Photo by LoggaWiggler @Pixabay

Would you like to know how to make castile soap at home? Here’s an easy recipe and everything you need to know to get started.

Homemade Castile Soap

You can be very creative with your homemade soaps – for example, the soap in the photo is made to look like a delicious cake!
Credit for photo above – thanks to Kristina D.C. Hoeppner of New Zealand!

Homemade castile soap is not hard to make – you just need to have the right ingredients and kitchenware. Soap making can be a fun and profitable hobby. It can be a great way to make gifts for your loved ones. Everyone seems to love homemade soaps!

Suggestion: Learn the basic castile soapmaking recipe I’ve included below, then get creative and try new things. I include links for many soap recipe ideas near the end of this page.
Get ready for castile soap making!
…you need to buy all your supplies first…

Soap making is a lot like cooking dinner, but you’ll need to be totally prepared with all your supplies, and you probably don’t have all these things in your kitchen yet.

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Get ready for castile soap making!

…you’ll need to buy all your supplies first…

Soap making is a lot like cooking dinner. You’ll need to be totally prepared with all supplies and ingredients. Here’s what you’ll need.

Protective clothing – necessary for homemade castile soap making safety. – …better safe than sorry!

You’ll be handling lye (very caustic) so be prepared with a good apron, rubber gloves, and safety glasses.


Chef Works Stripe Bib Apron with Pockets

A sturdy all-purpose apron with good all-over cover. Protect your clothing!

This apron is made from 65/35-Poly/cotton fabric with soil release finish. It measures 34.25″ length by 27″ width and is machine washable, tumble dry on low.

It is the #1 best selling apron on Amazon as I write this, with over 300 five-star ratings.

If you need an apron, this would be worth looking into. Amazon lists ten answered questions for this popular apron.

Safety Glasses

Lightweight Protective Safety Glasses

Inexpensive safety glasses will protect your eyes during the soap making process.

Protective Rubber Gloves

Protective Rubber Gloves

Absolutely essential when you’re working with lye.

Soap molds, lining material, and blankets – …lining materials can be plastic wrap or freezer paper.

Flying Insect Soap Molds

Decorative Soap Molds

These cute flying insect soap molds are attractive! They include a dragonfly soap mold, butterfly, ladybug, and bee. These molds can also be used for candy making. When you’re making soap, you’ll find your soaps come out of the mold easily when you first spray with a bit of rubbing alcohol. Another soap maker’s trick for getting soap out of molds is to put the mold in the freezer for a while first.

Heart-Shaped Soap Molds

Heart-Shaped Soap Molds

These silicone molds by Wilton can be used for cupcakes … but they are great for soap making too, and provide easy-release to get the soap out of the molds. These heart-shaped molds are a #1 best-seller at Amazon.

Plastic Wrap

Plastic Wrap

If you make your soap in a cardboard box, shoebox, or bread pan, line it with plastic wrap first. Alternative: freezer wrap, shiny side down.


Stainless Steel Scraper, Cutter, Chopper

If you make your soap in a plastic-wrap lined shoebox or bread dish, this will help cut it once it sets a bit.

Wool Blanket

Grey 70% Virgin Wool Blanket 62″ x 80″

Wool blankets are perfect insulation for your soaps during the molding process, which lasts for the first 24 hours after making the soap.


Soap squares sold in Paris. Photo from Pixabay.

Lye and measuring cups used in making castile soap – …be careful with the lye!

You will start by adding pure lye to water. Do NOT add the water to the lye.

The water first, then the lye!

Lye is incredibly caustic, so open the window and get a breeze going through the room, then open the lye.

Or – you could do this outside.

Do not try to do this around children or pets.

Do not use metal measuring cups or utensils.

Lye for Soap Making

Red Crown Lye for Making Handcrafted Soaps

Get yourself a supply of lye for many happy hours of homemade castile soap making.

Pyrex Measuring Bowl

Pyrex 1 Quart Measuring Bowl

I love my pyrex measuring cups. This one-quart measuring cup is great for making soap. You might need more than one.

Olive oil and fragrance – make your homemade castile soap sweetly scented – …essential oils for perfect fragrance. Pure and natural!

The best thing about making soap at home is that you get to choose the ingredients, so you can get the purest, best, most perfect oils and fragrances to make your soaps pure and natural, and just how you like them. As you get into soap making you’ll find dozens of ways to enhance your recipes with additives. But for now, get the basics. Olive oil and essential oils.

Zoe Extra Virgin Olive Oil

Zoe Extra Virgin Olive Oil

Get a good supply of olive oil. Palm oil and coconut oils are also very popular for soap making but some say the coconut oil is slightly drying. This is the brand of olive oil I’m currently using.

Orange Essential Oil

Orange Essential Oil

Orange essential oil gives soap a wonderful citrus scent – one of my favorites. However, any essential oil you love will do for your first soap making project. You can find a wide variety of essential oils at Amazon – such as lavender oil, peppermint oil, or rose hip oil. There are many to choose from.

Cooking utensils – …these are the types of things you can use for soap making!

