Castile Soap
Also known as: Dr Bronners, Liquid castile, Olive oil soap
Plant-based soap that works for body, hands, dishes, floors, and laundry. One product, many uses.
How it works
Castile soap is made by saponification — reacting plant oils (traditionally olive oil) with lye (sodium hydroxide or potassium hydroxide). The result is soap molecules with a hydrophobic (water-repelling) tail and hydrophilic (water-attracting) head.
How it cleans: Soap molecules surround dirt and oil particles. The hydrophobic tails attach to the grease, while the hydrophilic heads face outward into the water. This forms micelles that lift dirt away and suspend it in water.
Why it's different: True soap (saponified oils) is biodegradable and doesn't contain synthetic surfactants like sodium lauryl sulfate. It's alkaline (pH 8-9) which helps cut grease.
No synthetic detergents: Unlike most liquid "soaps" (which are actually synthetic detergents), castile soap contains no sulfates, synthetic fragrance, or preservatives like parabens.
Uses
- -Body wash — dilute 1:2 with water
- -Hand soap — in foaming dispenser, dilute 1:4
- -Dish soap — few drops, cuts grease well
- -Floor cleaner — 2 tbsp per gallon water
- -All-purpose spray — 1 tbsp per quart water
Why we recommend it
One genuinely multi-purpose product that replaces many. No synthetic detergents, no fragrance (or essential oil only), no preservatives.
Replaces / avoids
Caution
Don't mix with vinegar — the acid breaks down the soap into oils. Use separately.
Where to get it
Health food shops, online. Dr Bronners is the classic but there are cheaper options.
Mid-range