homemade castile soap recipe
using the hot process method

This do-it-yourself tutorial for homemade castile soap will be using the hot process soap making method if you prefer not to "cook" your soap look here for the cold process castile soap method.

Hot process reduces the cure time, requires less essential oils to scent, makes soap with a nice feel and some soap makers find it more convenient.

Castile soap has a long cure time which is 4 to 6 months to have a hard bar of home castile soap that will be divine and last a long time. For this information page we will be using the hot process soap making method to make a 100% olive oil soap. This will shorten the cure time but remember that the longer you let this handmade soap cure the better it will be.

Homemade castile soap is a wonderful gift to make for babies and those who enjoy a gentle wash product. Castile soap is named after the region in Spain where this type of soap originated from.

It is also a simple soap that can used for your face and sensitive skin. It is a easy to make and requires only 3 ingredients: olive oil, distilled water and sodium hydroxide commonly known as lye

You will start off the same way you would with the cold process soap making method.

Gather your ingredients and equipment, we are using a crockpot but you can always use a double-boiler.


You really need a stick blender for this recipe, a whip of spoon just won't make it happen. Prepare your workspace and make sure that you have protective gear which include goggles and gloves and long sleeves are a good idea.

We will be using this castile 100% olive oil recipe. Cold process and hot process soap making recipes are interchangeable.

Check out the general hot process soap making instructions before starting.


Weight your ingredients for your homemade castile soap.

600 grams olive oil

228 grams distilled water

77 grams lye

Heat the olive oil in the crockpot on the low setting you want to reach between 120° F and 160° F.

Slowly mix the lye into the water and dissolve all the crystals. When the lye-water solution is clear, gently pour it into the heated oil.

Then begin mixing with a stick blender. This will probably take longer than other soap recipes because this homemade castile soap recipe is using only 100% olive oil. Take your time. You may want to give the stick blender a break and mix a little with a whip. It should take about 10 to 15 minutes to achieve trace.

The soap recipe has achieved trace when you can drizzle some soap mixture on the top and it does not sink immediately. Trace may seem like a mystical thing but after a few batches you will know. Different oils, different soap making methods will create different types of trace.

The next step is to cook the soap mixture. Put the crockpot on low-medium and keep a watchful eye on it.

Mix it about every 30 minutes using a spatula or a spoon.

When you reach the 2 hour cooking mark you want to check to see if your soap is neutral.Your soap will have a thick and almost transparent texture.

There are 3 ways that you can do this.

-Phenolphthalein

-PH strips (may not be the most accurate for this purpose)

-Tongue zap test: using a gloved hand take a small piece of soap and put on your tongue, if it stings, continue cooking. If it does not sting than the soap is ready to mold.


Put the soap paste in a mold when it is neutral.

Tap the mold on the counter a few time to prevent air bubbles in your soap.

Cover with plastic wrap and let set for 24-48 hours.

Unmold and cut the soap and cure for a few weeks. If you give it a few months it will even be better.


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Find more variations of this castile soap recipes using additional oils

Make cold process castile soap