What makes a soap a soap and a shampoo a shampoo?

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SticksStones

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Hi everyone!

im really new here and i am so happy i found this forum!

anyway i wanted to cut plastics out of my life and start making my own shampoos, seeing that they seem easy enough (on youtube), however after a watching a few videos, i really dont understand what makes the difference between a soap and a shampoo.

from what i understand these are the only 2 differences.
1. most shampoos i see have a low or no Olive Oils
2. based on what i read, the hair prefers a more acidic soap while the body prefers a more alkaline?

Do teach me!
 
Shampoo is what we call syndet bars made with surfactants and not lye-based soap. Generally, soap has a ph too high for hair. While some here will disagree you will risk damage to your hair if you use soap as shampoo.
 
A lot of people on Etsy, etc are selling soap as shampoo. Words like sodium cocoate, sodium olivate mean soap. Olive oil + lye = sodium olivate. Sodium palmate = palm oil + lye. Etc. Shampoo bars have been on my list for a while but I haven't gotten around to them. Might be worth while to try them and see if you like them. I love the ones from LUSH. I use Honey I washed My Hair - I have very straight, very fine hair that's pretty dry. I found the purple juniper one way too drying.
 
There are words for different types of cleansers and words for how those cleansers are used. You can't really compare soap with shampoo -- it's like comparing an apple and an orange.

***

An apple-and-apple comparison of words for various chemicals used as cleansers--

A soap is any chemical made by reacting an alkali (NaOH for example) with fat or fatty acids in the chemical reaction called saponification.

Soap, as we use the word, is a surfactant, meaning a chemical that is a "surface active agent". Surfactants help other chemicals to mix together more easily. Not all surfactants are cleansers; surfactants can do many jobs, so there are many sub-classes of surfactants. The soap we normally make is a class of surfactant called a detergent, which means it is a surfactant that is good at helping water to mix with greasy dirt in a process called emulsification. Detergents are cleansers.

There are other soaps (ones we small-scale makers don't normally make) that have good uses as lubricants, for example. Soaps like this are not water soluble and do not have the ability to emulsify or clean. These soaps are not detergents, are not surfactants, and are not much on our soapy radar.​

Non-soap cleansers are any cleanser that's not soap. Just as saponification is the specific chemical reaction that makes soap, non-soap cleansers are created with other specific chemical reactions. You have to study each cleanser to learn how it's made. Like soap, these cleansers are also surfactants and detergents. On this forum you may see non-soap cleansers called "syndets" or synthetic detergents to distinguish them from soap.

***
Another apple-and-apple comparison of how cleansers are used --

Shampoo as the word is used in modern times is any cleanser intended for cleaning the hair and scalp. Shampoo can be soap or it can be a syndet or it can be a mix of the two. A shampoo could be formulated exactly the same as, say, a bath soap or a general purpose syndet cleanser. What makes it a "shampoo" rather than a cleanser for general bathing can be mainly what it's called on the label, not necessarily what's inside the bottle.

As others have pointed out, however, a shampoo is best made with syndets, because the high pH of soap is damaging to hair. It lifts the cuticle (scales on the hair strand) making the strand weaker and more prone to breakage. Since hair can't repair itself like living skin can, this damage is cumulative.

It is true that soap was used to clean hair before syndets were available; the first syndet shampoo was introduced in 1930. Before that time, hair was washed a lot less frequently, so the cumulative damage from using soap was minimized. Even so, an acidic rinse was often recommended to help repair the damage after washing the hair with soap. We wash our hair a lot more frequently nowadays. An acidic rinse only reduces the damage; it doesn't eliminate the damage.

This is the reason why all commercial shampoos are formulated with syndets, not soap. And this is why many small scale makers also make syndet-based shampoos, not soap labeled for washing the hair. Again, as others are pointing out, there are other small scale makers who make soap and label it for cleansing the hair, but there is a real risk that this type of product will damage hair, especially with long-term use. That's why most of us syndet shampoo makers avoid saying "shampoo" when talking about soap used to wash the hair.

***

Body wash is any liquid cleanser intended for cleaning the body. It too can be based on soap or synthetic detergents or perhaps a mix of the two. A body wash could be exactly the same formulation as a shampoo; it's just labeled differently.

(12/5 -- lightly edited for clarity)
 
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Thanks guys! really i appreciate it.

looks like all the watching of videos on people making bar soaps with lye are going down the drain.
 
Thanks guys! really i appreciate it.

looks like all the watching of videos on people making bar soaps with lye are going down the drain.
LOL - literally! I've just made my first batch of syndet shampoo bars, after agonising over it for a long time. I didn't really want to use chemicals or palm - but of course had to use both for my shampoo bars (many of the ingredients for shampoo are palm based). But hey - at least now I don't have plastic shampoo bottles!
 
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LOL - literally! I've just made my first batch of syndet shampoo bars, after agonising over it for a long time. I didn't really want to use chemicals or palm - but of course had to use both for my shampoo bars (many of the ingredients for shampoo are palm based). But hey - at least now I don't have plastic shampoo bottles!


Ohh do tell how they turn out! I kinda want to do it but then some people say its too much trouble for what it is and I havent looked in to where to hunt the ingredients...
 
DeeAnna, thanks for your detailed post. It made me think of all the people who have undergone chemotherapy, which left their hair (and various other body parts) permanently damaged. I can say from experience that commercial shampoo is not an option after chemo, at least not for me. I've been using handmade soap but didn't realize it was also damaging my hair. After reading your post, I decided to try some "no-poo" alternatives. There are a lot of sites that describe them. Here's one:

https://plantessentials.com.au/blogs/news/10-natural-alternatives-to-shampoo

So far, my hair is not happy with the changes, but it wasn't happy before either. I figure it's worth a try. Someone could probably make a mint selling a suitable shampoo alternative for chemo patients. Sad to say, there's no lack of potential customers.
 
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