What Is Castile Soap? What Are Its Uses and Benefits?

• What Is Castile Soap?
• What is Castile Soap Made Of?
• Why Does Castile Soap Have So Many Uses Where Other Soaps Don’t?
• Benefits of Using Castile Soap
• Body Care Uses of Castile Soap
• Home Care Uses of Castile Soap
• Does Castile Soap Expire?
• Liquid vs. Bar Castile Soap
• Frequently Asked Questions

What Is Castile Soap?

Castile soap originated in the Mediterranean region where many cultures made soap from olive and other vegetable oils. It gets its name from the Castile region of Spain, which was a soapmaking center for centuries. Castile soap contains only vegetable oils – no animal fats – making it vegan and biodegradable. The soap molecules found in Castile soap have one end that bonds to water and one that repels it. When combined with water, the result is that one end attaches to dirt, grime, and grease and removes it from the surface its applied to. Because of Castile soap’s plant-based ingredients, it’s not corrosive and can be effectively used to clean the body, home, pets, get rid of insects, and much more.

What Is Castile Soap Made Of?

Castile soap can be made of a variety of plant-based oils. Our own Dr. Bronner’s blend has coconut, palm, olive, hemp, and jojoba oils, which provides a soothing, moisturizing feel. Other oils, like avocado or walnut, can also be used.

Castile soap tends to be alkaline, just like most other soaps (about the same level as baking soda). That said, it’s not nearly as alkaline as bleach, making it not corrosive to skin and most surfaces.

• Pet cleaning
• Produce cleaning
• Plant spray for bugs
• Indoor spray for insects

Does Castile Soap Expire?

Dr. Bronner’s Pure-Castile Magic Soap does not carry a traditional expiration date, but it has a recommended shelf life of three years from its manufacture date. Once opened, use the Liquid Soap within 24 months—and no later than three years after it was made.

Diluted Castile soap has a shorter shelf life. Once it is mixed with water, the soap is no longer self-preserving. Make only what you expect to use within a couple of weeks, and replace any remaining mixture after about one month.

Liquid vs. Bar Castile Soap

Dr. Bronner’s Pure-Castile Magic Soap and Pure-Castile Magic Bar Soap are both plant-based real soaps that can be used to wash hands, face, body, and hair. Liquid Soap is easy to measure and dilute for household cleaning, and its scents are slightly more pronounced. Bar Soap is compact and works for many of the same jobs, though household cleaning recipes may require grating or dissolving it first—see our Bar Soap Dilutions Guide for instructions. The better choice comes down to the task and the format you prefer. Read our complete guide to Liquid Castile vs. Bar Castile Soap for more details.

Frequently Asked Questions

Castile soap is a concentrated, plant-based true soap with uses throughout body and home care. These answers cover the basics. Explore our Castile Soap 101 resource hub for more in-depth guides.

What is Castile soap?

Castile soap is a true soap made by saponifying plant oils with an alkali such as potassium hydroxide or sodium hydroxide. It contains no animal fats, and Dr. Bronner’s Pure-Castile Magic Soap contains no synthetic detergents. Learn more about the difference between soap and detergent.

What can Castile soap be used for?

Castile soap can be used to wash hands, face, body, and hair, along with everyday household jobs such as handwashing dishes, doing laundry, mopping floors, and cleaning hard surfaces. See our Pure-Castile Magic Soap Dilutions Cheat Sheet for measurements and our skin care guides for body-washing guidance.

Does Castile soap need to be diluted?

Not always. For body washing, the water already on your hands, washcloth, or skin provides much of the dilution. Many household uses, however, call for mixing the soap with water first. Prepare only a small amount of any prediluted mixture and use it within a few weeks. See the Dilutions Cheat Sheet for use-by-use guidance.

Can Castile soap be used as shampoo?

Yes, Castile soap can be used to wash hair, but results depend on your hair type and water conditions. Because true soap is alkaline, follow it with Dr. Bronner’s Organic Hair Rinse or a properly diluted acidic rinse, and allow some room to adjust the routine. Our guide to using Castile soap as shampoo explains the process and offers troubleshooting tips.

Can Castile soap be used to wash pets?

When diluted and used as directed, Dr. Bronner’s Pure-Castile Magic Soap can be used to wash dogs. Keep it away from the eyes and ears, and rinse thoroughly. If your dog is sensitive to essential oils, choose Baby Unscented, and avoid the Tea Tree scent. Cats can be sensitive to essential oils, so choose Baby Unscented when washing cats, keep the soap away from the face and ears, and rinse thoroughly. Please consult a veterinarian before using the soap to wash other animals. See our complete pet-washing guide for more instructions and precautions.