A working journal about cold process soap: saponification, cure times, superfatting, oils and the craft of making a bar that is actually worth using.https://rasatheory.in/enhttps://rasatheory.in/blog/activated-charcoal-in-soap/https://rasatheory.in/blog/activated-charcoal-in-soap/Charcoal soap is sold as a detox. What activated charcoal actually does in a rinse-off bar, how it compares with other black powders, and which claims lack evidence.Sun, 04 Oct 2026 00:00:00 GMTingredientscharcoalbuying soaphttps://rasatheory.in/blog/cosmetic-clays-compared/https://rasatheory.in/blog/cosmetic-clays-compared/Cosmetic clays differ in mineral type, swelling and ion-exchange capacity. Kaolin, pink, green, bentonite, multani mitti and rhassoul compared, with what is and is not proven.Sun, 04 Oct 2026 00:00:00 GMTingredientsclaysensitive skinhttps://rasatheory.in/blog/how-to-make-soap-last-longer/https://rasatheory.in/blog/how-to-make-soap-last-longer/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.Sun, 04 Oct 2026 00:00:00 GMTusing soapbuying soaphttps://rasatheory.in/blog/manjistha-in-soap/https://rasatheory.in/blog/manjistha-in-soap/Manjistha is Rubia cordifolia, Indian madder, a red plant dye used in Ayurveda. What it does in a soap bar, why its colour shifts with pH, and what is tradition versus tested.Sun, 04 Oct 2026 00:00:00 GMTingredientsmanjisthaindian botanicalsnatural colourhttps://rasatheory.in/blog/tangedu-tanners-cassia/https://rasatheory.in/blog/tangedu-tanners-cassia/Tangedu (thangedu puvvu) is tanner's cassia in English, scientific name Senna auriculata. Telangana's state flower: what the plant is, its uses and the evidence.Sun, 04 Oct 2026 00:00:00 GMTingredientstangeduindian botanicalshttps://rasatheory.in/blog/why-handmade-soap-costs-more/https://rasatheory.in/blog/why-handmade-soap-costs-more/Why a handmade bar often costs more: oil prices, weeks on a curing rack, retained glycerine, small batches and Indian licensing, with World Bank and Cosmetics Rules data.Sun, 04 Oct 2026 00:00:00 GMTbuying soapcold processhttps://rasatheory.in/blog/why-real-soap-is-alkaline/https://rasatheory.in/blog/why-real-soap-is-alkaline/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.Sun, 04 Oct 2026 00:00:00 GMTchemistryphbuying soaphttps://rasatheory.in/blog/how-to-read-a-soap-label/https://rasatheory.in/blog/how-to-read-a-soap-label/How to read a soap label in India: INCI names like sodium olivate, TFM and BIS IS 2888 grades, Legal Metrology declarations, and which marketing words mean nothing.Fri, 14 Aug 2026 00:00:00 GMTlabelsbuying soapcold processhttps://rasatheory.in/blog/superfat-and-lye-discount-explained/https://rasatheory.in/blog/superfat-and-lye-discount-explained/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.Wed, 29 Jul 2026 00:00:00 GMTsuperfatformulationchemistryhttps://rasatheory.in/blog/how-long-soap-needs-to-cure/https://rasatheory.in/blog/how-long-soap-needs-to-cure/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.Wed, 08 Jul 2026 00:00:00 GMTcuringcold processchemistryhttps://rasatheory.in/blog/what-is-saponification/https://rasatheory.in/blog/what-is-saponification/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.Wed, 24 Jun 2026 00:00:00 GMTsaponificationchemistrylye safetyhttps://rasatheory.in/blog/cold-process-vs-melt-and-pour-vs-hot-process/https://rasatheory.in/blog/cold-process-vs-melt-and-pour-vs-hot-process/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.Wed, 10 Jun 2026 00:00:00 GMTcold processmethodssaponification