Notes on cold process soap
The Craft
Cold process and hot process are both soapmaking: fats react with lye to make soap. Melt and pour is not. It is remelting a soap base a factory already saponified. The difference decides what you control, what you can add, and how long you wait.
Ingredients
Charcoal soap is sold as a detox. The real story is smaller and more useful: what activated charcoal does in a rinse-off bar, and which claims to ignore.
Ingredients
Cosmetic clays differ mainly in how much oil and water they absorb. Here is how the common ones compare, which is gentlest, and which suits which skin.
Buying Well
Most bars do not wear out, they dissolve. Six habits that slow that down, from the soap dish to the cure, and why a handmade bar rewards them more than most.
Who writes this
The Rasa Theory is written and funded by the small team behind Rasa & Root, a cold process soap and botanical oil workshop in India. Most of what is here began as notes to ourselves after a batch went wrong. Every claim links to a source, and tradition is never passed off as evidence.
What happens in the pot and on the curing rack: saponification, superfat, pH and time.
The Craft
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.
The Craft
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
Cure times by recipe type, what is actually happening during the cure, and which of the numbers everyone repeats are measured rather than inherited.
The oils, clays and Indian botanicals that go into a bar, with tradition and evidence kept apart.
Ingredients
Manjistha is Rubia cordifolia, the Indian madder root that dyes a soap rose to red-brown. Where it comes from, what it does in a bar, and what is only tradition.
Ingredients
Tangedu is Senna auriculata, the state flower of Telangana and a fixture of Bathukamma. What the plant is, where its name comes from, and what we can honestly claim.
Reading labels, judging a bar, and making the one you bought last.
Buying Well
A handmade bar can cost several times a supermarket one. Where that money goes: the oils, the weeks on a curing rack, the glycerine, and the work done by hand.
Buying Well
Saponified oils, INCI names, syndet bars and the word natural. A practical guide to telling real cold process soap from a decorated commercial base.
Why a small soap workshop in India is publishing a journal about cold process soap, who writes it, and the editorial rules it holds itself to from the first day.
