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How to make castile bar soap

February 20, 2012 by Karl

Soap berry berry berry

This article will show you how to make your own castile bar soap.  If you enjoy using natural soaps, this will show you how save money making it yourself for about $1 US per bar.

First something that needs to be said about soap.  There is NO WAY to make bar soap without using lye.  It is a physical impossibility.  The basic reaction that is needed to make soap, called ‘saponification’, cannot happen without some form of lye reacting with some form of oil.  Lye is actually a general term for a very strong alkali (the opposite of acid on the PH spectrum).  There are generally two alkali’s that are used in soap making, sodium hydroxide and potassium hydroxide.  Both are considered lye, but the potassium hydroxide is not strong enough to make a solid soap.  It is only used for making the liquid soaps in today’s world.

Soap manufacturers today do everything they possibly can to hide the fact that they use lye in their soap.  They have made up lots of names to hide it.  Dr. Bronners soap, which many naturalists are in love with as a natural soap, uses lye.  They hide the fact in their ingredients list by saying that they use “saponified oils”, which is the process of mixing lye with oil.  The public is afraid of the word lye, but they have no idea that it is used in every bar soap ever made.  Soap simply cannot be made without it.

The important thing in any soap recipe is using the proper proportion of lye and oil to form a PH neutral soap when completed.  In times of old, soap makers were not using a pure form of lye in their recipes.  The PH of the lye was not consistent, so their end product could end up being very alkaline, and burn the skin.  The story of “lye soap” burning the skin has been passed through the generations, creating public fear of the word.  When properly used, lye is our friend.  Lye (sodium hydroxide in this case), when mixed in the proper proportions with hydrochloric acid, produces a strong chemical reaction resulting in table salt, something we have been eating for hundreds of years.

The recipe below uses the proper proportions of oil and lye to create a PH balanced soap that will be very mild to the skin.

Here are a few tools you will need:

  • A digital scale capable of 5 lbs measurement.
  • 2 glass bulb thermometers that can measure up to 200° Fahrenheit.
  • A stick blender.
  • A high temperature plastic jar  (to mix the sodium hydroxide and water).
  • A long-handled plastic mixing spoon.
  • A ladle.
  • Two large plastic bowls.
  • Soap molds.


Here is the recipe:

  • All measurements are in weight – not fluid ounces.
  • All bars are assumed to be 4oz.


Full Batch Half Batch Quarter Batch
Makes 28 bars Makes 14 bars Makes 7 bars
24oz Cold Distilled Water 12oz Cold Distilled Water 6oz Cold Distilled Water
12oz Sodium Hydroxide (lye) 6oz Sodium Hydroxide (lye) 3oz Sodium Hydroxide (lye)
74oz Olive Oil 37oz Olive Oil 18.5oz Olive Oil
14oz Coconut Oil 7oz Coconut Oil 3.5oz Coconut


Caution: Whenever working with Sodium Hydroxide it is recommended as a safety precaution that you use rubber gloves, goggles, and any other protective gear that you may want to use in order to protect your skin or clothing from accidental splashes of the liquid.

  1. Add lye to water in a high temperature plastic container outside of house. Do not breathe fumes. Always add Lye to water (not reverse). Caution: Temperature of mixture will rise to approximately 195ºF. Stir mixture with plastic spoon.

  2. Mix oils and microwave to 110ºF.

  3. Allow lye to cool (place in bowl of cold water to speed up cooling).

  4. When both solutions are at 110ºF, add lye solution to the oil mixture. Blend with stick blender until the mixture reaches “trace” where you can see a film on top of the soap that traces the line of the stick blender. Ladle into molds.

  5. Handle bars with care for next two days. PH will be high and can burn the skin for the first 48 hrs.  The PH will settle to neutral after this.

  6. Place molds in freezer for 30 minutes to help separate the soap from the molds.

  7. Allow 6-8 weeks to air dry before use.


Distilled water is used to guarantee that the PH of the soap will be neutral when complete, and that no impurities are in the water that could affect the saponification process.  Distilled water can be purchased at any shopping center in a one gallon container.

