How to Successfully Transition to a Shampoo Bar With Hard Water

This guide will tell you everything you need to know about the transition to solid shampoo bars, including why they happen, and how to avoid it.

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Have you been wondering why shampoo bars leave your hair coated in wax?

Or why some people transition to them quickly, but you’re looking slimier with each wash...

And what’s the deal with apple cider vinegar? Is smelling like your local chippy really necessary?

After wasting money and damaging my hair, I have finally worked out how to tell which bars work and which don’t. I get asked so often that I thought I’d write about it because I am a huge fan of solid eco-friendly shampoo.

No matter what type of water you have, there are shampoo bars that will work for you. Keep reading until the end to find out which bars work best in hard and soft water.

This post has been created as part of a series of eco-friendly living guides, you can view the rest by clicking ‘free guides’ in the navigation menu. All shampoo bar content has been grouped together under ‘topics.’

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In this blog post:

1. What is the difference between soft and hard water?

2. Why does water type matter with solid shampoo?

3. Why do some shampoo bars make your hair feel waxy?

4. Is an apple cider vinegar rinse necessary?

5. How do you know the pH of a shampoo bar?

6. How do you overcome the transition phase when switching to a shampoo bar?

7. Which type of shampoo bars work in hard water?

8. How do you know if a shampoo bar contains surfactants?

9. What’s the deal with SLS?

10. What is the difference between sodium lauryl sulfate and sodium coco sulfate?

    >> A list of shampoo bars that work in all water types <<

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1. What is the difference between soft and hard water?

The difference between soft and hard water is the presence of minerals, mainly calcium and magnesium. The more minerals in your water, the harder it is. 

Rainwater is naturally soft. Minerals are added naturally as the water flows through rocks and the ground before ending up in our water systems.

In the South and East of England, water collects higher levels of minerals due to the chalk and limestone. In the North and West where there is granite, the water is much softer.

Soft water tends to have higher concentrations of sodium and sometimes tastes saltier.

You can find out your water type by going to the website of your local water provider, but if you are prone to limescale in your appliances (kettle, toilet, shower) then you probably have hard water.

The ten worst areas for hard water in the UK are:

• Dorset

• Essex

• Gloucestershire

• Hampshire

• Hertfordshire

• Kent

• Oxfordshire

• Surrey

• Sussex

• Wiltshire

The US States with hard water

Some American states are almost entirely consumed by very hard water; most of these are on the western side of the country. Whereas other states possess both hard and soft water so your water hardness will depend on your city.

Very hard water:

• Indiana

• Wisconsin

• Florida

• Utah

• New Mexico

Hard water:

• Ohio

• Michigan

• Kentucky

• Kansas

• Oklahoma

• Texas (West)

• Montana

• Nevada

• Idaho

• Las Vegas

• Wyoming

2. Why does water type matter with solid shampoo?

Water type is so important when choosing a shampoo bar.

If you have soft water, you can pretty much choose any bar you like and it’s much more likely to work. That doesn’t mean it will be good for your hair though.

If you have hard water, you will struggle to transition to most solid shampoo bars on the market due to the mineral content in your water. 

The most important piece of information you need to know, regardless of your water type, is:

Shampoo bars are not all made the same.

Read on to find out why and learn which solid shampoo is effective in hard and soft water.

3. Why do some shampoo bars make your hair feel waxy?

The reason that some bars leave your hair feeling waxy is that they are literally bars of soap. 

They are made from saponified oils, which is the technical name for mixing oils (like coconut or olive oil) with an alkali to make soap. It’s obviously much more complex than that but you get the gist.

If you have hard water, the soap molecules bind to the minerals in the water and leave waxy deposits in your hair. Even after washing it multiple times, your hair will look greasy and straw-like. 

If you have soft water, mineral build-up shouldn’t be a problem. If you have problems (which you probably will) it’s due to your hair type and the pH of the bar. There is more about this in the next section.

