Begin by adding the pure olive oil or avocado oil into a slow cooker or Instant Pot set to medium heat.

Measure out the potassium hydroxide, distilled water, glycerin, and fragrance oil, ensuring to zero out the weight of your containers.

In a separate container, mix the distilled water and glycerin together.

Wearing gloves and eye protection, slowly add the potassium hydroxide to the water (never the other way around) and allow the solution to cool to below 175°F.

Heat the oil in the slow cooker until it reaches a temperature between 160°F and 175°F.

Gradually pour the cooled potassium hydroxide solution into the heated oil while mixing vigorously with a hand mixer or immersion blender.

Continue mixing for about 7 minutes until the mixture achieves a gel-like consistency.

Cook the mixture for approximately 4 hours, stirring every half hour to prevent scorching.

To test the soap, dilute a small amount with warm distilled water in a jar, shake well, and check for clarity; if it is clear, the soap is ready.

If desired, add the fragrance oil at this point and mix thoroughly.

Store the finished gel soap in glass containers, allowing it to sit overnight with a lid on to fully dissolve.

For hand soap use, dilute the concentrated soap by filling a hand-soap container about a quarter full and topping it off with water.

Optionally, test the final product’s pH with a strip; it should read around 9.