Thursday, August 18, 2011

No-Sweat “Cold Process” Soap Making

I just got done making several batches of soap. I have been making homemade soap for several years now, and have probably made close to a thousand batches. It’s turned into one of my favorite hobbies. So today I thought I’d dedicate my blog post to soap making.

Now at first, you might think that soap making might not fit in with a blog titled “Creative Hospitality.” However I really think it does. My homemade soap is something I put in the guest bathrooms when we have overnight company. Most of the time I have soap curing in various locations throughout our house, and if guests ask about the soap or say they like it, I’ll often send a bar or two home with them. Many times in recent years I’ve had “soap making parties” at my house where I’ve had friends over to show them how to make soap; first I’ll have them watch me make a batch, and then I’ll let them try it themselves.

I realize there are many, many blogs out there in the blogosphere, dedicated just to soap making. So I know it’s a big topic. I also realize there a lot of different ways to make cold process soap making. Every soap maker has his/her own techniques. Here in this post, I am going to explain how I make my soap, and share some tips that I’ve learned from personal experiences (which aren’t always covered in the soap making books).

If you’re going to do this, it’s great to read up on the topic first. I have bought probably every soap making book that has been published. Each book has some good information to offer, but I don’t think any one book out there has all the essential information in it. The two most thorough books on the topic, in my opinion, are Smart Soapmaking by Anne L. Watson (Shepard Publications, 2007), and Country Living’s book, Handmade Soap (Hearst Communications, 1998). What I really like about these two books is not only do they have some excellent soap recipes, they also explain a lot of technical information about the soap making process. So these books are a good education in soap making. I also learned a lot just from trial and error.

Before going any further, I wanted to define our terms. For some people, “soap making” means buying the blocks of unscented soap from craft stores like Michael’s and Hobby Lobby—the “melt and pour” kits. That’s not what I do. I make what’s called “cold process” soap making. In a nutshell, cold process soap is made by mixing lye (sodium hydroxide and water) with fatty acids (usually a combination of oils and saturated fats, which stay solid at room temperature). You do not “cook” the soap ingredients together, as is done in “hot process” soap making. With cold process soap making, the only heating that’s done is to melt the saturated fats. By mixing the fats (which are acidic) with the lye (which as alkaline—a base), that triggers the “saponification” process (meaning you’re making soap).

The recipe I use is on page 31 of Country Living’s Handmade Soap book. Here it is:

15 oz. distilled water
6.3 oz. sodium hydroxide
20 oz. coconut oil
6 oz. palm oil
14 oz. olive oil
Fragrance /Essential oil
Optional: colorants, botanical or other additives for exfoliants (ground oatmeal or lavender leaves, etc.)

Weigh the water on a digital food scale. I have a ½ gallon plastic pail that I put the water in. In another small container (a disposable plastic beverage cup works fine) weigh the sodium hydroxide. Then sprinkle all the sodium hydroxide into the water, stirring the entire time. You now have your lye mixture. Set it aside to cool. Over the stovetop, melt the coconut and palm oils together in a 2 quart pot. Then let cool enough to be able to set the pot back on the digital scale. Add the olive oil. Then set aside to cool.

I have a sink in my laundry room, which I fill about 4-5 inches with cold water and ice cubes. I’ll set my pail with the lye mixture in there. I’ll usually put my pot with the melted fats in there too. How long they stay in there depends. Both need to cool down to around 90 and 100 degrees F. It usually takes the lye a little longer to cool down, so I’ll start that cooling first. The fats take less time to cool usually (because they aren’t usually on the stovetop that long), and the mixture will do some cooling down when I add the olive oil. So I may just leave the fats in the ice bath for just a few minutes. When both the lye and the fats are down to around 90 and 100 degrees (I try to get them both to the same temperature, so maybe both 90 degrees), then pour the lye solution into the pot with the fats/oil mixture. Use a stick blender to blend it together. Here’s are a couple photos of the two solutions being blended together:

When it traces, meaning it’s “saponified” (It may only take a few minutes to get to this stage with this recipe, because it is only making a relatively small amount of soap) and the mixture is now soap, quickly add your fragrance, colorant (optional) and additives (optional) and stir it a bit more. Then pour the mixture into your molds. In my case, I use the dairy cartons as molds. (Work fast at this point, because once the mixture has saponified, it will start to thicken quickly and if you take too much time, you may not be able to pour it into your molds). The way to tell if the soap is saponified, is it will have turned to an opaque, creamy color, and if you will be able to make a line in the mixture with your stick blender. Here’s a picture of a saponified mixture:

In each batch, I use about 1.5 ounces of essential oil (such as lavender) or 2 ounces of fragrance oil. That may be a little more than some of what the books recommend, but I find that if you use smaller amounts, the scent is hardly noticeable in the finished product.

Sometimes I add exfoliants, but usually I don’t. About the only time I add exfoliants is I put in coarsely-ground oatmeal with the oatmeal, milk and honey soap; ground mint leaves with the eucalyptus spearmint soap; and ground lavender leaves with the lavender soap. I used to make a cran-raspberry soap, and I put ground raspberry seeds (I tried grinding them, and even used my mortar and pestle, but I could never get the seeds small enough, because they’re so hard!) in that soap for exfoliants. However, I stopped doing that when friends told me their husbands were complaining about the raspberry seeds getting stuck in their chest hairs. Hmmm.

About colorants, I don’t always use them. I like the natural look for the most part, and a lot of the soap fragrances do turn the soap to a creamy, tan or light brown color anyway. But sometimes it’s fun to be able to put a little orange, purple or light red in the fruity fragrances, or a light green in the herby soaps. You can buy the soap colorants online. Most of them come a powder, and you mix a little glycerin in with them to make the dye.