4. Is an apple cider vinegar rinse necessary?

A shampoo bar company once told me that I needed to use an apple cider vinegar rinse to help my hair transition to their bar. 

This put me off completely, but I had already bought the friggin’ thing.

Fast forward a year and I finally understand why.

The next bit is science… but I’ve kept it simplistic so please bear with me.

‘PH level’ refers to how acidic something is. Your skin naturally has a pH level of 4-5, which means it is acidic (7 is neutral).

Despite being made from natural oils, soap is alkaline with a pH of around 9. It is an anionic detergent that changes the chemistry of the scalp when you use it instead of shampoo.

[pH1 is extremely acidic, pH7 is neutral, pH10 is the most alkaline]

When soap comes into contact with water it leaves behind alkaline residues in the strands of your hair. This builds up the more you wash your hair and eventually your hair may become damaged.

Using alkaline products on your hair can lead to:

• cuticle damage

• hair breakage

• frizz

• irritation

[Source]

Soap-based shampoo bar sellers say you should do a vinegar rinse to bring your scalp acidity back down (remember soap pH is 9-10) but vinegar has a pH level of 2-3 which is much more acidic than our skin. It might help rebalance your scalp, but it all feels very experimental to me.

Vinegar also won’t remove the mineral deposits from your hair, but I’ll talk more about that in section 6 (the transition phase).

5. How do you know the pH of your shampoo bar?

It is physically impossible to make a soap-based bar that is not an alkaline (source = soap-maker), so if the ingredients look like the ones in this list I’m about to share, you will need an apple cider vinegar wash, or some other pH balancing treatment:

Common main ingredients in a soap-based shampoo bar:

• Sodium Olivate (olive oil),

• Sodium Cocoate (coconut oil),

• Sodium Sunflowerate (sunflower oil),

• Sodium Shea Butterate (shea butter),

• Sodium Castorate (castor oil),

• Water (aqua) & a preservative,

• Glycerine.

Bars that use surfactants will be able to control their pH level (which is usually between 4.5 and 6), but that doesn’t mean they are created equally, so it is best to use a trustworthy brand or ask if you’re unsure.

If you have dyed or bleached your hair, it’s best to avoid using an alkaline shampoo as it will cause the colour to fade.

Note: Obviously everyone’s hair and skin are different, so if you’re happy with your soap-based bar then that is fine.

[My hair looking gross while trying to transition back in 2018]

6. How do you overcome the transition phase when switching to a shampoo bar?

When you start using a soap-based shampoo bar and your hair feels waxy, it is known as the “transition phase.”

Now, I’m no expert (I have never made a bar of soap), but as someone who’s tried multiple bars unsuccessfully, I’m suspicious of this term.

Some sellers claim that the transition phase is necessary to remove the build-up of chemicals, like silicones and parabens, but I’d been using natural liquid shampoos for years before trying a solid bar. So how does that work?

Baking soda can damage your hair

One way to cope with the “transition phase” is by using baking soda. To be fair, baking soda does remove the oil from your hair and leave it looking clean. It is, however, a strong alkaline (see above chart).

I spent 5 months trying to transition while learning from people who were practising the “no-poo method.” Want to know how it went?

[my hair when I started using baking soda - it was so clean and made me so optimistic]

My experience of transitioning and the no poo method

When transitioning to soap-based shampoo bars, the only time I didn’t look like a greasy slob was when I used baking soda. I used it no more than once or twice a fortnight. As I said earlier, I’ve always washed my hair once a week (maybe twice if I’m going somewhere nice on a random day).

Despite using an apple cider vinegar rinse afterwards, my hair started to fall out in tiny clumps, I had a flaky scalp, and my hair would snap in my fingers (I have long, thick hair and this has never happened to me before).

I didn’t stop there. I tried to use other natural ways of transitioning and conditioning (various foods, flours, powders) recommended by the “no poo method,” inspired by their successes. I was convinced that shampoo was manmade, synthetic and there must be a way to survive without it.

