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This is the first soap recipe presented on this blog. It is a basic recipe for natural olive oil soap, also known as castile soap, one of the most well-known ingredients for making handmade soap. It’s one of the simplest soap recipes. No need to purchase Castile soap when you can make it at home.
Castile Soap: the mildest soap of all
The olive oil soap, also known as Castile Soap is one of the most traditional and well known among handmade soaps. Actually, a soap is considered a Castile soap if it contains more than 70% olive oil in its recipe. This recipe, however, is 100% olive oil.
Technically, we can use any type of oil to make soap, but in fact each of them contributes with different properties to the final soap. For example, coconut oil contributes to hard bars and abundant foam, while sunflower oil contributes to softer and more moisturizing bars. However, too much coconut oil makes the skin “dry” and too much sunflower oil makes the soap bars too soft.
There are few oils that, used in 100% of the recipe, are able to produce good soaps and that is why many recipes contain such a varied mixture of oils, with well-defined quantities. The exception to the rule is olive oil and animal fat (and, surprisingly, also coconut oil). The purer the oil, the more natural and better the soap will be. For this reason, it is advisable to use extra virgin olive oil.
By itself, olive oil gives good bars of very gentle and nourishing soap for the skin without being dry, so it is especially suitable for sensitive skin. It produces a not very abundant foam that some may find “gelatinous”, others that have a creamy consistency. It does not generate abundant foam filled with bubbles like coconut oil, but there is nothing as moisturizing, silky and smooth as a bar of natural olive oil soap.
More Castile (100% Olive Oil) Recipes
More Single-Oil Recipes
Watch this video for Soap Making Safety instruction
Watch this video for the Cold Process Soap Making tutorial
Homemade Castile Soap Recipe
- Immersion blender
- Pyrex or stainless steel bowl
- Heat-resistant jug or pitcher for lye solution
- Digital scale
- Digital thermometer
- Measuring spoons
- Rubber spatula(s)
- Small strainer
- Cup / bottle for after trace ingredients
- Soap mold
- Safety goggles, gloves and mask
- 103 g distilled water (3,63 oz)
- 58 g lye (100% sodium hydroxide) (2,00 oz)
- 1 tsp fine salt / sodium lactate
- 450 g extra virgin olive oil (15,84 oz)
Add After Trace
- 8 drops grapefruit seed extract (GSE) or rosemary extract (RSO) (anti-oxidant)
- 14 ml essential oils blend (optional)
Essential Oils Blend 1
- 7 ml essential oil eucalyptus globulus (0,25 fl oz)
- 7 ml essential oil peppermint (0.25 fl oz)
Essential Oils Blend 2
- 6 ml essential oil cedarwood Atlas (0,21 fl oz)
- 8 ml essential oil lemongrass (0,28 fl oz)
|Refined olive oil||Sodium lactate||Lye|
|Grapefruit seed extract||Essential oil cedarwood||Essential oil eucalyptus globulus|
|Essential oil peppermint||Essential oil lemongrass|
|Rectangular soap molds||Pretty shaped soap molds||“100% handmade” molds|
|Buy Immersion Blender Set||Buy Pyrex bowl (4lt)||Buy easy pour pitchers|
|Digital scale||Digital thermometer||Measuring spoons|
|Safety gloves||Safety goggles||Safety mask|
- Wear goggles and gloves! Look at “Safety Recommendations” in the video above or in How to Make Soap From Scratch
- Watch the video above about "Cold Process Soap Making tutorial" or read the post How To Make Soap by Cold Process Step-by-Step for instructions on cold process soap making before starting. These are generic but important steps for all recipes.
- Assemble everything: ingredients, equipment, safety equipment. Prepare your workstations. Measure all the ingredients. Don’t start the recipe without having everything ready!
- You can choose between the essential oils blend 1 or the essential oils blend 2. Do not use both at the same time.
Heat the Oils
- Heat the olive oil to aprox. 45ºC
Prepare the Lye Water
- Make the lye solution according to How To Make Lye Water. Add fine salt or sodium lactate in the water, before or after doing the mixture. Mix it until the vapors start to dissipate. Strain it to catch any undissolved lye crystals.
Make the Soap Batter
- Use as a target temperature 38ºC for the oil-solution mixture. This recipe has a water discount to reduce trace time and cure time.
- Reach trace with the immersion blender. Recipes of 100% olive oil soap take time to reach it, you may need to use the stick blender for about 10-15 minutes. In the end, it should be an opaque pale yellow batter.
- 100% olive oil soaps take time to solidify. By using sodium lactate, your soaps will solidify faster. However, it is advisable to leave it in molds for up to 7 days.
- After trace, add the extract and essential oils. You can choose between the essential oils blend 1 or the essential oils blend 2. Do not use both at the same time. Mix with a spoon.
- Pour the soap batter in the molds with a pitcher (I don't recommend using box soap molds, only silicone ones). Sprinkle with alcohol or witch hazel. You can put in pre-heated oven for gel phase.
Molding and Curing
- Let the soap batter set for 2 to 7 days.
- Unmold and let the bars cure for 6 to 8 weeks. See How To Cure Handmade Soap.