Basic Cold Process Soap Recipe

This classic cold process soap recipe is perfect for beginners looking to start their soap-making journey. Combining olive oil, coconut oil, and palm oil creates a well-balanced bar with good lather, cleansing power, and moisturizing properties. This no-frills recipe produces reliable results every time and requires only basic fragrance or essential oil additions.

Ingredients

Oils & Butters

• 20.0 oz (567g) olive oil
• 13.0 oz (369g) coconut oil
• 12.0 oz (340g) palm oil
• 9.0 oz (255g) sustainable palm kernel oil

Lye Solution

• 4.7 oz (133g) sodium hydroxide (NaOH)
• 11 oz (312g) distilled water (mixed separately from oils, weighed before adding to oils)

Additives (Optional)

• 0.6 oz (17g) essential oil or fragrance oil (added at light trace)
• Mica or oxide colorants for color (0.5-1 tsp per batch)

Equipment Needed

• Digital scale (accurate to 0.1 oz)
• Two stainless steel pots
• Stainless steel or silicone spoon for stirring
• Stick blender
• Thermometer (for temperature monitoring)
• Soap mold (silicone loaf mold or wooden mold with parchment)
• Safety goggles and chemical-resistant gloves
• Paper towels
• Vinegar (for cleaning up lye spills)

Instructions

Step 1: Safety Preparation

Put on your safety goggles and gloves before handling lye. Set up your work area with vinegar nearby for emergency cleanup. Ensure good ventilation, as lye fumes can be irritating. Keep children and pets away from your work area.

Step 2: Mix the Lye Solution

Carefully pour 11 oz of distilled water into a stainless steel pot. Slowly add the sodium hydroxide (lye) to the water, stirring constantly. Never add water to lye, as this causes a dangerous reaction. The mixture will become hot (up to 180°F). Set aside to cool to 100-110°F.

Step 3: Prepare the Oils

Combine all oils in a separate pot:

• 20.0 oz (567g) olive oil
• 13.0 oz (369g) coconut oil
• 12.0 oz (340g) palm oil
• 9.0 oz (255g) palm kernel oil

Gently heat the oils to 100-110°F, stirring occasionally. The goal is to reach a similar temperature as your lye solution for better soap making results.

Step 4: Combine Oil and Lye Solution

Once both the lye solution and oils reach 100-110°F, slowly pour the lye solution into the oils while stirring gently. Pour steadily and keep stirring. Safety first: never pour oils into lye.

Step 5: Begin Stick Blending

Using your stick blender, blend the mixture on and off (pulse) for 30 seconds, then stir by hand for about one minute. Repeat this pattern for 8-12 minutes until the mixture reaches "light trace" (resembles thin pudding with a slight trail when the blender is lifted out).

Step 6: Add Color and Scent

If using colorants and fragrance, add them at light trace. Mix fragrance oil or essential oil thoroughly into the batter. Add colorants dispersed in a small amount of oil first to prevent streaking.

Step 7: Pour into Mold

Carefully pour the soap batter into your prepared mold. Smooth the top with a spatula. Some soapmakers insulate their molds with blankets to encourage gel phase, which can improve color and clarity.

Step 8: Initial Cure (24-48 hours)

Leave the soap undisturbed in the mold for 24-48 hours. The soap will heat up on its own (exothermic reaction), which is normal. After 24 hours, check if the soap is firm enough to unmold.

Step 9: Unmold and Cut

Once firm, turn the mold over and remove the soap block. Using a soap cutter or sharp knife, cut the loaf into 24 equal bars. If the soap is too soft to cut cleanly, wait a few more hours.

Step 10: Air Cure

Place bars on a well-ventilated surface, ideally on a rack that allows air circulation on all sides. Cure for 4-6 weeks in a cool, dry location. This allows excess moisture to evaporate and the soap to harden fully.

Tips for Success

• Invest in a digital scale accurate to 0.1 oz—volume measurements lead to inconsistent results
• Keep your lye and oils within 10°F of each other for optimal saponification
• At light trace, the soap should flow into the mold but hold its shape briefly
• Avoid overblending, which can lead to soap that's difficult to pour or that separates
• During curing, rotate bars occasionally to promote even drying and prevent flat spots
• Maintain curing room temperature between 60-75°F for best results

Variations

• Scented versions: Add lavender, eucalyptus, lemon, or rose fragrance oils
• Colorful bars: Swirl in mica colors or make striped bars with different oil blends
• Herbal addition: Add dried herbs like calendula petals or chamomile at trace (0.2-0.5 oz)

Cost Breakdown

Estimated Cost per Bar: $0.47

Related Recipes

• Lots of Lather Soap - Add castor oil for extra bubbles
• Bastille Soap - Increase olive oil to 80% for richness
• Lavender Oatmeal Soap - Add essential oils and exfoliating oats

Notes for Beginners: This recipe uses the standard 3% superfat, which leaves a small amount of oil unreacted for skin conditioning. If this is your first batch, don't be discouraged if your soap isn't perfect—each batch teaches you something new. Soap making is both science and art, and consistency comes with practice.