Castile soap is a natural, nontoxic vegetable-based soap that can be used for both body care and household cleaning purposes. It contains no animal fats or synthetic ingredients, making it both vegan-friendly and biodegradable. 

There’s a long list of ways you can use castile soap around the home. From body soap to dishwasher detergent and even as a natural deterrent for aphids. It’s versatile, natural and kind on the body and the Earth. 

Below, we break down what castile soap is and why it’s so versatile. Plus, we introduce 20 ways you can use castile soap and how to get the most out of it.

What is Castile Soap Made From?

Castile soap was traditionally made in the Mediterranean regions from olive oil. It gets its name from the Castile region of Spain. 

Modern castile soap recipes generally use a combination of vegetable oils such as olive, coconut, castor or hemp oils. It’s available both in liquid and solid forms.

All soaps, including castile soap, are made by heating fats or oils with an alkaline substance like sodium hydroxide or potassium hydroxide. In castile soap, vegetable fats are used rather than animal fats, making castile soap vegan friendly. 

The saponification process of vegetable fats produces a liquid called glycerin. In some types of soap the glycerin is removed before the end product is sold. In liquid castile soap, the glycerin is left in the mixture, making the soap softer and less drying for the skin. 

Castile Soap blocks infused with bay leaf, handmade in Australia by Urthly Organics.

Benefits of Castile Soap

• Made from natural ingredients

• Biodegradable

• Non-toxic

• Contains no synthetic preservatives, foaming agents or detergents

• Vegan, vegetable-based and cruelty free

• Antifungal and antibacterial

• Safe for pets and children

• Suitable for sensitive skin

• Moisturising and hydrating

• Multipurpose 

• Cost effective – a little goes a long way

Castile Soap vs Other Soaps & Detergents

• Safe and Natural: Castile soap is a highly effective multi-purpose cleaner that is 100% biodegradable, made from all-natural ingredients and free from toxic chemicals. Unlike many of the soaps and detergents you find widely today, castile soap is safe for pets and children, suitable for sensitive skin and won’t pollute waterways and ecosystems.
• Free From Toxic Chemicals: Many of the ‘soaps’ sold today aren’t true soaps according to the process described above of heating a fat or oil with an alkaline substance. They are more likely synthetic chemical detergents, and many of them contain harsh and toxic chemicals that are harmful to humans and more-than-human life. Ingredients like ‘sulphate’, ‘betaine’ and ‘glycoside’ are the tell-tale signs that a product is a chemical detergent rather than a true soap.
• Palm Oil Free: Many commercial soaps and detergents (including some brands of castile soap) contain palm oil. The palm oil industry has caused immense issues with climate change, deforestation and pollution. Opt for palm oil free soaps using sustainably sourced ingredients where possible.
• Support Local Makers: Castile soap is often manufactured small scale and locally, meaning you can choose to support local makers and reduce the carbon footprint of the soap.
• Bulk & Zero Waste Options: You can often find zero waste options for castile soap – either by refilling your own container or buying solid castile soap bars free from plastic packaging.

Liquid Castile Soap refills at our Vic Park store – simply BYO container and get as much as you need.

Liquid vs Solid Castile Soap

Castile soap comes in both liquid and solid forms. They are both equally effective at cleaning, though depending on what you are using the soap for, you may prefer one form over the other.

Many body care and cleaning recipes call for liquid soap. If you only have solid castile soap on hand, you can achieve the same effect by grating and diluting a solid castile soap bar into water. Solid castile soap is particularly handy for stain removal in laundry.

20 Ways to Use Castile Soap

Castile soap can be used for a range of purposes around the home including skin care and personal care, cleaning, and even as a natural pest deterrent in the garden. Get started using castile soap using the basic recipes below.

*Recipe adapted from Clean Green: Tips and Recipes for a Naturally Clean, More Sustainable Home by Jen Chillingsworth.

** Recipe adapted from David Suzuki 

How to Use Castile Soap Safely: Notes and Precautions

• Dilute liquid castile soap properly before using, it’s very strong! Dilution ratios vary from product to product, and from purpose to purpose. Consult the manufacturer’s instructions first.

• In general, don’t combine with vinegar or lemon juice - the alkaline soap reacts with the acid, converting the soap back to its original oils.

• Don’t use on colour-treated hair.

• While typically moistening, it can be drying for some people. Stop using if you notice skin irritation.

• In hard water, castile soap can form white deposits. Rinse deposits with a clean cloth to avoid build ups – or use distilled water instead of hard tap water to make your recipes.

• Adding water to castile soap will make it foam up – to avoid foaming, put water in your container first and then add the castile soap.

References & Further Reading: 

• Clean Green: Tips and Recipes for a Naturally Clean, More Sustainable Home by Jen Chillingsworth.

• Homemade Cleaners: Quick and Easy Toxic-Free Recipes by Mandy O’Brien and Donna Ford

• The Organically Clean Home by Becky Rapinchuk

• David Suzuki 

• Healthline