Flower Infused Homemade Castile Soap

by Renee Lindstrom, GCFP:  This post may contain Affiliate Links, thank you in advance for your support!  Renee

Flower Infused Castile Soap setting

Holding my breath this morning as I went to check on yesterday’s batch of home-made castile soap.  Why you might ask? It was due to the anxiety I had about a new strategy I used in the process of mixing these ingredients to make soap.

Making soap is always an adventure when using different hand-made infused water and oils.  Most recipes and calculators base soap making on a simpler recipe of; exact amounts lye, essential oils, clear water and oils,  while I infuse my oil and water with plant materials.  The oil is infused for up to six weeks before hand before it is filtered and the water is done the day before.  I use flowers, leaves, stems and roots gathered within a block radius of where I live that contain healthy ingredients for skin care.  I do not add scented perfumed or essential oils.  That means if the soap doesn’t set, time and effort has been lost. So viewing these boxes now,  I feel happy at this writing.  This batch is setting nicely!

The 37 oz. of olive oil in this recipe was infused with:

  • 27.3 %  Horsetail (read more about Horsetail)
  • 24.1 %  Lilac Flowers
  • 11.7 %  Calendula flowers
  •  4.5 %   Mock Orange Flowers
  •  3.8%    Peony Flowers
  • 28.4%  Lavender Flowers

Each infused oil’s hue was different after being infused for six weeks.

The water was infused with:

The Mullein stalks created a dark, almost black water which is the water I added lye to that is poured slowly into the oil.


The quantities in this  recipe was determined by the quantity of infused oil I had on hand.

The ingredients:

37 oz.                  Olive Oil

7 oz.                    Coconut Oil  – as a hardener

6 oz.                    Lye (Caustic Soda)  Not as readily available.  I sourced mine from a local old-fashioned #yyj hardware store who markets it as a drain cleaner (make sure there is no additives) and at a Mercantile Store called Bordens who sells it as Caustic Soda.  

12 oz.                   Water

2  tbsp                 Dried plant material


The supplies needed:

  • Large Metal Pot
  • Large Glass Jar
  • Metal Spoon with long handle
  • Mixer and/or Whisk
  • Cooking thermometers (I use two, one for the lye and one for the oil)
  • Molds (I used square cake molds with removable bottoms and square boxes all lined with parchment paper my first few times)

Safety Gear to consider:

Making soap was a necessity in my Grandmothers era and not an item that could be bought at the corner store.   She would have bought lye at the General Store or even had to make her own!  I can remember my mother mentioning she observed soap being made with lye, however it was never made throughout my childhood. Picking up the art now in this era focus and emphasis is on a need for safety when combining lye with water and then adding it to the oil.  This can create enough fear to stop someone from actively making their own soap.  Let’s demystify soap-making and suggest that one only needs to be careful and follow the directions.  There is no need to be afraid.  Let your creatively out and enjoy the process.  You will need the above safety gear especially if you are making big recipes.  I wear glasses already and use a recycled old-fashioned glass pickle jar which contains the off gases so I am not breathing them in.  I do wear gloves.

Process – putting it together

The process of making soap is simple.  I found it time-consuming only when measuring amounts of oil to add up to the amount in the recipe!

There are three easy parts in the process of mixing the ingredients for making bars of soap:

Part one

 Step 1:

  • measure the lye into its own container

Step 2:

  • measure the water into the large jar

Step 3:

  • *slowly add lye to the water while stirring with metal spoon

*Be aware that the lye is a chemical that will react with water by heating up.  It is important not to breathe the gassing off reaction of the lye and water mixture or to get splashed by it.

Leave this lye & water mixture to cool down to 90 to 100 degrees Fahrenheit (takes 10 to 15 min)

Part two

  • Heat Oil between 90 and 100 degrees Fahrenheit.

Part three

Step 1:

  • When both oil and lye water are between 90 and 100 degrees Fahrenheit take oil off heat and slowly whisk in lye infused water.

Step 2:

  • Stir oil, water and lye for five minutes on and five minutes off.  Let ingredients rest five minutes before starting to stir again. This is the process that creates saponification, turning fat/oils into soap.  (*The new strategy for these ingredients is the five minutes of resting.)

    Flower Infused Oil, Lye & Water Mixture – color due to Mullein Infused Water and Flower Infused Oils

Step 3:

  • When the mixture thickens and begins to leave trace add dry plant ingredients.  Take pot and pour mixture into your molds.

    Thickened Soap Mixture – change in color

Step 4:

  • Let soap molds sit for 24 hours
  • After 24 hours check your soap and if solid take out of molds and rest for six weeks.  (Time for lye to infuse completely in oil)

Step 5:  

  • Enjoy!

*For me in the past vigorously stirring the ingredients for Castile Soap continuously had led to the ingredients having a reaction to which creates a rice looking effect in the soap.   It led to the soap not infusing with all the oil therefore the soap was oily. Slowing the process does take longer, however the soap is creamier and immediately the day after there is no oil residue!

Infusing Plant Material with Oil 

Drying your own plant material

Traditional uses and properties of herbs are for educational purposes only.  This information is not intended to diagnose, treat, cure, or prevent any disease.  Every attempt has been made for accuracy, but none is guaranteed. Any serious health concerns or if you are pregnant, you should always check with your health care practitioner before self-administering herbs.