This is a true-to-tradition "soap shampoo": liquid castile soap (an olive/coconut-oil soap) thinned with a strong herbal infusion and a touch of oil. It's gentle and plastic-free. The one thing most DIY recipes skip — and the reason people say "natural shampoo ruined my hair" — is the acidic rinse afterward, which re-smooths the hair cuticle that alkaline soap roughs up.
Choose herbs for your hair
Rosemary & nettle — scalp and dark hair; chamomile — light hair and shine; lavender — soothing and calming scent; peppermint — tingly, clarifying. Use one or a blend.
Ingredients
- ½ cup liquid castile soap (e.g. unscented Dr. Bronner's)
- ½ cup strong herbal infusion (see below), cooled
- 1 tsp light carrier oil (jojoba or argan) for dry hair — skip for oily hair
- 10–15 drops essential oil (rosemary + lavender is a great combo)
- For the rinse: 1–2 tbsp apple cider vinegar in 1 cup water
Step-by-step
- Brew the infusion. Pour 1 cup just-boiled water over 2 tbsp dried herbs (or 2 herbal tea bags). Steep 15–20 minutes, then strain and cool. Use ½ cup.
- Combine gently. In a bottle, mix the castile soap, the cooled infusion, carrier oil and essential oils. Stir or swirl — don't shake hard, or it foams up.
- Bottle it. A pump or squeeze bottle works best. Label it with the date.
- Wash. Shake gently, apply a small amount, massage the scalp, and rinse well. It won't lather like detergent shampoo — that's normal.
- Acid rinse (don't skip). After rinsing, pour the diluted apple cider vinegar through your hair, then rinse again with water. This is what leaves hair soft and shiny.
💡 The adjustment period
Switching from detergent shampoo, your scalp may need 1–3 weeks to rebalance oil production. Stick with the ACV rinse through the transition and most people come out the other side with healthier hair.
Storage & shelf life
Because it's water-based with no preservative, use within 2–4 weeks and keep it out of direct heat. Make small batches. If it smells off or looks cloudy/separated beyond a quick shake, toss it.
Troubleshooting
Hair feels waxy/straw-like: you skipped or under-diluted the ACV rinse, or your water is hard — try a stronger rinse. Too drying: add the carrier oil and reduce castile soap. Not cleaning enough: add a little more castile soap or a clarifying rosemary infusion.
FAQ
Why doesn't it lather? Real soap lathers less than sulfate detergents; lather isn't cleaning. Is castile + ACV safe for color-treated hair? Soap-based shampoos can be harsh on color — do a strand test first. Can I make a "real" sulfate-free shampoo? Yes, with gentle surfactants (like decyl glucoside) and a preservative — a more advanced project we'll cover separately.