Lye (Sodium Hydroxide) can be purchased locally at any Lowes home center, and now Tractor Supply carries it too.  A two-pound container of Roebic Crystal Drain Cleaner is available for just over $12.  Make sure you buy the one that says 100% lye.  Or, you can purchase it in bulk HERE.  Two pounds are plenty to last more than two full batches.

Please note that sodium hydroxide is considered a hazardous substance, and shipping prices increase significantly because of this.  It is also used in manufacturing certain illegal drugs, and some states may regulate the sale of lye for this reason.

Soap molds can be purchased HERE or at many other internet soap supply retailer.

How to make your own Castile Soap like Dr. Bronners from on Vimeo.

I now have an article posted on how to use this bar soap to make your own liquid castile soap. Check it out HERE.


  1. Mandy says:

    Can you add colors and essential oils to fancy the soap up?

    • Karl says:

      You absolutely can Mandy. I didn’t include that in this post, but I may do that later. You add your essential oils right before you blend the mixture.

      • Mandy says:

        Thanks. I think I’m going to try this. 🙂

      • Karl says:

        Stay tuned. My next post will be on how to make liquid soap (like Dr. Bronners). It’s the exact same stuff for a fraction of the cost.

        • Susan Rogers says:

          Hi Karl – was interested in finding out when you are going to provide information on how to make soap like Dr Bonner’s. Can you let us know if you have done this yet and where we can find the information.
          Thanks ! Susan

          • Susan Rogers says:

            Hi Karl – thanks so much for getting back to me. Yes I did see your method of making the liquid soap by using a bar of the castille soap. What I am interested in is if you have the recipe for just making liquid soap from scratch without using a bar. It must be something to do with the measurement of materials.

            Really enjoyed your webcam instructions on the bar making…very clear.
            Looking forward to hearing from you on this.

          • Karl says:


            Sorry, I have never made liquid soap directly. Though it can certainly be done, and is the standard method for making liquid soap, it is a different process than making bar soap. Liquid soap typically uses sodium hydroxide (a more mild lye) instead of potassium hydroxide, which changes the recipe significantly.

            Maybe one day I will attempt making liquid soap directly, but this is not on my current agenda.


      • Tamisha says:

        Do you add the essential oils right before you blend to trace? I’m about to try and make soap for the first time and want to make sure I get it right. Also, is there a certain amount of the essential oil I should use?

        • Karl says:


          Yes, exactly….. just before blending. I use 10-15 drops of essential oil (depending on the oil and the potency).

          Hope it works out well for you!


    • amanda says:

      Hi can you post brand of coconut oil and essential drops you use in this video??? Thank you!

  2. Wonderful website you have here but I was wanting to know if you knew of any discussion boards that cover the same topics talked about here? I’d really like to be a part of community where I can get feedback from other knowledgeable people that share the same interest. If you have any suggestions, please let me know. Kudos!

  3. Ann says:

    I recently went to lowes to get the lye and was told that they no longer carried the roebic crystals..the closest they had was Enforcer Crystal Heat..can I use this?

    • Karl says:


      What state do you live in? Here in Pennsylvania they stopped carrying it for about a year and then started again about 6 months ago. What you may need to do is order it from Lowes on-line for in store pickup. Buying lye locally has been a big problem for soap makers over the years. You used to be able to get something called Red Devil lye, but that was taken off of the shelves about five years ago, and I haven’t seen it since. There seems to be a big issue with lye being used in the illegal drug processing operation.

      To answer your question about Crystal Heat. NO it is not suitable for making soap. You need to find something that is 100 percent sodium hydroxide. To my knowledge the Roebic is the only one available locally. Try the on-line order with in-store pickup at lowes. If that doesn’t work, you may need to buy it from Essential Depot and pay for the shipping.

      • Ann says:

        Ok I’ll try the online ordering..thanks..

        • Karl says:

          Keep us updated Ann. What state are you from?

          • Ann says:

            I’m from ky. Turns out they stopped stocking it so I could not order it for online pickup But I can get it from a Lowes farther away so that’s what I am going to do. It is about 50 miles away..

          • Karl says:

            Wow! Sorry you need to travel so far! I think this would be much more expensive when you figure time and gas into the equation than just ordering it from Essential Depot.

