Herbal Pharmacy | Making Natural Medicinal Soap

Have you ever been interested in creating your own natural body care products from scratch?

The Advanced Herbal Pharmacy course offered at Pacific Rim College provides students with hands-on learning in the preparation of herbal-based products such as shampoo, conditioner, toothpaste, deodorant, soap, and many more. Designed and instructed by Pacific Rim College graduate and medical herbalist, Krista Poulton, topics of study include plant constituent extraction, product preservation, and market regulations to prepare students to formulate, brand, and sell their own products.

I enrolled in this class following the wonderful experience I had in its prerequisite, Practical Herbal Pharmacy, which this advanced class builds upon. So far, natural soap making has been a highlight!

What is natural medicinal soap?

Natural soap or soap from scratch is made from a combination of oils, herbs, and lye (sodium hydroxide). Providing an alternative to conventional body cleansing products, natural soap can be made with as little as five ingredients. Many soaps found at drug stores can contain over 15 ingredients which include various synthetic fragrances and preservatives that are potentially irritating to the skin and harmful for the environment.

The herbs used in natural soap making are selected for their colour, smell, and medicinal offerings. Most commonly, herbs that are skin healing, anti-inflammatory, anti-bacterial, or aromatic are chosen. Some examples include calendula (Calendula officinalis), chamomile (Matricaria recutita), and lavender (Lavandula officinalis). These herbs can be included in a soap recipe infused into oil, powdered, or as essential oils.  

There are a few different methods for making soap. The hot-process involves cooking the soap, making it ready to use the next day. The cold-process shown below only uses heat to incorporate the oils and the soap must then be cured 4-6 weeks before using. All it takes is some basic kitchen equipment, sourcing good raw materials, and a basic understanding of soap chemistry to make your own natural medicinal soap.

How does soap work?

Soap is created through the process of saponification in which lye (sodium hydroxide) reacts with fatty acids in oil to create negatively-charged, polar molecules. These molecules make soap an emulsifying agent that can trap grease, oil, and dirt to be rinsed away in water. The addition of herbal powders and essential oils help to nourish and protect the skin.

Lye is a highly alkaline solution that is necessary for transforming oils into soap. It can be very dangerous in its raw form and needs to be carefully handled with gloves and goggles. Once the process of saponification is complete and the soap is cured for 4-6 weeks, no lye remains and the soap is absolutely safe to use.

 Making Medicinal Soap


  • Olive oil
  • Coconut oil
  • Water
  • Lye (sodium hydroxide)
  • Powdered herbs
  • Essential oils


The soap making process began by gearing up with goggles and masks to prepare the lye by mixing it with water and letting it cool.

Krista Poulton, instructor of Advanced Herbal Pharmacy and master soap maker.

We worked in groups of three to make a brick of soap with herbs and essential oils of our choosing. We were able to select any of the dried herbs from the herbal dispensary onsite at the college.

Herbs available at the Pacific Rim College Dispensary.

We then prepared the soap molds (baking pans) with parchment paper to prevent the soap from sticking.

The coconut oil was melted and mixed with the olive oil. 

The chosen herbs were powdered to be added to the soap. My group chose to make a rose and hibiscus soap with cedarwood essential oil.

     The cooled lye was then added to the oil mixture and blended until it reached a medium-thick pudding texture.

The powdered herbs and essential oils were added to this mixture and then poured into the prepared mold.

The soap was then sprinkled with dried flowers and covered with plastic wrap to be kept in a warm, undisturbed place.

The next week we returned to uncover the soap and cut it into bars. The bars are now curing for 4-6 weeks and can only be used once the water has evaporated and the lye has completely neutralized.

Calendula, rose, sweet orange, and lemongrass soap.
Layered lavender, chamomile, and rose soap.

Making soap from scratch is easy, fun, and very rewarding. If you are looking for detailed step-by-step instructions, information about ingredient sourcing, and an interactive learning environment, Advanced Herbal Pharmacy may be the class for you!

Here are some additional resources:


“Medicinal Soap.” Powerpoint. Pacific Rim College, Victoria, British Columbia.

Helmenstine, A. M. (n.d.). What Is Soap Made of and How Does It Clean? Retrieved March 26, 2018, from https://www.thoughtco.com/how-dos-soap-clean-606146


Photography and text by Liza Couse, a student in the Diploma of Phytotherapy program at Pacific Rim College.