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What is Castile Soap?

Named after the olive oil-based soaps originating in Castile, Spain, Castile soap can come in liquid or bar form, but it is made only from vegetable oils — i.e., no animal fats.

Like most soaps, which are on the more basic or alkaline side of the pH scale, Castile soap registers at about 8.9 on the pH scale. This is around the same level as baking soda and slightly more alkaline than mild dish soap, although less alkaline than bleach or corrosive tile cleaners.

Generally speaking, soap molecules (Castile soap molecules included) have one end that is attracted to water and another that avoids it. When soap is combined with water, it creates free-floating charged atoms that attract and capture dirt and other types of non-water-soluble molecules.

Castile soap and water can be used to lather up in the shower or to clean counters, sinks, bathtubs, floors, or toilets; it can get rid of insects that infest houseplants and can even replace laundry detergent.

Because Castile soap is biodegradable and nontoxic, it’s safe to use on pets and around kids. You can even clean vegetables with it, so long as it’s diluted enough.

For household use, check out all these different things it can do, along with some general dilution guidelines.


Hands/Face/Body- Small squirt of Castile Liquid Soap applied to wet hands or washcloth.

Makeup Removal- Wet face and lather several drops of soap into hands. Massage into skin. Rinse. HAIR A couple drops for close cropped hair or up to ½ Tbsp. (7.5 mL) for long hair, either worked directly into very wet hair or prediluted in a cup of water.

Bath- Approximately 2 Tbsp. (30 mL) soap for an average sized tub. (Doesn’t bubble, but still cleans.)

Shaving- Face, 10 drops; Underarms, 3 drops; Legs, ½ tsp. (2.5 mL). Work to a lather in wet hands, apply to area.

Teeth- 1 drop on a toothbrush. (Yes, it tastes like soap.) FOOT BATH ½ Tbsp. (7.5 mL) in a small tub of hot water.

Clearing Congestion- 1 Tbsp. (15 mL) of Peppermint or Eucalyptus in a bowl of steamy hot, but not boiling water. Breathe in mist with a towel draped over the head.


Dishes (Handwashing)- Pre-dilute 1:10 with water. Squirt on scrub brush.

Laundry- 1/3-1/2 c. (80-120 mL) soap for a large load in a regular washer. Add 1 c. (240 mL) vinegar to the rinse cycle. Optional: For extra whitening/deodorizing, add ½ c. (120 mL) baking soda to wash cycle. Halve these amounts for HE washers.

Handwashing Delicates- 1 capful soap in about 1 gallon (4L) cold water. Swish gently. Let soak 10 minutes. Swish again. Rinse with clean water. Gently press out excess water with a towel. Hang clothing or lay flat to dry.

Mopping (Wood, Laminate & Stone Flooring)- ½ c. (120 mL) soap in 3 gallons (12 L) hot water. Dunk mop (microfiber, preferably) and wring thoroughly. On wood and laminate, avoid excess water and mop up wet areas.

All-Purpose Cleaning Spray- ¼ c. (60 mL) soap in a quart of water in a spray bottle. Optional: For extra antimicrobial punch, add ¼ tsp. (1.25 mL) tea tree essential oil.

Windows- 1 Tbsp. (15 mL) soap in a quart (1 L) of water in a spray bottle. Spray and squeegee. Follow with a spray of pure club soda or half vinegar/half water and squeegee.

Toilet- Predilute 1:4 with water in a squirt bottle. Add ¼ tsp. (1.25 mL) tea tree oil. For best results, empty toilet. Squirt bowl thoroughly, sprinkle baking soda on the brush, scrub bowl, let sit 10 minutes, turn water on, flush.



Fruit & Veggie Wash-1 dash (approx. ¼ tsp. [1.25 mL]) in a bowl of water. Dunk produce and swish. Rinse in clear water.

Dog Washing- Wet dog thoroughly. Massage in enough soap to create a good lather. (Amount varies based on size, hair type, and overall dirtiness.) Rinse thoroughly.

Cleaning Makeup Brushes- Wet the make-up brushes in water. Add 1-2 drops soap to the bristles. Massage in gently for 10+ seconds, then rinse. Repeat as needed until water runs clear.

Plant Spray for Bugs- 1 Tbsp. (15 mL) in a quart (1 L) of water. Spray plants twice daily until infestation clears.

Ant Spray (Not on Plants)- ¼ c. (60 mL) Castile soap in a quart (1 L) of water. (This concentration will burn plants.)

Alternate Dilution Options

For a multi-surface cleaner, mix 1/4 cup soap with one quart water.

For a dish detergent, use one part castile soap to 10 parts water.

For a floor cleaner, mix 1/2 cup soap with three gallons water.

For a fruit and veggie wash, add one dash of soap to a bowl of water.

For a laundry detergent, add 1/3 to 1/2 cup soap per load, and add 1/2 cup vinegar to the rinse cycle (more on why in a minute).

For an insect-repellent for plants, mix one tablespoon soap with one quart water.

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