If you’ve been doing your own hair for a while, you’ve probably encountered shampoo bars before. And while they are not as popular as liquid shampoos, people have really begun to notice them over the recent years. Since they can’t leak/spill and aren’t regulated by travel bodies like TSA, these shampoos are particularly loved by people who travel a lot.

But this is not the only thing that makes them stand out. In fact, here are some major differences between shampoo bars and liquid shampoos:

Shampoo bars vs liquid shampoo

1. Packaging

While liquid shampoos usually come in plastic containers, shampoo bars come in plastic-free packaging materials like paper boxes or recycled paper. So if you are eco-conscious, bars are a better option for you.

2. Longevity

Since most liquid shampoos contain at least 80% water, they are way more dilute than bars. This means you will use more liquid to wash your hair and it won’t last as long as a shampoo bar. That’s why you can use the same bar for over 6 months and use a bottle of liquid shampoo for only 3 months.

3. Value

Since a single shampoo bar can last as long as 2-3 bottles 8-9 oz of liquid shampoo, it is much more economical to opt for the former. In the long run, using liquid shampoo will just cost you more money and extra trips to the store though shampoo bars might seem pricier.

4. Ingredients

Shampoo bars usually contain fewer ingredients than their liquid counterparts. Most of the ingredients in shampoo bars are usually natural oils and extracts. What’s more? Many shampoo bars are also handmade by small business owners who strongly believe in only using ethically and sustainably sourced ingredients.

On the other hand, liquid shampoos usually contain more synthetic chemicals and preservatives, and some people may thus perceive them to be less ‘clean’ than shampoo bars. 

5. pH

With a pH of 5 to 7, liquid shampoos are usually acidic or neutral. However, many shampoo bars are alkaline with a pH of above 8 just like normal soap bars. High shampoo pH can lead to hair issues, particularly for those with curly hair.

This is because a high pH raises your hair’s cuticles, leading to rough tangled hair that is then hard to rinse. As such, it is not uncommon to hear people complain about dry, frizzy hair when switching to shampoo bars.

6. Friction

Since many people use shampoo bar by rubbing it directly on their hair, it can produce a lot more friction than applying liquid shampoo on to hair. This can lead to more tangles and frizz.

7. Scum

If you live in a place with hard water, using shampoo bars will force you to use more shampoo than necessary, simply because getting a lather going will be difficult. And as a result, your hair will be more dried out than usual after every wash. 

Also, the chemicals in your shampoo bar will react with the minerals in the hard water, creating salts commonly known as soap scum. This scum will  deposit on your hair, leaving it stiff and coated with a waxy residue. It can also settle on your scalp and contribute to issues like product buildup and dandruff.

To get it out, you will need to use a dilute apple cider vinegar rinse after every wash or regularly use chelating shampoos. Liquid shampoos on the other hand are less likely to cause scum issues and chelating shampoos are usually found in liquid form too.

Shampoo bars aren’t for everybody

While shampoo bars are more eco-friendly, long-lasting, and economical than their liquid counterparts, they are more concentrated than liquid shampoos and require some technique to apply them properly.  As such, not everyone might find success using them. And to help you gauge whether or not they are a great fit for you, here are some qualities of a good shampoo bar candidate:

1. People with oily hair and scalps

Since shampoo bars are more concentrated than liquid shampoos, these products are best for those who have oily hair and scalps. The excess sebum and oil will counteract the harshness of the product, leading to higher satisfaction rates in this group of users. 

2. People whose hair isn’t curly

If you have curly hair, your cuticles are naturally raised and your hair is more sensitive and fragile. Also, curly hair tends to have drier ends, more tangles and frizz. Using a shampoo bar may cause more hair problems because bars are more concentrated and it might take some experimentation and practice to determine the best way to apply them.

How to choose a shampoo bar

Although many shampoo bars are alkaline, there are some exceptions. Some have been pH-balanced to have a pH of 5.5 to 6. Such bars don’t ruffle your cuticles as much and can be a great way to nourish your hair while reducing your plastic waste. In addition, some shampoo bars also don’t cause problems with hard water. But identifying these bars isn’t easy – most don’t state their pH on their packaging and you need to scrutinize the ingredient list to find both of these out. 

Don’t worry though, we know exactly how you can check whether a shampoo bar has a high pH – by checking its list of ingredients. Some of the ingredients that indicate a high pH include:

1. Lye/sodium hydroxide – this is an alkali
2. Saponified oils – these are the product of a chemical process that involves reacting oils with sodium hydroxide/lye. They are responsible for the waxy residue some shampoo bars leave in your hair.
3. Sodium stearate/sodium oleate/Sodium Palmitate – The scientific terms for saponified oils

Some gentle cleansing ingredients that you should look for instead include:

1. Sodium Cocoyl Isethionate
2. Cocamidopropyl Betaine
3. Coco-Glucoside

While these ingredients are not totally natural, these surfactants are the same ingredients you would find in gentle liquid shampoos and will make using shampoo bars a more pleasant experience. They are also compatible with hard water and will not create soap scum or leave a waxy residue on your hair.

How to use a shampoo bar while minimizing hair damage 

To reduce hair damage, you need to do more than choose a pH-balanced shampoo bar containing the right type of surfactants – this is only half of the equation. The other half lies with how you apply the shampoo. So to help you out, here is a simple guide:

1. Wet the bar and lather it between your palms first. If you can, try to dilute a small chunk of the shampoo bar with hot water
2. Apply as much as possible only to the scalp and upper portion. Avoid ends especially if you have dry hair.
3. Rinse Thoroughly. Since the soap will flow down your hair,  you don’t really need to lather the entire head of hair
4. If you feel a residue on your hair, mix 1 teaspoon of apple cider vinegar with 8-12 oz. of water and pour the solution around your scalp. Allow it to run down the length of  your hair and wait for a couple of minutes before rinsing it off with cold water.