A Word of Caution About Vinegar and Castile Soap

Dr. Bronner’s Castile soap and vinegar can clean an entire house. They are effective, versatile, biodegradable, and non-toxic. But the sole point of this post is to emphasize that these two should not be mixed directly. This is true for the castile soap and any acid – any vinegar or lemon juice.

Since there have been several recommendations in online recipes and on TV to mix these two together, I want to address this topic. It’s not a dangerous combination, but it’s definitely moving in the wrong direction as far as getting things clean.

Here’s why.
In great part it’s due to the fact that vinegar is an acid and the castile soap is a base. They will directly react with each other and cancel each other out. So, instead of getting the best of both (the scum cutting ability of the vinegar and the dirt transporting ability of the soap), you’ll be getting the worst of something entirely new. The vinegar “unsaponifies” the soap, by which I mean that the vinegar takes the soap and reduces it back out to its original oils. So you end up with an oily, curdled, whitish mess. And this would be all over whatever it was you were trying to clean – your laundry or counters or dishes or whatever.

Check out this picture of Dr. Bronner’s Peppermint Castile soap mixed directly with distilled white vinegar:

Dr. Bronner's soap mixed with vinegar

It doesn’t matter what else is in the solution, or in what order you combine them. If you end up with the soap and the vinegar in the same container, this reaction will occur.

The mom in me has to point out that if you have kids who wonder about the purpose of science class in “the real world”, you can show them this little reaction. Of course, drinking milk and orange juice at the same time will also point out why you should know your acids from your bases.

So, for cleaning, there is a better way. Use the soap to clean and the vinegar as a rinse agent.

One common complaint with using the castile soap, especially on hard or shiny surfaces is that it leaves a film behind. This film is caused by the soap reacting with minerals in the water. It is not actually soap itself left behind, but rather certain salts. When this builds up on sinks and tubs, we call this soap scum. Vinegar is a great way to cut this. So after you’ve handwashed your dishes with castile soap and rinsed them, dip them in a sink of vinegar water. Or after you’ve wiped down the sinks and tubs with soapy water, rinse, and then spray with a vinegar solution (about 1 cup vinegar/quart water).

I’ll give more time to windows later (one of the things I actually really enjoy cleaning), but briefly, for dirty exterior windows, spray them with my castile soap solution, wipe them with a chamois, then spray them with vinegar and squeegee. Works great! Better than Windex.

Also, on the hair, if you do not have our Citrus Hair Rinse, but just want to use vinegar or lemon juice, rinse the soap out of your hair first. Then apply the vinegar or lemon juice.

So Dr. Bronner’s Castile soap and vinegar are a fabulous one, two punch. One after the other. Not at the same time.

As a sidenote: This issue does not apply to combining Sal Suds with vinegar. Sal Suds, as a synthetic detergent, has a completely different chemical makeup and does not react with the vinegar in the same way. Vinegar would even add more degreasing power to the mixture.

390 thoughts on “A Word of Caution About Vinegar and Castile Soap

  1. Ive been cleaning with vinegar, water and castile soap for years and if you do it in the right order you do NOT get the white slick mess… I get a beautiful solution and it cleans wonderfully, no streaks eve on glass that the sun shines brightly through!

    • so do I; two table spoons of Liquid Castile in a 32 oz spray bottle fill it almost to the top with water…let it rest for a few minutes and add about 2 oz. of vinegar and it works great

    • You did not share what is the right order, Ratha Choup!

  2. I have a question, I can use lemon essential oil, or any citrus oil, on the unscented Castile soap to make my own scent?

    • Hi Renae – Yes! That’s a great thing to do. Lots of fun!

  3. Would it change anything if I only used a couple of drops of soap to a four-cup mixture of vinegar and water?

    • Nope. The soap would be totally undone by the vinegar and provide no benefit whatsoever.

