cold process soap

Soapmaking 101: Saponification & Superfatting

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The soapmaking process is part science and part art, with a little pinch of magic thrown in. Although soap is a ubiquitous part of our daily lives, some of the processes and ingredients necessary to make it are misunderstood. Words like saponification and superfatting aren’t part of our regular vocabulary, while ingredients like sodium hydroxide may sound off-putting. 

Here at Sea Witch Botanicals, we put a lot of effort into making sure we use the best ingredients and create the finest, nature-inspired products. We’ve chosen to make soap the way we do for specific reasons. We get a lot of questions about our ingredients and the process, so we wanted to share some of this behind-the-scenes information with you and clear up any misconceptions.


What is saponification?

Saponification is the science of turning fat or oil into soap. As it takes both fat and water to create soap, and oil and water are notoriously difficult to combine, something else is required to bind these ingredients together. That’s where sodium hydroxide comes into play.


Is sodium hydroxide dangerous?

Sodium hydroxide, also known as lye, is a nonorganic chemical that is a co-product of the electrolysis of salt. Traditionally, soap was made using leftover wood ash from cooking fires mixed with animal fat and water. By leaching water through wood ashes, early soap makers were creating their own lye. These days however, lye is made in a laboratory.

Lye is used in soapmaking to bind oil and water together. The chemical reaction that happens when lye is combined with liquid and fats causes the oils to break down into fatty acid chains while the lye is neutralized. Because lye has a very high alkalinity, it is considered caustic and can burn skin.

However, sodium hydroxide is only dangerous in its virgin form, and for the first 24 hours after it has been used to combine oil and water to make soap. Once the soap has cured for a day, there is no lye remaining, as it has been expended into the process of combining oil and water together.

This being said, it is very important to use precise math in the soapmaking process, to determine the proper amount of lye to use to make sure there’s none remaining in the final product. Due to the caustic nature of lye in its original form, most soapmakers prefer to superfat their soaps to make sure their final product is luxurious and conditioning.

What is superfatting?

Superfatting is the process of using less lye (or more fat) than industry standards so that there’s some leftover oil in the soap that’s not bound to lye. This leaves behind more unsaponified fat, providing more moisture in the soap.

Every oil requires a different amount of lye to turn it into soap. If you simply use the required amount of lye, you’ll end up with a soap that is 0% superfat. When calculating the amounts of fats versus lye needed for your recipe, you can either diminish the amount of lye or increase the amount of fat to superfat your soap.

Superfatted soap is less harsh and more moisturizing on the skin. It also gives the soapmaker a little more wiggle room with their calculations, since individual plants and oils can vary with their saponification values. This provides an extra level of safety in ensuring there’s no leftover lye. 


What’s the deal with palm oil?

The production of palm oil requires deforestation, as forests are burned to clear the area to grow oil palms. This burning produces a lot of carbon dioxide, contributing to climate change. When these cleared areas are replaced with a monoculture, it also impacts the biodiversity of plants and wildlife that live in these areas, as local wildlife can’t survive and soil is destroyed.

In 2004, a group called the Roundtable on Sustainable Palm Oil (RSPO) was formed with the goal of producing palm oil without damaging the environment. This nonprofit organization developed a set of environmental and social criteria for companies to comply with. Their commitment to no deforestation, no peat development, and no exploitation (NDPE) is the backbone of their efforts to change the way palm oil is grown and processed.

Palm oil is a commonly used ingredient in soapmaking. In the beginning times of Sea Witch Botanicals, we crafted our artisan soap bars with RSPO certified palm oil because we wanted to be able to boost that industry in the hope that more farmers and producers supporting this mission would be able to thrive. 

However, oversight of palm harvesting can be difficult to manage. For that reason, we set a sustainability goal to eliminate palm oil from our recipes to lessen the demand on the palm oil industry. At this point, we no longer use palm oil for our artisan bars, and it’s our 2021 goal to be completely palm-free.

Soapmaking methods: Hot Process vs. Cold Process

There are several ways to make soap, but here we’ll focus on the two methods that require doing your own saponification, hot process and cold process. 

The hot process method involves mixing heated ingredients to begin saponification, then “cooking” them in a double boiler or oven after pouring into a mold. The additional heat speeds up the process of turning fats into soap and neutralizing the lye. This means that hot process soap can be sliced and used immediately after cooling.

With cold process soap, no additional heat is added. The heat from the chemical reaction of lye meeting water is what causes saponification to occur. This method requires a long cure time to allow the water to slowly evaporate over time. The long cure time helps make the soap last longer and is considered one of the most “natural” ways to make soap.

In the Sea Witch Botanicals lab, we prefer to make cold process soap. Because we only use essential oils and never use artificial fragrances, this is the best way to preserve the final aroma we’re going for. Cold process is the best way to protect essential oils, which can be damaged or burned off in hot process soapmaking.

Now that you understand a little more about what goes into making soap, check out our line of high-quality, cold process vegan soaps!

1 comment

Alexa Jordan
Alexa Jordan

Those are beautiful! I just bought some botanicals to add ( and I hope I can make it look somewhat like yours, even if it’s a different blend.

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