Pig Tallow for Skin: The Old-Fashioned Fat Behind a Great Bar of Soap

Pig tallow—more commonly called lard when we're talking about rendered pork fat—has been part of traditional soapmaking for generations. But what makes this humble animal fat useful in a bar of soap? And what does modern science actually tell us about using animal fats in skincare?

There is no shortage of claims on the internet about tallow and lard being miracle skincare ingredients. Some are fascinating. Some are exaggerated. And some simply don't distinguish between putting raw tallow on your skin and turning that fat into a properly formulated bar of soap.

So let's separate tradition from chemistry and chemistry from marketing.

At Boner's Botanicals, we're interested in natural materials, traditional skills, and what happens when we put them to practical use.

And when it comes to pig fat, there is quite a story to tell.

What Is Pig Tallow?

First, a little terminology.

Strictly speaking, tallow generally refers to rendered fat from animals such as cattle or sheep, while lard refers specifically to rendered pork fat.

In everyday conversation, however, people sometimes use "tallow" as a general term for rendered animal fat.

For this article, when we're talking about pig tallow, we're talking about rendered pork fat—lard—used as an ingredient in soapmaking and skincare.

Rendered fat is primarily composed of triglycerides. Those triglycerides contain fatty acids, and the particular combination of fatty acids affects the physical and chemical characteristics of the fat—and ultimately the soap made from it.

Pork lard commonly contains substantial amounts of oleic, palmitic, stearic, and linoleic acids, although the exact proportions can vary depending on factors such as the animal's diet and the source of the fat.

That fatty-acid profile is where our story begins.

Why Should We Care About Fatty Acids?

Because your skin is not simply a waterproof covering.

The outermost portion of the skin, called the stratum corneum, functions as a highly organized barrier between your body and the outside world.

Researchers describe this barrier as a structured lipid system containing three major classes of lipids:

• Ceramides

• Cholesterol

• Free fatty acids

Together, these lipids form organized structures between the cells of the stratum corneum and play an important role in limiting water loss and protecting the body from environmental exposure. [1][2]

This is one reason fats and fatty acids have attracted so much attention in dermatology and cosmetic science.

But there is an important distinction:

The fact that the skin contains fatty acids does not automatically mean that applying any particular animal fat will repair or improve the skin.

Skin biology is considerably more complicated than that.

What's In Pork Lard?

The fatty-acid composition of lard is one of the reasons soapmakers have historically valued it.

Among its major fatty acids are:

Oleic Acid

Oleic acid is a monounsaturated fatty acid and is also found in numerous vegetable oils, including olive oil.

Palmitic Acid

Palmitic acid is a saturated fatty acid commonly found in both animal fats and plant oils.

Stearic Acid

Stearic acid is another saturated fatty acid. In soapmaking, it contributes to characteristics such as hardness and the physical structure of the finished bar.

Linoleic Acid

Linoleic acid is a polyunsaturated fatty acid and an essential fatty acid for humans.

The proportions of these fatty acids vary from one sample of lard to another, so it would be misleading to claim that every batch of lard has an identical chemical profile.

Nevertheless, the general composition gives us a useful explanation for why lard has been such a useful traditional soapmaking fat.

From Fat to Soap: What Actually Happens?

Here's where things get really interesting.

A bar of soap made with lard isn't simply a block of fat.

During soapmaking, the fat undergoes a chemical reaction called saponification.

In simplified terms:

Fat + sodium hydroxide → soap + glycerin

The triglycerides in the fat react with sodium hydroxide, producing salts of fatty acids—the molecules we recognize as soap—along with glycerol (glycerin).

Scientific literature describes animal fats such as tallow and pork lard as traditional soapmaking fats and explains that their fatty acids are converted into soap salts during saponification. [3]

So when you hold a properly made, cured lard soap bar in your hand, you're not simply rubbing pork fat onto your skin.

You're using a completely different material created through chemistry.

And that distinction matters.

Why Lard Can Make a Beautiful Bar of Soap

The fatty acids present in a soapmaking oil or fat influence the characteristics of the resulting bar.

In general, saturated fatty acids such as palmitic and stearic acid contribute to hardness and durability.

Unsaturated fatty acids such as oleic acid influence other properties of the finished soap, including its feel and cleansing characteristics.

That's one reason experienced soapmakers rarely formulate a bar around a single fat or oil.

Instead, different fats and oils can be combined to balance characteristics such as:

• Hardness

• Lather

• Creaminess

• Cleansing ability

• Conditioning feel

• Longevity

• Overall bar performance

Lard therefore isn't necessarily interesting because it is some magical ingredient.

It's interesting because its chemistry makes it a useful soapmaking fat.

But What About Lard and Skin?

