Ready to dive into soapmaking for beginners? Let’s walk through the science, safety, ingredients, and process of making your own soap. You can absolutely do this, even if it feels confusing right now. Let’s learn how to make everything from baby soap to dish soap, right in your kitchen.
The science and ingredients of soapmaking
Soap is the byproduct of a chemical reaction between lye and oil.
You can’t have one without the other,, any more than you can have water without hydrogen or salt with sodium. Soap needs oil and it needs lye, or it’s not soap.
When you mix oil and lye (in the correct amounts) they blend together, the molecules go all crazy and they form something new: soap!
The basic process of making soap is:
- Mix water and lye, set aside to cool
- Melt oils, set aside to cool
- Blend lye water and oils to form a soap “batter”
- Pour into mold and let harden for a day
- Turn out of the mold, cut into bars and let cure for 2-3 weeks.
But of course, each step has a bit more to it.
If you’d rather watch the video
Do you really need to use lye?
One more time: you can’t make cold process soap without lye. You can make melt and pour soap, which involves melting down already made soap and adding fun stuff to it. There’s nothing wrong with this, but it’s not really soapmaking.
Lye is also known as sodium hydroxide and is a very caustic substance. It was traditionally made from ashes, but now can just be purchased easily. It is used both for soap making and as a drain cleaner, as it will eat away at greasy build-up in pipes.
Caustic is the opposite of acidic, but lye is so caustic that it as dangerous as a strong acid. It can eat through skin, leave marks on countertops, and cause blindness if it splashes in your eyes.
But don’t be scared. If you follow soap safety guidelines (more on that later), you’ll be fine.
The role of oils in cold process soap making
So… lye doesn’t sound super appealing. Don’t worry, the oils in your soap recipe are going to transform it into something completely different. Picking oils is the most fun part of creating a soap recipe. Each oil will bring its own property to the finished product.
- Castor oil creates lots of lather
- Olive oil is very moisturizing
- Coconut oil helps harden the bar
- Shea butter nourishes the skin.
The best soap recipes will have a blend of hard and liquid oils.
Calculating the right amount of oils and lye
Note: If you have no interest in making up your own recipes, then don’t even worry about this. I just wanted to include it so you understand the basic science behind it all.
So here’s where it gets a little trickier. We already know that this is a chemical reaction. So it’s not like making a pasta salad where you just throw things in and hope for the best. Everything has to be precise.
The lye is basically going to “gobble up” the oils and saponify them. (This just means it will turn them into soap.). But each oil requires a certain amount of lye to be saponified. It is a chemical property of that oil, known as its “saponification value”, like the freezing point of a liquid. It’s different for each one.
The way we figure this out is to use something called a lye calculator. There are many of them available for free online. My favorite is from Majestic Mountain Sage.
This post contains affiliate links, meaning that if you make a purchase after clicking on a link I may earn a small commission at no additional cost to you. As an Amazon associate, I earn from qualifying purchases.
Things you’ll need for cold process soap
We’ve already discussed oils and lye. What else do you need for soapmaking?
- Water. You have to mix the lye into water to create a liquid solution
- A digital scale. Remember, this is chemistry and things have to be precise.
- A stick blender. Mixing by hand doesn’t always work and things might not saponify properly.
- Old pots and an old spatula for melting oils and blending things. It’s nice to have a dedicated soap pot.
- A mold to pour the soap into. This can be as simple as a box lined with freezer paper.
- Safety gear
Optional: essential oils, fragrance oil, colorants.
Sources for soapmaking supplies
You can find the scale, molds, and stick blender at Amazon.
There are many shops dedicated to soapmaking. Some of the best are Nurture Soap, Brambleberry, and Bulk Apothecary.
Safety for soap makers
So we’ve established that lye is dangerous. But it really is, and it’s dangerous in different ways at every part of the soap making process. Many people get scared and overwhelmed by the prospect of working with lye, but it doesn’t have to be scary.
Yes, it deserves respect and proper gear, but it’s not scary.
To me, one of the most important aspects of working safely is that you need to be able to concentrate. Interruptions will cause you to make mistakes, be careless, knock things over, etc. Make sure little ones are out of the room, and never try to make soap when you’re in a rush.
Safety gear you will need:
- Goggles. Lye water can blind you!
- Long sleeves
- A mask
- Rubber gloves
First, be absolutely sure that your lye is stored totally out of the reach of children and pets. It comes in a pellet or flake form that is very concentrated and dangerous.
When you are mixing it with the water, it will shoot way up in temperature and will also release fumes. So you’ll need to be outside or near an open window. And you’ll need gloves and eye protection at this stage as well. The caustic lye solution can blind you if splashed in your eye, or burn your skin.
Now, when you set the lye water aside to cool, you need to be careful. Make it very clear that it’s a dangerous solution. It could be fatal to anyone drinking it
The actual process, step-by-step
Step One: Prepare
First of all, get ready. Have your recipe printed out (you can find my cold process soap recipes here.) Get out your scale, your stick blender, your oils, and your lye. Have your mold ready to go as well.
Make sure you have a distraction-free environment and a safe place to set things aside as they cool.
Step Two: Make the lye water
Everything needs to be measured separately before you begin.
