The Craft
Why Is Soap Alkaline? What pH-Balanced Bars Really Are
True soap always tests alkaline, usually between pH 8 and 11. Here is why that follows from the chemistry, and what a bar sold as pH 5.5 actually contains.
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The Craft
What happens in the pot and on the curing rack: saponification, superfat, pH and time.
The Craft
Superfat and Lye Discount, Explained With a Worked Example
Superfat and lye discount are the same adjustment described from opposite ends. Here is the arithmetic, worked in full, and how to pick a number.
The Craft
How Long Does Soap Need to Cure? Cold and Hot Process
Cold process soap needs about 4 to 6 weeks to cure, and olive-heavy bars longer. What changes during the cure, and how to tell when a bar is actually done.
The Craft
What Is Saponification? The Chemistry of Every Soap Bar
Saponification is the reaction that turns fat and lye into soap and glycerine. Here is what happens molecule by molecule, and why no lye survives it.
The Craft
Cold Process vs Melt and Pour vs Hot Process Soap
The three common ways to make soap differ in chemistry, control and cure time. Here is what genuinely separates them, and which one suits what you want.