          • Lady Angel says:

            Ann I know this reply is rather late, as I see the date of your post on was back in Feb.. . .

            I usually get my Lye from Ace Hardware. If you dont have one locally, you can order online.

            Their brand is Rooto, or something like that, and the 1 lb jar says Drain Cleaner. . . Check the label- it will say 100% Lye or Sodium Hydroxide.

            The other place to get lye- online is at They have good prices and deliver quickly. If you sign up for their newsletter, you get notice of sales and specials too. . . Hope this helps!

          • Another late reply, but might help others who are looking locally. I get my Roebic at Tractor Supply here in the Dallas area. If you have a Tractor Supply near you it would be a good place to check. 🙂

          • Karl says:

            Thanks ScrimplyThrifty! I’ll need to update the article with this info!


      • Peggy says: sells Red Devil for 10.00 for 2 pounds total cost with shipping is around 18.00

  4. Ann says:

    I actual work 5 miles from the store so its not that bad.

    • Karl says:

      Let me know how it goes….. and if you are on facebook, please share this page with your friends (at the top). I can use as much exposure as possible. Thanks!

  5. Ann says:

    I will..I’m really looking forward to making the liquid.. I’m assuming u use the potassium hydroxide for that.. Where do u buy it?

  6. Orly says:

    When does the “dangerous” part is over with the sodium hydroxide? once it is melted into the water or when it is joined to the oils?

    • Karl says:

      Once it is mixed with the water and the water is clear you are past the most dangerous part. You can still burn yourself if you touch the liquid before mixing it with the oil, but once it is mixed with the oil it becomes very mild. 24 hours later it should be ph neutral.

  7. Orly says:

    Thanks for the quick answer! Great videos too!
    I try making the soap but there are several problems:
    1. The soap did not harden enough even after 2 days.
    2. The color of the soap is not homogeneous, it has darker stripes in it.
    What can be the explanations for this? What did I do wrong?

    • Karl says:


      It’s hard to respond with this little information. It could have had to do with the temperature you had both the lye and the oils prior to mixing, or it’s possible you didn’t get it to trace prior to pouring.

      You say the soap didn’t harden enough even after two days. At this stage, you may still be able to put your finger print into the soap, but if it’s still liquid there is definitely a problem. Try letting it sit for a few more days to see if it sets up then.

      Are you sure you used 100% sodium hydroxide?

  8. Danielle says:

    I would like to make this into liquid shop shortly after releasing it from the mold. Is this okay or should I wait until it has cured for 2 months Thanks

    • Karl says:

      I would wait at least 48 hours from trace. At that point the bar should be ph neutral. If it’s not, it could eat through the bag before it has turned to liquid.

      • Lady Angel says:

        Eat through the bag?? What bag? LOL
        I always use a stainless steel pot or
        plastic bucket to make my liquid soap!

    • Lady Angel says:

      Yes Danielle, you can make liquid soap from the bar soap just after it comes out of the mold, in 24 to 48 hrs. . . Best to use gloves when you shred it up though, as Karl says, it isnt quite PH ready, Also, with this being a Castile soap, it will be somewhat soft. . . which make it harder or even easier to shred it, depending on how you do it (Salad shooters are great for this!) Fresh shredded soap, hot water, a little washing soda, and you have a liquid soap!

  9. mslilypad says:

    I see you are using a dry weight scale to measure your liquid. It looks like your 4 cup quart jar is has quite a bit more than the one cup of water your recipe calls for. That seems to work as I was viewing your video everything went together ok. I do want to try this as I make my own laundry detergent and that work very well.

  10. Mya says:

    I have a book with soap recipes but they all start with a “soap base” instead of making it from scratch like this one. I was wondering if I could use this recipe to make bars that I can hand grate and melt later to use as the “soap base” for the recipes in the book that have the add-ons (like honey, oatmeal, flower buds, essential oils, etc) Your help is appreciated!

    • Karl says:


      Thanks for posting! I’m glad you like this article. I have tried melting this soap down as a base, but it doesn’t work. For some reason this soap simply will not melt. I don’t know why. However, you certainly CAN add what ever you want to the recipe before it hardens, such as flower buds, essential oils, coloring, etc. I don’t know why anyone would want to put Honey in a soap, but I guess you could add that also before it hardens. There is certainly room for experimentation.



