Have you ever wondered how those luxurious bars of cold process soap get their gentle lather? The secret lies in a scientific process called saponification, and a key player in this reaction is sodium hydroxide, often referred to as lye or caustic soda.
We know the term "lye" can sound a bit intimidating, but fear not! Let's break down the science behind it and how it contributes to the beautiful, handcrafted soaps you love.
The Magic of Saponification
Imagine fats and oils (like olive or coconut) as long chains with a round "head" on one end and a long, fatty "tail" on the other. Sodium hydroxide, on the other hand, is like tiny scissors. When these two ingredients are mixed just right, a chemical reaction occurs. The "scissors" (lye) cut the long chains of fat and oil at the bond between the head and the tail. These smaller pieces, called fatty acids, then have an interesting property: the head end loves water (hydrophilic), while the tail end shuns it (hydrophobic).
This love-hate relationship with water is what creates soap! The fatty acid "tails" clump together, avoiding water, while the "heads" with their affinity for water reach out and grab onto water molecules. This creates micelles, tiny spheres with the fatty acid tails tucked inside and the water-loving heads on the outside. These micelles are the secret to soap's cleaning power. They trap dirt and oil (which also dislike water) inside the micelle, allowing you to rinse them away easily.
So, the saponification process not only breaks down the fats and oils, but it also rearranges the molecules to create these amazing little cleaning agents!
Does Lye Remain in the Final Soap?
The short answer: no! The saponification process uses all the lye to create soap molecules. Here at Ivory Creek Handmade, safety is our top priority. To ensure all our cold process soaps are free from lye, we follow two key practices:
- Lye Calculators:Â We rely on trusted lye calculators to precisely measure the amount of lye needed for complete saponification. These calculators take into account the specific oils and butters used in our recipes, ensuring the exact chemical reaction occurs to convert all the lye into soap.
- Super fatting: We also use a technique called super fatting. This involves adding a small amount of extra oils and butters beyond what's needed for complete saponification (typically between 3 - 5%). These extra oils and butters aren't used up in the reaction and remain in the final soap bar. Not only does this ensure a small safety margin is built into the process, it also gives the soap bars that extra luxurious feel as the extra oils nourish and moisturise your skin leaving that pampered feeling.
Through a combination of these methods, we guarantee our cold process soaps are luxuriously lathering and completely safe for you to use.
So next time you reach for your favourite Ivory Creek Handmade soap, remember the secret ingredient – sodium hydroxide – that plays a vital role in creating the luxurious, nourishing product you love!