Eventually, I just wanted nice hair again. I realised that the success stories of transition phases and baking soda were all word of mouth and not evidence-based.

Maybe a transition to soap and water can be done with the softest water and a specific hair type, I can’t say for sure, but seeing my hair fall out was enough to send me back to low-poo liquid shampoo (still free from SLS, parabens and silicones).

Once I tried shampoo bars again, they contained naturally-derived cleansing agents and I never had to transition. It’s been a year and a half and my hair feels lovely and healthy.

The following sections will focus on the other type of shampoo bars, which do not need a transition phase.

7. Introducing solid shampoo for hard and soft water

Now that we’ve discussed soap-based shampoo bars, I’m moving on to the second type. Surfactant-based solid shampoo. Sometimes known as ‘detergent-based’ or ‘syndet’ which sounds harsh, but it doesn’t have to be.

A surfactant “increases the wetting properties of a liquid.” 

It is a cleansing ingredient, also used in liquid shampoo, that removes dirt, oil, and grease (and mineral deposits!) from your hair.

Shampoo bars that use naturally-derived surfactants are very effective in hard water. Unlike soap-based bars, they don’t leave a greasy, waxy, soap scum residue and you should look clean the first time you use it.

As you know, hair type and thickness can vary dramatically. A good shampoo bar maker will use multiple surfactants (at different strengths) to create the perfect pH for specific hair types.

There is no transition phase when you switch to a surfactant-based shampoo bar and no need for an apple cider rinse. I do like to use a conditioner bar too though. Mainly because it’s a totally different product and benefits my thick hair, but I know some people are happy without it.

8. How do you know if a shampoo bar uses surfactants?

I listed the ingredients found in a soap-based bar in section 5. While it’s easy to recognise a bar of soap due to its main ingredients being oils and butter, a surfactant has a more “chemical” sounding name.

It is important to remember surfactants can differ in how much they foam, how mild they are, their pH level, manufacturing quality, and source. A lot of science and testing has happened behind the scenes, which means they tend to be more expensive. I have noticed that the cheaper bars use palm oil and the expensive ones use coconut oil.

There are 4 different categories of surfactants. Some are more cleansing than others and some can be irritating in high quantities. They are not all naturally derived - some can be sourced from petroleum.

To avoid being irritating, a shampoo bar may contain multiple surfactants which allow it to increase its cleansing power and keep it gentle on your skin.

Think of it like this, a small amount of 3 ingredients, is milder than a large amount of one. 

The following surfactants are derived from coconut or palm fruits and are commonly used in shampoo bars:

• Sodium Cocoyl Isethionate 

• Sodium lauryl Sulfoacetate

• Sodium Coco Sulfate

• Decyl Glucoside 

• Lauryl Glucoside

• Coco Glucoside

• Cocamidopropyl Betaine

• Disodium Cocoamphodiacetate

• Disodium Lauryl sulfosuccinate

NOTE: “natural” is an unregulated term often manipulated in marketing. Both shampoo and soap have to go through a chemical process to make it into the final product.

Photo by KIND2

9. What’s the deal with SLS and why do people avoid it?

Sodium lauryl sulfate (SLS) gets a lot of bad press. It is widely used in all sorts of commercial products such as: face wash, shower gel, toothpaste and household cleaners because it is cheap to produce and highly effective.

SLS can be derived from petrol or palm oil. You should always make sure that the company making the shampoo uses naturally-derived ingredients and sustainable palm oil that is certified by a third party.

The main reason people avoid SLS is that it is a skin irritant. It can be harsh on your whole body as well as your scalp, and in some extreme cases has caused hair loss or weakening.

Personally, SLS makes me itch (a lot) and gives me dandruff, but I do have very sensitive skin. It can be especially aggravating to people with skin conditions, like eczema.

There are a lot of false claims about it on the internet, including rumours it causes cancer which has not been backed up by evidence. It’s also worth noting that not all products using sodium lauryl sulfate are equal.