  11. Brittany says:

    Hi Karl, thank you very much for this informative video! I am just wondering how long after you make the soap it takes to solidify. Mine has been out for 12 hours and has not solidified past the consistency of thick pudding. Thank you so much!

    • Karl says:


      I’m guessing, by the time you read this, that you have already found your soap has hardened. From my experience it takes 24-48 hours for the soap to harden. It all depends on how closely you measured your ingredients and how well the soap came to trace when you mixed it. Temperature at mixing can also have a big impact. The good news is that you are almost certain to have the soap harden, even if it takes a few days longer than anticipated.

      I hope this helps!


  12. Shelly Fuqua says:

    Thanks so much for your great video and recipes! For the first time I feel confident I can make my own soap. If you use all olive oil instead of coconut/olive oil mixture will it cut down on the lather? I would like to use all olive oil but I want it to lather too. Thanks!

    • Karl says:


      I’m glad you found this helpful!

      I’m not sure about lather when switching to all olive oil. I suspect it could dry out your skin. However when you change the type of oils used, or the quantities of different types of oil used it effects the amount of lye needed in the recipe to end up with a PH neutral soap when completed. If you do choose to try it, please use a lye calculator to determine the proper amount of lye for your new recipe.

      Here is a lye calculator you can use. There are many of them on the web:


  13. Eleni says:

    Hi great recipe but I wanted to know if this recipe can be used as just an oil if glycerine was added! Thanks

  14. Stephanie says:

    Thanks so much for posting this! This was my first try at making soap and the directions and video were very easy to follow. I made it last weekend and have a few questions about the result. When I poured it into my molds it looked like there were tiny bubbles all over the top. Also, I have now removed them from the molds and it has been sitting for about a week. It appears that the bottom of all the soap is going to be very crumbly because of the bubbles I saw. Also, with the last mold I poured I can see what looks like streaks of oil (darker yellowish streaks). That only happened with my last bar though. Do you know what may have caused this? My temperature may have been a little cooler than 110, maybe 107 because I accidently cooled the lye mixture too much and then had to set it in hot water to warm it back up All of it does look like soap though so I think I’m at least on the right track. Thanks again!

    • Karl says:


      Did you use a stick blender with interchangeable blades? The bubbles could have been used by the blade that you have on the stick blender. That’s just a guess. I’ve never seen the bubbles you are referring to. It also sounds like the bottom of your bowl didn’t get mixed well. The temperatures you have listed should not have a drastic effect on the soap.

      I hope this helps.


      • Stephanie says:

        Thanks Karl! I don’t believe the blades are interchangeable. It is just a two sided blade and only has two speed settings. The blade or speed may have been an issue. Is the soap still safe to use even if it didn’t mix completely? I want to use it for laundry detergent so I’ll have to follow your liquid soap directions, but didn’t know if the lack of mixing would cause a problem with the effectiveness of the soap. Thanks again!

        • Karl says:


          If the soap hardened, you should be OK. One way you can check it to be sure is to place a piece of soap in distilled water and let it dissolve overnight. Then take some PH test paper and check the alkalinity of the soap water. It should be PH neutral (7.0). You can get PH test strips where ever pool supp.ies are sold (Walmart has them in season). Again, you should be OK, so I wouldn’t sweat it.



  15. Stephanie says:

    Also another quick question, if I am going to make the liquid Castile soap do I still need to let the soap sit for 4 to 6 weeks before I make the liquid soap?

    • Karl says:


      That’s a common question. No, you only need to let it sit for 48 hours until the soap PH neutralizes.

      Good luck!


  16. Stephanie says:

    Ok so I bought aquarium ph strips and tested the liquid Castile after 5 days and it looks like the ph is about 8.5 so I guess I must have done something wrong. I wasn’t too sure what trace was so maybe I didn’t mix it enough. I’m assuming it’s not safe to use at that ph?

    • Karl says:

      Yeah, unfortunately I think it needs to be tossed. You used distilled water I assume? If not, you may want to test the PH of your tap water just to see. You can also test your test strips by putting it in some distilled water. Distilled water should be reading 7 on the nose.