    • Hi T – When I wash clothes with the castile, I add vinegar to the fabric softener spot in my washer. Then it is only added during the rinse cycle. For dishes, if you wash with castile, I rinse in plain water and hand dry them. If you wanted them to drip dry, add another step of dipping them in a sink of water with a cup or so of vinegar in it in order to eliminate any hard water spots on the dishes.

    • Hi Cherie – Kleen Green does not list their ingredients, so I don’t know what’s in them or how they’d react with our castile. They give categories, but not specifics, which is kind of frustrating. You can try asking them about adding Castile.

  4. Regretfully, I didn’t know about this before washing our three cats in an ACV+Dr. B’s Baby Mild mix to fight fleas. Now all three cats are losing hair on their heads, where we applied the most of the mixture. I feel awful! It’s been about a week since the bath and we thought the greasiness would go away, like with other products, but the cats are still a little slimy. I’ve tried searching the internet, but can’t find an answer: how do we clean up unsaponified soap (especially from fur)?

    • Hi Molly – What you have with the ACV/soap combo is the original oils. Your cats are probably ingesting the oils that are left on their fur, and although they are organic, it still might not be best for their tummies in quantity. Washing your cats again with just the unscented Baby Mild soap will help tremendously.

  5. Thank-you, Lisa, for this VERY informative article! I recently had a contractor come in and change out the original 1960″s “orangey” trim in our little ranch style home with a clean, craftsmen inspired trim that’s painted white. Now, in the cleanup stage, I want to deep clean my original oak hard wood floors.
    I’ll take your advice and start with the Dr. Bronner’s Castile soap, then come back s e p e r a t l y with the vinegar in a one-two clean punch!

  6. Can unscented Dr. Bronner’s Castille soap be mixed with hydrogen peroxide at the same time?? Thanks!

    • Hi Laurie – Soap and hyrdrogen peroxide is another combination that doesn’t do well. Hydrogen Peroxide, or OH, is slightly acidic and in reacting with the soap will break down. You won’t get the antibacterial benefit of the peroxide. Best to use them separately. I’m currently working on a more comprehensive guide that addresses other combinations such as this one. It should be up soon!

  7. Hi Lisa
    Is that white film (salt residue) on the dishes safe to consume?
    Can I still eat from that dishes without rinsing them with vinegar?

    • Hi Alona – Yes, it’s safe to consume. You don’t have to rinse the dishes with vinegar. That step is just for extra shine.

  8. I used white vinegar, water and Dr. Bronner’s peppermint castile soap mixed together to make an ant repellant because I did not have any peppermint essential oil around. And then I was taken aback by the resultant chemical reaction and found this article. The GOOD news is it worked great for my purposes. I sprayed it outside along the base of the house and in the grass. The ants were immediately stopped, and I had no fear of toxicity to plants or when my cat decided to roll in the grass because he liked the smell so much. So it may not be a good combo for cleaning, but it’s fantastic as a natural ant repellant.

  9. Thank you Lisa! Unfortunately, I didn’t see this until after I combined the two in my laundry load and found the white mess 🙁 If I followed the directions on the bottle, it clearly says to add the vinegar to the RINSE cycle but I was trying to save me the step… is there a way to get the white spots off of my clothes or am I going on a shopping spree?

    • Hi Dawn – I’m sorry that happened! What you have on your clothes is oil. Try giving them another wash but without the vinegar this time. If you happened to have Dr. Bronner’s Sal Suds, use that. It is slightly more effective at tackling spots.

  10. I have found that because I wash my hair with Dr. Bronner’s and then rinse with vinegar I get an oily tub/shower from the vinegar ‘unsaponifying’ the soap still hanging out in the tub. At least I assume that’s what’s happening. Am I the onlt one? And is there a way around this without having to clean my shower every time between washing and doing a rinse on my hair?

  11. Hi! Can you combine Castile Soap with rubbing alcohol to clean & disinfect? If so, what’s the ratio??

    • Hi Cristina – The benefit of adding rubbing alcohol to the Castile soap is negligible. However, it will not react as does the vinegar. If you would like to add alcohol, keep the concentration of it under 5%.

