Basic Cold Process Shampoo Bar Recipe

A few years ago, I was going through the awkward transition to sulfate-free shampoo. I had tried the baking soda/vinegar combo, and it worked well initially; however, in the winter, my hair became very dry. As I was looking for another option, when I was browsing Pinterest, I came across the idea of a shampoo bar. I did some research and learned that the only thing needed to make shampoo soap versus regular soap, was the addition of castor oil. Some of you soapmakers have probably been making shampoo bars all along without knowing it! Castor oil not only adds a nice lather, but it makes hair shiny, and we all like shiny.

Since I had wanted to learn to make soap anyhow, I set out to do it. I made a few batches following other recipes and eventually came up with this basic recipe of my own. I alter it for my other more creative soaps, but this basic recipe is simple (5 or less ingredients), and uses ingredients that can be easily found and purchased. I have a few additives that make the bar smoother, harder, and slightly more bubbly, but they are optional.

Making cold process soap is a bit like making cook-and-serve pudding. It is lengthy to describe, but a relatively simple process. And if handling lye scares you (thanks to the Woman in Black movie), just realize that you have probably handled other strong chemicals such as Drain-o or Clorox, without incident. Just make sure you respect their potency and take adequate safety precautions, and there is nothing to be scared about.

A few notes on tools and purchasing. You need 1 large bowl for oils, 1 medium bowl for water, a small bowl for lye, 2 spoons, rubber gloves, an immersion blender, and a kitchen scale. With the exception of the rubber gloves, kitchen scale and immersion blender, I got everything at the thrift store. I have even seen immersion blenders there as well, but I was impatient and didn't wait until they had one. I keep all these stored together in a locked suitcase with the lye, so that my younger daughter can't get into them, and we don't have a chance of lye getting into our food :( You may also want a pair of safety goggles and a kitchen thermometer, but they aren't mandatory.

Lye is the other ingredient that is harder to find. You can find food grade Sodium Hydroxide online, but it does cost a little more. You can find it at Lowe's or Home Depot with the other drain openers; just look for one that is 99% or 100% pure sodium hydroxide. Some will say 99% pure because of the other naturally occurring substances that cannot fully be removed from the sodium hydroxide, while others say 100% lye, because nothing else has been added. Roebic drain cleaner is one I found locally. It was $15 for 2 lbs, just to give you a rough estimate. It is normally the most expensive ingredient in the process.

Ingredients:
Coconut oil
Olive oil
Lard
Lye (Sodium Hydroxide) *(see note for where to purchase)
Water (I use tap water, though some soapmakers only use distilled water)
Essential oil as desired for fragrance

Optional additives:
table salt
sugar
borax

The soap making process. If you have never made soap before, you will want to read through this next section; otherwise, you can skip to the recipe below.

Start out by measuring placing your small bowl on the kitchen scale and taring it to 0. Carefully measure the lye into the bowl. Most recipes give you a range of lye that will effectively work. This gives you a margin of error of excess fat (called super-fatting), so that you don't end up with a soap that zaps you because you have too much lye. I have no idea how our grandparents figured this out, but nowadays, this is where lye calculators come in handy. I use the lye calculator at thesage.com. The amount you use depends on how harsh of a soap you desire. If you want uber-cleaning power, you use more lye; if you want it to be very conditioning you use less. If you leave a large amount of excess fat, you want to make sure you use oils that won't go rancid quickly. Showering with a rancid soap bar would be gross. I usually use around the 5-7% excess fat range, right in the middle. Since I am using these for hair and body, this leaves me enough conditioning for our Utah weather, without making my hair greasy.

Next, fill your medium bowl with water. I like to use a bowl with taller sides, to avoid any splashing later. The amount of water is also a range. Again, I typically use right in the middle of the range to keep things simple. However, if it is really hot outside, you can use a little more water to give you more time to mix the oils and lye solution; alternately, if it is really cold, you could use less water to speed things up a bit, so that your arm doesn't fall off while mixing :)

Take the water and the lye outside to your garage or carport. Make sure you have adequate ventilation. I always open my back garage door and do it right there. Put on your rubber gloves , and goggles if you wish. This next part is important: Pour the lye into the water. NEVER add water to the bowl of lye. Start stirring. You will see the chemical reaction take place as the water suddenly starts bubbling. This is where the bowl with taller sides is nice, so you don't get splashed on. Keep your face and nose free of the fumes if you like breathing. Once the bubbles stop and all the lye is dissolved you can go inside for the fun stuff.