  17. Stephanie says:

    Yes I did use distilled water and just tested that to be sure and it was at 7. I’m not giving up though and hopefully things will go good the second time around. Thanks again for the advice!

  18. John Heisler says:

    We made liquid laundry soap for the first time the other night, it cost $2.50 to make 5 gal. of concentrate(that equals about 12 gal. of store bought at $7 a gal). We’re going to make this soap tonight and I can’t wait to see how it turns out! Thanks for making the instructions so easy to understand.

    • Karl says:

      Glad to help! Let us know how it works out!


      • John says:

        We mixed the soap by hand for 1 hour, got smart and put the plastic spoon in my drill for 30 minutes until I thought we reached trace. The soap finally solidified enough to cut today. The top was soft and the bottom harder, very crumbly. Research indicated the soap got too cool while mixing by hand. My wife tried some of the soap as a test (we’re going to let it dry more) and while soft, it worked very well! I am pleased with the results and offer this suggestion; USE A POWER MIXER FROM THE START! Unless you have your soap over a heat source, hand mixing takes to long. I will use a paint mixer in my drill for our double batches in the 12X36 trough mold.

        • Karl says:


          Thanks for the feedback. It certainly sounds like something isn’t right with your batch. Was everything weighed before you started? Were the temperatures correct when you mixed them? Did you use 100% Sodium Hydroxide? I’m curious to know what may have gone wrong.



          • John says:

            Everything was weighed on a digital scale, temperature was perfect and we used 100% lye (Red Devil). I’m thinking the problem was the hand mixing taking so long that the mixture cooled. The soap is getting harder every day, but it appears to be “two toned”. It does work though! No harshness and it cleans well. The next time I’ll use a power mixer from the start.

  19. Dana says:

    Hi Karl,

    Bravo!!! I made the soap bars which turned out great!! 48 hours after I used one bar to make liquid castile and that turned out brilliant as well! On my way to use liquid to make other products such as dish soap, shampoo and body wash!

    Thanks much!

  20. Andrea says:


    I have tons of issues finding soap that I can use with all of my skin allergies and this could help me out without spending a ton of money. However, I’m allergic to coconut oil, is there another alternative that will provide the same/similar results?


  21. Sheri says:

    When making the bar castile soap do you just use regular olive oil that you can purchase at the grocery store?

    • Karl says:


      Yes, you can use regular olive oil. The Extra virgin will make the soap smell of olive oil, so if you don’t care, I would recommend the cheap stuff to keep it smelling better.


  22. Sheri says:

    Thank you very much and will let you know how my batch comes out next week. Merry Christmas from Central Texas!

  23. MrsB says:

    Oh my gosh! I’m sooo excited over this recipe! My daughter has VERY sensitive skin, and I have to use all natural products throughout our house. This can get VERY expensive, so I was soo excited when I found this <3 Thank you thank you!

    • Karl says:

      Great! Glad I could help! Tell us how it goes!

      • MrsB says:

        I just remembered I forgot to let you know how it went! It went AMAZING! My daughter’s skin has been doing AMAZING all year! Thank you for showing me how easy it is to actually make soap 😀 I also ran out and got books to delve more into soap making, and now I just can’t stop making soaps!

  24. Loraine says:

    Can I replace the sodium hydroxide with potassium hydroxide? Would the quantity for each ingredient change? Apart from the recommended safety precautions will there be additional precautions to take due to the replacement of sodium hydroxide with potassium hydroxide? Thanks in advance

    • Karl says:


      NO! You cannot simply replace one type of lye for another. The recipes are VERY specific for the type of soap you want to make. If you want to make liquid soap with potassium hydroxide you will need to find a recipe for that somewhere else. My method shows people how to make liquid from bar soap.

      I hope this helps.


      • Peggy Dence says:

        Soap 101 has a beautiful liquid Castile soap tutorial and recipe. Look for it online. Otherwise, has a link to it. It uses Potassium Hydroxide and olive oil and glycerine. It’s the easiest recipe I’ve seen, and I’ve been studying a book about liquid soap. Mine turned out to be a beautiful clear amber color. It’s sequestering right now. I hope this is helpful! Peggy

  25. Lexie says:

    Hi there. I’ve noticed that everyone uses a plastic stick blender. My stick blender is metal (I’m guessing stainless steel). Can I use that or will it react in some bad way with the lye and oils?