  12. UNFORTUNATELY used it on my cat who has long hair! What can I do to help him out? I used dawn and he’s still matted.

    • Hi Janet – I’m so sorry I didn’t see your question earlier. You may have found a solution already, but in case I can still help, know that what is matting your cat’s hair is all the oils that were released. If you wash him again but without the vinegar, you should be able to get him clean. The Dr. Bronner’s Unscented Baby Mild Castile soap is a great option for cats.

    • Hi from Oregon~I highly think Dr. Willards water would do the job~GREAT for us to drink/heals anything!
      Give the water for any animals & they will not have flea’s~~
      GREAT products..You buy it and use only with Distilled water.. I get the DARK kind~only …and I use 1/4cup to a Gal. of the distilled water…It helps heal about anything~I have used it for 30 years!
      I buy it online…
      Email for any questions….

  13. Hi there! I know this article was written quite a few years ago, but I’m researching what natural detergent would work with vinegar. I currently steep orange or lemon peels in vinegar for a few weeks to make a liquid that I use on a lot of surfaces for cleaning/disinfecting (the citrus oil is the magician there). After reading recently how terrible of an actual CLEANER vinegar is, I’m wondering if adding a saponin like soapberry liquid would classify as a detergent and make an actual CLEANER… or if it would end up making a pointless mess, lol! I’m so disappointed that Sal’s Suds has Sodium Lauryl Sulfate in it!

    • Hi Leiha – I’m sorry to hear your frustration! Vinegar really doesn’t get along well with surfactants. It likes to be left alone. Your best bet is to use a soap or detergent mixture by itself – 1/4 c. of Dr. Bronner’s Castile in a quart of water. Vinegar makes a great glass cleaner, but it doesn’t pick up germs and dirt as well as soap or detergent. Regarding the SLS in Sal Suds, I wrote an article addressing the concerns about it: http://www.lisabronner.com/there-is-no-cancer-risk-from-sls-sodium-lauryl-sulfate/. I hope it helps.

  14. Hey-
    I got a recipe from Dr. Axe site to clean a dirty oven with castile liquid soap 2 Tablespoons, plus 1 1/2 cup of baking soda and 1/4th cup either of organic white vinegar or apple cider vinegar and a touch of water to make a paste-
    You brush this mixture on the oven surface until completely coated-allow it to sit overnight and then wearing gloves you wipe clean with a sponge and clean water-supposed to come out sparkling clean-Ever heard of this before?
    Thanks for your input-

    • Hi Debbie – I haven’t heard of this for an oven cleaner, but it’s worth trying. If you keep the ratio of vinegar and baking soda in check, then the vinegar will react with the baking soda before it can react with the castile. Baking soda is more reactable. I’m sure there’s a more chemistry-ish term for that.

    • Hi, the products of a reaction between vinegar and baking soda are carbon dioxide gas, water, and a little bit of salt. So they also cancel each other out (acid-base reaction). Not much point of including vinegar in this recipe either, I’m afraid!

    • Debbie i did this to my oven a couple weeks ago, it was a nightmare. It left a white film on my oven I could not get off, I then had the brilliant idea to bake it off, bad idea. It started putting out this horrible smell in my house. I waited for things to calm down and aired the house out then spent a good amount of time removing it all with just water. I probably won’t see a reply I happened upon all this information, just wanted to share my experience. I have the sal suds also I’ll do some research and see if that is worth venturing as an oven cleaner 😉

  15. Hi Lisa, I wash my hair with Dr. Bonners soap mixed with coconut oil and my hair sticks together. I use alot of hair conditioner afterwards to no great affect. If I use ACV on my hair after I rinse won’t this leave an oily film on my tub? and is there a better conditioner to use ? Thanks for your time.

