Making shampoo bars with olive oil is a rewarding process that combines traditional soap-making with hair-friendly ingredients. Olive oil is prized for its gentle, moisturizing properties, but it creates a bar that can be soft and low-lathering if used alone. For an effective shampoo bar, you’ll need to blend olive oil with other hard oils and butters-like coconut oil and shea butter-to create a balanced bar that cleanses without stripping.

Why Olive Oil Works (and What to Watch For)

Olive oil is rich in antioxidants and squalene, which mimic the scalp’s natural sebum. It produces a mild, conditioning bar that’s ideal for dry or sensitive hair. However, 100% olive oil soap (Castile soap) is very soft, takes months to cure, and offers little lather. For a shampoo bar, aim for 30-40% olive oil in your oil blend. This gives you gentleness without sacrificing hardness or bubbles.

Basic Cold Process Shampoo Bar Recipe

This recipe yields a gentle, conditioning bar suitable for most hair types. Always wear safety gear when handling lye (sodium hydroxide).

  • Olive oil - 35% (e.g., 175 g)
  • Coconut oil - 30% (150 g) - adds lather and hardness
  • Shea butter or cocoa butter - 15% (75 g) - condition and hardness
  • Castor oil - 10% (50 g) - boosts lather and moisturizes
  • Sunflower or sweet almond oil - 10% (50 g) - light feel
  • Lye (sodium hydroxide) - use a soap calculator to get exact amount based on your oil weights
  • Water or a liquid (aloe vera juice, distilled water) - typically 2:1 ratio of lye to liquid
  • Optional additives - 1-2% essential oils (lavender, rosemary), clays (kaolin for gentle cleansing), or silk proteins

Step-by-Step Instructions

  1. Prepare your lye solution. In a well-ventilated area, carefully add lye to cold water (never the reverse). Stir until dissolved and let cool to about 100-110°F (38-43°C).
  2. Melt your solid oils and butters (coconut oil, shea butter) over low heat. Then add the liquid oils (olive, castor, sunflower). Heat gently until all are melted and no solids remain. Let cool to the same temperature as the lye solution.
  3. Combine and blend. Slowly pour the lye solution into the oils. Use a stick blender in short bursts, alternating with stirring, until you reach “trace” - the batter thickens to a pudding-like consistency.
  4. Add extras. Stir in your chosen essential oils, clays, or silk. Mix well.
  5. Pour into molds. Silicone loaf molds work well. Tap gently to release air bubbles.
  6. Insulate and cure. Cover with a towel for 24 hours. Unmold and cut into bars. Place bars on a rack in a cool, dry place to cure for 4-6 weeks. Olive oil bars need a full cure to become hard and gentle.

Tips for a Great Olive Oil Shampoo Bar

  • Don’t skip the coconut oil. Without it, your bar will be slimy and lather poorly. A 30% coconut oil level is safe for most hair; if you have very dry hair, reduce it to 20% and replace with more olive or almond oil.
  • Add a citric acid rinse. Soap-based shampoo bars are alkaline (pH ~9), so rinse with diluted apple cider vinegar (1 tbsp per cup of water) to restore hair’s natural pH and reduce buildup.
  • Store properly. Keep bars on a draining soap dish between uses to extend their life.

Frequently Asked Questions

Can I use only olive oil? Yes, but the bar will be very soft, take months to cure, and produce a slimy, low-lather shampoo. It’s better to blend, as described above.

Is olive oil shampoo bar good for oily hair? It can be too heavy. Reduce olive oil to 20% and increase coconut oil to 40% for more cleansing. Add a little lemon essential oil or rosemary.

Making your own olive oil shampoo bars lets you control exactly what goes into your hair care routine. With a balanced recipe and patience during curing, you’ll create a bar that cleans gently, moisturizes, and lasts for weeks. Happy soaping!