these two posts about using extracts in shampoo bars. Make sure you preserve any bar with extracts well as they are more likely to be contaminated than those without.

Creating a shampoo bar from scratch: Botanical extracts

Creating a shampoo bar from scratch: Exfoliating botanical extracts

Can we add clay?

updated June 12, 2020

I know it seems like a good idea to increase the hardness, but when clay meets water = mud, and that’s not a great feature in a shampoo bar. I can’t stress this enough – clay’s also very hard to preserve, so adding it to a shampoo bar and leaving it in a little bit of water can cause some serious contamination.

Why can we add cationic or positively charged things to an anionic or negatively charged shampoo bar with problems?

edited November 11, 2023

Normally, we don’t want to combine anionic (negatively charged) or cationic (positively charged) ingredients together as they’re opposite charges and don’t play well together. But we can make them work because we don’t have all that annoying water to cause problems.

If we make a liquid shampoo and add a bunch of Incroquat BTMS-50 to it or make a conditioner with Incroquat BTMS-50 and add a bunch of anionic surfactants to that, it will create this “gunky” solid and ruin the product.

So how can we use these ingredients in a shampoo bar? There’s no water. We need that water to create that hard complex, so without it, there’s no worries!

This is a vital part of this process: You need to melt the emulsifier to ensure it’s mixed well in the bar because if you have big clumps of it – like people who cut up full conditioner bars to mix them into a shampoo bar or make a 2-in-1 with shampoo on one side or the other – will find complexing happening after the bar is exposed to water, which we don’t want when the bar is sitting in its container in the shower as we’ll get all that horrible white gunk.

Related posts:

My response to the YouTube video, “Why you do NOT use Incroquat BTMS-50 in a shampoo bar”…

Q&A: Why can cationic and anionic ingredients be used together in solid shampoo bars?

My response to the YouTube video, “Why you do NOT use Incroquat BTMS-50 in a shampoo bar”…

Can I combine cationic ingredients with non-ionic or anionic surfactants? (Short answer: Yes, but they have to be the right ones.)

Creating cleansing conditioners: A rant about not combining anionic and cationic ingredients, plus loads of links to formulas

Creating a shampoo bar from scratch: Conditioners & cationic polymers

Questions from the Zoom workshop: Adding conditioners to shampoo bars

Question: How can we add a cationic polymer to an anionic product, like shampoo, body wash, or facial cleansers?

Q&A: Why can cationic and anionic ingredients be used together in solid shampoo bars?

Why don’t I press my shampoo bars?

I don’t press my bars, I melt them. I use a lot of liquid ingredients in my products or waxy ones that need to be melted. If I pressed mine, there would be little pellets of Incroquat BTMS-50 that would do nothing for your hair. Everything needs to be melted and mixed together so your hair can benefit from the ingredients. Plus, if you press the bars and leave the noodles intact, how can you adjust their pH? They’ll be little pH 9 to 11 noodles pressed with stuff that might be pH reduced.

You can’t press my bars, you have to melt them. See above.

If you prefer pressed bars, then my formulas probably aren’t the right ones for you. See above.

Please read this post on how to melt SCI properly and well in a double boiler. I have been melting SCI noodles, flakes, and prills since 2006, and I haven’t had problems with it when I’ve done it the way I outline here…

Reduce the heat so it’s not splashing into the container, add your SCI and other surfactant ONLY in a glass container, and heat until melted. If you’re using prills, it should only take 5 to 10 minutes at the most. If you’re using noodles, it might take longer. If you’re using powder, it isn’t necessary to heat it at all!

Why don’t I use water in shampoo bars? 

Because it’s pointless: Water brings nothing special to a shampoo bar. It doesn’t make a bar milder, the way a liquid surfactant would; it doesn’t increase lather, bubbles, or foam; it doesn’t make it work better in hard water; and it doesn’t offer anything that film forms, hydrates, conditions, moisturizes, or does anything for our hair.

It can also cause preservation issues if you’re using botanical extracts, clay, and such.

And it makes it much harder to melt sodium cocoyl isethionate (SCI).

As an aside, always use distilled, reverse osmosis, or de-ionized water in our formulas.

What do we know about mineral water? It contains minerals, like sodium, potassium, calcium, and so on. These minerals can do things like reduce the foaming, bubbling, and lathering of the bar, like it does in hard water; it can form complexes on your hair and shower, soap scum, that are hard to rinse off and make hair look dull; and they can act as electrolytes in a bar to make it softer and fall apart, the way we find aloe vera might do to a bar.

Related post: Shampoo bars: Please don’t use 100x or 200x aloe vera powder in them!

