What Is Castile Soap? Uses and Benefits

bars of soap and liquid castile soap display on white waffle fabric with wooden brush and loofah

Treehugger / Sanja Kostic

Castile soap (pron. ka-ˈstēl) is a highly effective and versatile cleaner made from vegetable oils. It originated in the Castile region of Spain, where olive oil was combined with sodium carbonate to create a hard white soap that was sold throughout Europe as early as the 16th century. Since then, production has evolved to include other plant-based oils, such as coconut, palm kernel, hemp, and jojoba, which give soap makers greater control over properties such as lather, but the soap remains free from animal fats, making it ideal for vegans.

Castile soap comes in many different scents, both in liquid and bar form. Liquid tends to be more popular because it’s easier to use, but bar soap is cheaper. If you want to convert it to liquid form, you can chop or grate a five-ounce bar, soak in four cups of water for 24 hours, then blend at low speed for 30 seconds and store in a glass jar. The resulting soap has a creamy consistency that differs from regular liquid castile soap, but is still a strong cleaner. You can find castile soap in well-stocked grocery stores and bulk food stores. The most well-known and widely distributed brand is Dr. Bronner, but many soap companies have their own versions.


When it come to versatility, castile soap wins the day. It can be used for personal care, as well as house cleaning purposes, which makes it a smart investment. Below are some great ways in which to use castile soap at home.

Dish Soap

hands wash glass jar with loofah and castile soap in metal sink

Treehugger / Sanja Kostic

Castile soap is great at cutting through greasy dishes, and it gets an A from the Environmental Working Group for being a 'product of low concern'. You can make a washing solution with one part castile soap and 10 parts water, or add a generous squirt of concentrated liquid while you’re filling the sink with hot water. It won’t create suds, but your dishes will be sparkling clean. Rinse well.

All-Purpose Cleaner

hands clean wooden table with reusable glass bottle soap spray and pink towel

Treehugger / Sanja Kostic

Warm one quart water and add one-quarter cup castile soap. Mix and pour into a spray bottle. Use this to clean counters, appliances, furniture, floor stains and messes, dusty surfaces, and more. Spray and wipe with a clean cloth. For more scrubbing power, sprinkle the surface with baking soda before spraying.


folded laundry with grated castile soap, liquid castile soap and baking soda

Treehugger / Sanja Kostic

Castile soap is not a typical detergent, but it can be used to clean clothes and bedding. Use one-third cup per normal-sized load (or half of this for an HE washer), but add one-half cup white vinegar to the rinse cycle. Lisa Bronner of the Dr. Bronner company also recommends using grated bar soap as a powdered form of laundry soap (one cup grated soap bar mixed with four cups baking soda), but still use vinegar with the rinse. You can add a squirt of concentrated liquid soap to a sink of warm water to soak delicates.

Foaming Soap

essential oils, olive oil, and liquid castile soap on cutting board in metal sink

Treehugger / Sanja Kostic

If you own a foaming soap dispenser, you can refill it with a homemade formula. Mix two tablespoons liquid castile soap, one-half teaspoon olive or fractionated coconut oil, and a few drops of your preferred essential oil. Top up with water, gently mix, and it’s ready for use.

Face and Body Wash

person in round-tiled stand-up shower scrubs forearms with loofah body scrub

Treehugger / Sanja Kostic

Wet hands and face, add two to three drops concentrated liquid soap to hands and rub to lather. Apply to face and rinse well. Add a squirt of concentrated liquid soap to a wet washcloth or sponge and rub all over your body in the shower or bath. You can also make your own body wash solution using castile soap, honey, olive oil, and essential oils.

Makeup Remover

woman's face in profile while she uses cotton puff to clean makeup off face

Treehugger / Sanja Kostic

Mix equal parts castile soap, fractionated coconut oil or almond oil, and witch hazel to make an effective homemade makeup remover that’s also moisturizing. Soak reusable cloth pads or cotton rounds in the solution and wipe gently over eyes and face. Rinse with water.


woman shaves legs with metal razor on green couch with tan pillow

Treehugger / Sanja Kostic

Castile soap lathers beautifully, which makes it ideal for shaving. Wet your hands and skin, add four to five drops of concentrated soap to your hands and rub until foamy. Apply to legs, underarms, or face, then shave and rinse.

