DIY Home

How to Make Soap at Home (Even if You Failed Chemistry)

Lessons in lye.

August 12, 2020
Photo by James Ransom

My experimentations with homemade soap began when I started to get enamored with making things at home the long way: making and maintaining my own sourdough starter, painting my own kitchen cabinets, and repairing my own clothes. Even if time-consuming, I found that doing things myself, from start to finish, was immensely rewarding. It gave me a far greater appreciation for the goods that came my way, and made me a lot more conscious (in a good way) of the quality of ingredients. 

As time went by and my life got busier, my hobbies started taking up less of it. However, somehow, soapmaking stuck around. Although it can seem very complicated at first, and therefore off-putting to some, I’ve actually found it has one of the best effort-to-reward ratios of all the “pioneer crafts” I’ve tried. Much like knitting, it’s a meditative activity and a creative outlet—but unlike knitting, just a few evenings or weekends of work reap great rewards, as well as furnish me with loads of readymade gifts for the people I love.

With just some tools (many of which are old friends in the kitchen), and armed with an understanding of how it all comes together, homemade soap really doesn't feel that much more ambitious than some of the more adventurous baking projects I've embarked on over the years—and the results are well worth it (and fill your home with delicious scents, much like freshly baked goodies). Once you have a base recipe down, you can also play with shapes, colors, scents, and additives to customize each batch, and make them your own. 

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Here's how you can begin.

DIY Soap with Caitlin Pike

What you’ll need:

Ingredients:
16 ounces coconut oil 
14 ounces palm oil, preferably from a responsible source (alternatives to palm oil can be found here.)
21 ounces olive oil, the cheapest you can find
19 ounces distilled water
sodium hydroxide (lye), a 2 pound container of which will make about 4 batches of soap
7 teaspoons essential oil or fragrance oil (optional)

Tools:
Large heat-safe vessel such as an enamelware soup pot*
Measuring cup or small bowl*
Heat-safe vessel, ideally with a handle, such as a heavy glass pitcher*
Silicone spatula or other stirring utensil*
Instant-read thermometer*
Immersion blender*
Scale that can measure in grams and ounces
Soap mold or a 9-inch by 12-inch baking pan*
Plastic wrap (if using a baking pan)
Waxed paper or parchment paper
Teaspoon and additional measuring cup (if using fragrance)
Old towel or blanket
Sharp, thin knife
Rubber gloves
Safety goggles

*Any tools that touch lye should NOT be reused for cooking!

DIY Soapmaking with Caitlin Pike

Notes on safety, lye, and sourcing tools:

Although the process of making soap is by and large simple and safe, it is necessary to practice caution during the process that involves handling lye. Lye is a caustic salt (also refered to as sodium hydroxide) that mostly comes in crystalline form and if handled incorrectly can burn skin and eyes. To protect yourself, remember to always wear gloves, eye protection, and long sleeves, and work in a well-ventilated area. Keep your face away from the lye as you mix it, and keep pets and children away from it as it's cooling. But don’t worry about your soap being unsafe—all the lye will be used up in the saponification process (the reaction between lye and fat that makes soap and renders the lye safe to handle) and none will remain in the finished product.

If you're at all concerned about working with lye, an easy way to ensure none remains in your finished soap is to use a little more fat than the amount that would exactly be cancelled out by the saponification process. This is called "superfatting," and will almost definitely be covered in any calculator, chart, or other resource used for developing soap recipes.

For soapmaking, I recommend purchasing lye marked as "pure" or "food-grade," and shop for it online rather than in stores. I don't recommend buying lye that's specifically marketed as a drain opener (its other primary use) for this process because it might have other ingredients as well. It comes in different forms, little beads or little flakes; it doesn't matter which you choose for this process. (Interestingly, lye is also used in some recipes. I've haven't done it yet, but I've been wanting to try making these Bavarian-style soft pretzels.)

Although soapmaking becomes cost-effective if you do it often, making your first batch can seem like a bit of an investment since none of the tools can be reused for cooking (a good reason to make soap again and again). I’ve linked above to low-priced options for many of the tools required, and thrift stores are also a great option for items like the pitcher and pot. Oils for soapmaking can be purchased in 7-pound bags, which will keep costs down quite a bit if you're making more than one batch.

