How to Wash Your Hair with Castile Soap

In the world of natural beauty, changing up your hair care routine can be one of the toughest to achieve. There’s no set regimen that works for everyone, and the potential detox period can be enough to make you give up on the spot.

Some of you may remember my honey hair-washing experience. Yes, I washed my hair with honey…for an entire month. I gave it an honest go, but my hair just never felt clean. Now I’m onto something new — castile soap.

Castile soap is a natural, vegetable-oil-based soap that has many, many uses. Surely you’ve come across Dr. Bronner’s famous “18-in-1” castile soap that boasts a multitude of uses, like washing your hands/face/body/hair, brushing your teeth, cleaning your dishes, washing your windows, scrubbing your bathroom and more.

While I’m no expert in washing hair with castile soap, I have certainly picked up quite a few tips along the way. If you’re an experienced castile washer and have your own tips to share, please do so in the comments!


Leave yourself some extra time. This process is actually super simple, but it does require a few extra minutes to get yourself prepped. I make my washing and rinsing concoctions just before getting into the shower, but you could prep in advance, too! Being organized is key, so store all of your materials in the same area if possible.

Dilute, dilute, dilute. Castile soap is extremely alkaline, which means that it can quickly disrupt your hair’s natural pH balance if you use too much. Trust. I’ve made the mistake. Dilute your soap in purified water. I know it’s way easier to use water straight from the tap, but even the cleanest tap water is likely to contain levels of chlorine and heavy metals that can be harmful to your precious locks. I use my beloved ZeroWater filter, which you can learn more about here. The necessary ratio of soap to water will differ from person to person (and even from day to day) but, with a little bit of experimenting and patience, you’ll quickly become a pro. I use a ratio of 1 tablespoon castile soap to 2 cups purified water. Start with that, and experiment from there.

Get a squeeze bottle. Personally, I use big glass jars, but this requires really swift movements in order to pour the mixture exactly where I want it. It might be helpful to use a squeeze bottle instead – especially when you’re just starting out. Just make sure it’s BPA free. ;)


Follow with an acidic rinse. This step is crucial! I repeat: CRUCIAL. Since castile soap is very alkaline, it requires a follow-up rinse of something acidic like lemon juice or apple cider vinegar to restore the pH. I’ve used both, and they’re both excellent! Again, dilute the acidic agent in purified water. I do about ¼ cup of lemon juice or ACV to 2 cups water, but again, this is up for experimentation. If you’re using apple cider vinegar, your hair may retain a bit of the smell, but this will likely dissipate more and more with each wash, until you can’t smell it at all. I also like to add in a few drops of essential oil – lavender has been my recent go-to. After you do the rinse, run cold water over your hair to seal it. Word to the wise: Be sure not to mix your acidic agent and castile soap together – they’ll cancel each other out!


Finish with an oil. Since we’re no longer using conditioner, we must find another way to add some extra moisture. Oil to the rescue. You can really use whichever kind works for you: avocado, coconut, argan, jojoba, almond, apricot. Just make sure it doesn’t contain any unnatural additives. I’ve become quite fond of the John Masters Organics Dry Hair Nourishment & Defrizzer. It’s made of the perfect mix of carrier and essential oils: jojoba, olive, evening primrose, flax seed, lavender, cedarwood and rosemary. It smells incredible and leaves my hair moisturized, sleek and shiny.

Use a natural dry shampoo. One of the reasons I love washing with castile soap is that I don’t have to wash my hair as often as I used to. All I need is a little dry shampoo to keep it looking fresh. I often use pure arrowroot flour with nothing else, but I also love these by LuLu Organics and Fat & the Moon. Learn more about making your own dry shampoo here!

Be open to experimentation. Going all natural with hair care is not an easy feat. Be open to experimenting with different ingredients, different brands and different ratios – and most importantly, do it all with love. Remember why you decided to do this to begin with: you care about yourself deeply, and you deserve to look and feel like the beautiful goddess you are.

If you have your own tips for washing hair with castile soap, please leave them in the comments!

Photos of Brigette by Aroldo Marquez.

Follow Brigette on Instagram, and have a look at her blog Hummusbird!


  1. Hey! I love your hair color and length and I don’t know if it’s the light/picture but the overall finish doesn’t look great to me. It seems to lack shine and body (the hair looks very thin/stringy at the bottom) so I’m not sure about the routine you describe. I really don’t mean to criticize your hair, I’m sure it’s very nice and probably different in real life but the pics don’t make me want to try the routine :(

  2. as much as i’d love to be using castille soap, it’s a no no for coloured hair :(
    on lisa bronner’s blog she states: “One disclaimer – don’t do this on colored hair. The alkalinity of the soap opens up the hair follicles, where the color resides. The color will drain out and fade quickly. Colored hair needs acidic products only. (Soap, by nature, cannot be acidic. Only detergents (shampoo) can be.)”


