If you have ever been curious about the world of handmade soap, chances are you have heard of cold process soap. This type of soap making produces an artisanal-looking handmade soap that can be scented with natural essential oils and botanical elements. Grab a few friends and learn how to make soap!
Cold-process soap is part science and part art. You certainly will need to follow the step by step directions carefully, but if you do, you can produce the most lovely bars scented with essential oils and colored with botanical elements. These handmade soap bars are a project you can make at home that looks like it came from an artist’s gallery. Plus, cold-process soap has no additives that are bad for the earth and it is gentle on sensitive skin.
How to Make Soap for Sensitive Skin
Many bath and body “soaps” that are commonly sold are not actually soap. You will notice that they are called a beauty bar or body wash. These are detergents, not soap.
Real soap (such as the cold process soap in this tutorial) goes through the saponification process. This is a fancy term for converting fats, oils, lye, and water into soap and glycerin. After the chemical process has completed, the soap is completely safe and gentle on skin.
Even better, the glycerin coats skin and gives skin a silky soft feeling.
Handmade Soap Methods
There are many methods to making handmade soap such as melt and pour, cold process, hot process, milk soap, and rebatching.
There are pros and cons to each of these methods. I have made soap all of these ways, and each produces a very different type of soap.
How to Make Cold Process Soap
I like cold-process soap most as my everyday soap. I usually make soap in big batches every year so I have plenty to choose from throughout the year and plenty more to give away.
Cold-process soap makes a wonderful gift for yourself and others, but it does require following the instructions to the letter. If you are a first-time soap maker, partner with a friend and make handmade soap together – it helps to have a buddy system and it’s a lot of fun! If you are are an experienced soaper, there are three recipes down at the end for the soap shown in this post:
- Lemongrass Ginger Coffee Kitchen Soap
- Rosemary Spearmint Energizing Shower Soap
- Orange Vanilla Cinnamon Soap
All are made with natural vegetable ingredients, pure essential oils, natural colors, and herbs from the garden. You can feel good about taking care of those who use your handmade soap.
Ingredients
All cold process soap will have fats and lye ingredients. Start with a basic soap-making recipe such as this moisturizing olive oil soap.
Mix temp 115°F
Oils
- 7 oz coconut oil
- 17 oz olive oil
- 2 oz grapeseed oil
Lye mixture
- 78 grams sodium hydroxide (NaOH)
- 215 grams filtered water
Step by Step Soap Making Instructions
If you are not using a kit, the first and most crucial step in cold-process soap making is to weigh the raw ingredients (fats, lye, water) precisely. Prep everything that you will need and lay it out accessibly before you begin.
Soapmaking measurements are done in weight, not volume, so be sure to get a good kitchen scale and weigh out the ingredients.
Safety reminder: It’s best to wear protection when making soap as lye can burn your skin. Until the oils and lye have turned into soap (48 hours after making the recipe) it’s best to protect yourself. Always wear rubber gloves, safety goggles, and keep your work area free from kids and pets.
Heat the Oils
Gently (slowly) heat oils in a stainless steel pot on the stove. Alternatively, use a microwave and heat for two minutes on high, and then at shorter intervals until you reach the temperature listed in the recipe.
Prepare Lye Ingredients
Using room-temperature distilled water, weigh the amount specified by the formula into a heat-resistant glass bowl or large Pyrex measuring cup. While stirring, slowly add the measured amount of lye. I repeat, SLOWLY.
It’s important to note that you add the lye to the water, not the water to the lye.
Stir until dissolved. This mixture will get super hot quickly so be mindful of that. Also, the fumes are terrible, so if you can stir from below the fumes (with lye on the counter and you crouching below as you stir) outdoors or at least with windows open, that would be best.
Place glass container in an ice-water bath and cool to the required temperature. For this basic recipe, it’s 115 degrees. Get accurate temperature readings with a candy thermometer in the middle of the solution.
When both oils and lye/water are at the required temperatures (as stated in your recipe), slowly pour lye/water into the oils while rapidly stirring in small circles. Always add lye/water to oil, not the other way around.
Thicken the Mixture
Continue to rapidly stir the mixture until it thickens to the consistency of pudding (called “tracing”). The mixture is ready to be molded when a drizzle mark from the spatula remains for a few seconds on the top of the mixture. Speed up the tracing process by using a hand blender to mix. Be careful not to over mix.
Add Essential Oils and Colorants
Add essential oils, natural colorants, and herbs or exfoliants at this stage (see recipes below). Work fast as the mixture will quickly start to thicken.
There are many options for coloring and scenting soap but I avoid perfumes, fragrance, and artificial colors. I like handmade natural soap scented with pure essential oils and colored with natural dyes.
As you can see by these three recipes, it looks beautiful and it smells even better!
Pour into Mold
Pour mixture into 1L milk cartons and staple the tops shut. Wrap the cartons in a large towel and set somewhere warm for 48 hours like the top of the fridge. The cartons will feel warm and will get hot as the mixture neutralizes and turns into soap.
Unmold and Cut
To unmold your soap, peel off the milk cartons and cut each full 1-liter carton lengthwise into 3 equal sections for shower soap, and 4 equal sections for hand soap. Flip each section so that it appears to be a square from the top, and cut into 3 equal sections.
Cure
Place each bar on a wire rack in a cool, dark place to cure for three weeks. After three weeks, soap can be buffed with a cotton cloth and wrapped for gifts.
Cold Process Soap Add-ins to Try
Once you get the basic recipe down, you will find that it’s incredibly versatile! Here are just a few ways you can “dress up” cold process soap.
Lemongrass, Ginger, and Coffee Kitchen Soap
- Add 1 tablespoon dry, finely ground coffee at trace
- Scent with 15ml lemongrass and 5ml ginger essential oils
- Color with turmeric
To get the two-toned look in this soap, I filled half of the milk carton with one color and topped it with another. This makes each of the bars unique. The purple in the above soap was lavender-scented soap colored with ratan jot and mixed with dried lavender buds.
Rosemary and Spearmint Energizing Shower Soap
- Scent with 10ml rosemary and 10ml spearmint essential oils
- Color with sage powder
- Gently stir in spirulina powder to make a darker green swirl
- Add in 1/4 tsp of finely chopped dried mint tea leaves
To get the two-toned look in this soap, I filled half of the milk carton with one color and topped it with another. This makes each of the bars unique.
Orange Vanilla Cinnamon Soap
- Add 1 tablespoon dry, finely ground coffee at trace
- Scent with 7ml orange, 7ml cinnamon, and 7ml vanilla essential oils
- Color with cinnamon
- Gently stir in cocoa powder to make a chocolate color swirl
- Top with dried saffron
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