Now we get to the question that causes the most confusion.

Does lard itself have benefits when applied directly to skin?

There is some scientific interest in the compatibility between animal fats and skin, but the evidence needs to be handled carefully.

A 2024 scoping review examined the existing scientific literature concerning animal tallow and its relationship with skin. The researchers found evidence relevant to the composition and potential compatibility of tallow with skin, but they also identified significant gaps in the research.

In particular, the authors concluded that more research involving controlled human studies is needed to determine the benefits and potential adverse effects of topical tallow as a cosmetic ingredient. [4]

That's a very important conclusion.

It means we can reasonably discuss the chemistry of tallow and its fatty acids.

It does not mean we should tell people that tallow has been clinically proven to cure dry skin, eczema, wrinkles, or other skin conditions.

Science doesn't currently support making those blanket claims.

The Skin Barrier Connection

So why does the subject keep coming back to fatty acids?

Because the skin barrier depends heavily on lipids.

The stratum corneum contains an organized mixture of ceramides, cholesterol, and free fatty acids. These lipids form highly structured layers that help control water movement through the skin. [1][2]

Research into skin cleansing has also demonstrated that cleansing can affect these lipids.

Surfactants help remove oils, dirt, and other substances from the skin—but cleansing can also remove or disturb some of the skin's own lipids.

Researchers have therefore investigated ways of incorporating physiologically relevant lipids, including fatty acids such as stearic acid, into cleansing products to help preserve the skin barrier. [5]

That is an interesting piece of science.

But again, there is an important difference between:

"Fatty acids are important components of the skin barrier."

and:

"A bar of lard soap repairs your skin barrier."

The first statement is supported by substantial research.

The second is a much stronger claim—and isn't established simply because lard contains fatty acids.

Lard Soap Isn't the Same as Tallow Balm

This distinction deserves its own section.

A leave-on tallow product and a lard-based bar of soap behave very differently.

A balm or moisturizer containing rendered animal fat remains on the skin.

A bar of soap is designed to be used with water and then rinsed away.

During soapmaking, the original triglycerides undergo saponification and become soap salts and glycerin.

So if you're interested in the skincare properties of raw or rendered tallow, you're looking at a different type of product than a lard soap bar.

This is why claims about "tallow skincare" shouldn't automatically be applied to "tallow soap."

They are not the same thing.

Why Did People Use Animal Fat for Soap in the First Place?

The answer is wonderfully simple:

It was available.

Before modern industrial oils became cheap and widely available, communities worked with the fats they had.

Animal fats could be rendered and stored.

Plant oils could be pressed where suitable crops were available.

Alkaline materials could be produced from ashes or obtained through other traditional processes.

The result was soap.

Animal fats therefore have a long history in soapmaking—not because our ancestors had access to modern dermatological research, but because the chemistry worked.

Modern science has since given us a much better understanding of why it worked.

Lard Soap: Tradition Meets Chemistry

There is something satisfying about taking an ingredient that might otherwise be discarded and turning it into something useful.

Rendered pork fat can become part of a carefully formulated bar of soap.

The transformation is straightforward but fascinating:

Pork fat → fatty acids in triglycerides → saponification → soap

And the characteristics of those fatty acids help determine the characteristics of the finished bar.

That makes lard more than an old-fashioned curiosity.

It is a functional soapmaking ingredient with a long history and a chemistry we can understand.

SEE IT IN ACTION: Making Bar Soap With Pig Tallow

Watch the complete soapmaking process and see how rendered pig fat becomes part of a finished bar of handcrafted soap.

Why Use Pig Tallow in Modern Handmade Soap?

There are several reasons a modern soapmaker might choose lard.

1. Traditional soapmaking

Lard has a long history as a soapmaking fat.

2. Fatty-acid composition

Its combination of saturated and unsaturated fatty acids contributes useful characteristics to a finished bar.

3. Hardness and longevity

The saturated fatty acids in lard can contribute to a firm bar that holds up well during use.

4. Availability

For people who raise or process livestock, rendering fat can provide a practical way to make use of an otherwise underutilized material.

5. The satisfaction of making something from scratch

This may be the least scientific reason—but it might be one of the best.

There is something deeply satisfying about taking a raw natural material and turning it into something useful with your own hands.

SEE IT IN ACTION: Another Lard Soapmaking Experiment

This second soapmaking demonstration shows another approach to working with pig tallow/lard and turning it into a handcrafted bar.

Is Lard Soap Better Than Plant-Oil Soap?

That's not a question science can answer with a simple yes or no.

Different fats and oils produce soaps with different characteristics.

Olive oil, coconut oil, palm oil, castor oil, lard, tallow, and other fats each bring different fatty-acid profiles to a formulation.

