How Does Soap Work?

goat milk soap

When we try to clean things, whether it’s our hands or our clothes, water is doing most of the work of cleaning by flushing out all the dirt and stuff we’re trying to remove.

But adding soap makes the water more effective. Soap does this in two main ways.

Two Ways Soap Helps Clean Your Skin and Clothes

1. Soap reduces the surface tension of water.

Have you ever spilled some water on a table and watched the water sit there as a drop? That occurs because of the surface tension of the water. Adding soap reduces this surface tension and allows the water to spread out and absorb more easily into the things (such as your clothes) that you wish to clean.

When something reduces the surface tension of water we call it a surfactant (short for "surface-active agent").

Fletcher using Goat Milk Laundry Soap
"Love, love, love the laundry soap...light, fresh scent and cleans thoroughly with just a single's one of your items that is on my "regular" shopping list. Thanks again for your wonderful products!" - Karen B.

2. Goat milk soap provides a way for the dirt and oil to mix with the water so they can be washed away.

In order to remove the dirt and grease and oil from your hands and clothes, you need to wash them away. But most of us know that water and oil don’t mix. Goat milk soap makes it possible for oil and water to mix.

If you remember your chemistry, you’ll know that soap, dirt, oil, and water are made up of molecules. There are hydrophilic molecules which are attracted to water. And there are hydrophobic molecules which repel water.

Michael in bathtub with Purity Goat Milk Soap
"I am very satisfied with my Purity Goat Milk Soap, I love the way it cleans and moisturizes my skin and also how quick my orders are sent and delivered. Also I like using pure and healthy products on my skin, and I’m glad that I have found your products to be just that!" - Diane D.

A soap molecule is unique because it has one hydrophilic end and one hydrophobic end. So it acts as a bridge and attaches to a water molecule at its hydrophilic end and a dirt or oil molecule at its hydrophobic end.

When you rinse off your hands or your clothes, the hydrophilic end of the soap molecule gets washed away with the water and drags the hydrophobic end (and the dirt/oil) along with it.

So the soap sticks to the water and the oil sticks to the soap and it all goes down the drain!

Washing hands with Lemongrass Goat Milk Soap
"I have used the Goat's Milk Lemongrass soap before and love the scent of this soap. It leaves my skin feeling clean without residue." - Shane E.

Why Does Hot Water Clean Better?

Hot water can clean your skin and clothes better than cold water because the oils and fats melt in hot water, which makes them attach more easily to the hydrophobic end of the water molecule.

And that makes them easier to flush away with the rest of the dirty water.

Nautical Goat Milk Soap
"Nautical smells so fresh and clean. The soap itself truly does keep your skin more hydrated and I have noticed a difference in the appearance, it seems to be glowing and fresher looking. My only complaint...why didn't I know about you sooner? Will not be going back to my Dove. I am looking forward to washing my way through your various scents! I am hooked on your soaps!" - Sandra B.

Does Soap Lather Matter?

Soap lather itself does not clean your skin. So judge a goat milk soap by how your skin feels after using it, not by how much it lathers.

What Makes the Soap Suds?

When you rub a bar of goat milk soap over your skin, there is friction. This friction introduces tiny air bubbles to the surface of the wet soap. Remember how we discussed that soap molecules have two ends? One that loves water (hydrophilic) and one that hates water (hydrophobic)?

The water hating end wants to get out of the wet soap, so it attaches itself to the nearest air bubble. These air bubbles are soon covered in the hydrophobic ends of the soap molecules.

The air bubbles are now trapped, and lots of trapped air bubbles covered in soap molecules are what we call soap lather.

Washing hands with goat milk soap
"Love your Oatmeal Milk & Honey soap! Love the scent and lathers great! I started using when having chemo treatments as my body was extremely dry and flakey. The soap is gentle and nourishing. Thankfully the treatments are over but I continue to use. It’s the Best!" - Janet C.

How to Improve Soap Lather

There are many things that affect how well a goat milk soap lathers.

Quality of your water.
Hard water retards lather, while soft water enhances it. So if want to improve your soap lather, continue a water softener.

Condition of your skin.
If your skin is particularly greasy (from dirt or from lotion), there is little friction when the soap rubs over your skin. This introduces fewer air bubbles and therefore less lather.

Many of you find that if your hands are greasy, the first time you wash them, you get little lather. If you rinse and wash again, the second time you wash there is much more lather.

Condition of the soap.
A brand new bar of goat milk soap usually doesn’t lather as well as one that has been used a few times.

The longer a soap has been cured the better it will lather as well. So if you're looking for the strongest lather, consider buying soap ahead of time and letting it continue to age at your home.

Older soaps will also last longer, but remember that any added scent will start to fade 9-12 months after the soap has been made (and not purchased).

Ingredients in the soap.
Different goat milk soap ingredients produce different types (bubbly or creamy) and amounts of lather. Olive oil soaps will not have as bubbly a lather as other soaps.

    You can watch how Goat Milk Stuff soap lathers in this old video:

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