Keep your soap-making crock pot and utensils separate from similar things you use for cooking. When you make soap you’re using poisonous lye – you don’t want any trace of that in your food!

Crock Pot

Ceramic Coated Crock Pot

A large crock pot provides a convenient place to cook your soap on low heat. Do not use a soap making crock pot for cooking food!

Immersion Hand Blender

Immersion Hand Blender

Easy stirring with an immersion hand blender!

Wooden Spoon

Wooden Spoon

An old-fashioned wooden spoon is one of my favorite soap-making utensils.

Digital Kitchen Scale

Digital Kitchen Scale

A digital kitchen scale can help you measure the ingredients. Very important!


Digital Timer-Thermometer

Get a good cooking thermometer so you can keep your soap at 100 to 120 degrees while cooking.

Last Minute Preparations

  1. Get your soap molds or box ready. Remember to line the box with plastic wrap or an alternative.
  2. Put on all your protective clothing: apron, safety glasses, rubber gloves.
  3. Open the window or do this outside.
  4. No children or pets can be present. The lye is extremely poisonous!

Soap Ingredients

  • 10 ounces distilled water with no fluoride
  • 5 ounces pure lye (sodium hydroxide)
  • 40 ounces olive oil
  • 1 ounce essential oil of your choice

Soap Making Instructions

  1. Put the water in a pyrex one-quart measuring cup. Add the lye, stirring carefully. HOLD YOUR BREATH while adding the lye – then leave until the fumes are gone.
  2. In your crock pot place 40 ounces olive oil and add the essential oil. Then add the water/lye mixture, stirring constantly with a wire whisk or your wooden or plastic spoon. Stir thoroughly but do not splash. Careful! You must try to get the water/lye to meld with the oils. They will turn into a murky, opaque and creamy mixture and then will begin to thicken.
  3. Use a stick blender (sold above) to stir. You can use a wooden spoon, but it will take a long time to get to trace. Alternate with a wire whisk.
  4. This can take anywhere from five minutes to several hours. Using the stick blender will make it a lot faster.
  5. Keep this mixture at 100-120 degrees.
  6. Trace! Yes, you need to get this to trace meaning you raise your spoon up and see the soap mixture make traces as it cascades back into the pot. You might want to watch the video below to see what tracing looks like.
  7. When it traces, you can stir in any additives you might want to try (oatmeal, lavendar buds, etc.) and then pour this into your box or mold.
  8. The boxes should be placed on warm blankets, then covered with a board, styrofoam or cardboard, then more warm blankets. Wool is ideal. Experiment with this process as results will depend on your climate. Less insulation may be needed in warmer climates.
  9. Let your soap sit for about 24 hours, then unmold and slice if need be.
  10. Store your soap in a cool dry place SIX weeks (minimum) to mature before using.

How to make LIQUID castile soap – …similar to Dr. Bronners…

You’ll need to cook it for several hours after reaching trace. The video explains how to determine if your soap is ready, and what to do next.

NOTE: The liquid soap uses potassium hydroxide flakes (KOH) instead of lye. Purchase below.

Potassium Hydroxide Flakes

Potassium Hydroxide Flakes

This is used for making LIQUID castile soap.

Castile soap recipes and ideas – …a few sources for alternative soap recipes.

Soapmaking manual – Learn more and get expert ideas on making soaps, and creative tips.

Smart Soapmaking

Smart Soapmaking: The Simple Guide to Making Traditional Handmade Soap Quickly, Safely, and Reliably, or How to Make Luxurious Handcrafted Soaps from Scratch for Family, Friends, and Yourself

This is a lovely book with a long title by Anne L. Watson.

Anne is a retired historic preservation architecture consultant living in Washington state. She writes fiction, and has published a book about cookie molds.

More importantly, she writes soapmaking books!

There’s this one, and also you might be interested in Smart Lotionmaking: The Simple Guide to Making Luxurious Lotions, or How to Make Lotion That’s Better Than You Buy and Costs You Less, and Milk Soapmaking: The Smart and Simple Guide to Making Lovely Milk Soap From Cow Milk, Goat Milk, Buttermilk, Cream, Coconut Milk, or Any Other Animal or Plant Milk.

Though this lens gives the basic instructions for making castile soap, Anne gets into details and she’s got plenty of experience to share along with her own creative ideas and advanced soap making techniques. Her recipes are: Anne’s Shea Butter Supreme, All-Veggie Grocery Store Soap #1, All-Veggie Grocery Store Soap #2, Grocery Store Shortening Soap, Non-Veggie Grocery Store Soap, Olive Palm Soap, Chris’s Avocado Soap, Aaron’s Hazelnut Soap, Almond Facial Soap, and Anne’s Longer-Lasting Soap. Then she explains how you can create your own soap recipes! You get the science behind the soapsuds!

I very much believe that owning at least one soapmaking manual is essential for a soapmaker – and this is definitely one to consider. Not only does Anne put her down-to-earth and professional advice into these pages, but also she will answer direct questions if you have any. That’s priceless!

Your comments are welcome… – …suggest a fragrance or additive ingredient…