The finished bar depends not only on the fat itself, but also on the entire recipe, the proportions of ingredients, the amount of alkali, the water content, the curing process, and how the finished soap is used.

So rather than declaring one fat universally "better," it's more useful to understand what each ingredient contributes.

That's the soapmaker's approach:

Know your ingredients. Know your chemistry. Then formulate accordingly.

What Does the Science Actually Support?

After looking through the research, here's the short version.

We know:

• The skin barrier depends heavily on organized lipids including ceramides, cholesterol, and free fatty acids. [1][2]

• Pork lard contains significant amounts of oleic, palmitic, stearic, and linoleic acids.

• Animal fats such as lard and tallow have long been used in soapmaking.

• Saponification converts triglycerides into soap salts and glycerin. [3]

• Fatty-acid composition affects the characteristics of the finished soap.

• Cleansing can influence the lipid components of the skin barrier. [5]

• Scientific researchers are actively interested in the potential compatibility of animal fats with skin.

We don't yet know:

• That topical tallow is universally better than plant-based moisturizers.

• That tallow or lard cures eczema or other dermatological diseases.

• That applying raw tallow "rebuilds" the skin barrier.

• That lard soap is inherently superior to every plant-oil soap.

• That everyone will have the same experience using an animal-fat soap.

That's an important distinction.

Natural doesn't automatically mean better.

And "traditional" doesn't automatically mean scientifically proven.

But neither does the absence of massive clinical trials mean an old-fashioned ingredient is worthless.

Sometimes the most interesting place to be is right in the middle:

where tradition meets chemistry.

The Boner's Botanicals Take

At Boner's Botanicals, we're interested in natural materials—not because nature needs exaggerated marketing, but because nature is already pretty damn interesting.

Pig lard has been used for generations.

Modern chemistry explains why it can make an effective bar of soap.

Modern dermatology explains just how important lipids are to the skin barrier.

And modern research is beginning to investigate the relationship between animal-derived fats and skin.

The science is interesting.

The history is interesting.

And the soap is even more interesting when you understand what is happening inside that little bar.

So the next time somebody asks:

"Soap made with pig fat?"

The answer is simple:

Yep.

And there's a lot more chemistry behind it than you might think.

A Note About Skin Sensitivity

Everyone's skin is different.

Traditional soap can be more alkaline and may feel drying or irritating to some people, particularly those with sensitive or compromised skin barriers. Cleansing itself can also affect skin lipids. [5]

If you have a diagnosed skin condition or persistent irritation, talk with a qualified healthcare professional rather than relying on internet skincare claims.

And as always with handmade soap, proper formulation, accurate measurement, appropriate handling of sodium hydroxide, adequate curing, and responsible labeling are essential.

References & Further Reading

[1] The skin barrier: An extraordinary interface with an exceptional lipid organization.

[2] Feingold KR. Thematic review series: skin lipids. The role of epidermal lipids in cutaneous permeability barrier homeostasis.

[3] Skin Cleansing without or with Compromise: Soaps and Syndets.

[4] Russell MF, et al. Tallow, Rendered Animal Fat, and Its Biocompatibility With Skin: A Scoping Review. Cureus. 2024.

[5] Ananthapadmanabhan KP, Mukherjee S, Chandar P. Stratum corneum fatty acids: their critical role in preserving barrier integrity during cleansing.

Scientific sources

Here are the actual research sources behind the article:

• 2024 tallow-specific scoping review: Russell et al., Tallow, Rendered Animal Fat, and Its Biocompatibility With Skin. This is probably our most important citation because it directly examines the evidence surrounding animal tallow and skin and, importantly, identifies the gaps in human research. PubMed — Tallow, Rendered Animal Fat, and Its Biocompatibility With Skin (PubMed)

• Skin-barrier lipid science: The stratum corneum's barrier is built around organized lipids including ceramides, cholesterol and free fatty acids. PubMed — The skin barrier: An extraordinary interface with an exceptional lipid organization (PubMed)

• Epidermal lipid/barrier review: This review provides the classic description of the skin's permeability barrier and its lipid composition. PubMed — The role of epidermal lipids in cutaneous permeability barrier homeostasis (PubMed)

• Soap chemistry: This review specifically discusses soap as fatty-acid salts produced through saponification and identifies tallow and pork lard among traditional soapmaking fats. PMC — Skin Cleansing without or with Compromise: Soaps and Syndets (PubMed Central (PMC))

• Cleansing and skin lipids: Research reviewing cleansing explains how surfactants can affect stratum-corneum lipids and why fatty acids such as stearic acid have been investigated in cleansing formulations. PubMed — Stratum corneum fatty acids: their critical role in preserving barrier integrity during cleansing (PubMed)

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