Cold-process soap is basically the mixing together of oil (fatty acids) and lye (sodium hydroxide) together to trigger the saponification process, which is the chemical reaction between a base and acid to form a salt. Sounds like magic? It is! Part chemistry and part artistry (or craft). The name “cold-process” is used to differentiate between a hot-process, or melt and pour soap making. It’s actually a little bit of a misnomer as there is some heat involved in melting your harder superfats, butters, and/or waxes, however the rest of the process is cold.
What’s Natural? I believe making natural soap means avoiding use of ingredients that are toxic, produced in ways that are harmful or unethical, or artificial. That means I carefully source where my oils, fats, butters, hydrosols and essential oils come from, or I make them myself from herbs that I grow in the garden. Not an affiliate (yet, lol) but my favorite source of everything I don’t make or grow myself is Mountain Rose Herbs and I order essential oils from Floracopeia.
In order to get the best results from your cold-process soapmaking, there are a few essential items you’ll need.
- Immersion/”stick” blender used for soap only. An immersion blender is used to quickly and easily combine the liquids and oils to smooth trace.
- Crockpot or double boiler used for soap only. I use a crockpot to slowly melt my butters, waxes and oils while I am freezing my liquids. You can also use a double boiler or a glass bowl over a soup pot.
- Candle/Candy Thermometer. These are the large glass variety and are necessary to know temperatures before combining liquids and fats. Some people use fancy digital infrared thermometers like these. Whatever works for you and your budget.
- Ice trays/molds for freezing liquids. Listen up – this is a great tip. I use dedicated ice molds to freeze all of my liquids (water, hydrosols, milks, etc.) before I combine them with the lye. This keeps the temperature down (and explosions less likely) while you are combining the lye, and it comes to mixing temperature much faster.
- A good quality kitchen scale. You will be weighing and measuring each ingredient carefully, so a good scale is a must. There are many different varieties and it doesn’t have to cost much. Something like this or this is great.
- Soap molds. Obviously we need to put the soap into something when we’re done batching. This is personal preference, although most soapmakers who make large quantities use a loaf mold like this. I’ve used a combination of oval, square and shaped molds in the past.
- Goggles and gloves and other protection from lye.
Let’s talk Lye and Safety
Okay, let’s talk lye. I know, I know. A lot of people (including me!) shy away from using any kind of chemical because it is scary and distasteful. It’s a harsh reality of soap making. There just is no way to make a good soap without using caustic soda. As I said above, making soap is the mixing together of oils, waxes and butters (acids) with lye (a base) to start the chemical process known as saponification. Mixed together, they form a new compound, soap, which will be gentle and of a “normal” (body relatable) PH.
So the reality of working with lye means that you have to follow some basic, but important safety rules. You will need gloves and eye protection when mixing your lye. Some folks use a mask when pouring and measuring. I’ll admit that the first time I used it, I looked like I was heading into a clean room! But I’ve since become more comfortable. I still cover my eyes and use gloves, and I wear an apron as getting even a drop on your skin burns like mad. Make sure you open windows to ventilate the area well while you are working with the lye. Also keep near the sink in case you do get some on your skin, you can flush and wash. Always add lye to water, never water to lye. Adding lye and water creates an exothermic chemical reaction that can actually POOF and erupt right out of the container if you are not careful, which is why I recommend freezing your liquid (water, etc.) for soaping and adding the lye slowly to combine. Finally, make sure to use an appropriate vessel/bowl to mix in. You want something heat resistant and not metal (since some metals can react with the lye and form noxious gases). I use glass Pyrex bowls, but there are some heat resistant plastics that work okay.
If you still want to make soap, but don’t want to use lye, look into the melt and pour kits that you can buy. These are essentially hardened blocks of material that you melt on your stove and pour into your own molds.
When formulating your recipes, you’ll begin by choosing oils that will make up the bulk of your recipe, such as Coconut and Olive oils (in percentages from 15-50%), and those which will be used to ‘Superfat’ your recipe. Superfatting means adding extra oils at the end of the process that will be free-floating rather than combining with the lye and transforming into soap. Essentially, superfatting is the difference between a bar of soap that’s purely cleansing and a bar of soap that’s cleansing, moisturizing and nourishing to your skin.
There are MANY oils to use in your soapmaking. Each oil, and the amount that you add of it, will alter your soap properties. Some oils, such as Apricot kernel or Almond oil are wonderful at contributing to your soap’s lather as well as being moisturizing and nourishing for your skin. Other oils, such as Evening Primrose, Kukui nut, Neem, or the new rage, Argan oil, are purely for healing, nourishing and moisturizing the skin with various antioxidants, vitamins and minerals (superfat oils), and while they don’t add to lathers, they can help with stabilizing what is already inherent in your base formulation (usually olive and coconut) . They should be used sparingly, in percentages from 5-8%.