The lye and water are measured separately, then you add the lye to water, not the other way around. You can remember this with the saying “snow floats on the lake”.
Mix the lye and water thoroughly, until the lye dissolves. It will be hot. Set it aside to cool in a safe, well-ventilated place.
Step Three: Measure and melt the oils
Next, measure out your oils, separately.
Some people prefer to melt the solid oils first, then add the liquid oils, then heat everything up. Or can just dump it into one pot and heat everything up together. Do it right on the stove, on low.
You want everything thoroughly melted and 140 degrees. Be careful with firm butters and waxes: they take longer to melt.
Step Four: Let both components cool
Now, everything has to cool down, separately. The next step is to blend them together with your stick blender. They can be around 100-110 degrees in temperature, or you can let them cool even more.
As long as the oils are still melted and the lye and oils are relatively similar in temperature, it will work fine.
The cooling stage will take around an hour.
Remember: Make sure your ingredients are in a safe place!
Step Five: Blend!
Now for the fun part. Pour the lye water into the melted oils and blend with your stick blender. At first, it will just seem very liquid, with droplets of oil floating around. After a minute or so, it will become one consistency, with no oil splotches. Then, the batter will start to slightly thicken.
Do not use a food processor or regular blender for this. It is too dangerous. to have a caustic solution like this splashing around.
You can stop blending when your soap batter reaches “trace”. Trace means that when you lift up your blender and soap batter comes off of it, that soap batter will rest on top of the pot, leaving a trail, rather than immediately sinking in.
Some soap makers prefer a thin trace, and some will keep their immersion blender working until the soap is more of a pudding consistency. This is largely personal preference and as you make more handmade soap, you’ll develop your own style.
(At this point, you would add color, essential oils, or fragrance oil if you were using them, but I wouldn’t recommend either for your first batch.)
Make sure to wear gloves and safety goggles during this stage; there’s a high risk of splashing.
Step Six: Pour and cure
Once you have reached trace, immediately pour the soap batter into the mold. It will start hardening right away, so move quickly.
You have a few options with molds:
- a silicone mold that forms a loaf
- a cavity mold that forms individual bars
- a lined soap mold made out of wood
Pour it right in and smooth out the top with a spatula.
Once it is has cured for 24 hours, it’s time to unmold. It still needs time to finish drying out so the bar can get harder. (Castile soap will take up to two days.) You can just leave the bars on an old towel for a few weeks.
Gel phase during curing
As soap cures, it will heat up. Sometimes it will heat up a lot and go through something called “gel phase”. It gets bright, translucent, and very hot.
It’s not a problem, and some people prefer it, because it makes colors brighter in the finished soap.
You can force gel phase by putting the soap in a 120-degree oven for one hour, then turning the oven off and leaving it in there for 24 hours. Or by wrapping it in old blankets.
Or if you don’t want gel phase, you can put the soap in the freezer.
Cleaning up after soapmaking
There are a few ways to handle this. You can rinse out everything from the pots and tools before it hardens into soap. You’ll need to be careful if you choose this method, because the lye is still very caustic at this stage.
You could also let everything sit and turn into soap and then just wash it out then. That is usually what I do.
Fun for the more advanced soap maker
Once you have the method of cold process soap down, you can create your own recipes or add in fun things.
Great additions to handmade soap:
- poppy seeds
- coffee grounds
- essential oils
You can also add natural colorants, or many different colorants and create a swirl.
Instead of using water to create your solution, you can substitute goat milk, tea, or other liquids.
You can sprinkle the top of the soap bar with flower petals, herbs, or decorative glitter. The possibilities are endless. Really.
What about hot process soap?
Hot process soap uses heat to force the gel phase during saponification. It “cooks”, rather than just curing at room temperature. The process is similar to cold process soap except the batter is heated before pouring.
It is frequently made in a crock pot.
Make it along with me
Beginner-friendly soap recipes to choose
- Recipes with only a few oils are simplest to measure and not as expensive to buy the supplies for. Try a recipe that’s 30% olive oil, 30% palm oil, 30% coconut oil, and 10% almond oil.
- Look for a recipe with no strange ingredients, like beeswax or honey (they are lovely in soap but behave a bit differently).
- Don’t attempt a swirl or fancy design.
- Try a recipe with very few oils, like homemade bar soap for dishes.
Recipes for the more experienced soap maker
- One of my favorites is my cold process shower soap recipe, which has lots and lots of lather.
- Beeswax and honey soap makes a hard bar that is a beautiful gift or guest soap
- Mango butter soap has a lot of luxury oils and is extra moisturizing.
- Or check out this list of my favorite books on soapmaking for more recipes.
I get it! Soapmaking is not for everyone, and if you can’t have a distraction-free work area for a few hours (because of kids, pets, or other reasons), it’s best not to attempt it.
You can also explore melt and pour soap, which has all the fun of picking fragrance and color, without the safety concerns.
Go forth and make soap
Now, of course, reading something is one thing, and doing it is quite another.
I encourage you not to get stuck in the research phase, and to move on to actually trying your hand at soap making.
For even more help, you can subscribe to my YouTube channel, where I share new soapmaking tutorials regularly.