    • Hi Alexa – What kind of hair conditioner are you currently using? If you’re using a conventional one, it’s not going to be acidic enough. You need some sort of acidic rinse here – either apple cider vinegar or the Dr. Bronner’s Hair Rinse. ACV won’t leave an oily residue. Quite the opposite. The coconut oil would be more prone to leave the residue. It’s also possible, depending on the ratio of soap to coconut oil, that you aren’t getting much of the benefit of the soap. Since part of the way soap works is to grab on to oil molecules, it might be so busy grabbing on to those coconut oil molecules that there isn’t much left to clean your hair. You might want to treat your hair ahead of time with the coconut oil, and then wash it all out with soap as a follow up. Then do an acidic rinse to condition.

  16. I’m looking to use Dr. Bronner’s Castile liquid soap in a DIY shampoo concoction. I bought all the necessary ingredients, then upon further research learned that it’s really not good to use a Castile soap shampoo, which as a pH of 9+ and then use an ACV rinse with a pH about 3. I’ve read that this drastic change in pH can have negative effects on your hair in the long run. Even usung a high pH shampoo without the subsequent ACV rinse is bad. So my question for you, Ms. Bronner, is do you know of any shampoo recipes using your soap that have a pH of at least around 8 or lower so we’re not damaging our hair?

    • Hi A – You can’t reduce the pH of soap without destroying it. You’d have to go with some sort of detergent based shampoo. Everyone’s hair is different, but if it helps, know that I’ve been using soap and ACV (or Dr. Bronner’s Hair Rinse) for over 7 years and I think my hair is healthier than it has ever been. There are alternatives though. Check out this article written by our Rafi Loiederman, A Definitive Guide to Hair Washing.

  17. Hi Lisa! I am so grateful that you are still answering on this thread. My tub sink has become slow to drain after going through a couple of bottles of the baby mild soap. I read that other consumers experienced the same thing over a period of time using dr. Bronner. Other than snaking the drain, is there a way to “break down” the soap/oil build up? For reference, I already used drano. It did not help. I have not yet used vinegar. Any recommendations will help. I love your soap dearly. Thanks!

    • Hi Cathy – If Drano didn’t help, there is nothing natural that I could recommend. Drano is insanely powerful stuff, and not only is there nothing more powerful, I would not want to risk the chemical interaction of putting any other substance down there. Most likely you have a physical clog – like a child’s toy or something. Drano would eat through hair, but it wouldn’t dissolve a big hunk of plastic. If you take off the U-Bend under the sink, you’ll probably find some lost treasure. I have instructions on how to do that here: http://www.lisabronner.com/deodorizing-the-sink-with-vinegar-and-baking-soda/. HOWEVER (And I capped that because this is a biggie) because you might have Drano still in the pipe, I recommend extreme caution in opening it up to see.

      I really don’t like Drano, as you can probably tell. It’s designed to eat through things and it doesn’t stop with us.

  18. Is it okay to use half castile soap and half water in the auto dish washer ?m

    • Hi Carla – I apologize for my delayed response. I do not recommend using the Castile soap in a dishwasher. I’ve seen people online that do it, but I have found that if your water is the slightest bit hard, it’s going to leave a film of minerals on your glassware.

  19. Okay, didn’t read this before hand. What do you do once you have used the soap with vinegar and an essential oil and it left a waxy mess? At this point I’m not necessary looking for a natural solution to get rid of the wax, I just want the pencil wax gone. Please help!

    • Hi Donald – I’m sorry to hear this happened to you! If you still have some soap left, use that to clean up the mess. Soap and water will grab all those oils off your surfaces.

  20. Hi Lisa I have psoriasis on my scalp and have read that doing a hemp cold press warmed oil treatment that stays on over 8 hours then wash a few times with Castile soap,then finish with ACV will remove flakes and doing this treatment 3 to 4 times first week then every two days and then every 3 day’s , a week , in time it actually cleans scalp and can keep psoriasis off scalp for year so so. Have you heard this? Looking for help😞

    • Hi Leslie – I haven’t heard this, but I am intrigued. My brother suffers from Psoriasis and has a quite a time finding effective remedies. It makes sense that hemp oil would help. Can you let me know how it works out for you?