How to make soap at home:

1. Mix the lye. Put on your rubber gloves and safety goggles, and set up in a very well-ventilated area such as next to an open window. If you have access to the outdoors, take this step there. Use your scale and measuring cup to carefully weigh 201 grams of sodium hydroxide and set it aside. Then, weigh 19 ounces of distilled water into your glass pitcher or other sturdy, heat-safe vessel. Now, carefully pour the sodium hydroxide into the pitcher of water, and stir just long enough to make sure it all dissolves. This creates a chemical reaction that heats the water to over 200° F and produces strong fumes at first, so work quickly and be extra careful here—I try to hold my breath while I stir. (Safety note: Always work in this order and add lye to water. Never add water to lye, which can cause spattering of the hot lye solution or even an explosion.)

The lye now needs to cool to below 100° F. I usually place mine outside on my porch to speed up this process. Depending on how cold it is out, it can take between 30 and 90 minutes for the lye to cool, which is why I recommend getting this step out of the way first. 

Mis the Lye for DIY Soapmaking

2. Prepare the mold and measure out fragrance. If you're using a wooden loaf mold or a baking pan, carefully line the inside with waxed paper or parchment paper so its easier to get the soap out later. I often use some masking tape to help hold everything in place. If you use a silicone mold, you can skip this step.

If you like the simplicity of plain rectangular soap bars and think you’ll make more than a couple batches of soap, having a wooden loaf mold like the one shown here makes the process easy and consistent. (I’ve found eBay and Etsy to be good sources for wooden versions at lower prices.) Other options include silicone and PVC plastic molds, which come in many shapes and patterns. If you’re not ready to invest yet, a 9 by 12-inch baking pan or Pyrex dish that have seen better days and that your kitchen is willing to part with should also work just fine for this recipe. 

Now is also a good time to measure out your essential oils into an extra measuring cup, for ease of adding them later. Blending fragrances is probably one of the most fun parts of making soap. For this batch, I used 5 teaspoons of orange essential oil and 2 of sandalwood. Synthetic fragrance oils also work well and are generally less expensive than pure essential oils. Mixing fragrances is akin to mixing spices and other ingredients when experimenting with cooking a dish—here is a great set of tips for having fun with blending fragrance oils. You can also opt to make unscented soap (if you're very sensitive to scents and perfumes) and simply leave this ingredient out. 

3. Melt and mix the oils. You can now prepare the blend of oils to which you’ll add the lye. If you're using oils that are solid at room temperature, such as the coconut and palm oils in this recipe, you’ll first need to melt them so they can be poured, either by placing the container in a saucepan of simmering water or by melting them in the microwave.

Once your oils are in a liquid state, place your large pot on the scale and weigh (or re-weigh, if you've already done so) each oil into it for precision. Stir everything together and then check the temperature with a heat-safe thermometer. For the next step, the oils need to be between 80 and 100° F. I often find that mine are already in the correct range from being melted, but if not, place the pot on the stove over low heat until the oils reach the proper temperature or set aside to cool down.

Blend and Pour Your Soap  DIY Soapmaking by Caitlin Pike

4. Blend and pour your soap. 
When both your lye and your oil mixture are between 80 and 100° F, you’re ready to blend. After removing the pot from the heat to a trivet or heat-safe surface, put your gloves and eye protection back on and carefully pour the lye into the pot of oil. They’ll begin to react with each other, turning the mixture cloudy. Begin blending with your immersion blender, and over the next 3 to 5 minutes you’ll see the mixture become thicker and more opaque. You're aiming for a mixture with the consistency of a runny pudding. If you lift the blender out and let some drips fall across the surface of the mixture, you should see them leave a visible pattern, called “trace,” before sinking back in.

Once the soap mixture has reached trace, stir in the fragrance oil, if using, until blended. Carefully pour the finished mixture into your lined soap mold, and cover with the lid (or plastic wrap, if your mold has no lid). Being sure to keep it level, wrap the whole thing in a towel or blanket to insulate it, and leave undisturbed in an airy out-of-the-way place like a shelf for 24 hours. 

