Making green soap

There is a singular magic in the world of fiber arts that happens when you stop buying generic supplies and start creating your own tools. For me, that moment arrived when I brewed my first batch of green soap—a golden-emerald gel that transformed my wet felting from a soapy struggle into a smooth, tactile joy.

My Journey with Homemade Green Soap

I remember the distinct frustration of my early felting days, standing over a sink with dry, cracked hands and a piece of Merino wool that felt more like straw than silk. I was using harsh commercial dish detergents that stripped the natural lanolin right out of the fiber. It wasn’t until I read an old French tapestry manual about “savon mou” that I realized I was using the wrong chemistry.

Lisa Mandel

My first attempt at making this traditional potassium soap was in a tiny apartment kitchen, wearing oversized goggles and feeling like a mad scientist. When the mixture finally turned from a cloudy mess into a translucent, amber-green paste, I knew I had unlocked something special.

Using soap you made yourself to wash a fleece you shore yourself is the ultimate act of crafting self-sufficiency.

What This Craft Really Entails

Green soap, often called soft soap or “savon noir” in Europe, is technically a potassium soft soap. Unlike the hard bar soaps we use in the shower, which are made with sodium hydroxide (lye), this soap uses potassium hydroxide (KOH). This different chemical alkali creates a soap that doesn’t crystallize into a hard bar but stays as a viscous, water-soluble paste.

The process is almost exclusively a “hot process” method. You cook the oil and lye solution in a slow cooker or double boiler to force the saponification. It requires heat to neutralize the caustic ingredients and transform them into a safe, usable product. The beautiful green color usually comes from using Pomace olive oil, which is extracted from the skins and pits of olives and is rich in natural chlorophyll.

In the textile industry, this type of soap is legendary because its high pH helps open the scales of wool fibers gently, accelerating the felting process without damaging the protein structure.

This craft is perfect for intermediate soap makers or fiber artists who are comfortable with precise measurements and safety protocols. Have you ever wondered why professional felters seem to work so much faster? Often, it’s because their soap provides the perfect “slip”—lubricating the fibers just enough to glide, but grabbing them just enough to tangle.

Essential Materials and Tools

Key Techniques and Skills

• Lye Safety & Handling: Understanding how to safely mix KOH into water (always add flakes to water, never water to flakes) to avoid volcanic reactions.
• Trace Identification: Recognizing when the mixture has emulsified enough to stop separating, often looking like thick applesauce.
• Heat Maintenance: Keeping the soap batter between 160°F and 180°F to ensure the chemical reaction completes effectively.
• The Clarity Test: Taking a small nugget of cooked paste and dissolving it in hot water to check for cloudiness (unsaponified oils).
• Dilution: Mastering the ratio of paste to water to create liquid soap of different viscosities.
• Neutralization: Sometimes using a borax or citric acid solution to lower the pH slightly if the soap tests too “bitey” (alkaline).
• Scenting: Adding essential oils only after the cook is finished and cooled slightly to prevent burning off the fragrance.
• Storage: Packing the hot gel into jars immediately to prevent air pockets.

Potassium Hydroxide is much more volatile than standard lye; it heats up instantly and fiercely when it hits water, so your ventilation must be excellent.

Skill Level and Time Investment

Advantages and Challenges

Why I Love It:

• Fiber Kindness: It cleans and felts wool without stripping it harsh chemicals, leaving the fiber lively and glossy.
• Cost Effective: A single batch of paste can last a hobby felter an entire year since it is highly concentrated.
• Multi-Purpose: The undiluted paste is an incredible scour for raw fleece, and the diluted liquid is great for household cleaning.
• Eco-Friendly: It is 100% biodegradable and safe to use in greywater systems or garden runoff.
• Skin Benefits: Olive oil-based soap is humectant-rich, meaning it doesn’t dry out your hands even after hours of wet felting.
• Aesthetic Joy: There is a deep satisfaction in seeing jars of glowing, emerald-green gel on your studio shelf.

The Struggles:

• Chemical Risk: You are working with caustic chemicals and high heat, which is inherently dangerous.
• Physical Effort: Stirring the thickening paste requires significant arm strength as it reaches the “taffy” stage.
• Finicky Process: Sometimes a batch just won’t clear up, remaining cloudy no matter how long you cook it.
• Equipment Sacrifice: You really should not use your soap pot or blender for food ever again.

