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Soap is useful for helping remove sweat and dirt from your skin, so many people include it as a regular part of their personal hygiene routine.
You have plenty of options for buying soap in stores, but it’s also possible to make soap at home. Making a mild soap can be both fun and cost effective. Plus, you can choose the ingredients and scents based on your preferences.
Interested in giving it a try? Read on for tips to make homemade soap and a recipe to get you started.
Soap, by definition, is fat or oil mixed with an alkali. The oil comes from an animal or plant, while the alkali is a chemical called lye. In bar soap-making, the lye is sodium hydroxide. Liquid soap requires potassium hydroxide.
Combining and then heating oil and lye results in soap. This chemical reaction is called saponification. Without lye, saponification isn’t possible, so lye is necessary to create soap.
A note on lye
Some people are concerned about lye. On its own, this highly corrosive substance can irritate the skin, eyes, and respiratory system. However, when done properly, saponification turns lye into soap. No lye will remain in the final product.
The following are basic soap-making supplies, many of which you can find online:
- slow cooker
- plastic, glass, or stainless steel container (for measuring lye)
- heavy duty plastic, glass, or stainless steel container (for mixing lye and water)
- digital kitchen scale
- silicone spatulas (that are used only for soap-making)
- immersion blender (with stainless steel shaft)
- candy thermometer (that is used only for soap-making)
- silicone loaf mold (or individual molds)
- soap cutter
Avoid using aluminum or tin containers to handle lye, since this can be unsafe.
Soap-making safety equipment
You’ll also need safety equipment, such as:
- safety goggles
- rubber or latex gloves
- oven mitt
- long-sleeved shirt
- well-ventilated work area
To make this DIY soap with coconut and olive oils, you’ll need:
- 20 oz. coconut oil
- 10 oz. olive oil
- 9 oz. distilled water
- 4.78 oz. 100 percent pure lye
- 20 to 40 drops of essential oils, if desired
- colorants (optional)
- dried herbs or flowers (optional)
Calculating fat to lye ratios
While you can adjust the ingredients to make smaller or larger batches, it’s important to calculate a safe amount of lye. The safe amount for your recipe depends on the type and amount of oil you use.
Always calculate the amount of lye using the Handcrafted Soap and Cosmetic Guild’s lye calculator.
There are two methods for making bar soap from scratch:
- Hot process. In hot process soap-making, external heat accelerates saponification. Most soaps can be used the next day, though it’s ideal to wait 1 week if you want a harder bar.
- Cold process. Cold process uses the internal heat that’s naturally produced during saponification. The bars will completely harden in 4 to 6 weeks.
Below, you’ll find instructions for hot process soap. This method is beginner-friendly and has a fast turnaround. It makes 30 ounces, or 7 to 10 bars, of custom bar soap.
Later in the article, we’ll explore some other options and offer tips for choosing your own bar soap ingredients.
- Measure your ingredients and put on your safety gear.
- Set the slow cooker to low.
- Add the coconut oil to the slow cooker. As it melts, prepare the lye solution. Slowly add the lye to the water. (Do not add water to lye — this is unsafe.)
- With a spatula, carefully stir the solution as you add the lye. It’ll become hot and release fumes, which is OK.
- Set aside the lye solution. Let cool for 15 to 20 minutes.
- Check the oils. If the coconut oil has completely melted, add the olive oil. Stir well.
- Check the temperature of the oils using the candy thermometer. Once the oils have reached 120 to 130°F (49 to 54°C), place the immersion blender on the side of the slow cooker.
- Gently pour in the lye to avoid splashing. Stir slowly.
- Set the blender to low. Stir the mixture, moving in circles. Keep the blender immersed to avoid air bubbles.
- Continue blending and stirring for 10 to 15 minutes, or until the soap has reached trace. This is when the oils and lye solution have thickened and look like pudding.
- Cover the slow cooker. Cook on low for 50 minutes. If the mixture bubbles, stir it gently.
- Turn off the slow cooker. Let cool until the mixture drops below 180°F (82°C). Add essential oils and colorants, if using. Mix well.
- Pour the mixture into the soap mold. Smooth the top with a spatula. Tap the mold onto your work surface to eliminate air bubbles. Top with dried herbs, if using.
Reminder: Never mix water into lye, since this can cause a dangerous chemical reaction.
A standard bar of soap is 3.5 to 4 ounces. The above recipe creates approximately 30 ounces. Depending on how you cut the soap, you’ll get 7 to 10 bars.
