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My First Hot Process Soap (Castile Crockpot Soap)

The scent of lavender still transports me back to that sweltering summer day. My grandmother, a woman who could coax life from even the most barren soil, decided we were making soap. Not just any soap, mind you, but a fragrant, skin-loving Castile soap crafted right in her trusty old crockpot. I remember the bubbling, almost magical transformation of oils and lye, the air thick with anticipation and a faint, alkaline tang. It wasn’t just a recipe; it was a lesson in resourcefulness, patience, and the simple pleasure of creating something from scratch.

Recipe Overview

Prep Time: 30 minutes
Cook Time: 1 hour
Total Time: Overnight cooling + 2-4 weeks curing
Yields: Approximately 6-8 bars (depending on mold size)
Dietary Type: Vegan (if lard is substituted)

Ingredients

16 ounces water (goat’s milk should be partially frozen) or 16 ounces goat’s milk (goat’s milk should be partially frozen)
2 ounces castor oil
13 ounces coconut oil
26 ounces olive oil
12 ounces lard (can substitute with shea butter or another hard oil for vegan option)
1 1/2 ounces beeswax (can be substituted with candelilla wax for a vegan option)
7 5/8 ounces lye (sodium hydroxide)
1 ounce essential oil (optional, for fragrance)

Equipment Needed

Kitchen scale
Pot
Crockpot
4-cup measuring cup
Smaller measuring cup
Protective clothing (gloves, eye protection)
Stick blender
Plastic drawer trays or molds
Freezer paper or parchment paper
Large knife
Cutting board

Instructions

Weighing the Solid Oils: Using your kitchen scale, carefully measure the coconut oil, lard (or substitute), and beeswax (or substitute). Tare the scale with your measuring container to ensure accurate measurements.
Melting the Solid Oils: Place the solid oils in a pot and gently melt them over low heat. Avoid overheating; remove the pot from the heat when there are still small pieces of unmelted oil. The residual heat will melt the rest.
Heating the Liquid Oils: Measure the liquid oils – castor oil and olive oil – and pour them into your crockpot. Turn the crockpot on to low to gently warm the oils. Again, avoid overheating.
Combining the Oils: Once the solid oils are nearly melted, add them to the liquid oils in the crockpot. Cover the crockpot to retain heat.
Preparing the Lye Solution: In a well-ventilated area, measure the water (or partially frozen goat’s milk) into a 4-cup measuring cup. In a separate, smaller measuring cup, carefully weigh the lye. Always wear protective clothing, including gloves and eye protection, when working with lye.
Mixing the Lye and Water: Slowly and carefully pour the lye into the water while stirring constantly. The mixture will become very hot. Stir until all the lye crystals are completely dissolved.
Cooling the Lye Solution: Place the lye solution under a vent with the fan on to cool for approximately 5 to 10 minutes. Do not touch the glass container as it will be very hot.
Combining Lye Solution and Oils: Slowly and carefully pour the lye solution into the oils in the crockpot while stirring continuously.
Neutralizing Lye Residue: Prepare a soapy/vinegar/water mixture in your sink. Use this solution to rinse all containers and utensils that have come into contact with lye, neutralizing any caustic residue.
Achieving Trace: Stir the mixture briefly, then switch to a stick blender. Blend in short bursts (15-30 seconds at a time) to prevent overheating the blender. Rest between bursts. The mixture will transition from clear to opaque, thickening to resemble vanilla pudding. “Trace” is achieved when a drizzle of the mixture from the stick blender leaves visible ridges on the surface instead of immediately disappearing. This may take 2-3 minutes for this recipe, but longer (5 minutes or more) for pure olive oil soap.
Cooking the Soap: Cover the crockpot and let the soap “cook” on low heat for about an hour.
Monitoring the Cooking Process: During cooking, the mixture will become translucent again. It will rise up at the sides, forming wave-like patterns. By the end of the hour, the entire mixture should be translucent, with the “waves” collapsing into the center.
Glycerin Formation: You may notice a pool of liquid in the center, which is glycerin. Glycerin is a natural byproduct of saponification and is beneficial for the skin. Stir it back into the mixture.
Preparing the Molds: Turn off the crockpot. While the soap is cooking, prepare your molds. Line plastic drawer trays or other suitable molds with freezer paper (shiny side up) or parchment paper greased with coconut oil.
Pouring into Molds: Carefully pour the hot soap mixture into the prepared mold(s). Tap the mold(s) on the counter or floor to evenly distribute the soap and release any trapped air. Use your gloved hands to gently smooth the surface, being careful as the mixture is very hot.
Cooling and Hardening: Allow the soap in the mold(s) to cool and harden for at least overnight. The crockpot can be scraped clean for immediate use of the soap residue.
Unmolding and Cutting: Once the soap has hardened, lift the paper to remove it from the mold(s). Peel the paper off the soap block. Place the block on a cutting board and use a large knife to cut it into bars.
Curing: The soap bars need to cure for 2-4 weeks. Place the bars in a cool location with good airflow, standing them upright if possible. Rotate them occasionally to ensure even hardening.

