DIY / Micro Homesteading

Making Cold Process Soap

So you want to make soap, eh? This is a key aspect of running a suburban homestead. Plus there is the added benefit of it being part scary and part fun. There is definitely a bit of a Breaking Bad feeling when making soap. You get all geared up (or at least you damn well should), cause this stuff is no joke! It’s pretty much like being a crazy baking scientist who is hoping they don’t burn their eyes out or skin off. So what I’m trying to say is you HAVE TO BE CAREFUL when making cold process soap. You need to use lye, which is the same thing the bad guys use to dissolve dead bodies when the pigs are too full…just sayin’

Disclosure: Some of the links below are affiliate links, meaning, at no additional cost to you, I will earn a commission if you click through and make a purchase.

So assuming I haven’t completely scared you off and only instilled in you a healthy bit of lye fear, let’s move on. This post is going to be about making cold-process soap. There are two other main methods being “melt and pour” and hot process soap. The first I don’t really consider a method of making soap as you are just melting and moulding something someone else already made. As to the latter, it is similar to cold process soap except that it uses an external heat source to accelerate the saponification process. But more on that later.

cold process soap

That is a picture of the orange essential oil soap I made the other day. It’s really quite pretty and smells amazing (if only this post was scratch and sniff)! So let’s take a look at the process involved in making cold process soap so that you can try it yourself in your own suburban homestead.

Lye Safety

As I mentioned (maybe once or twice), you need to be careful when making soap. Primarily when using Sodium hydroxide, or as it is more commonly called lye or caustic soda. This stuff is no joke, it can easily cause blindness or chemical burns. I also wasn’t joking about it being able to dissolve flesh. It 100% can, so please treat it with respect and a healthy dose of fear.

Make sure that you are wearing long sleeves and that you have at least socks on your feet. Safety glasses are a must and you may or may not want a mask as the lye water can get pretty stinky and isn’t very good to breathe in. Oh, and of course you will absolutely need to get yourself some good gloves. I would suggest you grab some nitrile gloves as they are heavy duty and latex-free so its win-win. Now that you are aware of the necessary safety gear let’s move on.

P.S. I’m not kidding about the gear…get it and wear it, all of it. I would seriously suggest you watch this video from Soap Queen on lye safety.

cold process soap

Can you make soap without lye?

So you may be wondering why you would put something that can dissolve dead bodies into something that goes on your skin. This would be a very valid question to have. So let me explain why we use lye and what your alternatives are if you are dead set against it.

So let’s first look at what lye is and what role it plays in the traditional soap making process. You don’t get true soap without the occurrence of a chemical process called saponification. So what the heck is saponification, other than a big fancy word? Well it is the chemical reaction that occurs between an acid (fatty acids from oils/butters) and a base (lye) which forms a salt (which we call soap). So by definition, if you have soap then you don’t have lye as it is all used up in the creation of the soap. This is why it is so important to use proper recipes and/or soapcalc to make sure that you only have the necessary amount of lye.

So the longwinded answer is no, you can’t make real soap without lye. But there also isnt any lye in the finished bar of soap. Not even a little bit. Which is a good thing really when you think about it.

Essential vs Fragrance Oil

It is a personal decision about whether or not to use fragrance oil. It can be tempting as there are so many more options if you do choose to go down the fragrance oil route. I get most of mine from Mystic Moments. I would suggest you get at least 100ml as you need 2oz for most recipes, so it goes quickly. There are loads of other places you could get essential oils from, I just mention Mystic Moments as it is what I have used and I love them. But you do you if there is somewhere you swear by then, by all means, use that.

Fragrance oils

As I said there are unending smell potentials if you decide to use fragrance oils. This is because they are created in a lab by very smart people. So they can create just about any smell that can not or does not exist in nature. While this can be very exciting (and I have been sucked in myself) there is something you should know. They don’t always fare so well during the cold process soap process. This means that you may choose the most amazing smelling fragrance only to have it all but disappear from your cured batch of soap. I had this exact issue happen to me with a batch of watermelon soap. So you will have to play it by ear.