  3. My mother washed my hair with Castile soap when I was a child, and rinsed with lemon. She used the bar directly. Your post brought back a lot of memories! Now that I’m an old lady, I find my scalp is dry and itchy lately, so perhaps Castile is the answer.

  4. i’ve been on the natural haircare path for a month now and it’s been great! i haven’t tried castile soap, but i rinse with acv each time i wash my hair! (i’ve been experimenting with honey when it feels dry or clay when it’s oily) my hair is thicker, healthier feeling, and less frizzy than it’s ever been.
    if you’re starting the natural hair game, whether that be castile soap, baking soda+acv or other methods, I would advise, from personal experience, to make sure and use a good clarifying shampoo before you begin your journey! otherwise you’ll be working with all the old buildup of your previous shampoos, conditioners, and hair products.

  5. I have been washing with castile soap for about a year now. And I use coconut oil as a conditioner. I absolutely love it. It makes my hair feel so amazing, its so affordable, and it last longer then bought shampoo.

  6. I always dye your hair, do hair, sometimes hair extension, usually her hair conditioner is also different, so now my hair becomes dry rough, read your article, I’m going to try to do more hair care I hope it can be restored.

  7. I have tried different methods of natural hair washing but my hair never felt clean, but I have come across these amazing natural shampoo bars and they are amazing, I will never use anything else again! It’s from Beauty and the Bees a little shop in my home state Tasmania, Australia. They also have an online shop and people all over the world have given rave reviews. I have naturally curly/wavy hair and the nettle one is fab, also the beer shampoo gives extra body and bounce. You can rinse with Apple cider vinegar as a conditioner. They are full of natural ingredients like olive oil, coconut oil, castor oil, honey and all sorts of herbs and great things for hair growth and health! And are quite inexpensive at $12 au a bar. I can’t be more positive about these shampoos, if you like shampoo bars and natural products you will love these!

  8. Castile soap is something new for me. I normally use hair loss concealer on my thinning hair which are working fine for me. I would suggest others to use them instead of going after any medications.

  9. Just a thought: go ahead and mix Castile soap in purified water, but you’re still rinsing and washing in straight up tap water. So you don’t really have to go the extra mile (and dollar) using purified water.

  10. Sorry – I gotta disagree with “so” who left the first comment.
    I think this blogger’s picture above looks amazing. Her hair is expressing itself with texture and bounce. To me, it looks very lively.
    Part of realizing natural beauty is being able to recognize health. This sometimes means a little re-envisioning of beauty too. Do you think those goddamn Pantene hairstyles are what we’re trying to achieve anyway?

  11. Really, really excited to try this castile soap for shampoo! I have been all natural with my hair care for five months now as an attempt to reverse pretty bad hair loss, unfortunately I found out today that the all natural shampoo I have been using is actually rated at a high hazard toxicity by the EWG… Not so natural after all. So this blog post is giving me hope and encouragement during this speed bump.
    I have been loving cocoa powder as dry shampoo for my brown hair! I think I might try mixing it with arrowroot powder to see what it does because you make it sound so great! I use castor oil every day as my conditioner and I’m looking forward to interchanging it with avocado and coconut oils.
    Thank you for your blog posts, throughout my journey and all the hours of research I have been doing I have not found anything this amazingly resourceful.
    Much love xox

  12. When you say finish with an oil how to apply the oil? While you’re still in the shower on your wet hair and give it a rinse after. Or on towel(t-shirt ;) ) dried hair or on completely dry hair?


  13. I decided to ditch commercial shampoos and conditioners about 2 months ago. I started with a blend of coconut milk and jojoba oil and other ingredients but it left my hair a huge greasy mess! I then switched to Baking Soda and a ACV rinse and immediately the greasiness was gone. However after about a month of that my hair just didn’t feel like it was actually being cleaned. I have been trying Castille soap and an ACV rinse for two weeks now but my hair still feels really greasy. Anybody have some tips? Or would my hair still be in the process of getting use to it? I hope this is something that won’t happen everytime!

  14. I’ve been using Dr. Bronner’s unscented castile soap for shampoo for a few days now as I have eczema and my scalp and ears can get suuuuper itchy. This has seemed to quiet the itching on my scalp quite a lot. I use a little and rub the suds on my ears also. I was going to experiment with using some essential oils mixed in as well, and I often put argan oil in my hair after rinsing as my hair has always been dry and fragile.

  15. Please make sure if you have eczema or dermatitis (like me) to ALWAYS finish with a diluted ACV (1TSB + 1cup water) as Castile shampoo is highly alkaline with a pH of 9.
    Skin has a pH of 5.5, so a diluted mix of ACV and water poured over the scalp and combed through the hair will do the trick. Do not rinse.
    Be careful if you suffer from these skin conditions as alkalinity is a disaster for people like us!

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