What Is Castile Bar Soap? Benefits and Uses

Castile bar soap is a simple, natural soap made from plant-based oils like olive, coconut, or sunflower. With no animal fats or synthetic additives, it's a gentle, biodegradable, and vegan-friendly choice for everyday use. 

Loved for its versatility, castile soap is a go-to for households that care about wellness, sustainability, and cutting down on clutter. Whether you’re streamlining your routine, switching to plastic-free options, or soothing sensitive skin, these humble bars do it all. 

So, what makes castile bar soap so special? Let’s explore the benefits and uses of castile soap, how it differs from other types of soap, and how to turn your bar into a multi-purpose cleaner.

What Is Castile Soap? 

Originally made in the Castile region of Spain, castile soap traditionally contains olive oil as the primary fat. Today, it often includes a blend of nourishing plant-based oils such as coconut, sunflower, or palm-free alternatives. 

Unlike conventional soaps, which are often made with animal fats or synthetic detergents, castile soap is fully biodegradable, vegan, and gentle on the skin.

Interestingly, science backs its gentle cleansing properties. A 1999 study even found castile soap was more effective at healing certain surface wounds than traditional treatments like bacitracin or saline. Although more research is needed, it makes sense given its minimal and mild ingredient profile.

When this eco-friendly soap is molded into solid bars, it provides all the same natural cleaning power of its liquid cousin with even less packaging and waste.

Castile Soap Ingredients

One of the best things about castile soap is how simple and transparent its ingredient list tends to be. While each bar may vary slightly depending on the brand or intended use, most follow a similar plant-based formula that includes:

• Olive oil

• Coconut oil

• Sunflower oil

• Water

• Sodium hydroxide (used in saponification, and fully reacted in the final product)

• Optional essential oils for scent

Compared to conventional soaps, which often contain synthetic detergents, artificial fragrances, and preservatives, castile soap sticks to the basics. That means no parabens, no sulfates, and no mystery additives—just clean, conscious ingredients you can feel good about using on your skin and around your home.

Benefits of Castile Bar Soap

There’s a lot to love about castile bar soap. Here are just a few standout reasons why it earns a spot in so many eco-conscious homes:

1. Multi-Purpose Magic
   One bar, so many uses, from your body to your dishes (scroll down for more!). 

2. Safe and Sustainable
   It's non-toxic, biodegradable, and made from simple ingredients.

3. Skin-Friendly
   Ideal for sensitive skin thanks to its gentle, nourishing oils. 

4. Plastic-Free
   As with all bar soaps, it’s a zero waste alternative to plastic bottles and pumps.

5. Budget-Friendly
   It lasts for weeks with proper care.

Uses of Castile Bar Soap 

Castile bar soap is one of the most versatile tools in a natural home. Here are just a few ways to put it to work:

• Gentle Hand and Body Wash
  A creamy lather that cleanses without drying out your skin.

• Plastic-Free Dish Soap
  Curious how castile soap stacks up against traditional dish soaps? Visit our blog on eco-friendly dish soap. We recommend the Meliora Organic Castile Dish Soap.it's powerful, planet-friendly, and safe on skin.

• Stain Stick for Laundry
  Rub directly onto fabric to help lift stains before washing.

• Pet-Friendly Wash
  Mild enough for your furry friends, especially in unscented soap form.

• Cleaning surface wounds
  There’s some evidence to suggest that castile soap can help clean and support healing in surface wounds when properly diluted. That said, a 2015 study found that saline was more effective than castile soap when treating open fractures, so for anything more than a minor scrape, it’s best to consult your healthcare provider before use.

• Everyday Surface Cleaner
  Suds it up with a sponge for a natural, effective wipe-down. You’ll find even more inspiration in our eco-friendly cleaning tips blog!

How to Make Liquid Castile Soap from Bar Soap

If you prefer liquid soap, you can easily transform your bar into a DIY liquid castile soap at home:

1. Grate 1 cup of castile bar soap.

2. Warm 4 cups of distilled water and remove from heat.

3. Stir in the grated soap until it dissolves.

4. Cool and pour into a reusable bottle. Shake gently before use.

This simple method lets you customize your soap for different tasks, whether it’s refilling a hand soap pump or creating an all-purpose spray.

Best Castile Soaps at EarthHero

Ready to try castile soap for yourself? These are a few of our top picks:

1. Meliora Organic Bath & Body Castile Soap Bar

A gentle daily cleanser made with organic ingredients. Available in lightly scented and unscented soap versions.

2. Meliora Organic Castile Dish Soap

A great zero-waste alternative for your kitchen. Effective on grease, yet kind to your hands.

3. Liquid Gold All-Purpose Castile Soap

This liquid castile soap is a workhorse, perfect for cleaning your home, washing dishes, or even doing laundry. Just dilute as needed.

What is Castile Bar Soap Good For?

Still wondering what castile bar soap is good for? The short answer: almost everything. It’s a minimalist’s dream, ideal for:

• Travelers packing light

• Families seeking baby-safe products

• Campers using biodegradable essentials

• Anyone cutting back on plastic waste

Final Thoughts: A Simple Switch with a Big Impact

At EarthHero, we believe small changes create big ripples. Choosing castile bar soap is an easy, everyday way to protect your health and the planet. It cuts through clutter, minimizes waste, and supports brands doing good.

Whether you're starting your sustainability journey or just looking for a smarter soap, this little bar is a big win.

Browse our full collection of soap bars and find your new go-to today.