Homemade Baby Wipes

These are a greener alternative to sewage-clogging, microfiber-shedding wipes. Use one-half roll sturdy paper towels (preferably recycled) and put in an airtight container, i.e. old baby wipes box or plastic ice cream tub. Combine two tablespoons liquid castile soap with two cups hot water, one tbsp almond oil and one tablespoon lotion. Soak the towels in the liquid and wait 10 minutes before using.


person holds white towel over head while lowering face to pot filled with steaming water facial

Treehugger / Sanja Kostic

This is most effective with peppermint- or eucalyptus-scented liquid soap. Fill a bowl with hot, near-boiling water and add two to three drops of soap. Hold your head over the bowl to inhale the steam; put a towel over your head for a more concentrated effect. Your nasal passages should clear quickly.

Pet Shampoo

small black and white dog gets scrubbed with castile soap

Treehugger / Sanja Kostic

Wet your dog’s hair and then add a squirt of liquid soap. Work it in with your hands for a generous lather, then rinse thoroughly.

Plant Care

hand uses reusable glass bottle to spray castile soap mixture on plants as pest deterrent

Treehugger / Sanja Kostic

If you’re having trouble with bugs on your houseplants, mix one tablespoon castile soap with one quart water. Spray this on the leaves to deter the pests.

Brush Cleaner

hands clean makeup brush with castile soap by swirling in palm over patterned rug

Treehugger / Sanja Kostic

You can clean your makeup brushes and water-based paint brushes using castile soap. Add a squirt of concentrated soap to a bowl and top up with warm water. Add brushes and let soak for a few minutes until softened, then rub gently. Rinse until water runs clear. Alternatively, for makeup brushes, put two to three drops of soap into your wet palm. Rub the brush head around your hand, then rinse and reshape the bristles.

Produce Rinse

bowl of carrots, zucchini, and green onions soak in castile soap mixture on woven placemat

Treehugger / Sanja Kostic

If you’re concerned about dirt and bacteria on fresh fruits and vegetables, combine one tablespoon castile soap (preferably citrus) with one gallon water. Swish the vegetables around for a minute, then transfer to a towel to dry.


display of liquid and bar castile soap on wooden cutting board with baby's breath

Treehugger / Sanja Kostic

Castile soap has become tremendously popular in recent years. Eco-minded shoppers are attracted to its environmental profile, its affordability, and the ethical production standards of certain manufacturers.


The appeal of castile soap lies in the fact that it cleans as effectively as many conventional, chemical-laden formulas, minus the environmental hazards. The soap is biodegradable and free from synthetic preservatives, detergents and foaming agents. For anyone wishing to reduce their personal chemical burden or wanting to minimize children’s or pets’ exposure to harsh cleaning substances, castile soap is a good choice. The fact that it’s made entirely from vegetable oils, rather than animal fats, is attractive to vegan users. Dr. Bronner’s liquid soap containers are made from 100 percent post-consumer recycled plastic.


Castile soap is a highly concentrated liquid that can be purchased in large quantities, which cuts down on cost and packaging waste. Dr. Bronner, for example, sells its liquid soap in containers as big as a gallon, and many zero waste and refillery stores offer castile soap on tap, allowing shoppers to refill their own containers. For people concerned about buying large amounts, it keeps for three years, so don’t worry about it losing efficacy while sitting under the bathroom sink; with so many potential uses, you’ll find ways to use it.

Ethical Production

Dr. Bronner has set the bar high with its production standards. Its castile soaps are made with Fairtrade- and organic-certified ingredients sourced from Sri Lanka, Ecuador, Palestine, India, Kenya, Ghana, and more. Farmers are taught regenerative agriculture practices to improve soil quality, paid living wages, and ensured good working conditions.

These initiatives are part of the company’s goal to prove that ethical production can be scaled to meet growing global demand, while continuing to improve quality of life for farmers in developing countries and remain free from chemical herbicides, pesticides, and GMOs. You can read all about its ethical sourcing practices and innovative agricultural startups in "Honor Thy Label," a book written by Dr. Gero Leson, the company's vice-president of special operations.

In other words, while using these soaps, your conscience can be as clean as your home and body!

Frequently Asked Questions
  • Can I wash my hair with castile soap?

    Yes, you can wash your hair with castile soap, although it will likely require an acidic conditioning rinse afterward to feel smooth since castile soap does not contain the silicones and waxes that conventional shampoo does.

  • Can I brush my teeth with castile soap?

    You can, but your mouth might taste like soap for the rest of the day. It's recommended more as an emergency cleaner, not a regular go-to.

  • Is castile soap safe for vegans?

    Castile soap is made from vegetable oils, such as coconut, palm kernel, hemp, and jojoba oils. It contains no animal fats, making it vegan-friendly.

View Article Sources
  1. Dr. Bronner’s.” Environmental Working Group.