There are two main ways to make real soap from scratch: cold process and hot process. Most handmade soap you'll find online is cold process. We make ours hot process — and that choice shapes everything about how our bars look, feel, and behave.
Two Ways to Make Soap
Both methods start the same way: oils and fats meet lye, and saponification turns them into soap and glycerin. The difference is heat.
Cold process relies on the natural heat of the reaction alone. The soap is poured into a mold raw, and saponification finishes over the next 24–48 hours. The bars then cure for four to six weeks before they're ready.
Hot process adds external heat. The raw soap is cooked for hours until saponification completes in the pot, before it's ever molded. The bar goes into the mold already finished soap.
Why We Chose Hot Process
First, completeness. Because saponification finishes in the pot, there is never a period where partially reacted soap sits curing on a shelf. A hot process bar is fully saponified soap from the day it's cut.
Second, character. Hot process soap has a rustic, hand-hewn look — no two bars are identical, and the texture tells you a person made this, in small batches, not a machine.
Third, control. Cooking the batch lets us work with a wide range of oils and additives, and it suits small-batch production: we can make exactly what we need, exactly when we need it.
What It Means for Your Skin
- Fully reacted soap. The oils and lye have completely converted into soap and glycerin before the bar is molded.
- Retained glycerin. Like all real soap, hot process bars keep their natural glycerin — a humectant that draws moisture to your skin.
- Still worth a rest. Even fully saponified soap benefits from a short cure of one to two weeks to harden and last longer. We handle that before your bar ever ships.
The Honest Trade-Offs
Hot process bars look rustic rather than polished, and they can be slightly more challenging to swirl into intricate designs. We think that's a fair trade for what we gain: complete saponification, flexibility with small batches, and a bar with real handmade character. If you want your soap to look like it came out of a factory, hot process isn't for you. If you want soap that is handmade — visibly, honestly — it is.
Frequently Asked Questions
Is hot process soap gentler than cold process?
A properly made bar of either type is gentle. Hot process guarantees full saponification before molding, which removes any risk of unreacted lye in the finished bar.
Does hot process soap need to cure?
It doesn't need a long cure for safety, but we rest every bar briefly so it hardens and lasts longer in your shower.
Why does hot process soap look different?
Cooking gives it a rustic, textured appearance. It's the signature of soap finished by hand in the pot.
About the author: Viola is the founder and soap maker behind The Garden Soapery, a small-batch hot process soap workshop in Santee, South Carolina, founded in 2015 — a former truck driver who taught herself soapmaking from a book. Every purchase supports soap donations to homeless and foster care communities: 2,500+ handmade bars donated since 2015. Read Viola's full story →