Natural Liquid Body Soap | Two Ways To Make It At Home

Natural liquid body soap comes in two forms: a true soap made from scratch using potassium hydroxide and plant oils, or a simpler castile-based body wash that blends liquid soap with moisturizers—both avoid synthetic detergents and preservatives.

Walk down any natural body-care aisle and you will see bottles labeled “liquid body soap” that are actually synthetic detergent blends with a natural-looking label. The real thing—a soap made from oils and lye—is rarer. You have two practical routes: make true liquid soap from scratch using potassium hydroxide, or blend a fast castile-based body wash that takes ten minutes. Each serves a different kind of DIYer. Our favorite all natural liquid body soap products take the guesswork out if you want to skip making it yourself.

True Liquid Soap vs. Castile Body Wash: What’s The Difference?

The key chemical difference is the alkali used. True liquid soap requires potassium hydroxide (KOH), which reacts with plant oils to create a liquid soap paste that you later dilute. A castile-based body wash starts with ready-made liquid castile soap and simply adds moisturizers and thickeners—no lye involved.

True liquid soap produces a longer-lasting, more concentrated product with a classic soap feel, but it demands safety gear and a 2-to-3-hour cook time. The castile route is faster, gentler on sensitive skin, and much easier for a beginner. Neither is “better”—they fit different skill levels and time budgets.

Making True Liquid Soap From Scratch

Making real liquid soap from oils and potassium hydroxide produces a versatile soap paste you can dilute into months of body wash.

What you will need: 600g olive oil, 105g coconut oil, 45g castor oil, 143g potassium hydroxide (KOH), 430g distilled water for the lye solution, plus another 900–1400g distilled water for dilution. Safety is non-negotiable: wear gloves, goggles, and an apron, and work in a ventilated area—solid KOH causes serious burns and its fumes are caustic.

The process: mix KOH into the water (never water into KOH) until clear, then combine with warmed oils in a slow cooker. Blend with an immersion blender until the mixture reaches “trace”—a mayonnaise-like thickness. Cover and cook on low for 2–3 hours, stirring every 30 minutes, until the paste turns translucent. Once cooled, dissolve the paste in distilled water at a 1:2 or 1:3 ratio, then add essential oils for scent. The Savvy Homemade liquid soap tutorial walks through each stage with exact measurements.

Making A Castile-Based Body Wash (No Lye)

This route skips the caustic chemicals entirely and works with ingredients you can buy at any natural grocery store.

The simplest recipe: combine ⅓ cup liquid castile soap, ⅓ cup honey, and ⅓ cup carrier oil (jojoba or almond). Whisk gently—do not shake, which creates bubbles that never settle. For a thicker, creamier wash, add ¼ cup aloe vera gel, 1 tablespoon shea butter, and ¾ teaspoon guar gum. The critical step: mix the guar gum into the oils first, before adding the castile soap, or it will clump into unbreakable lumps.

Store the finished wash in an opaque, sterilized bottle. Because homemade versions lack commercial preservatives, use them within 1–2 months and keep them out of direct sunlight. If separation occurs, a quick shake before each use brings it back.

FAQs

Can I substitute sodium hydroxide for potassium hydroxide?

No. Sodium hydroxide (NaOH) makes bar soap, not liquid soap. Liquid soap requires potassium hydroxide (KOH) to produce a soft, dilutable paste.

Why did my homemade body wash separate?

Separation usually means the oils and water were not fully emulsified, or the thickener amount was too low. Add a pinch more guar gum or xanthan gum to the next batch, and always shake well before each use.

Is DIY liquid soap safe for sensitive skin?

True liquid soap is alkaline (pH ~9–10) and may dry sensitive skin unless neutralized with citric acid. Castile-based washes are gentler at pH 5–7 and typically suit sensitive skin better without adjustments.