    • Karl says:


      I don’t see any reason why you couldn’t use it, though the lye may take it’s toll on it’s outside appearance. If that’s an issue, you may want to consider buying a cheap plastic one. Keep in mind that even the plastic ones have stainless steel blades.



  26. Gabe says:

    Hi Karl,

    Loved the updated video. I am curious about your stick blender. In your mayo video you say that it’s the same stick blender that you use in soap making but you clean it real well. How do you clean it after soap making? Do you use copious amounts of water, soap and water, vinegar?



    • Karl says:


      Good question. Yes, you guessed it. I use lots of soap and water to start, turning the blender on in the soapy water. Then I wipe it down with vinegar. This said, it is still much better to have separate items for soap / food making, but I’m too much of a cheapskate for that.



  27. stefania says:

    I don’t have a scale. What do these measurements convert to in ounces or cups?

    • Karl says:


      If you are going to make soap you need a scale. Don’t try it without. You will end up with a soap that will burn your skin if you do.


  28. jean says:

    Karl..I have an odd shaped soap mold that was made for me. I am a new soaper and I don’t know how to find a recipe to fit the mold, can you please help me out? The measurements are 15 in. long, 3 1/4 in. wide 2 3/4 in. high. The oils I would like to use are olive, coconut, palm and castor. Thank you so very much….jean

    • Karl says:


      I would take a watertight bag, place it in the mold, and fill it with water until it reaches the top of the mold. Then I would weigh the water in the bag. This will give you the total weight of your needed liquids (approximate). Now you can make your own recipe based on the oils that you want. I would use about 2/3 olive oil, with the remaining third split between the palm and caster oils. Now do a simple web search for a lye calculator. Plug your oil numbers into the calculator and it will tell you how much lye (sodium hydroxide + water) you will need to make soap with these oils.

      I hope this is helpful!


  29. Betty K says:

    Thanks for taking the time to post the great video on making Castile soap! Also, I would like to know what brand, and where you purchase your thermometers and soap molds. Thank you!

  30. plainjane says:

    Maybe I missed it, but do the soaps not need to cure after they come out of the molds? My goat milk soap has to cure for several weeks – this castile soap does not?

    • Karl says:


      Step 7 – Allow 6-8 weeks to air dry before use.


      • jane says:

        Oh thanks, I see it. I came straight from Vimeo to the comments section, you didn’t mention it in the video. I should have read the recipe more closely.

  31. Just made a small batch today (veteran CP soaper here), which made nine beautiful white small 2 1/2 x 3 inch bars with hardly any scent at all. Turned out way better (so far) than my old castile recipe). Very excited to use it since I’ve been reading on all the uses of the Dr. Bonner’s soap (but too cheap to buy it). Planning on using it for shampoo and in the garden to keep the bugs off my plants. So many other uses to explore too. I’m going to have a hard time waiting the 48 hours before making the liquid soap….but I will. 😉

  32. Laura says:

    What are the best options for coloring? Is there a specific product that should be used? Thanks in advance!!

  33. Tanya says:

    I was following the video:
    And instead of using potassium hydroxide I grabbed the wrong bottle and used sodium hydroxide…I’ve already added the sodium hy./glycerine mix to the oils.
    Is there something I can do to fix this or should I just toss!? 🙁

    • Karl says:


      I’m guessing that you have a very hard mess! I think you are safest in tossing it and starting over. Good luck!


      • Tanya says:

        Your are soooo right! 🙂 Waiting for it to cool down so I can salvage my crockpot. Can’t believe I did that…all that is left to do is laugh.

  34. Tracy A. Goode says:

    Why do you use both olive oil and coconut oil? Can you just use one or the other?

    • Karl says:


      The coconut oil gives the soap a good lather and helps to make the bar harder. Yes, you can use one or the other, but you would need to adjust the amount of lye in the recipe using one of the on-line lye calculators.