  21. I just purchased the citruscastile soap. I want to use as a body wash and cleaner. I have a dispenser for body wash. My question is should I dilute it in the dispenser. My husband has used several body washes and they don’t cut the odor besides having produkcts in them I really don’t want to use.
    Thank you in advance.

    • Hi Theresa – What sort of dispenser is it? Let me know if it’s a foamer or what.

  22. Hi Lisa & Friends. Any suggestions 4 using ur Castille soap 2 clean carpet stains. Particularly a old vomit(barf) stain I was unaware of. Thx in advance.

    • Hi Diana – A subject with which I am all too familiar. I know you’re asking about the Castile, but this post on Sal Suds for carpet stains shows you that I have been right where you are. For deep stains, make up a spray bottle with the All Purpose Castile solution – Fill a 1 qt spray bottle almost to the top and then add 1/4 c. of soap. Spray the stain and then rub it in with a damp cloth so that the carpet fibers are coated but not saturated. Let it sit about 10 minutes, perhaps with the damp cloth over it so that the spot does not dry. Then, with several clean damp cloths, rub the spot, getting a new clean cloth as your cloths become soiled. Make sure the carpet is thoroughly rinsed of soap or else the soap remaining will grab hold of dirt and make your carpet look dirtier. Keep “rinsing” with those damp cloths until all the soap is out. The stain should be gone, too! Let me know how it goes.

  23. I put some rosemary mint essential oil in the unscented liquid Castile soap and within a day or so it coagulated. I don’t understand why? Can you help me make sense of it?

    • Hi Karin – That sounds weird to me too. Can you give me a few more details about the essential oil you added – were there any other ingredients in it except pure rosemary and peppermint essential oils? If you have the brand, I can look it up.

  24. I am making a laundry detergent using liquid Castile soap, baking soda and salt… I was planning to use vinegar as my fabric softener(placing it in my Downy ball so it would only be released during the rinse cycle) will this cause a huge mess doing it like that?

    • Hi Kasey – I haven’t personally used a Downy ball for vinegar, as I just put it in my washer’s fabric softener cup, but based on what I’ve read and comments from a few others, it sounds like it works just fine. If you give it a try, let me know how it goes!

  25. Most any essential oils or carrier oils I dilute in Organic Liquid Castile makes the Castile whitish, too thick to go through a soap dispenser (coagulated). Since I don’t use preservatives, when I add a bit of water to thin it out, I add Vitamin E to lessen spoilage. I don’t make large quantities for fear of contamination from adding water. I have not noted what EOs cause this sludge, and what EOs don’t. It would be nice if someone posted the details, for us who did not do Chemistry in school.

  26. I used Dr B’s unscented Castile soap as a shampoo and body wash and felt it left a residue on my skin and hair. Any tips for avoiding that? I tried using it to clean dishes by hand too but not sure if it worked well. We do have hard water in this area from all the limestone.

    • Hi Arlo – As you pointed out, the hard water may be interacting with the Castile soap. Following up with an acidic rinse will restore the pH balance to your hair. You can use a dilution of 50% water and 50% apple cider vinegar or our Organic Hair Rinse. If your dishes are spotted after washing, that again is the result of hard water. Drying them right away will eliminate water spots or switching to Sal Suds, which does not interact with hard water.

  27. Castile soap made my drains slow after a period of time.
    1)What should I do so that I can keep using my castile soap?
    2) You mentioned not to mix castile and vinegar due to acid/base cancellation , but can you mix Dawn, etc. with vinegar or does it have the same reaction as castile?