To keep your green soap strictly traditional and deep green, avoid mixing in lighter oils like coconut or palm; stick to at least 80% pomace olive oil.

Real Project Applications

In my studio, the primary use for this soap is wet felting. I recently worked on a large seamless vessel using Gotland wool. I dissolved about two tablespoons of my green soap paste into a gallon of hot water. The solution was slippery enough that my hands could glide over the delicate layout without displacing the fibers, yet it rinsed out instantly when the work was done.

Another fantastic application is scouring raw fleece. I once bought a greasy, skirted fleece that was full of barn dirt. Commercial scouring agents are expensive and often smell chemical. I used my green soap paste directly on the tips of the locks. The high pH reacted with the grease to create a natural surfactant, lifting the dirt away effortlessly.

I also use a diluted version of this soap to wash my finished knitwear. Unlike modern detergents that coat fibers in silicones, green soap cleans the fabric while allowing the wool to breathe and retain its natural bounce. It’s gentle enough that I’ve even used it to wash delicate silk scarves without any color bleeding.

The Learning Experience

The first time you make this, you will likely hit the “separation phase” and panic. The oil separates from the water, looking like a curdled soup. I remember frantically texting a soap-making friend, convinced I had ruined it. She told me to “stick blend it into submission.” She was right.

Learning to trust the chemical reaction is the hardest part. You have to watch the pot transform from milky liquid to applesauce, then to mashed potatoes, and finally to a glossy, dark gel. It requires patience that modern crafting often skips. But when you test that first bit of paste and it lathers beautifully, the feeling of accomplishment is massive.

“Making your own soap isn’t just about cleaning; it’s about controlling the very foundation of your fiber work.”

For resources, look for communities focused on “liquid soap making” specifically. Many general soap forums focus on bar soap and will give you the wrong advice for potassium lye. Books on historical housekeeping often contain fascinating variations of these recipes using wood ash, though buying pure KOH is much safer for beginners.

Comparison with Similar Crafts

Common Questions from Fellow Crafters

Q: Can I use regular drain cleaner lye for this?

A: Absolutely not. Most drain cleaners are Sodium Hydroxide or contain metal shavings. You must buy chemical-grade Potassium Hydroxide flakes from a soap supplier.

Q: Why is my soap cloudy?

A: Cloudiness usually means there are unsaponified oils left (you didn’t cook it long enough) or you used tap water with minerals in it. Always use distilled water.

Q: Is it safe for sensitive skin?

A: Yes, if cooked correctly. However, because it’s designed to clean wool, it can be quite stripping if you don’t “superfat” it (add extra oil). I recommend wearing gloves if using the concentrated paste.

Q: How long does the paste keep?

A: I have jars that are over two years old. The high pH makes it very hostile to bacteria. Just keep it in a sealed jar so it doesn’t dry out.

Q: Can I add scent?

A: You can, but olive oil soap has a distinct earthy smell. Strong scents like eucalyptus, lavender, or tea tree work best to cover the base note.

Q: Do I need a precise scale?

A: Yes! Soap making is chemistry. Being off by even a few grams of lye can result in a soap that burns your skin or a oily mess that never sets.

Never attempt to cook this on a gas stove with an open flame if you can avoid it; if the alcohol or oils splash, it is a fire hazard. A crockpot is much safer.

My Personal Results and Insights

Final Thoughts and My Recommendation

Making green soap is not for the casual crafter who wants a quick win. It is hot, sticky, and requires a healthy respect for chemistry. But if you are serious about fiber arts, wet felting, or raw fleece processing, it is a game-changer. The control you get over the quality of your materials is unparalleled.

I highly recommend this for intermediate to advanced makers who are looking to deepen their understanding of their materials. It bridges the gap between being a consumer of supplies and a master of your craft. Even if you only make it once a year, that jar of emerald gold on your shelf will serve as a reminder of your capability.

The best part? When you finish a project and wash your hands with your own soap, you realize you haven’t just made art; you’ve curated the entire experience from start to finish.