Lush uses SLS in a lot of their shampoo bars. I personally don’t see this as an issue. Lush is transparent about their ingredients, production and use of sustainably-sourced palm oil. They are strongly against animal testing and hold their suppliers to high standards. 

If you are happy using a bar that is made from sustainably sourced SLS and it doesn’t irritate you, then what is the issue?

10. What is the difference between sodium lauryl sulfate and sodium coco sulfate?

Sodium coco-sulfate is a gentle alternative to SLS and SLES. It is derived from coconut oil and has no known health concerns. Many ethical, natural brands that I adore and respect use this ingredient in both liquid and solid shampoo. The Soil Association also considers it acceptable when certifying brands as organic. 

Lately, there has been a lot of criticism for this surfactant, usually by soap-makers suggesting sodium coco-sulfate is too similar to SLS and shouldn’t be considered a “natural” ingredient.

In some ways this is correct, both surfactants are made in the same way, but the claims people are making are not always completely accurate.

The difference between SLS and SCS is:

• SLS is made using isolated lauric acid. Lauric acid is a fatty acid found in palm oil, coconuts, human breast milk, cow’s milk, and petroleum jelly from crude oil.

• SCS is made using whole coconut oil. Coconut oil contains lauric acid as well as several other fatty acids.

By using all the fatty acids in coconut oil, the final product has a much more complex structure with large molecules that prevent SCS from penetrating the skin and causing irritation.

SLS, however, has a simple structure and small molecules which allow it to penetrate the outer layer of the skin and irritate underlying skin cells.

It's always important to consider if the information is coming from a biased source.

I have noticed that the people criticising sodium coco-sulfate and saying it’s “derived from SLS” are usually on blogs of companies selling products that don’t use SCS (including some soap-based shampoo bar brands). Claiming that other companies are lying about being SLS-free is a very big play on words - sodium coco-sulfate contains lauric acid, not SLS.

These articles often use the “natural vs chemical” argument too which I find slightly bizarre as soap also goes through a chemical process when it is being made. It’s not like any type of shampoo bar grows on a tree…

Using SCS in shampoo bars

Sodium coco sulfate is still a sulfate. If you have curly hair, you may want to avoid it.

I have used SCS in a few different bars now, some bars have used a mixture of surfactants and pH balanced their shampoo. Other bars (usually the cheap ones) have only 1 surfactant and this makes their cleaning power a lot harsher.

Like I’ve already mentioned, not all bars are made with the same or are tested to the same high standards. However, different people have different preferences and I do think there is a place for bars with stronger cleaning power.

Tap to pin this to your zero waste Pinterest Board:

Which shampoo bars work in hard (and soft) water?

The following shampoo bars all use surfactants and so should work in hard water.

If you’ve been using cheap mainstream shampoos for a long time and think you’ve got a build-up of silicone, you will need to remove it by washing your hair with a clarifying shampoo containing surfactants.

I would recommend using an eco-friendly liquid shampoo such as Faith in Nature (comes in 100% recycled bottle but contains the sulphate ALES) or Green People which contains SCS)

Once your hair is free from product build-up then I’d try a shampoo bar.

If you’re using a product containing silicones (dimethicone) you will probably be unsuccessful at swapping to a sulphate-free shampoo bar.

If you’re unsure about which bar suits your hair type then have a look at this: which shampoo bar suits your hair type.

CLICK THE FOLLOWING IMAGES FOR A LIST OF BARS THAT WORK IN HARD WATER:

A note on storing shampoo bars

Your shampoo bar will last longer and be less likely to crumble if you dry it in between uses. A soap dish that allows the water to drain away without pooling underneath is ideal.

Here are a couple of options:

• Bamboo soap dish (UK)

• Bamboo soap dish (US)

Have you made the switch to shampoo bars yet?

Share your experience in the comments below (even if it is just to reassure me I’m not the only person who walked around looking like I never washed for months).

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