How to Make Your Own Soap: All-Natural Castile Olive Oil Bar Soap Recipe

dec1_2013 005I never – and I do mean never – expected I would be making my own soap. I always assumed the ingredients were too caustic, the process too difficult, and the whole shebang just too darn hard.

Thankfully, I was quite wrong.

As we began talking more and more about increasing the DIY-ness of our lifestyle, my husband got me a book that has become one of my favorite sources of inspiration… Making It: Radical Home Ec for a Post-Consumer World by Kelly Coyne and Erik Knutzen. It has reshaped my mentality regarding “make vs. buy” and all that is possible.

Anyway… they have a quick and easy way to make soap that makes the process not only virtually foolproof, but also surprisingly simple to master. By the second batch I felt like a pro. Truly.

I will share it here – complete with loads of notes and additional thoughts/advice I can offer. This is by no means fancy soap. No stamping or raffia woven in or crazy colors. Just good, functional, wonderful, healthy soap! (We love it.)

*    *    *

Okay. There are many points of possible tension-bordering-on-panic in this process – especially when you are new to it. And that’s ok. Caution is good. But if you read through all the directions at least 2-3 times before you start – and then keep the book or this post handy as you go through, you should be fine. Honest. Especially if you remain careful and calm. 🙂

I’ll list out all the equipment and ingredients you will need… but another insight I can offer is that I personally find it way less stressful to have separate items that are dedicated to soap-making. At least for the ones that touch the lye in its un-saponified state. Not everyone does this. If you choose to use the same equipment for soap-making and cooking… just make sure you are very, very thorough in your clean-up process afterward. Very. Very.


  • counter-top blender (make sure the mixing jar is glass, not plastic)
  • digital scale
  • glass container (a clean jar works very well – just be sure to use something heatproof)
  • spoon or chopsticks for mixing the lye (make sure you don’t use anything aluminum)
  • gloves (I use a pair of old leather driving gloves)
  • eye protection
  • kitchen towel or cloth
  • soap mold (I use an empty milk carton that has been rinsed thoroughly with warm water)
  • rubber spatula


  • 2 oz sodium hydroxide (lye)
  • 6 0z distilled, filtered, or bottled water (in a pinch, I have used boiled water that has cooled with no issues)
  • 16 oz olive oil
  • 1 tsp essential oil(s)

A quick note about the ingredients: I highly recommend using lye in the form of crystals or beads (as opposed to liquid lye). It’s so much easier to control where the lye goes, to ensure you can clean up spills quickly and easily, and it just helps decrease the worry factor. I’ve got crystals, which are fine, but I’m buying beads next time because I think they’d be even less stressful to work with.

In addition, I’d highly recommend scenting the soap. My husband doesn’t mind the unscented soap (it smells sort of olive-y, I guess)… but my daughter and I aren’t crazy about it. So now I’ve begun adding lavender and rosemary essential oil to the batch, and it makes a big difference. You can scent with any oil of your choosing – coming up with great combos is part of the fun!

Finally… don’t worry about buying expensive olive oil for this project. In fact, according to Kelly and Erik – the cheaper the better. So hunt down the cheapest, largest tin o’ oil you can find. You want a pure olive oil (not extra-virgin) that is lower grade but not mixed with any other type of oil.


General safety information before you start: The dangerous part of this project is the lye. You’ve got to be careful with it, because it can burn skin, eat through clothing, etc. So being careful is a must. Make sure all pets and children are safely out of range. Wear long sleeves, long pants, and make sure your feet are covered. Don’t skip your protective eyewear. Don’t skip the gloves.

If you do have a spill. Don’t panic. Clean it up as quickly as you can. The lye crystals or beads will not start to react until they touch water… so if you can clean things up without water (dustpan, paper towel, etc.) you are much less likely to have any problems. Dispose of any spilled lye in the trash (rather than putting it down your sink!). If you do get any on your skin, rinse immediately with water for several minutes, then wash with soap. If you missed any, you’ll feel an itching sensation prior to burning. Just re-rinse and wash the area to ensure all the lye has been removed. If you get lye in your eyes at any point, flush with cold water for several minutes and go immediately to the hospital.