  35. sarah says:

    Hi Karl, I have a question about your castile soap I made a half batch and my scale on does gram so I had to convert everything over to grams from oz and the first 24 hours after I let it set it had a watery top and then now that its been sitting for over 24 hours its really liquidy but it still has that creamy yellow color I don’t know if I need to let it sit longer or if im doing something wrong any help would be much appreciated

    • Karl says:


      Are you using SODIUM Hydroxide? It almost sounds like you are using potasum hydroxide from the results. Honestly, there are WAY too many variables for me to troubleshoot what went wrong from what you described.


  36. Colleen says:

    Hello. I see that you poured your cold process soap into individual soap molds. I thought that was not possible because it would not get hot enough to allow the soap to saponify. Is that incorrect? Also, did you let your molds with the soap in it just set out on the counter until it hardened the next day or did you cover them with a blanket to allow them to heat up? I appreciate you taking the time to answer my questions as I am a new soaper and I still have a lot to learn.

    • Karl says:


      I’ve never heard of either of these issues. I have always placed the soap in the molds and then right on the counter. There seems to be a lot of bad rumor in the soap making world.


  37. Carol Roper says:

    I was told I could use Drano from Lowe’s, so I bought some. I thought it said 100% lye, but now see it says caustic stabilizers, carrier, dye. Is it okay to use?

  38. Tracy A. Goode says:

    Adventures in Soap Making: So, I was all excited about making my first batch of soap (I’ve been making my own laundry detergent for a year now, so this was a move up into a new and fascinating world.) I went online and found a two pound bottle of food-grade lye-sodium hydroxide-and ordered it. After it came in, I went to the store to get my oil.

    Olive oil was fairly expensive, even for the light stuff, so I decided I’d use Canola oil–it was on sale. The coconut oil was easy; I already had it in the pantry for a recipe for homemade Mounds and Almond Joy candies. Went to the lye calculator, calculated for a 1/4 batch of soap–no need to do more when I’m just learning this, right?

    I borrowed my dad’s kitchen scale and his immersion blender for the big day. Carefully, I weighed out the ingredients–oils, lye, and distilled water. I had a bottle of flowery scent next to me, ready to go.

    Outside we went and mixed the lye and water. Inside we went with the solution to get the oils out of the microwave. At 110 degrees on each, I poured the oils into the lye solution. (This may be part of where I went wrong.) I added several drops of the scent. In went the immersion blender, on low–and in less than a minute, I had this creamy looking lump of solid material. Pour into molds? More like spoon in and smooth with a spatula.

    Hmm…I didn’t think it should happen THAT fast. So, I go looking online. No, I should have PULSED the immersion blender. Okay, now what?

    I decided to let it sit for a few days, then see what I had. When I took the (not smooth) creamy colored blocks out of the molds, and cut them into bars, they LOOKED okay–but they had no scent at all. Still, I decided to shred them, melt them, and reform them. It shredded like room temperature cheese. And best of all–NO pockets of icky, miserable lye! It was solid all the way through! (Had I known that without shredding, I’d have stopped there.) Took the now mozzarella-looking mess to the stove, and added distilled water–and added distilled water–and added distilled water till I got this lump(ier)mess in the pot.

    Hey! (came the bright idea) Let’s add some red food coloring and SWIRL it through! If I can’t have a nice floral scent, at least I can have a marbled look, right? So I did.

    Poured the whole gloopy mess into a 9×13 baking pan and it looked SO pretty. It might not have been perfectly smooth; it might have looked somewhat like the congealed cheese found on nachos after two days (don’t ask–just take it I have a brother); but it had pretty red swirls through the creamy surface.

    A sigh of relief–I’d done it. I put the soap in a spare bathroom to dry, away from animals, husbands and grown sons who are fascinated by my “experiments.” Now, it would just have to dry enough to take it out in a few days and let it finish air drying. I went to bed, a satisfied soap-maker.

    Two days later, I go to check the soap. My pretty red swirls were gone. Instead, I had a very soft, still almost liquid Neon PINK pan of clear gel soap. Okay–let it sit longer, I thought. BUT in the meantime, I cut one quarter out, put it in a ziploc bag with even MORE water to make it really liquid. Regardless that it was the consistency of jelly, regardless that I had somehow messed up what sounded so easy–it bubbled and frothed and cleaned so well.