This method that I use for making soap is called cold process, where no additional heat is used to facilitate or speed up the saponification process. Hot process, on the other hand, uses an external heat source to accelerate it. While cold process soaps take longer to cure (the next stage, below), the choice to use one or the other is entirely personal.

DIY Soapmaking with Caitlin Pike

6. Cut and cure your soap. When your clock indicates that 24 hours is done (don't try and rush it), your soap is ready to be removed; many wooden loaf molds have fold-down sides or removable bottoms to make this process easier. If you’ve used a baking pan, you may need to use a knife to help pry the soap loaf out. Cut the loaf into bars with a sharp knife. 

Naturally, you don't want your soaps to crumble when you cut them—and soapmakers have all sorts of ideas on which tools to use to cut soap with. Some use guitar strings, others use butcher's knives. Still others opt for specialty tools like this (and this). Some DIY-ers even fashion their own instruments. I use a ruler and score the top of the loaf with a sharp knife before cutting to make sure everything stays straight and even. I like generous bars, so I cut them about an inch thick.

Your work is now done, but the bars need to cure for 4 to 6 weeks (remember what I said about patience?) before being used. This time allows the water in the bars to fully evaporate, resulting in a harder and milder soap. Leave the soap to cure on a paper bag or baking rack in the same airy location. If you use a paper bag, turn the bars once or twice during the curing time to make sure all sides are equally exposed to air.

Cleaning up:

The pitcher, measuring cup, and spatula just need to be thoroughly rinsed with water. For the pot with raw soap residue in it, I usually wipe it out first with paper towels before washing it with dish soap and water. Use any tools that touched the lye only for soapmaking, and store them away from the kitchen, ideally on a shelf separate from other kitchen tools in common use, to prevent any chance of confusion.

Creating your own recipes:

This recipe is only one of practically endless combinations and ratios of fats, lye, and other ingredients that you can use to make soap. A lot of the fun of soapmaking is in exploring new recipes and seeing what turns out. Some of my favorite combinations have been orange and sandalwood with poppy seeds, lavender and clary sage with dried lavender blossoms, and rosemary and cedar wood with dried thyme.

You can also change the ratios and types of fat to make soaps with different properties, as well as using liquids other than water (such as milk). Online oil charts and lye calculators can help you finish your recipe. The proportions for this particular recipe are taken from Susan Miller Cavitch’s The Soapmaker’s Companion, a good all-around resource for learning about the science of soapmaking, exploring options for ingredients and techniques, and troubleshooting problems.

Congratulations, you’re a soapmaker! Now get creative and have fun—but please be safe.

This DIY first ran a few years ago; it's back again because it's the best stay-at-home summer project we know (and, well...science is amazing)! 

This post contains products independently chosen (and loved) by our editors and writers. Food52 may earn an affiliate commission on qualifying purchases of the products we link to.

Photos by James Ransom

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Caitlin Pike

Written by: Caitlin Pike

Maker of comforting things. Lover of Chicago, cats, yoga, and weird bitter liqueurs.

35 Comments

Dominique D. August 13, 2020
Since this has just been reposted, a few things as an experienced soap maker and professional chemist:
1- Do not just sub out palm oil because you disagree with its use. The fatty acid profiles of other oils are different, and you'll end up with drying soap, soap that doesn't lather, etc., unless you sub in Lard or Tallow. Check other recipes online if you want to make that substitution for the correct ratios.
2- It is no longer recommended to make your lye water in glass pitchers. Use one of those plastic juice pitchers we remember from the 1990s (mine's a Rubbermaid 2 1/4 quarts #5 plastic).
3- You do no need to soap between 80 and 100F. Most of us add the lye water to the oils at around 130F...Each solution should be no more than 10F apart from one another (ie. the lye is 130F and the oil is sitting at 120F, or vice versa).
4- Don't waste your orange or citrus essential oils in making cold or hot process soap like this...it will not survive the saponification. You can use other oils such as rosemary, or lavender, but citrus just doesn't work. If you want a citrus, buy a citrus fragrance oil formulated for soap making from a soap supplier website.
5- The best molds are shoe boxes!! Line your shoebox with butcher paper (the kind that has a plastic side, and a parchment side), with the plastic side facing the soap surface. If you cover and insulate your box with blankets, it will go through a high heat 'gel' phase. If you don't cover it, it won't gel (or may just gel at centre). Gel is not important, it's just for looks.