Expert Tips & Tricks

Temperature Control: Maintaining low and consistent heat throughout the process is crucial to prevent scorching and ensure proper saponification. Use a reliable crockpot with a low heat setting.
Lye Safety: Always add lye to water, never the other way around, to prevent dangerous splattering. Work in a well-ventilated area and wear appropriate safety gear.
Trace Consistency: Achieving the right “trace” is key to a successful batch. Too thin, and the soap may separate. Too thick, and it will be difficult to pour.
Curing Matters: Don’t skip the curing process! It allows excess water to evaporate, resulting in a harder, longer-lasting bar of soap.
Superfatting: Adding a small percentage of extra oil (superfatting) after the cooking process can increase the moisturizing properties of the soap.

Serving & Storage Suggestions

The wonderful thing about handmade soap is that you can enjoy it immediately after it has cooled and hardened, although it is best after it has cured for a few weeks. Store your cured soap bars in a cool, dry place away from direct sunlight and humidity. Properly stored soap can last for years. Once you begin using a bar, store it on a well-draining soap dish to prolong its life.

Nutritional Information

Please note: Soap is not meant for consumption; therefore, nutritional information is not applicable.

Variations & Substitutions

Vegan Castile Soap: Substitute the lard with shea butter or another hard vegetable oil and substitute beeswax with candelilla wax.
Scent Variations: Experiment with different essential oils to create unique scent blends. Consider lavender, peppermint, tea tree, or citrus oils.
Herbal Infusions: Infuse your oils with dried herbs like calendula or chamomile for added skin benefits.
Colorants: Add natural colorants like turmeric, spirulina, or clay to create visually appealing soaps.

FAQs (Frequently Asked Questions)

Q: Why is it important to use safety gear when making soap?
A: Lye is a caustic substance that can cause burns if it comes into contact with skin or eyes. Protective gear such as gloves and eye protection is essential to prevent injury.

Q: Can I use a different type of oil in this recipe?
A: Yes, you can adjust the oil blend to suit your preferences, but be sure to use a lye calculator to determine the correct amount of lye needed for the new oil combination.

Q: How long does soap need to cure?
A: Soap should cure for at least 2-4 weeks to allow excess water to evaporate, resulting in a harder, longer-lasting bar.

Q: What is “trace” and why is it important?
A: “Trace” refers to the point when the soap mixture has thickened enough to emulsify and will not separate. It’s crucial for creating a stable, consistent soap.

Q: My soap is crumbly. What did I do wrong?
A: Crumbly soap can result from using too much lye, overheating the mixture, or not reaching trace. Ensure accurate measurements, careful temperature control, and proper blending.

Final Thoughts

Embarking on the journey of making your own soap is an incredibly rewarding experience. It’s a chance to connect with time-honored traditions, control the ingredients that touch your skin, and create something truly unique. Don’t be afraid to experiment with different oils, scents, and colorants to tailor your soap to your personal preferences. Gather your supplies, embrace the process, and enjoy the satisfaction of crafting your very own batch of luxurious, handcrafted Castile soap. And remember, share your creations and experiences – the soapmaking community is a wonderfully supportive and inspiring place to learn and grow.

My First Hot Process Soap (Castile Crockpot Soap) Recipe