Making Soap Bars at Home from Scratch: CP Method

Making soap from scratch at home is fun. Not only you control what goes in your soap but also you can give it as many colors, shapes and flavors as you wish, thus creating ideal personalized soapy gifts.

Today I will write about cold process soap, as it is the number one soap that every wannabe soap maker should start with.

I am new to home made soap as well, and I did my research before I started. The main concern in making soap at home is using lye. If one wants to make soap from scratch, there’s no way around it: lye is needed. The alternative is buying melt and pour soaps and work with those (this being a great activity to do with the kids).

Using lye, requires special protective gear. As far as I can tell, handling lye is as dangerous as frying a chicken. It will burn your skin when in contact. So it’s best to be safe than sorry and be well equipped: just in case.

The soap maker’s protective gear: rubber gloves,safety goggles; long sleeve clothing. 

The soap making equipment:


  • digital scales;
  • stainless steel pot for the oils,
  • Pyrex measuring cup for the lye solution,
  • plastic bowls for weighing the ingredients separately;
  • two candy thermometers for taking lye solution’s and oil mix’s temperature
  • stick blender, rubber spatula, stainless steel spoon
  • soap molds or muffin trays, milk cartons, wooden boxes, etc lined with grease proof paper


CP Soap making method: 

  • Have a recipe or create your own. Whatever you do, run it through a lye calculator. I like this one as it gives me the option to choose grams or oz pr percentage. I prefer weighing my ingredients in grams.
  • Gather and weigh the soap ingredients: oils, essential oils, distilled water (teas, coffee, fruit juices), lye (Sodium Hydroxide for the solid soap),    
  • any other ingredients that you may want to add to your home made soap: flower petals, dry powdered leaves, oats, clay, colors, etc.
  • Place your distilled water in the fridge and other liquids (juice, tea, milk,  coffee) in the freezer.
  • On a double boiler, heat up your oils. Add the hard oils (coconut oil, Shea butter, etc.) first, let them melt and then add the soft oils. Allow the temperature to drop to 100° F to 125°F – in this time, make the lye solution.
  • Put on the safety gear. Take your distilled water, your ice cubes and the lye outside or in a well ventilated area. Add the distilled water to your Pyrex container. Add the ice cubes n there as well. Add the lye crystals gradually mixing until dissolved and the ice cubes melted. There may be fumes coming out so try not to breathe them in. The lye solution should cool to 100° F to 125° F fairly soon… depending on ow cold your water was and how hot the environment is.
  • When the oils and the lye solution are around the same temperature ( 100° F to 125°), gradually add the lye solution to the oils and mix with a rubber spatula while doing so.
  • When you finished pouring the lye solution to the oil mixture, start blending with the stick blender. Blend in short bursts or longer ones, all the time being careful not to splash. Blend until you reach trace.
  • Tracing looks like a slightly thickened custard, not instant pudding but a cooked custard. It will support a drop, or your stir marks for several seconds. Not it’s time to add your essential oils, colors, and other additions. Mix well.
  • Pour the soap to your soap molds, cover with grease proof paper, wrap in a towel and put the newly born soap out of the way for 24 hours.
  • After 24 hours, take the soap out of the mold. If you find is still kind of soft, put it in the fridge for an hour. This should make it harder and easier to slide out and cut.
  • Cut the soap in desired shapes and put it somewhere cool and well ventilated to cure for at least one month. The longer, the better.

Here’s a basic tried and tested Castile Soap Recipe.

Did you ever make CP soap from scratch? How lye shy are you? Do you use your rubber gloves? Do you have any any tips for soap makers?