If that hasn’t scared you away entirely(!), here is how you put it all together:

  1. Measure the lye and water using your digital kitchen scale. (Remember to zero the scale for whatever container you are using to hold the lye before you move to step 2.) The scale should read exactly 2 oz for the lye. To measure your water, you can either measure using the scale (after zeroing with your container) or you can use a liquid measuring cup. Either way, you want as close to 6 oz on the nose as you can get.
  2. Mix the lye and water. The best way to do this is to either use a funnel to ensure you don’t spill, or carefully spoon the lye bit by bit into the water. NEVER PUT THE WATER OVER THE LYE. You’ll create a very unfortunate volcano. This process will create some fumes and a lot of heat – so it’s best to be near an open window or even move outside as you transfer the lye. This is the time to wear your gloves! The glass container will get hot, so touch it sparingly – and stir the water carefully (once all your lye is in). Then set aside for at least 5 minutes. (You want the water to change from cloudy to clear before you add it in step 4.)
  3. Get your oil and blender ready. Check your blender one more time to make sure it’s ready to go. Measure out 16 oz of olive oil using your scale or a liquid measuring container (I always just use my pyrex measuring cup). Put the oil in the blender.
  4. Add to the lye water to the blender (make sure it’s clear). You should definitely wear your gloves and goggles when you do this – just to be safe. Pour slowly and carefully, then put the lid on the blender. Cover the lid with a towel or cloth to give you extra protection from splashing.
  5. Mix until you reach trace. (Trace is the stage you want your soap in where it’s thick enough to mold but not yet thick enough to set up.) This is the trickiest part because there is no set time for mixing. The easiest way to make sure you go long enough to get trace but not too long is as follows: Mix for 30 seconds and check your mixture for trace. (You can do this by dipping in your mixing spoon or chopstick from step 2 and then letting the soap dribble off the spoon back into the blender. As soon as the surface of the soap holds memory of the dribbles (you can see the spoon’s path or the lines/swirls don’t sink back into the soap and disappear), it’s time to mold. Until then, just mix in 10-20 second increments – checking each time for trace. This way you are sure not to miss it.
  6. dec1_2013 001Once  you’ve reached trace, add in your essential oil(s) and mix for 5 more seconds. Then, transfer the soap into your mold. You can use an old milk container or any kind of container lined with plastic wrap. Carefully scrape the soap out of the blender into the mold; try to get as much out as you can. Pinch closed the top of the milk carton or lay something stuff over your mold (like cardboard or wood) and set somewhere cool and dry. Let it sit, undisturbed, for 24 to 48 hours.
  7. Clean up all of your equipment and soap-making ingredients carefully. (Keep your gloves on for this. The raw soap is caustic until it has cured.) Use a paper towel to remove any leftover soap from your blender and dispose of it in the trash. Wash everything with warm, soapy water (and then I usually run it in the dishwasher on the sanitize cycle just to be safe).
  8. dec1_2013 003Check your soap after 24 to 48 hours to see if it’s ready to cut. The soap will be soft, but should not be sticky or wet. If it is still wet enough to show a fingerprint, allow it to sit another 2 days and then recheck. (Olive oil soap sometimes needs to set up to a week before being ready to cut.) Once the soap is soft but no longer slimy, carefully unpeel the milk carton from the soap (or remove your plastic wrap).
  9. SHomemade soap - ready to cutYou can cut your soap into bars using a very sharp knife or a cutting wire. (I use a knife, which works just fine.) You can make your bars any size you like. The soap will be soft, sort of like a cheese brick. Set the bars on a drying rack (like a cookie cooling rack) and cover with a clean towel (this will ensure they stay dust-free).
  10. midsept 003Allow the soap bars to sit an additional 4 weeks to harden (someplace cool and dry is ideal). This ensures they will no longer be caustic to your skin. After 4 weeks, you can store them however you like and use at will!

4 responses to “How to Make Your Own Soap: All-Natural Castile Olive Oil Bar Soap Recipe

  1. Lovely! I’m going to give this a whirl. Is lye easy to find?

    • Relatively… though finding the beads or crystals (and I’d strongly encourage beads!) might be a bit trickier. I got mine from Amazon, but you could also check out your local hardware store. There are also loads of places that sell soap-making supplies, so that’s an option too. Just poke around a bit so you can find a price that’s right. Best of luck to you – let me know how it turns out!

  2. Pingback: 5 Green + Easy Resolutions for the New Year | Do It Now + Green

  3. Pingback: How to Make Your Own Shaving Soap: Homemade Natural Coconut Shaving Soap Recipe | Do It Now + Green

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