I make my soap in quart-sized dairy cartons. I get about 10-12 bars of soap (4-6 ounces each, depending on how large I cut them of course) in each batch of this recipe. To me, that’s a good sized batch. This way I can make several batches, each in a different scent. Here are some soaps that have just been poured in dairy cartons:

Once you’ve poured the soap into the dairy cartons, they will need to stay in there for around 6-8 hours to set. After it’s hardened to the point that it will hold its shape, you can peel off the dairy carton containers and then cut the block into bars. Here’s a photo of the soap being cut:

What will happen after you pour the mixture into dairy cartons, it will get very hot, then it will harden, and then it will turn into a “gel stage” where it looks like the cooled fat from a roast turkey. During the gel stage, it’ll be all mushy. Then after that it will harden “for real” this time. (I had to learn about this the hard way once. I didn’t realize the soap hardened temporarily before turning gel-like, and I actually started to peel off the dairy cartons. I walked away for a bit and then returned to find the gel had basically “exploded” in blobs all over the room. Not a fun mess to clean up!)

Once you’ve cut the block into bars, you will need to put it on trays of some kind so that it can cure. This soap recipe takes about 2-3 weeks to cure. During the curing process, the soap hardens more (A harder soap lasts longer in the shower!) and neutralizes as far as alkalinity. You don’t want a soap that’s either too alkaline or too acidic, but rather a nice, mild bar that’s neutral as far as pH. (You can buy pH strips from chemistry and soap making supply houses if you want to test your soap’s pH level before you use it.) With the recipe I’ve included here, it’s only just barely alkaline immediately after it’s made. Then after curing, it is completely neutral.

Here is a photo of some soaps curing in my laundry room. This was taken a couple years ago. Nowadays I don’t cure all my soaps together in the air space; supposedly they can soak up scents from neighboring soaps if they cure together in the same room.

You will need to have some basic equipment for soap making: a pot to melt the fats in and mix up the soap, a plastic spoon for mixing the sodium hydroxide and water together, a quart-sized pail for holding the lye solution, a stick blender, and two thermometers, one for the lye solution and one for the fats. These items should all be dedicated to soap making. In addition, you’ll need goggles for your eyes and perhaps gloves for your hands, and a digital food scale.

You’ll have to order all of your supplies online. Craft stores like Michael’s and Hobby Lobby, as much as I love them, for the most part, only carry supplies for “melt and pour” soap making. For instance, the soap colorants they sell are designed for melting and pouring soap. They don’t work in cold process soap making. (There is something about this process that destroys the color. I have tried this a number of times. You can put a whole bottle of those kind of colorants in and they fade away to nothing as soon as you put it in the soap mixture.) Now you could use their soap scents, but they come in such small bottles and are very expensive. It’s much better to buy larger bottles of fragrance and essential oils online.

My favorite online soapmaking sources are:

Wholesale Supplies Plus



Majestic Mountain Sage

It took me a while to learn which soap scents “work” and which ones don’t. Some sound good in their descriptions in the online catalogs, but then you order them and they smell like bug spray. Some scents smell good in the bottle, but then after the soap making process, the smell changes and sometimes turns into something quite putrid. Other times, the scent smells good in the bottle and in the soap after you’ve made it up, but then after a couple weeks or even a day or two of curing, the smell has just about gone. I have probably spent hundreds of dollars, discovering through trial and error, which fragrances work and which ones don’t. (Now there are still a lot of fragrances I would like to try, but haven’t done as much of that kind of testing lately. That gets expensive!)

If you’d like fragrance recommendations, I suggest the coconut, lime & verbena and black raspberry vanilla scents from Wholesale Supplies Plus; the “fruit slice” scent and 40/42 lavender essential oil from Pinemeadows; the oatmeal, milk & honey and honeysuckle scents from Brambleberry; and the eucalyptus spearmint, juicy pear, plumeria, and cucumber melon fragrance oils from Majestic Mountain Sage. These oils, in my experience, have all been fool-proof and have consistently turned out well every time.

You’ll have to buy your sodium hydroxide from another source, other than the online retailers listed above, since they don’t sell it. It’s not something you may able to buy locally either; I have never been able to find it for sale anywhere in stores in my area. I buy “food grade” sodium hydroxide from AAA Chemicals ( for $13.49 plus postage and handling for 4 – 2 lb. bottles.

Always wear eye covering. I had to learn this lesson the hard way once when some of the soap mixture splashed in my right eye. I had a friend over to make soap with me when this had happened. We had poured the lye into the fats and the mixture had just saponified (and it was still quite alkaline!). We tried washing it out, but it still stung like crazy and the vision in that eye was a bit blurry. Then a minute or two after going back in the kitchen and trying to resume the soap process (I try to stay on task with my projects!), my friend just looked at me with a horrified look. My right eye ball (which the soap mixture had splashed in) had dilated completely so that it was one big black circle. It stayed that way for 12 hours, until—thankfully—going back down to normal and the vision in that eye normalizing too. So…I have always worn goggles since!

Well, that’s enough of my rambling for now. I could tell you lots more about soap making, but this is probably more than enough to pique your interest.

Happy soap making!


  1. I can verify that these are WONDERFUL soaps! I've been the blessed recipient of 3 "flavors" and LOVE how they both clean and moisturize!

  2. Thank you for sharing, I would love to learn how to meke my own saop!

  3. Thank you for your blog on soap making. I had to learn something that I have never tried before for a college PSYC Learning and Motivation course. Your blog was written wonderfully. Thank you for the links, I went to for my lye, that stuff is hard to buy. Also, drops in little samples with every order :) I got a scent to try.

  4. can you make bar soap for kenyan market.