You should really look into soap websites, like the Soap Queen, and tutorials on youtube. Susan Miller Cavitch's book is a bit outdated, though the basics are still good.
This recipe should make you about 15 to 20 bars.
 
Jennifer May 24, 2018
Hi how many bars of soap will this make and what is the approx. oz of the individual bars? I have to make 200 bars for my nieces wedding and trying to figure out recipes.
thanks
 
Mona October 8, 2017
Please don't use palm oil. There are NO responsible sources. Coconut is better. But it will require the recipe be recalculated. Please just don't use Palm. Also, if you just leave your soap pot over night is is much easier to clean (as it is now just a soapy pot) than the oily caustic mess it is straight after making the soap.
 
Dominique D. August 13, 2020
You can't just sub in coconut oil for palm oil. Each oil has a very different fatty acid profile, and will yield a different soap product. You need palm oil to have a bar with good lather and moisturising properties. Coconut oil's fatty acid profile is way too drying on the skin once saponified.
A good alternative to palm oil is LARD. Choose lard if you wish, but the ratios will need to be recalculated for perfect saponification without leftover lye.
 
Lmathes July 12, 2016
I've always wanted to make my own soap, thanks for this. Can I sub shea butter into this recipe and if so, how would I do it, please?
 
sashalina June 17, 2016
I've always wanted to learn to make soap, thank you for an easy and clear recipe. One question: I've never seen distilled water outside my high school chemistry class. Where does one get it? Or can tap water be used? Filtered tap water? Thank you!
 
Author Comment
Caitlin P. June 17, 2016
You can find distilled water in gallon jugs at grocery stores, big box stores like Target and Walmart, and sometimes at drugstores. It's usually with the other bottled water. However, tap water will probably work fine as well. If your water is hard (high mineral content) it can cause issues, and distilled water lets you be more consistent from batch to batch, but it's unlikely to cause any major problems.
 
Johanna June 2, 2016
There is no such thing as "responsibly sourced" palm oil. No one should be using palm oil. www.saynotopalmoil.com/
 
arcane54 June 2, 2016
Johanna, is there a substitute?
 
Johanna June 2, 2016
I know there is. Just don't know what. Urban Cabin Soap Co. does not use palm oil. You can look at those ingredients. www.urbancabinsoapco.com
 
Heather T. June 2, 2016
I use organic beef tallow in place of palm oil. It creates a silky, moisturizing soap, and saves a lot of waste from butchering cattle.
 
Panfusine June 2, 2016
This recipe is Foolproof, I've even played around with the different oils, (just keeping the final volumes the same. made about 4 batches with different scents and ingredients) since the article was published last year.
 
Heather T. January 14, 2016
Cannot wait to make a batch. But quick question - how large of a stock pot should I invest in? I have an 8 quart I can devote to soap making but wasn't sure if that was a sufficient size.
 
Author Comment
Caitlin P. January 14, 2016
Your 8-quart pot should work perfectly for this recipe. :)
 
Erin June 22, 2015
What size load soap mold do you recommend for the recipe noted above? Do I melt all oils to fluid ounce or go by weighted ounces?? Thanks!
 
Author Comment
Caitlin P. June 22, 2015
A 4-lb or 5-lb wooden loaf mold will work well. (for example: http://www.amazon.com/Wooden-Soap-Molds-Make-Colapsable/dp/B00IDVTH7A)

Use weight, not fluid ounces.
 
Marian H. May 27, 2015
There are actually 3 kinds of "trace". During the thin trace, when drizles leave a thin trace on the surface, it would be good to add the essential oil so that the oil will surely be evenly distributed before the soap seizes or gets too hard to pour. Also, some essential oils actually react with the soap and quicken the tracing so it is ideal to add the essential oils at this stage. At medium trace, when the drizzles on the surface are thicker and take a longer time to sink in, it is good to add the fine powders like cocoa or turmeric, or crushed dried herbs. At full trace, when a limp sits on the surface and takes bit of time to sink in, is the best time to quickly fold in heavier additives like oatmeal and flowers so that they won't settle on the bottom as when you add them in during thin trace.
 