Essential oils

If you are making cold process soap then you should definitely have some essential oils in your tool kit. I love sweet orange essential oil, lavender essential oil and pink grapefruit essential oil, so I have them on hand all the time. The wonderful thing about essential oils is that they are all-natural. They are a concentrated hydrophobic liquid made up of chemical compounds from plants. They are volatile, which means they will easily evaporate at normal temperatures. Essential oils get their name as they basically contain the very “essence” (input smell here) of the plant.

The most common method of extracting essential oils is through the use of steam. This distillation process uses both steam and light pressure, which pass through the selected plant material. This causes the essential oils to be released. As the vapour cools and condenses, the essential oils separate from the hydrosol (floral water) and rise to the top.


When it comes to colourants, much like fragrance, you have two main choices. Natural colourants or micas. Which you use may depend on if you are trying to keep your soap 100% natural vs trying to get a specific colour. Micas (much like fragrance oils) will always give you more options to choose from. Micas also tend to give more vibrant colours than the more natural options.

One thing that is important to note regardless of the type of colourant that you use is the fact that the cold process soap making process can alter colours (sometimes drastically). This can be true of both micas and natural dye options. When choosing micas typically the seller will show you how it will perform in cold process vs melt and pour etc. Pay attention so you aren’t disappointed when you unmold your precious soap.

Some natural options for colouring your soap include:

  • Madder root – red to purple
  • Rose pink clay – brownish pink
  • Saffron – yellow
  • Sage – green to brown
  • Paprika – orange
  • Indigo powder – deep blue
  • Spinach – light green
  • Tumeric – yellow
  • Alkanet root – purple to blue

Cold Process Soap Supplies

So now that you have decided to make your own soap you will need a bunch of supplies. I’m not going to lie it’s cheaper to go to the store and just buy a bar of soap. But where is the fun in that? Not to mention all the sketchy ingredients… So while there is a certain amount of start-up cost in getting the reusable supplies and a reoccurring cost for the ingredients, at least you know what’s in your soap. You also have the ability to customize the formula to be right for you and your skin type. But more on that later. First, let’s look at the supplies you will need.

Reusable supplies

In terms of the reusable supplies, you will need the list isn’t huge, but these things are necessary. So let’s begin:

It may look like a lot, but if you are serious about making your own soap then these are sound investments.


If you live in Canada then there are three sites that I use and they are:

If you are in the USA, then there is pretty much one place to get all your supplies from and that is Bramble Berry. They have pretty much everything you could ever dream to want.

The Great Palm Oil Debate

There is no denying that the cultivation of palm oil has had a huge impact on the planet. It is grown in large plantations mostly in Malaysia and Indonesia as well as other Soth Asian and African countries. Its cultivation has been linked to the destruction of the rainforests and orangutang habitats. So why use it at all?

Palm oil helps to harden the cold process soap and is a secondary lathering agent. However, unlike lye, it is not your only option for the role it plays in soapmaking. If you do include palm oil in your recipes, then make sure that it is labelled as RSPO. This identifies it as meeting the standards of the Roundtable for Sustainable Palm Oil vendors. They help to ensure that there are guidelines for certified growers, with a focus on sustainability. But beyond that, they push for legal, social and environmentally responsible management.

Using lard (or tallow)

If you set against using palm oil, then one main substitute is lard or tallow. However, this brings up another issue. This is a non-vegan/vegetarian alternative, and this may or may not be an issue for you. Using lard/tallow will result in a nice hard bar that stands up well in the shower which produces creamy bubbles that are mild on skin. Historically it was the fat of choice. If you are running a full homestead and you butcher your own meat, this is a great way to ensure there is no waste.

If you decide to use lard/tallow then you can buy them from the store or take your fat offcuts and render them down to separate the fats.

cold process soap

Silicone vs wood molds

This is another personal choice. I tend to use the silicone loaf pans for smaller batches of soap. Wood ones are better for large batches as they are more sturdy.

Silicone has the advantage of being easier to unmold, also they don’t require lining. They also give the soap a nice smooth finish and they are easy to clean and maintain. One negative is that if you use strong fragrances they can embed themselves in the silicone. It is also possible for soda ash to end up on the mold instead of just your soap. Wood is very strong and has natural insinuating properties.