Mineral water adds nothing to a shampoo bar or any other surfactant based product, so it’s not a good idea to use it. Reverse osmosis water, distilled water, or de-ionized water should be used in our formulas, not mineral water, not spring water, not tap water, not boiled tap water, not well water. We want water that’s at the right pH without all those extra things that can cause contamination, complexes, emulsion failures, or thinned out surfactant based products.

You can read a longer post on this topic by clicking this link – Why don’t we use water in shampoo bars?

Lots about pH

updated June 12, 2020

Before we get to more about pH and why it’s important, please read this post Q&A: Why do people use apple cider vinegar rinse after washing with alkaline products? Why not just make the shampoo bars with very low pH? as I go into alkaline products, using soap as shampoo, and what happens when we use alkaline products on our hair, such as damage and colour fade.

pH is important. I don’t know how to stress this enough. Something that is too alkaline – a pH 8 and over – will damage your hair. This is not my opinion; this is science fact. (I have links at the end of this post…)

Related post: Chemistry time! Acids, bases, and pH

Anyone who tells you it doesn’t matter doesn’t know enough to know they’re wrong.

Oils don’t have a pH. I saw someone saying coconut oil has a pH of 3.5 to 5 so it’ll bring down the pH of a shampoo bar made with SCS. It won’t. pH doesn’t exist without water, and oils don’t have water in them. So they won’t impact the pH.

If the bar contains sodium coco sulfate (SCS) as the main ingredient – even as low as 10% – it’s highly unlikely it will not be in the right pH range for hair. It has a pH of 9.5 to 11, and we want the bar to be pH 4 to 6. Someone said Stepan makes an SCS that’s pH 7, but I’ve never seen it for sale at any of my suppliers. If you see a recipe made with SCS, ask the writer what the pH is.

If you want to use SCS, you have to alter the pH. Please don’t use vinegar to alter the pH.

If someone claims their pH is balanced, ask them for the initial pH, how exactly they altered it and how much it took to alter it, and the final pH. I take pictures of my results, which I’ve shared all over this blog.

You cannot test the pH of a bar by putting a bit of water on it and laying a litmus strip on it.

You cannot test the pH of a bar by lathering up your hands and putting a litmus strip on it.

If you’d like to know more about pH from a scientist, check out this post on Unicorn Chemist’s Facebook page.

I quote Jane Barber of Making Skincare from this post on my Facebook page.

My opinion of pH strips is all over my groups and website. Most strips, like home microbial test kits, are pretty useless. Not worth even using. But, I did come across some pH strips in my tests which gave a vague indication, these are the ones sold by lotioncrafter which come in 0.5 units, 3 colours each unit. If someone really has to use pH strips then those are the ONLY ones I’d suggest. Ideally formulators should really use a calibrated meter, especially for formulas which are pH sensitive, like those using varisoft EQF65, carbomers, polymeric emulsifiers, surfactants and esters which can hydrolyse at certain pH levels, organic acid preservatives etc.

Related posts: The new pH & pH meters section of the blog, which includes information on how to create a solution to test pH, how to test and adjust pH, and how to make pH adjusting fluids, like citric acid and distilled water or how to use triethanolamine

How to test the pH of our products and more! 

Do you need to alter the pH of your product?

Can I use pH strips? Can I use a meter?

If you’re a beginner, I really don’t suggest trying to alter the pH of a bar. It’s not easy, it’s kind of a pain in the bum, and you have to not only get a good meter, but you have to learn how to use it, how to dilute the shampoo bar, how to titrate the acid, and so on. If you really want to do it, then check out the pH section of the blog. I suggest creating bars using sodium cocoyl isethionate (SCI), which are pH balanced, while sodium coco sulfate (SCS) is not.

It’s like learning how to drive a standard car. You’re learning how to drive, which is all new, and you’re learning standard, which is hard. Learn how to drive, get good at it, then learn how to drive standard.

Speaking of SCS, why are you all okay with it when you aren’t okay with sodium lauryl sulfate (SLS)? They’re really close relatives, with SCS being slightly milder. But it’s still a sulfate. I mean, I don’t care much about SLS, but the people who have been going on for years about how SLS is evil seem to be the ones most likely to be using it. It’s just weird to me…

Finally…I’m done talking about handmade soap as shampoo. Again, alkaline shampoo will damage your hair. The only people who argue that it won’t are people who use soap on their hair. I’m not joking about this. It never comes up in non-soaping or science based groups because no one wants to use soap on their hair. If you want to use it, use it. I don’t show up in your soaping conversations talking about how great my surfactant based body wash is and how you can use it as toothpaste or deodorant, so please stop bringing it up when I talk about shampoo. I don’t make soap and this isn’t a soaping page. I’m not saying you can’t have conversations about soap on this blog and this isn’t a slam on soap as a well made bar is really lovely, but I’m tired of having it intrude on every single discussion about shampoo bars.

