From Potion to Soap: The Enchanted Magic of Saponification

Michael Douglas-Smith
Aug 27
4 min read

Updated: Aug 28

Once upon a time, in a little soap pot, oils met lye in a swirling dance. With a dash of alchemy and a sprinkle of patience, they transformed - never to be the same again. This enchanting process is called saponification, and it's the spell that turns simple ingredients into the bubbly bars we can't live without.

While it might sound mystifying, this process is actually the foundation of many soap-making techniques used today.

In this blog we will discuss

what saponification is,
the basic ingredients required for saponification,
what happens during saponification and
the end product

Understanding saponification not only sheds light on the science behind soap but also reveals the beauty and utility that arises from this age-old tradition.

What is Saponification?

At its core, saponification is a hydrolysis reaction where triglycerides (aka fats and oils) react with a strong alkali, like sodium hydroxide (for solid soap) or potassium hydroxide (for liquid soap). When the fat molecules interact with the alkali, they break down into glycerol and fatty acid salts. This results in the formation of soap, the versatile substance that cleanses our skin and environments.

The process can be performed in a variety of ways, from hot process to cold process soap-making, each offering unique characteristics and end products (We will dive into the cold process method in an upcoming blog).

In essence, saponification is what gives soap its cleansing properties and creates that delightful lather we all enjoy.

The Ingredients of Saponification

The basic ingredients required for saponification are quite simple:

fats and
an alkali.

Fats aka triglycerides can come from plant sources like olive oil, coconut oil, or palm oil or animal fats like tallow or lard and even a combination of fats.

Each type of fat will require a certain amount of alkali thar impacts the soap's final qualities, including its hardness, lather, and moisturizing properties.

An alkali solution is a liquid substance that has a pH of more than 7 (as opposed to an acidic solution with a pH of less than 7), and contains more hydroxide ions than hydrogen ions.

An alkali is produced by mixing sodium hydroxide and/or potassium hydroxide with a liquid like distilled water to form what is also known as a “lye solution”

The alkali or "lye solution" used is crucial as it catalyzes the saponification reaction. Sodium hydroxide makes bar soap, while potassium hydroxide results in liquid soap. The two combined create shave soap!

So, as you can imagine, the alkali ingredients not only drive the saponification process but also influence the soap's texture and performance.

Close-up view of bubbling soap mixture during the saponification process — Swirling Mixture During Soap-Making Process.

What Happens During Saponification?

During saponification, oils and fats meet lye (i.e. sodium hydroxide + distilled water) and a lively molecular transformation begins under forced conditions (using an immersion blender).

The immersion blender swirls the fatty acid molecules and lye rapidly so they start “dancing” together, bonding and shifting as the mixture heats up.

Once the ingredients are emulsified (aka fully blended together), they will represent a texture that can appear anywhere from thin gravy, to pancake batter or even pudding. These different textures allow the soap maker to play with different designs, but all in all, they indicate the mix is ready to be poured into a mold.

Pouring Emulsified Ingredients into a Mold

Shortly after, a chemical reaction begins to generate heat on its own (sometimes close to 200 degrees!) in a process called exothermic reaction.

Freshly Poured and Texturized Batter Going Through the Exothermic Reaction as it Turns to Soap.

This exothermic reaction often leads to the gel phase, where the soap becomes thick, hot, glossy, and jelly-like. In this warm phase, molecules are continuing to move rapidly, aligning into a new structure: soap and glycerin.

The darker areas between the waves indicate gel phase

As the mixture cools, the molecular dance settles, and a solid bar of soap begins to form: cleansers and moisturizers bonded in perfect balance.

The Results of Saponification

The result of saponification is soap and glycerine (that’s it). These two together make a product that has countless uses beyond just personal hygiene.

The soap can be crafted with various scents, colors, and textures, catering to personal preferences and needs.

Soaps Crafted with Different Scents, Colors and Designs

The glycerin produced as a byproduct during saponification is a humectant, meaning it attracts moisture to the skin (see next week's blog to learn more about glycerin!).

You can't see glycerin, but you can feel it when using the soap. It gives a smooth, silky and slightly slick feel and sometimes to the touch when the soap is dry.

Many artisan soaps retain this glycerin to enhance their moisturizing properties, making them gentler on the skin compared to commercial soaps that often strip this beneficial component away.

Eye-level view of an assortment of colorful handmade soaps — Freshly cut Bars of Glycerin-Rich, Handcrafted, Douglas-Smith Soap .

Ready to Wield Your Wand?

Soo there you have it, the bubbling, swirling magic of saponification revealed!

Saponification is a captivating process that embodies science and provides infinite opportunities for art expression. Through the combination of fats and an alkali solution, a transformative reaction occurs, yielding not just soap but an array of possibilities for skin care and cleaning solutions.

Now its YOUR turn to create your own enchanted bars of soap! Join us for our monthly soap-making classes in the button below and learn first hand how oils, lye and a little bit of creativity and magic come together.

Grab your blender wand (or spatula) and let's make some suds.