Unmolding from wood molds can be a bit easier as they tend to have better airflow that silicone molds.

Making your own recipe

Once you get the hang of the basics of the cold process soap process you can branch out and start to get fancy. Do you prefer a more moisturizing soap? Maybe you like more suds? These are all things that can be customized. BUT, you can’t just wing it. This is chemistry people, so I refer you again to my earlier warnings. So repeat after me… WE DO NOT MESS AROUND WHEN USING LYE. What this means is that if you want to change the recipe you have to figure out the new amount of lye water to use. So how the heck do we do this? We play it safe and use SoapCalc that’s how.

Now before you go off clicking on the link I need to warn you, SoapCalc is hella intimidating! But once you walk through it slowly it starts to make sense. There are lots of YouTube videos explaining how to use it. Some of the ones I would recommend are:

How to use SoapCalc Lye Calculator

How to Use SoapCalc (It’s Easy)

That said I would not suggest forging your own path using SoapCalc until you have a few batches of soap under your belt using a proven recipe. It also gives you a benchmark to decide how you want to tailor your own recipe.

Basic Cold Process Soap Recipe

So this is pretty much the recipe off of SoapQueen who as I mentioned earlier is the soap guru. I didn’t buy the premade mixes of soap as I wanted to go through the whole process (and it was super expensive to ship to Canada). The recipe below is for a 10″ loaf mold.

  • 10.9 oz. Coconut Oil (32%)
  • 10.9 oz. Palm Oil (32%)
  • 10.9 oz. Olive Oil (32%)
  • 1.4 oz. Castor Oil (4%) 
  • 4.9 oz. Lye
  • 11.3 oz. Distilled Water
  • 2 tsp Sodium Lactate
  • 2 oz Essential or Fragrance oil
  • 1 tsp mica/pigment (optional)

Making the lye water

  1. Using a heatproof glass measuring cup measure out the 11.3oz of distilled water.
  2. In a separate glass bowl measure out the 4.9oz of lye.
  3. Carefully and SLOWLY add the lye to the water while stirring continuously (NEVER ADD THE WATER TO THE LYE. This can cause it to explode).
  4. Set aside to cool to 49-54C (120-130F)

Before you start

Get all your safety gear and put it on. Make sure you have your scale and thermometer and all your glass bowls and measuring spoons ready and within reach. Plug in your stick blender and have your mold ready to go. In order to prevent the soda ash tragedy, make sure you have your spritz bottle with 99% isopropyl alcohol nearby and ready to go.

Making the base

  1. Melt all your oils completely and make sure they are thoroughly mixed (this is crucial for palm oil)
  2. In a large glass bowl measure out all the oils and set aside to cool.
  3. In a small glass bowl measure out 2oz of your desired essential or fragrance oil and set aside.

Mixing it all together

  1. Check the temperature of your oils and lye water. They should be within the 43-54C (110-130F) range.
  2. Carefully add 2 tsp of Sodium lactate into the lye water and give it a stir.
  3. Measure out 1tsp of mica (if using) and add it directly into the oils.
  4. Place the stick blender into the oils and bang it gently on the bottom of the bowl a few times. This is called ‘burping’ and it is important to make sure that there is no air trapped around the blades of the blender. We don’t want to introduce air bubbles into the batter. Any time you take the stick blender out of the batter it is necessary to burp it. trust me you will know it if you don’t. I’m talking deer in the headlights. It makes a distinctive sound. Is it the end of the world? No…but just burp it ok?
  5. CAREFULLY and SLOWLY pour the lye water down the shaft of the stick blender into the oils.
  6. Pulse the stick blender for about 10-20 seconds to start mixing the oils and lye water. You should see it start to change colour, use the stick blender to stir the mixture a bit.
  7. Alternate between blending and stirring for about 1 minute. You should be at thin trace at this point. Add in the essential/fragrance oil and use the stick blender to completely incorporate it into the batter.
  8. Keep blending and checking to see when you have reached a thick trace. So it should be like thick pudding and it should hold any peaks.
  9. Set your stick blender aside and get your mold.
  10. Carefully pour the batter into the mold, you can (carefully) bang the mold on the counter a few times to help it settle. Just be careful as soap batter can burn. But you still have your gloves and safety glasses on (you do right????) so you should be fine.
  11. Using a spoon or fork you can make a design on your soap. If you are adding anything to the top such as poppy seeds, lavender flowers, dried citrus rind etc now is the time to add it.
  12. Spritz with 99% isopropyl alcohol.
  13. Set aside the loaf of soap and wait…..patiently.