Here are some scientific resources on pH and how it affects hair. I’m not joking when I say I could fill an entire 100 page e-book just on this topic. Here are just a few things I think are interesting and helpful.

The Shampoo pH can Affect the Hair: Myth or Reality?

CONCLUSIONS: Alkaline pH may increase the negative electrical charge of the hair fiber surface and, therefore, increase friction between the fibers. This may lead to cuticle damage and fiber breakage. It is a reality and not a myth that lower pH of shampoos may cause less frizzing for generating less negative static electricity on the fiber surface. Interestingly, only 38% of the popular brand shampoos against 75% of the salons shampoos presented a pH ≤ 5.0. 

The Chemistry of Hair Care

Note: The test is subtle but shows expected results if done correctly. Observations of hair in each pH sample should include:

  • pH 2.0: hard; smooth; not resilient; breaks easily
  • pH 6.0: not as hard; smooth; very resilient; resists breaking
  • pH 10.0: rough; not very resilient; tends to break easily
  • pH 12.0: very rough; not resilient; tends to break very easily

Not a study, but for hair dressers and good information…

Hair Cosmetics: An Overview

Creating larger batches of shampoo bars: Scaling up! 

Added July 19, 2022

It isn’t a simple as just making larger batches. There’s a lot to take into consideration when scaling up, like how to heat up and cool down large quantities as well going over or under when weighing, and how that’ll affect the final hardness. There’s too much to detail here, so I’ll recommend reading this longer post I wrote on the topic as part of a series on scaling up our batches.

What can you substitute for LSB in a shampoo bar?

Added July 19, 2022

I don’t think we can find the surfactant called LSB any more – in North America at least – as it’s been altered to have a very short shelf life of 6 months, so what can you do as a replacement? The short answer is that you can use any liquid surfactant suitable for your hair type. 

You can find out so much about surfactants in my giant surfactant section of the blog, always found under the “ingredients” tab in the menu bar.

I liked LSB for my oily hair as it contained disodium Laureth Sulfosuccinate (DLS) with SLSa. If you wanted to create a shampoo bar for oily hair, consider using another liquid surfactant that might be good for oily hair in the same proportions. I’d suggest something like sodium 14-16 Olefin Sulfonate (Bioterge® AS-40) or just straight disodium Laureth Sulfosuccinate. If you wanted to create something for dry to normal hair, you could use Cocamidopropyl Betaine (this is not coco betaine), a foaming protein, sodium methyl taurate (liquid), or any other liquid you can find in your supplier’s shops.

Remember that when you alter the surfactant, you may alter the pH, so please test and adjust it as necessary. This is vital when you start using glucosides, like decyl glucoside, lauryl glucoside, or coco glucoside.

If you’d like to learn more about substituting surfactants, I recommend reading the linked posts on shampoo bars on this site, the e-books I’ve written about surfactants, or the e-book on making shampoo bars. I have a lot of information on substitute solid surfactants and liquid surfactants in my Body cleaning bars you will love e-book, which has more updated information on making solid cleansing bars for hair and skin.

You can also check out my e-books, Surfactants: Milder combinations for gentler products or my e-book, Surfactants, part one: A reference guide. 

How much SCI can I use in a shampoo or other solid bar?

The recommendation from the Cosmetic Ingredient Review (CIR) in 2013 is that we can use 53% active surfactant matter in a rinse-off formula. It’s slightly higher than the 47.5% or 49.5% that gets batted around the internet, but it’s important to note that this is 53% active SCI surfactant, so the amount of powder, prills, noodles, flakes, or pellets you use will depend on the active surfactant matter of the specific type of SCI you have.

If your SCI is 85% active surfactant matter (ASM), 100 grams of SCI will have 85 grams of active SCI with fatty acids making up the other 15%. If you used 50 grams of this SCI in a 100 gram bar, you’d have 42.5 grams of SCI, well below the recommendations of the CIR. If you use 75 grams of this SCI, you’d have 63.75 grams, which is higher than recommended.

If your SCI is 65% ASM, and you use 50 grams SCI in a 100 gram shampoo bar, you’d have 32.5 grams of SCI, again, below the recommendations of the CIR.

Read more about this in these posts…

Q&A: What’s the safe as used percentage for sodium cocoyl isethionate (SCI)?

Tips & techniques: Quick look at active surfactant matter (ASM)!

Math and active surfactant matter calculators