Lye goes into water

Hooray, you made it this far! Now, place the large bowl on the kitchen scale and tare it to 0. Otherwise you have to do lots of math, and, while that doesn't bother me, simple is better. Add your first oil. Tare the scale to 0. Add the second oil. Tare the scale to 0. Add the third oil.

Fats and oils on kitchen scale

Now, put the oils in the microwave (you could do this in a large pan over med-low heat on the stove if you needed) and microwave on 70% power for 3 minutes. Stir. Repeat until all the solid fats are melted. Now you wait until the lye solution and the oils are both warm but not hot to touch. If you are measuring with a thermometer, wait until they are around 115 F. This is a good time to get your molds ready and put away the fats, scale, lye, and other utensils, write a blog post, drink some tea, etc.

Get creative with your soap molds. You can pay for fancy molds, but unless you make a lot of soap, you can probably find free containers around your house. Don't use metal. Raw soap can eat right through it. I have used silicone muffin tins, old tupperware containers, plastic drawer dividers, and cardboard boxes lined with parchment paper. Small plastic yogurt containers, and glass pans also work well. In other words, use what you have.

When both the fats and the lye solution are not too warm to touch, add the optional ingredients (sugar, salt, borax) to the lye solution and blend well with the immersion blender. Then pour the lye solution into the oils. Again, you always add the lye to oil, never the reverse. This keeps the chemical reactions small and controlled. Start stirring with your immersion blender.

Lye solution goes into oils

When your mixture starts to turn opaque and thicken, add your essential oils. I use around 2 - 2 1/2 TB for this recipe, but you can add more or less to suit your nose. Essential oils or fragrance oils will speed up trace of your soap. Trace is simply the thickening of the mixture that occurs as the oils start to react with the lye. This typically takes 1-5 minutes with an immersion blender, or 15 minutes (or longer) if stirring by hand. This is where this process really seems a lot like making pudding. When you have a thin pudding-like liquid, you can pour the soap into the prepared molds.

Stirring with immersion blender. Starting to thicken like pudding.

Cover the top of your molds with plastic wrap, wrap them in a towel, and place them in a warm corner overnight. If it is cold outside, I place the molds on a heating pad set on low heat. Over the next several hours, the liquid will continue its chemical transformation into soap. You will see the middle of your molds get dark and translucent if the reaction goes well. This is called the gel stage.

Here you can see my fancy soap molds - boxes lined with parchment

Bundled up and ready to continue the chemical reaction

After your soap reaches gel stage, turn off the heat and allow the soap to harden for a few days to a few weeks. It is safe to use the soap after it has hardened up. If you don't reach gel stage, you have two options. You can put it up on a high shelf and wait several months (6-8 months) before using it, or you can try putting it on a heating pad or in a crock pot on low heat for 24 hours. The soap can re-liquefy and go through gel stage, at which point you can remove it from heat to harden up.

As long as the soap has gone through gel stage, it is safe to use as soon as you cut it; however, the longer it has time to sit and harden, the smoother it is when you use it. New, soft, soap also dissolves faster as you use it. I like to cut my soap loaf into bars, use one, and allow the others to continue to harden on a rack until I need them. Even a soft, fresh soap is still so much nicer than store-bought soap, that it is worth it, IMO. It will feel different (almost slimy, at first) if you are used to store bought soap, but your skin will thank you for your efforts, and you will come to prefer it over anything else!

Basic Shampoo Bar Recipe 
by Cydne Wright

all ingredients are measured by weight, not volume, i.e. use a scale, not a measuring cup

Fats & oils:
16 oz coconut oil
16 oz olive oil
16 oz lard
8 oz castor oil

Liquid:
16 oz water (range 14-21 fl. oz)

Lye: 7 7/8 oz
  range:
  0-4% excess fat = 8.38-8.05 oz lye,
  5-8% excess fat = 7.96-7.71 oz lye,
  9-10% excess fat = 7.63-7.5 oz lye

Optional additives:
1 tsp sugar (lather)
1 tsp salt (hardness)
1 tsp borax (smoothness)
2 TB of essential oils or fragrance oils

In a well-ventilated area, add lye crystals to water; stir. Measure fats and oils and melt on medium heat. Allow both liquids to cool until warm / lukewarm to touch; around 115 F. When warm, add additives to lye solution and blend well with immersion blender. Slowly pour lye solution into bowl of oils. Blend with immersion blender until Trace. Add essential oils or fragrance oils. Blend until the consistency of a light pudding or gravy. Pour into molds, cover and place in a warm area until Gel stage is reached. Allow to harden for a few days and then slice into bars. Allow to continue to air dry until desired hardness is reached.