Marian H. May 27, 2015
This article is well-written, especially for beginners. Those that don't have molds for soap on hand might want to use cardboard or paper boxes like shoeboxes or the smaller food containers like the ones in which cheese is packed in my country. They need to be lined with parchment or waxed paper before the soap is poured in. Using these boxes is great because you can recycle or reuse containers that are otherwise thrown away and they can be disposed off after soapmaking if you worry about pets or kids getting at your soap-making tools. I usually stack my boxes and reuse them until they fall apart. It is also helpful to keep a spray bottle of white vinegar beside you for a quick spritz in case of splatters. The vinegar, being an acid, neutralizes the lye which is alkaline or base, saving you from skin irritation or burns. Of course, after the spritzing, you will still need to wash the affected area with water and soap.
 
Author Comment
Caitlin P. May 29, 2015
Thank you for taking the time to add all this great information, Marian!
 
Jennifer G. May 27, 2015
Your tutorial left out that one should never use aluminum containers or utensils and why.
 
Author Comment
Caitlin P. May 29, 2015
True! (For anyone else reading this, it's because lye will corrode it -- same goes for tin, iron, and teflon.)
 
cfelten May 16, 2015
I would strongly suggest that anyone interested in soapmaking subscribe to any one of a number of Yahoo email groups on the subject. There are many generous soap makers out there who will share sources, tips for soaping with various fragrances (they are not all well behaved), and hold the new soapmaker's hand through the first batch. Make sure every inch of your skin is covered, wear your goggles and gloves, keep a basin of water laced with vinegar (in case of splashes the vinegar will help neutralize the lye) nearby and enjoy the wonderful creative world of soapmaking.
 
m T. May 16, 2015
Another question about colors. So orange essential oil gives soap a yellowish color. What other colors can be used in soap? How about a turquoise?

Also, what do you know about adding some form of oatmeal, like in Aveno?
 
Author Comment
Caitlin P. May 18, 2015
For coloring you can purchase colorants (http://www.brambleberry.com/Colorants-C181.aspx) or use natural options (http://www.diynatural.com/natural-soap-colorants/) to get a wide variety of colors.

You would add oats at trace, right before pouring. It's nice if you grind the oats smaller first using a food processor or blender.
 
Noreen May 16, 2015
I have bought many soap making books but I never tried because it seemed so complicated. You made it so simple and easy!
What can I use to mildly colour the soap and is there any special preparation for a fancy soap mould?
 
Author Comment
Caitlin P. May 18, 2015
For coloring you can purchase colorants (http://www.brambleberry.com/Colorants-C181.aspx) or use natural options (http://www.diynatural.com/natural-soap-colorants/). The preparation for a specially shaped mold shouldn't be any different from a loaf mold like the one shown here.
 
rob May 16, 2015
After the soap is partially used, and no longer has its good shape (from a mold) can it be melted down, and re-molded?
 
Author Comment
Caitlin P. May 16, 2015
I've never done this so I'm not sure, but if you normally do this with other soaps, this shouldn't behave any differently.
 
Gwen May 14, 2015
Palm oil is not an environmentally friendly ingredient. Too many animals in Asia are losing their habitats due to deforestation.
A viable alternative?
 
Author Comment
Caitlin P. May 14, 2015
3 possibilities:

- Replace with an equal amount of lard or beef tallow (these are considered the most similar replacement fats in terms of what properties they'll contribute to the finished bar.
- Purchase palm oil from a sustainable supplier such as the one linked in the article (http://www.soapqueen.com/business/on-palm-oil/).
- Use the resources linked at the end of the article to create a recipe using different oils.

Good luck with your soapmaking!
 
Panfusine May 14, 2015
Wow, thanks for the awesome tutorial.. Did this batch of soap have any color added to it along with the fragrance? or is that buttery yellow color the natural shade of the soap?
 
Author Comment
Caitlin P. May 14, 2015
The orange essential oil I used imparts that nice color!
 
Trena H. May 14, 2015
Great article! I love making soap. It's so fun and easy once you get the hang of it.
 
Desiree @. May 13, 2015
What an awesome post! Though I'll admit that my brain wanted these photos to be about making butter rather than soap. I'm a little nervous about using lye, but I'd love to be brave and give this a shot.