Castile Soap

I. General Information

A. Scientific Name:

No strict botanical name (traditionally Olea europaea – olive oil base)

B. Alternative Names:

Olive oil soap, vegetable soap, natural soap, pure soap

C. Pronunciation:

Kas-teel

II. Sourcing and Origin

A. Source:

Plant-based oils (olive, coconut, hemp, jojoba, or other vegetable oils)

B. Geographic Origin:

Castile region, Spain → now worldwide

C. Method of Processing:

Saponification (mixing plant oils with lye to create soap)

III. Properties and Uses

A. Physical Properties:

Concentrated, liquid or bar, mild natural scent, biodegradable

B. Chemical Composition:

Fatty acid salts + glycerin, no synthetic detergents

C. Primary Uses:

Personal Care – body wash, face wash, shampoo, shaving, baby-safe cleanser (unscented/diluted)

Household Cleaning – all-purpose cleaner, dish soap, floor cleaner, laundry detergent alternative

Specialty Uses – pet shampoo (dogs), produce wash, biodegradable camping soap

D. Key Benefits:

Gentle, eco-friendly, cost-effective, versatile, vegan, non-toxic

IV. Safety and Considerations

A. Potential Allergies:

Can cause dryness/irritation if used undiluted or with sensitive skin

B. Best Practices for Use:

Always dilute, store sealed, use unscented for sensitive users

C. Special Precautions:

Don’t mix with vinegar/lemon; not safe for cats; may leave residue in hard water

V. Fun & Educational Facts

A. Historical Context:

Originated in medieval Spain, prized as luxury soap for royalty

B. Did You Know?

Dr. Bronner’s popularized modern Castile soap in the U.S.

C. DIY Recipe Idea:

DIY Foaming Hand Soap (1:3 soap-to-water + essential oils)

All-Purpose Cleaner (1:20 soap-to-water in spray bottle)

Gentle Face Wash (1:4 soap-to-water dilution)