What Is Glycerin and Why Does Handmade Soap Have More of It?

Have you ever washed your hands or stepped out of the shower after using a handcrafted soap and thought, Why does this feel so different?

Part of the answer may be something you can't see at all: glycerin.

It's one of those ingredients you've probably seen listed on lotions, creams, cleansers, and other skincare products. But what many people don't realize is that when traditional soap is made, glycerin doesn't have to be added.

The soapmaking process creates it naturally.

And when we make our cold process soaps at Aspen Kay Naturals, we leave that naturally occurring glycerin right where it was created—in the finished bar.

So, What Exactly Is Glycerin?

Glycerin—also called glycerine or glycerol—is a clear, water-attracting substance widely used in skincare and cosmetic formulations.

In cosmetic science, glycerin is known as a humectant. Humectants attract and hold water, which is one reason glycerin is so commonly included in products designed to help skin feel hydrated, soft, and comfortable. Research has extensively examined glycerol's relationship with hydration of the skin's outermost layer.

But here's the part we think is especially interesting:

Glycerin is naturally created when real soap is made.

How Does Soap Naturally Make Glycerin?

A little chemistry is happening behind every handcrafted bar.

Traditional soap begins with fats and oils. These oils are largely composed of molecules called triglycerides, which contain fatty acids attached to a glycerol backbone.

When the oils are combined with sodium hydroxide—commonly called lye—a chemical reaction called saponification begins.  During this reaction, the components of the oils are transformed into soap, and glycerin is produced naturally as part of the process.  So when we talk about the glycerin in traditional cold process soap, we're not necessarily talking about an extra moisturizing ingredient being poured into the batch.

We're talking about something that develops naturally while the soap itself is being made.

Pretty amazing, isn't it?

Naturally Occurring Glycerin vs. Added Glycerin

This is also where some confusion around glycerin comes from.

If you've seen glycerin on the ingredient list of a skincare product, it may have been intentionally added to that formulation. That's added glycerin.

In traditional cold process soap, glycerin is also created during saponification as a natural part of turning oils into soap. That's naturally occurring glycerin. Chemically, glycerin is glycerin. The important distinction is how it got into the product. In our cold process soaps, glycerin is created as part of the soapmaking process and remains within the finished bar.

Why Does Glycerin Matter in Skincare?

There's a reason glycerin appears in so many skincare formulas.

As a humectant, glycerin has an affinity for water and is widely used in cosmetic formulations intended to support a moisturized, conditioned feel. Studies have found associations between glycerol and hydration of the stratum corneum—the outermost layer of the skin.

For a handcrafted cleansing bar, naturally occurring glycerin is one of several characteristics that can contribute to the overall experience of using traditional soap.

And for us, keeping it in the bar simply makes sense.

What Happens to Glycerin in Commercial Soapmaking?

This is where the story gets a little more complicated.

In some traditional large-scale soap manufacturing processes, glycerin can be separated from the soap during processing. Purified glycerin is valuable and has many uses in cosmetics, personal-care products, foods, and pharmaceuticals.

However, not every commercial bar is manufactured the same way.

Some contain glycerin. Some may have glycerin added to the finished formulation. And many products commonly called "soap" are actually formulated with synthetic cleansing ingredients rather than being traditional soap made primarily through saponification.

That's why comparing a handcrafted cold process bar with every product in the commercial soap aisle isn't always an apples-to-apples comparison.

The ingredient list—and the way the product is made—matters.

How Much Glycerin Is Naturally Produced in Cold Process Soap?

You may see estimates suggesting that naturally produced glycerin represents roughly 6–8% of a finished cold process soap formula, but the exact amount isn't universal. It depends on the oils and fats used, the formulation, water loss during curing, and other manufacturing variables. Rather than focusing on one percentage, we think the more meaningful point is simple:

Traditional saponification creates glycerin, and our cold process method leaves that naturally occurring glycerin in the finished soap.

Nothing needs to be extracted from the bar before it reaches you.

There's More to a Great Bar Than Glycerin

Glycerin is only one part of the story.

The oils, butters, botanicals, clays, formulation, curing time, and craftsmanship all influence the character of a finished handmade soap. Our bars begin with thoughtfully selected oils and butters and are made using the traditional cold process method.

Once poured and cut, they're given time to cure—typically 4 to 6 weeks.

There's no rushing that part.

During curing, excess water gradually evaporates and the bars become harder and longer-lasting while developing the lather and character we want from our finished soap.

What About Superfatting?

Another term you'll often hear when learning about handcrafted soap is superfatting.

A superfatted soap is formulated so that the amount of oil used exceeds the amount needed for complete saponification according to the soapmaker's formulation. This leaves a portion of the oils unsaponified in the finished bar.

For soapmakers, it's another way formulation can influence the feel and performance of a handcrafted bar.

Combined with naturally occurring glycerin and carefully selected oils and butters, it is part of what makes traditional cold process soap such a unique cleansing experience.

Why We Keep the Glycerin in Our Soap

For us, this is one of the things we love most about traditional soapmaking. We don't need to make soap complicated.  We start with quality oils and butters. We allow saponification to do what it has done for generations. We give our bars time to cure properly.

And the glycerin created along the way? We leave it right there in the bar.

It's one of the beautiful little pieces of chemistry behind a process that has been used for generations.

Real Ingredients. Traditional Soapmaking. Real Care.

We still use the cold process method because we believe there's something special about doing things the traditional way—even when it takes longer.  Every batch begins with carefully selected ingredients, goes through the natural process of saponification, is cut into individual bars, and then gets something that's increasingly rare these days:

Time.

Time to cure.
Time to develop.
Time to become the bar that eventually makes its way into your home.

So the next time you pick up one of our cold process soaps, remember that there's more happening inside that little bar than you might think.

The glycerin wasn't simply added to the story.

It was created while the soap was being made. 🌿

This article is provided for educational purposes and discusses soapmaking, cosmetic ingredients, and their traditional cosmetic uses. Aspen Kay Naturals products are intended for cleansing and cosmetic use and are not intended to diagnose, treat, cure, or prevent any disease or medical condition. Individual experiences may vary.