Soap finishing steps
Generally, here’s what the final steps involve:
- After pouring the soap into the mold, let it sit for 24 hours.
- Once cool, carefully remove the soap from the mold.
- Cut into bars with a soap cutter or knife. If you used single soap molds, simply pop them out.
- You can use your soap at this point, but you may want to let it dry for another week. This will improve its hardness and quality.
Hot process soap has a rustic look and homemade appearance. But if you prefer more refined bars, consider trying the cold process method.
Keep in mind, too, that DIY soap tends to have a lighter scent than traditional, store-bought soap. You can use more essential oil for a stronger smell, but this can be costly, especially if you use more expensive oils. . Plenty of people also prefer the fainter scent of homemade soap.
For an enjoyable and safe soap-making experience, follow the tips below.
Tips for soap-making
- Always work in a ventilated area when preparing the lye.
- When adding lye to water, avoid touching the container with bare hands or breathing in the fumes.
- Never add the lye solution if the base oils are above 180°F (82°C).
- You can use individual soap molds, which don’t require cutting.
When using essential oils:
- The number of drops will usually depend on the oil’s quality and your personal preference. You might start with 20 drops if you prefer a lighter scent, and go up to 30 drops if you prefer a stronger scent. This may take some experimentation.
- Fragrance oils are usually more concentrated, so you may want to start with fewer drops.
- It often helps to stick with one scent and one colorant until you understand how they affect the finished soap.
The basic ingredients of soap are:
- animal fat or vegetable oil
- 100 percent pure lye
- distilled water
- essential or skin-safe fragrance oils (optional)
- colorants (optional)
Fats or oils
The best fat or oil depends on your preferences. Traditionally, soap was made with animal fat, but today, plant oils are widely used.
Depending on your oil, the finished soap’s hardness and lather will vary. Examples of fats and oils used in soap-making include:
- olive oil
- coconut oil
- avocado oil
- almond oil
- jojoba oil
- hemp oil
- cocoa butter
- mango butter
- shea butter
Use oils from animal or vegetable sources only. Soap can’t be made with petroleum-based oils.
Water is an essential ingredient. It’s used to make a lye solution, which is combined with oil. The water helps the oil and lye complete the saponification process. By the time the soap hardens, most of the water will have evaporated.
It’s recommended to use distilled water. Some soap-makers use other liquids, such as:
- goat’s milk
- coconut milk
These options can be tricky to work with if you’re a beginner, so you may want to stick with water for your first try.
Soap doesn’t need a scent to get your skin clean. But if you’d like to add a pleasant smell, you can use essential oils or fragrance oils.
Essential oils are mostly plant-based, and you can combine them to create custom aromas. Fragrance oils are synthetic. When selecting fragrance oils, look for skin-safe options.
Following a recipe is helpful when you’re a beginner, but what if you feel ready to start experimenting with your own scent and ingredient mixes?
Before you start making your own concoctions, it’s important to get acquainted with the basics of soap-making.
Creative experimentation can absolutely add more fun to the process. But getting some basic experience first can help you understand how to safely handle the ingredients and prevent creative detours from becoming safety hazards.
Tips to keep in mind:
- Using recipes will help you understand the proper proportions of lye versus oils required to avoid making skin-irritating soap. For example, crumbly soap is an indication that it contains too much lye.
- Different oils can lead to a different finished product. By trying out varied recipes that use different oils, you can get a feel for the type of soap each oil produces. Then, when you’re comfortable, you can start experimenting.
- Deciding on the soap’s purpose beforehand helps you determine a target superfat percentage or oil to lye ratio. Superfatting refers to the amount of oil remaining in your finished soap. So, a bar designed to cleanse and moisturize, for example, would have a superfat percentage of about 15 percent.
- Playing with the fragrances, oil types, and water alternatives in existing soap recipes can help you come up with a recipe of your own.
Remember: Using a lye calculator can help you (safely) align your ingredient proportions with your desired result.
Soap-making offers a creative way to enjoy natural, gentle soap. It takes time to master the process, so don’t be discouraged if your soap isn’t perfect. The more you experiment, the better your soap will be.
Always follow safety measures and work slowly. For one-on-one guidance, consider taking a soapmaking class.
If you don’t want to work with lye, use a melt-and-pour soap base, which you can find online. This base has already been saponified, so you can experiment with soap-making until you’re ready to make it from scratch.
Recipe adapted from The Prairie Homestead