Hey there! It's Kathleen, the Owner and Maker behind West Grove Soaps, and today I'm sharing what Cold Process soap making is and why we use it here at West Grove Soaps!
Here at West Grove Soaps, I handcraft all-natural botanical bar soaps using the long-standing, tried and true, Cold Process method. That's why it's so chill in my studio 8-)
Cold Process? Can you elaborate?
I sure can! But let's quickly back up a little bit to the various kinds of soap making.
When making bar soap, there are 3 methods you can use — all resulting in a fantastic bar of soap:
- Cold Process
- Hot Process
- Melt & Pour
Melt & Pour
Melt & Pour is a great introduction to soap making for beginners. Here's how it works:
- Purchase a premade soap base
- Melt it down
- Add your favorite scent
- Pour into a mold
It's easier, saves time, and saves money on separate ingredients. It's a great way to get comfortable with:
- Working with hot oils
- Measuring essential or fragrance oils
- Pouring hot soap batter into molds
Did I start with Melt & Pour? No — I jumped straight into Cold Process at a beginners workshop. But I still think Melt & Pour is a great starting point!
Cold Process vs. Hot Process
Despite the names, both methods rely on heat and both go through a chemical reaction called Saponification. What distinguishes them is the intensity and duration of heat, and the curing phase.
What they have in common:
- Both require oils, a water discount, and Sodium Hydroxide (lye) — learn more about lye in this blog post!
- Ingredients are emulsified with the lye solution using an immersion blender
- Can demold and cut within 48 hours after molding
- When lye combines with fatty acids in oils, saponification begins
- The hot, caustic soap batter cools and crystallizes into the soap we know and love
Now, let's look at what makes them mortal enemies!! I mean, let's look at how they differ!
Hot Process (HP)
Hot Process relies on external heat — typically a crock pot — throughout the entire blending process.
- Temperatures usually reach at least 130°F
- Constant heat speeds up saponification
- Batter hits a "gel phase" — becoming very thick and jelly-like
- Produces beautiful, rustic-looking soaps
Potential "cons" to HP soap making depending on your soap desires:
- Thick batter makes intricate designs harder to achieve
- Adding scents too early can burn off fragrance, resulting in milder-scented bars
Major Pro: Once cooled in the mold (~24 hours), HP soaps are ready to use almost immediately. Ideally cure for 1–2 weeks to harden, but great if you're in a time crunch!
Cold Process (CP)
Cold Process does not rely on external heat. Heat is internally generated by the lye reacting with fatty acids in your oils and butters. External heat is only used to melt hard butters.
Unlike HP, Cold Process will:
- Give you a more fluid batter longer, giving you more time for intricate swirl designs!
- Not guarantee of a "gel phase" like in HP
- Require a 4–6 week cure time for excess water to fully evaporation resulting in a harder, longer-lasting bar
Why West Grove Soaps Uses Cold Process
I use Cold Process because I love the freedom of making intricate designs. And while a faster turnaround would be nice, I truly love the idea of "slow crafting". I feel that when something takes a long time to make, it brings me stronger feelings of appreciation, value, and dedication!
While I love Cold Process, I really want to give Hot Process a try someday!
Thank you for stopping by and be sure to check out my Signature Suds Collection of plant-based, handcrafted, small batch, COLD PROCESS SOAPS! WOO!
— Kathleen