How to Make Homemade Soap

Whip up a batch of handcrafted soap with a few ingredients

Illustration depicting different soap making methods
Illustration: Catherine Song. © The Spruce, 2018 

Making soap at home is a practical and satisfying skill to learn. Whether you'd like a natural alternative to store-bought soap or you're a crafty person looking for a new creative venture, making soap is fun and not always as difficult as you might think. There are four methods of making soap, two of which are the most common.

Making Soap: A Basic Chemical Reaction

Soap is the result of a basic chemical reaction between fats or oils and lye. The process of achieving the chemical reaction is called saponification. By carefully choosing a combination of quality oils, adding your favorite fragrance or essential oils, and swirling in a lively colorant, your handmade soap suddenly takes on a charming, rustic character.

1:33

Watch Now: How to Make Your Own Soap

Basic Methods of Making Soap

There are four basic methods for making soap at home. Two of the most popular methods are the "melt and pour" and cold process. The hot process and rebatching are more advanced methods.

  1. Melt and pour: This easy process involves melting pre-made blocks of soap and adding your own fragrance.
  2. Cold process: The cold process is the most common method of making soap from scratch using oils and lye.
  3. Hot process: A variation of the cold process method, the hot process requires cooking the soap is actually cooked in a slow cooker or oven.
  4. Rebatching: This method grinds up and re-blends batches of poorly made homemade soap.

Each method has pros, cons, and variations. Review the two most popular methods to select your method.

Melt and Pour Soap Making Method

Making soap with a melt and pour base is safe, easy, and convenient. The base has already gone through the saponification process, so you won't need to handle lye. First, purchase pre-made blocks of uncolored, unscented soap “base” from a craft store or soap supplier. The soap base is then melted in a microwave or a double boiler. When the soap is fully melted you can add fragrance, color, and additives. Pour the mixture into a mold and the soap is ready to use when it hardens.

Pros of Melt and Pour Method
  • Easy and inexpensive

  • Few ingredients needed

  • No lye needed

  • Great for beginners

Cons of Melt and Pour Method
  • A quality base is best

  • Ingredients not always natural

  • Usually contains extra glycerin

  • Limited creativity

To get started with melt and pour soap making, you'll need a few tools after you purchase a soap base.

  • A microwave or double boiler
  • A heat-resistant bowl for the microwave
  • Measuring spoons and whisks
  • Fragrance, color, or additives, as desired
  • A mold

The most popular soap bases are white or clear glycerin. For a more luxurious soap, try a base made with goat's milk, olive oil, or Shea butter. You'll cut the soap base up into chunks to help it melt faster. If you use a microwave to melt the chunks, put the base in a microwave-safe bowl and stir at 30-second intervals until the chunks are liquid and smooth. Or melt in a double boiler over low heat, stirring until liquid and smooth. Then, allow the base to cool to 120 degrees Fahrenheit, then stir in colorants, fragrances, and additives of your choice. Finally, pour the mixture into your soap mold, wait a day until the soap is hardened and dry, remove from the mold, and your creation is ready to use.

There are a few tricks to know about when making melt and pour soap. The melted base will be thin, which means additives may sink to the bottom unless you wait until the base cools a bit before adding in. Melt and pour soap cools and hardens quickly so you'll have to learn to time it right when using additives. If the base is too hot, it can burn and become gloppy and tough to work into a mold.

Some additives work better than others in melt and pour soaps. Try sandalwood powder or dried calendula flower petals for best results. Many herbs tend to change color in the soap. Other additives include exfoliants, fruit seeds, and milk powders.

Cold Process Soap Making Method

The cold process method is a little more complicated and takes longer than melt and pour soap. It also involves using lye, which is a caustic substance. To make cold process soap, you'll heat your choice of oils in a soap pot until they reach approximately 100 degrees Fahrenheit. Then, you'll slowly add a lye-water mixture and blend the soap until it thickens to trace. After the mixture reaches trace, add fragrance, color, and additives, then pour it into a mold. The raw soap takes about 24 hours to harden and a few weeks to cure before it’s ready to use.

Pros of Cold Process Method
  • Made from scratch

  • Ingredients can be customized

  • Technique allows for greater creativity

Cons of Cold Process Method
  • More tools and clean up required

  • Need to safely work with lye

  • Technique requires 4 to 6 weeks for soap to cure

To get started making cold process soap, be prepared to need more equipment and clean-up time than you would with melt and pour soap. Work where there's a heat source and access to water. There are several tools you'll want to have on hand for this method of soap making, but begin with the basics:

  • Animal fats or vegetable oils
  • A pitcher of lye-water
  • A soap pot
  • Fragrance or essential oil, as desired
  • Natural or synthetic colorant, as desired
  • A mold to pour the raw soap into
  • Safety gear

You'll need to have a cool, dry place where the soap can cure. Since this method of soap making includes the saponification process, you're able to use fresh additives such as milk and fruit. Fresh additives can be included because the high pH environment of the saponification process preserves the ingredients and prevents the formation of bacteria or mold. The texture of cold process soap is also thicker, which means you can use heavier additives that won't sink to the bottom.

Take note that any vanilla ingredient might not be a reliable additive in cold process soap making because of the potential alcohol content, and it may turn your soap brown. Once you learn how to make cold process soap, take your talents to the next level and make homemade shampoo soap bars.

Safely Working With Lye

Lye is a caustic ingredient. When working with lye, wear protective gear including eye goggles, gloves, long sleeves, and pants to fully cover any exposed skin from spillage.