What is trace?

Trace is reached when the oils and lye water have emulsified. This represents the start of the saponification process. There are multiple stages to trace and it will continue to thicken as it passes through them. Depending on what you are doing you may need to reach different stages of trace. If you are planning on making swirls in your soap then you will most likely need thing trace. This will allow more working time and let you get the desired pattern for your bar.

So how do you know if you have achieved trace? This is tricky for a soap newb but gets easier to determine as you get more familiar with the process. Basically, you want to be able to see a “trace” of what you have done. So if you lift the stick blender out of the batter and swirl it around in the air (obviously keeping it above the bowl) you should see traces of the swirls on top of the batter.

Thin Trace – No oils is visible and it has the consistency of thin cake batter

Medium Trace – Consistency of thick cake batter

Thick Trace – Consistency of thick pudding/custard and it will hold its shape when poured

Gel Phase

Making cold process soap introduces you to a whole new vocabulary. From saponification to trace and now gel phase. So what exactly is this new and wonderful thing? It is the stage of saponification when the soap batter heats up. It starts when you pour your soap batter into the mold. You will know that it has started as the soap will turn translucent in the middle and it will spread to the edges. You have to choices, you can either choose to either avoid or force gel phase. Let’s take a look at why you would choose one option over the other. I should point out that soap does not need to go through gel phase for it to be awesome. So there is no need to worry!

Avoiding gel phase

Choosing this option will depend on two things. The look of the soap you would like and on your ingredients. Avoiding gel phase will lead to a soap that is duller with a pastel look. Aside from aesthetics, the prime reason to avoid gel phase is due to ingredients you may be using. If you are making a batch of soap that contains either milk or honey you are going to want to avoid gel phase. Both can become scorched if exposed to the higher temperatures. So you will want to keep your oils and lye water much cooler, around 32-38C (90-100F). You will also want to put the mold somewhere cool. This can either be in the fridge/freezer or depending on the time of year it could be in the garage.

Forcing gel phase

If you want colours that pop then you will want to make sure your soap goes through gel phase. You will want to make sure your oils and lye water ate between 49-54C (120-130F) when you start the emulsification process. This is key if you are using natural colourants as they tend to be duller than the micas. Gel phase also has the added benefit of shortening curing time, you can expect soap to be ready in 4-6 weeks. You will also notice that your soap is shinier once unmolded if the soap has gone through gel phase.

Things that can (and do) go wrong

So you made your first (or 50th) batch of cold process soap and suddenly it’s not looking like the picture. Something has gone terribly awry… Let’s look at some common soapmaking issues that you will most likely run into at some point.

Soda Ash

So you have poured your soap batter into the mold, you come back a few hours later and it looks all grey and crusty!!! Like WTF? You, my friend, have soda ash (Sodium carbonate), which sounds like an STD but it’s not (thank god). Chances are you either forgot (I did this on my last batch) or didn’t know that you should spritz your new soap with 99% isopropyl alcohol. Failure to do this will result in the abovementioned soda ash, which while unsightly is not really a cause for concern.

Soda ash is created when unsaponified lye reacts with the carbon dioxide that is naturally present in the air. It looks like a white ashy film that occurs on the soap bars and crushes your dreams (Pitch Perfect reference there for any fans). Don’t worry the soap is totally safe to use soap with soda ash on it, but it can cause the bars to become a bit crumbly.

It tends to occur when you are working with thin trace (for swirls) or when lye water and oils are lower than 100F. Using the isopropyl alcohol acts as a backup, helping to form a barrier between the soap and surrounding air.

Soap not hardening

There are two main causes of soap that will not harden. They are not enough lye/too much water or not enough hard oils/butter. When there isn’t enough lye in the recipe the soap will not properly be able to go through the saponification process. This can lead to a soft bar of soap that will not harden. Another cause can be not having enough hard oils or butters in your recipe. Soap that has contains more soft oils than hard oils can take a very long time to unmold (such as Castille soap). Adding Sodium lactate to the lye water can help to speed up the hardening process.