    This was at Thanksgiving. Now, we are two-thirds of the way through January and the remaining “bars” are still like neon jelly. But in my bathroom is a Rubbermaid condiment dispenser of neon pink liquid bath soap that cleans well and bubbles nicely. My sons are happy with it, my husband is as well. For myself, I’m looking forward to my next batch, but enjoying this one in the meantime.

    • Karl says:

      I’ve never tried the recipe with canola oil. I would question the lye calculator that you used. Some of them come up with different results. Wish I could help more.


      • Tracy A. Goode says:

        I used the lye calculator that you recommended. I don’t know what the problem was; all I know is that I can’t wait to do this again.

        • Karl says:

          Sorry, without actually watching you in the process I can’t say what may have gone wrong. Make sure you are following the instructions EXACTLY.

          Good luck.

  39. louise says:

    Hi from the uk…just about to make my first batch, had to order the sodium hydroxide from ebay, just wanted to say many thanks for the clear instructions, hoping this soap help improves my sons eczema…

    • Karl says:

      Let us know the results Louise!

      • louise says:

        My soaps look fantastic thanks, The smaller amount recipe made 6 bars with the mold I used…I added a little coconut fragrance..They look lovely and smell lovely, wish I could use one now 🙂 once again, thanks for making my first soap-making experience so easy.

  40. Ashley Heath says:

    I am very excited to experience the soap making process. Does anyone have experience or advise in adding vitamin E oil to the original recipe?

    Thank you for the wonderful information!

    • Karl says:

      You can add a few tablespoons of vitamin E oil right before mixing with the lye. I don’t think you will see much result from it though.

  41. darlene says:

    I tried this but it has been 24 hr and my soap is still soft

    • Karl says:

      Make sure you are using 100% sodium hydroxide.

      • sarah says:

        Karl I have a really biG PROBLEM,i made the soap using ingredients you mentioned but instead i used the warm method which was mixing the NaOh with water an leaving until mixed on the same time while its mixing, you put a pan full of water and let it boil,after you put the oils togrthr in a smaller pan and let it sit on the boiling bigger pan, when the cocnut oil is dissolved and the naoh is also you mix it then start beating it with a beater, until it gets creamy then it gets to the volcano fase()saponification it erupts and then you beat it and repeat this again, then you put it in a reciepeint and in 24 hrs u can use it again…
        But mine didn’t get thick…
        if i leave them 6-8 weeks will i be able to use it please help, i used up my ingredients …

  42. a girl in ohio says:

    Hi Karl! Great site! I have made soap once before in the crock pot with lard as my oil base. I was just wondering if you have tried this and what the measurements would be? It turned out okay but I would like to try the cold process instead of the hot process to see if I like the bars better. I like to use lard as my base because it is available to me as I raise my own pork!!! Thanks Kelly

    • Karl says:

      A Girl in Ohio,

      You are in territory that I have not gone into. I would guess there is a lye calculator online that would have pork lard in it, but I would also guess that the properties of the lard would very widely, and thus make it difficult to have consistent results with a ph neutral soap as the end product. Sorry I can’t help more.


  43. Leslie says:

    Hi Karl
    Can I substitute Hemp oil for some of the olive oil? I noticed some Castile soaps use it as an ingredient. Or maybe a blend…olive, hemp, coconut and jojoba?

    • Karl says:


      Yes, you can substitute any oils that you want, however, whenever substituting oils you need to find a lye calculator on-line to re-calculate the amount of lye you use. This is critical to changing any oils or oil quantities.


  44. Erika says:

    Hello Karl,

    Thank you for sharing this recipe. I made it a couple of days ago and I just couldn’t wait to try out the soap. I cut a small bar and lathered up with it today. It turned out quite nice, thanks again for sharing.

  45. Diana says:

    Hi Karl I’ve just followed your video on making castile soap. All very clear and easy, but, alas, after sitting overnight in the moulds it is still a thick, creamy consistency.

    What can be done to t urn it into a soap bar?


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