How to Make Soap From Old Bars

Updated March 23, 2017

A bar of soap is often taken for granted. It is relatively inexpensive, so it is easy to forget the profound effects it has on daily life. Yet soap not only keeps a person clean, but it also keeps him healthy.

Still, bar soap inevitably shrinks with use. Eventually a bar of soap becomes too small to use effectively, or it begins to break into pieces. When this happens, drop it into an airtight container to save it. Once enough of these old bars are saved, they make nice new bars of soap in just a few steps.

Grate the old bars of soap with a kitchen grater. Alternatively, grind them in a blender with just a little bit of water added, about a tablespoon or two, depending on how much soap you are grating. You want it just to grate the soap and not be fluid.

Put the grated soap in a kettle and add just enough water to cover the soap. Allow the mixture to soak overnight. Stir it occasionally with a wooden spoon while it soaks.

Bring the mixture to a boil and remove it from the heat. Add one tablespoon of vegetable oil for each cup of soap mixture. Mix well.

Pour soap into moulds and cover with a cloth. Allow bars to cure for two to three weeks before using.


Soap moulds are available at craft stores. A creative mind might also find household items such as mint tins, candy moulds, or other things that can be used. Additional ingredients are easily added when making a new bar of soap from old bars. Add essential oils, dried flowers, herbs, or any ingredient you'd prefer after the soap is removed from the heat and has cooled slightly. Herbal tea is also a suitable substitute for plain water when creating the mixture. Write your recipe down when adding extra ingredients. This way you can do it again when you love what you've made. Wrap the newly cured bars of soap in coloured cling film and place in a bowl in the bathroom for a colourful as well as functional decoration. Liquid hand soap is also easy to make from old bars. Place slivers in a hand soap dispenser and cover with warm water. Add a marble or two and shake prior to dispensing.


To successfully make new bars of soap out of old ones, do not mix soaps of different bases. For example, glycerine soaps should only be made into bars with other glycerine soap.

Things You'll Need

  • Soap slivers
  • Vegetable oil
  • Water
  • Kettle
  • Wooden spoon
  • Molds
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About the Author

Jennifer Thompson started editing for her own online business in 2001, then began online editing and writing for others in 2005. Her articles have been published with "Sportsman's News" on Fox News and for a number of other successful ventures.