    • Hi GJ – Slow drains are certainly no fun! Presuming your drains don’t have a clog caused by hair or a small Lego (if you too live with Lego-playing kids), the slow-up is most likely caused by soap scum. To remove and prevent soap scum build-up, you can do a weekly drain deodorizing by putting about 1 cup of baking soda down the drain followed by vinegar. Use a washcloth or towel to contain the reaction in the drain, let it sit for several hours or overnight, then rinse with very hot water. Here’s a how-to blog post: http://www.lisabronner.com/deodorizing-the-sink-with-vinegar-and-baking-soda/. Regarding your second question, detergents such as Dawn will not have the same instant reaction with vinegar as the Castile soap, but it will have a slight reaction. While not harmful, there’s also no real benefit.

  28. Hi! I want to try using Dr. Bronner soap as an all purpose cleaner. I don’t love the scent of vinegar, so was wondering if I could use lemon juice or something else after using the soap instead of vinegar?
    Thanks for the tips!

    • Hi Mushka – It’s even easier than that! A damp rag is all you need. I prefer microfiber (bought in bulk), but whatever you have will do the trick.

  29. I unfortunately followed a recipe online of Castile soap and vinegar to clean my floors. I now have oil all over my floors. Any recommendations to remove this?

    • Oh no! How frustrating that must have been! Just wash your floors again with the Castile soap, and it should pick up any remaining oil. You’ll want to use 1/2 cup of soap to 3 gallons of hot water.

  30. Lisa Bronner?
    Any relation to Dr. Bronner’s?

    Thanks for this information.
    It makes sense!!

    • Hi Kyle – Yep! He was my granddad. Glad the info helps!

  31. I’m noticing in the ingredients label of Dr. Bronner’s Pure-Castile Liquid Soap, citric acid. This seems to contradict the directive to not mix with an acid such as white vinegar and or lemon juice.

    • I’m glad you’re paying attention! The purpose of the citric acid is to balance the pH of the soap by neutralizing any unreacted hydroxide that’s leftover from the saponification reaction. Each batch of soap is carefully tested to see how much of the alkali is leftover, and then just enough citric acid is added to catch those. The citric acid reacts so quickly with the hydroxide that it completely bypasses the soap molecules. However, if we were to add too much of the citric acid, it would indeed undo the soap molecules and create an oily mess.

  32. What about adding lemon essential oil to a diluted Castile soap mixture in a spray bottle? Since it comes from lemon, is the EO an acid, too, that will unsaponify the soap?

    Also, is there anything you should not mix with Salsuds? (That is what I use more than Castile soap.)

    • Hi Beth – Sal Suds is alkaline, so any acid is going to react with it a bit, albeit not as quickly as with the Castile soap. A bit of vinegar is fine, but not too much. And feel free to add the lemon essential oil to your Castile soap – it’s not an acid, so there’s no interaction.

  33. Hi Lisa,

    Degreaser I use have castile soap, baking soda, water and lemon oil. Does lemon oil undo the soap too? Should I not use lemon, lime or orange oil with castile soap?


    • Hi Icha – No, using lemon essential oil (or any citrus essential oil) would not have the same effect since it is not an acid.

    • Don’t understand how Lemon or any citrus essential oil is “not an acid”, per your last comment to “Icha”? Please educate and thanks!

    • Hi Antoinette – It comes down to what part of the fruit the juice and essential oil come from. Lemon juice comes from the lemon’s pulp and has a low pH. Therefore, it’s acidic. On the other hand, lemon essential oil is cold-pressed from the rind and it’s pH is neutral.

  34. Hardwood Floors–I’ve read various proportions on cleaning hardwood floors. If I use 2 drops of castille soap mixed with 2 cups of warm water and use a spray bottle it says you don’t need to follow up with a vinegar rinse. Does that sound right?

    • Hi Nancy- The typical dilution is 1/2 cup liquid Castile soap in 3 gallons of hot water. Most spray bottles are 1-quart (8 cups), in which case use 1.5T of Castile to 1 quart water (put the water in first to prevent bubbling). A squirt bottle works well for mopping too. You do not need to rinse with vinegar. Here’s a list of dilutions and other uses for our Castile soap: http://www.lisabronner.com/dilutions-cheat-sheet-for-dr-bronners-castile-soap/

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