Nothing is more unsightly in a batch of soap than ricing, ok well maybe soda ash is. In any case ricing sucks. It is caused when one or more ingredients in the fragrance oil bind with the hard oils in the batter. This causes little lumps in the batter, leaving you with what looks like rice pudding. You may be able to use the stick blender to get rid of it but beware as this can lead to a much ticker trace than you intended.


There are multiple reasons that can cause your precious soap to crack. They are as follows:

  • Too many hard oils/butters
  • Lye heaviness
  • Temperature
  • Dry ingredients

If you hard butters/oils such as beeswax or cocoa butter then try to keep them to 15% or less of your total oils. Using too much lye leads to lye heaviness, which can make your soap can be dry and crack easily. If you let your soap get too hot it can also crack. Typically you should keep your oils between 110-130F when working with the batter. Once poured, during gel phase the soap can get up to 180F. Adding ingredients such as sugar or honey can cause temperature to go even higher, increasing chances of crqacking.


This can easily be confused with ricing, however, the main difference is that with separetion you will see the oils separate from the rest of the batter. Again, the main culprit is fragrance oil. Sepaartion occurs when the fragarnce oil cant be incorporated into the batter. Trying to stick blend to correct the issue can very quickly lead to seizing.


Curing is crucial as it gives your soap time to progress through the saponification process. Thus ensuring to don’t irritate your skin using soap that still contains active lye. It also gives the bars time to harden up properly so that they don’t turn into mush as soon as you take them into the shower. Cause nobody has time for that. When the soap has been unmolded and cut, the next step is curing.

It is important to make sure that there is enough space between each bar to allow for proper air circulation. The other crucial component is adequate time. Most cold process soaps need to cure for 4-6 weeks, after which time it is safe to use. On my to-do list is building this awesome food storing rack from Ana White that I plan to use as a soap curing rack. The curing process is important as it gives time for any excess water to evaporate. This leads to a harder bar of soap that will last longer in the shower.

The last steps: Unmolding, Cutting and Storing

Assuming you haven’t encountered any of the above-mentioned pitfalls then you must excitedly be awaiting the unmolding of your new soap. This is an exciting step, getting to see the fruits of your labour! It is important to make sure you don’t unmold too soon (or too late).

You can safely unfold soap about 2-3 days after it has been put in mold. Just make sure that it is firm to the touch. Hopefully, you used Sodium lactate in your recipe as it does make unmolding easier. If you are using a silicone mold then start by pulling gently on one side. Work your way around the mold and then flip it upside down in one hand. Use the other hand to pull up on the mold. You should be able to see it gradually come away from the mold. This can take a bit of time (and patience) but stick with it and soon you will have a lovely loaf of soap.

Now is the time to carefully cut your loaf of soap into bars. You can use a knife or you can get yourself a soap cutter. I think it is important to keep any soapmaking tools separate from normal kitchen utensils so I grabbed a soap cutter.

So that my friends is how to make cold process soap. Are you just curious about making soap? Have you tried it before or are you a seasoned pro?


  • Shayla
    May 24, 2019 at 12:39 am

    I’ve been so scared of making soap completely from scratch, but this post for cold process soap makes it so straight forward and easy! Definitely now on my to do list!

  • Laurie
    May 24, 2019 at 4:52 am

    My friend and I tried this recipe last night and wow what a success! Awesome 👏🏼

  • Elizabeth Morrill
    May 26, 2019 at 10:04 pm

    Super informative! I want to give this a try!

  • Jessica
    May 27, 2019 at 12:19 am

    I’ve always wanted to make soap! This year my kids and I are going to try it so this came in very handy. I’ll save this so we can reference it when it’s time to make our soap.

  • Brianna
    May 30, 2019 at 7:13 pm

    Wow super informative!

  • Sarah
    May 31, 2019 at 4:46 am

    Wow! I’m so impressed, and now I’m totally inspired to try this myself. My girls would have a blast doing this with me. Thanks for all the awesome info!


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