I use 5-12 % shea and/or kokum butters in my soaps. I love the nourishing, silky texture I get from these butters and they add hardness and longevity to your bar. Just a little in the superfat stage = yummy soaps! I also use 2 oz. of beeswax to my bars. It creates a lovely scent and hardness to your bar or compensates for the soft butters that you may have superfatted in!
As well as oils, butters and wax, you may choose to add fragrance oils, herbs, flowers, roots, coloring agents and/or mica powders. Some of you might prefer to leave your soap as is and allow the natural aromas to speak for themselves. I like to add scent to mine, usually essential oils, but every now and then, I’ll pick a stabilized and blended pure-fume oil (made from ‘mostly’ essential oils and some fragrance oil) instead of purchasing, say, 3 oz. of jasmine or rose, which would make my soap cost prohibitive.
The very basic process for cold soap making is: make, mold, cure. Of course, these are pretty generic terms that cover a few steps each.
- Make. Arguably the most important part of creating your soap is to come up with a recipe. This, to me, is really the essence and craft of soapmaking. Of course, I am a licensed cosmetologist, Herbalist, Aromatherapist and Holistic Health Practitioner, as well as a Hedgewitch. Crafting a soap from scratch, utilizing the most beneficial plants, oils, and aromas for a specific skin issue or to achieve a grand end result is the real magic and fun for me. Coming up with a recipe can be daunting, so you can poke around on the internet (like my site or Pinterest) and try other people’s ideas before you try crafting your own. Tanya from Lovely Greens does some fabulous soapmaking, and gives many recipes. Brambleberry is a fantastic place for supplies, videos and a couple of basic recipes. They also have a lye calculator on their website, if you poke around a bit. When formulating your recipe, you will need a lye calculator. It’s also very helpful to check the percentages of the oils that you are adding without having to do the math in your head. Above all, make sure you write it down somewhere to keep track of your results. If they were good, chances are you’ll want to recreate it and if they were bad, you’ll want to know where to change it.
Once you’ve crafted or borrowed a recipe, you’ll need to assemble your equipment and ingredients. I have essentially three stations when I make soap. The first is the wet/cold station by the sink. At this time, I will have already pre-measured my liquid, whether it’s water or hydrosols or goat’s milk and put it in ice cube trays in the freezer. I will have a large glass bowl in the sink for when I am ready to add the lye. I have my goggles and gloves, glass measuring cup and bowls. I keep my scale nearby and measure my oils out to put in my second or warming station, which is the crockpot. By the crockpot, I will have my immersion blender ready and plugged in, my thermometer, a rubber or silicone spatula, my coloring agents, herbs, flowers and essential oils for adding after trace. The third station is my molding station, where I will set up my molds on racks. I also cover the counter with wax paper that I will transfer to the top of the molds after they have cooled slightly and smooth the very tops of the bars.
- Measure your liquid and Freeze. Then measure your lye into the frozen liquid in a bowl in the sink. Freezing your liquid helps the exothermic reaction of adding lye to water be a little less volatile. These temperatures can quickly escalate to over 200 degrees. Freezing the water keeps the temperature down to a more manageable (and less scary!) level. Stir carefully with a rubber spatula to combine and be careful not to splash your arms. You want to time the cooling down of your lye solution with the cooling down of your oil solution as they should ideally be at or very near the same temperature of about 100-115 degrees.
- Measure your oils. Into the crockpot on LOW or warm, one at a time, add your hard oils, butters, wax and then your liquid oils last. These will take a little bit to melt down, especially if you are using beeswax. Watch carefully, stir often, and pull the pot out of the warmer when they have all combined. You’ll then be cooling them down to about 100-115 degrees.
- Slowly and carefully add your lye solution into your oils. Using the immersion blender, blend consistently until a light trace is reached. Trace is the term that soapers use to describe the stage at which their soap is combined and ready for the next steps. You can tell you’ve reached this stage when you drizzle a little bit of the mixture over the surface of the pot and it leaves a “trace” or pattern. Something like the consistency of a good sauce coating the back of a spoon. Trace is reached generally within a few minutes using this technique.
- Add in your extras. Once you’ve reached trace, you’ll want to add your fragrance, colors, exfoliants, herbs, flowers, honey or oatmeal. Working quickly, gently fold in your extra ingredients until well blended and even.
- MOLD – Pour into your molds. Again, working quickly (the soap will start to harden immediately as it cools) pour your soap into the waiting molds and smooth the top with a rubber spatula. I like to use wax paper over the top to gently smoosh the soap into the mold and flatten on top. Tap the filled mold on the counter a couple of times to dislodge any air bubbles and evenly distribute the soap.
- Let sit for 24-36 hours before unmolding. If you have used a loaf type mold, now is the time to cut the bars.
- Cure for 4-6 weeks in a cool, dark place.
This is just a very basic overview of the process of soapmaking. Check back for new recipes and posts.