Shampoo Bar vs. Natural Soap - What's the Difference?

Should you find yourself perusing the ingredient lists that are available (in full, always) on my products throughout the site, you may notice some differences between the shampoo bar ingredients versus the soap bar ingredients and scratch your chin.

After all, one ingredient list appears undeniably more "natural" than the other, right?

Well, I am here to shed some light on the subject!

Shampoo bars are what we in the industry call syndet bars (synthetic detergent) meaning they are made by blending together manufactured detergent powders and then pressed into bars, a process quite similar to making liquid shampoos.

Alternatively, natural soap bars are made the old-fashioned way with plant oils or animal fat and sodium hydroxide lye. I know some of you are going to read "synthetic detergent" and think "Oh, no!", but hold on, let me explain when and why these bars are necessary.

First, let's talk about what makes soap...soap.

Soap happens when we combine alkaline lye with water and fat.

When we combine these ingredients, they react together in an exothermic (heat releasing) reaction to form soap. The process is quite intense, both chemically and thermally. As the batter turns into a bar, the oils, water, and lye, come together and transform into little soap micelles that, ironically, look like bubbles. These micelles draw dirt and oils into themselves and hold it, so it can easily be washed away with water. Pretty cool right?

Soap comes in many shapes and colors, and we can manipulate the qualities of the bars by using different fat and lye contents. At the end of the day, a bar of lye soap can be a three-ingredient ode to simplicity, or an artful symphony of exotic ingredients.

However through the modern lens, lye soap bars have a few shortcomings. We are able to bridge those occasional gaps with syndet bars.

Syndet bars do not have to directly undergo the intense chemical process of becoming soap. That process is generally done elsewhere in a lab to isolate the bubble-makers from the coconuts. With that step completed separately, it's easier to enrich these bars with nourishing, but often delicate and volatile, proteins, enzymes, and extracts.

Additionally, the pH of most syndet bars can be adjusted.
For the skin on most of your body, a lye soap is just fine, even though it is slightly alkaline and your skin is acidic, the skin hardly misses a beat as it renews itself continuously; however, there are some instances in which we need to maintain that delicate pH balance.

Take our hair for example. Hair is not revitalizing and recreating itself every minute of every day like our skin is. It's dead. Should that balance be disrupted consistently, it can cause irreparable damage. Read more about your hair's pH needs in this post.

Many skincare professionals would also argue that your face should be cleansed with a balanced cleanser as well. That, to me, ventures into more subjective territory. Personally, I alternate between a very nice, balanced gel cleanser and olive oil soap, and both are very satisfactory for my sensitive, often dry, skin.

Lye soap pH cannot effectively be adjusted. A soap bar exists at an alkaline pH of 8-9, and if it's manipulated into a lower pH range, it's structural integrity is compromised and we see loss of lather and smooshy bars. No bueno.

At the end of the day, it's all up to you. Your goals and values determine what you choose for your personal care routine. Even though lye soap doesn't always check every box from head-to-toe, it can check nearly all of them. The important thing is that we know which product to use in what situation. I hope that this post has made you feel more informed!

The personal care industry is fraught with opposing information, just like everything these days. I'm just one gal, but I try to help clear air and answer questions whenever possible!

As always, feel free to let me know if you have questions! You may comment below or reach out via the website's chat box to your right. Please be sure to subscribe to emails! I'm not much one for social media these days, but I try to post to the blog regularly, and I send a newsletter about once a month!

Talk soon!
Courtney B. 


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