Grow My Goodness!

Cold Process Soap Making - The Basics

History tells us that soap was invented by the ancient Babylonians as early as 2800 B.C. That's almost 5,000 years ago! Back in those times, it was made from simple wood ash and animal fats. Many improvements have been made to the soap-making process and recipes, but one thing remains the same - the chemical reaction called "saponification" that takes place when alkali is mixed with water and oils, creating a whole new substance - bubbly, cleansing SOAP!

For years, making soap at home was considered a chore, and housewives celebrated when it became readily available at cheap prices in the stores. Today however, a new movement is happening. People are becoming more concerned with what they put into and onto their bodies, and getting back to natural ingredients is becoming a wide trend. Whatever your reasons are for your interest in soap-making, get ready to become addicted! Let's "Soap my Goodness!"


Required Equipment:
  • electronic kitchen scale
  • large (at least 4-cup) Pyrex measuring cup
  • large glass or stainless steel mixing bowl (do NOT use aluminum!)
  • large stainless steel spoons, and/or nylon mixing spoons
  • silicone kitchen bowl scraper/spatula
  • stick blender
  • instant read thermometer
  • soap molds
  • cutting tools

It is highly recommended that ALL soap making equipment is used ONLY for soap making. Keep all equipment and your soap-making supplies together in a safe place, away from pets and children, to ensure they do not end up back in the kitchen cabinets.

Disposable Items:
  • disposable paper cups - for measuring and weighing lye
  • old newspaper or disposable table covering to protect from any spills
  • paper towels - to wipe up minor spills
Safety Gear:
  • safety glasses
  • disposable rubber or latex gloves
  • nose/mouth dust filter face mask

Note: Cold process soap making uses sodium hydroxide (lye), which is caustic, becomes very hot, and creates fumes when mixed with water. It is VERY important to take caution during the process and wear protective eyewear, gloves and a face mask. Always work in a well ventilated area, away from young children and pets.


The Main Ingredients:

Soap is basically made of up 3 major ingredients:

  • Sodium Hydroxide (Lye),
  • Water and,
  • Oils

When these 3 components are mixed together in the correct amounts, a chemical reaction takes place which converts the mixture into a brand new substance - SOAP! This chemical reaction is called "saponification".

Sodium Hydroxide, or lye, is first mixed with a liquid, usually water, in order to easily disperse the lye molecules in with the oil molecules. During the saponification and curing stages, most of this liquid is evaporated. When mixing the lye and liquid, it is EXTREMELY IMPORTANT to add the lye to the liquid and NOT liquid to lye. Adding liquid to lye can result in an explosive, volcanic-like eruption that can be extremely dangerous. Memorize this - lye into liquid! (You could add to that, "liquid to lye - you die!")

When lye is added to water, the temperature increases rapidly to about 180 degrees F and fumes will be seen. Appropriate safety measures should be taken to avoid spills and breathing in the fumes. Safety glasses, rubber gloves and a dust mask should be worn as well as long sleeves and pants to protect yourself. The water and lye mixture should be stirred well to ensure the lye is fully dissolved. It should then be placed in a safe place to allow it to cool.

Now that you have been rightfully scared silly about the dangers of working with lye and the importance of knowing and taking the appropriate safety measures, lets continue on with the fun!

Water is the most common liquid used in soapmaking. While tap water can be used, it contains many minerals and impurities that may affect the quality and shelf-life of your soap. For this reason, it is recommended to use distilled water in your home-made soaps, lotions and potions, as it is the purest form available. Always use cool liquids in soap making as the addition of lye to hot liquid will quickly accelerate the heating process.

Water is frequently replaced with other liquids such as goats' milk, coconut milk, beer, tea, herb-infused waters, etc. The options are endless, but it's important to know that a straight substitution might not always be possible. Depending on the liquid used, the quantity may need to be adjusted, or the process may need to change. This is especially true for liquids such as goat's milk or any liquid which has sugars or starches, which will be adversely affected by the high temperatures caused by the addition of lye.

There are many different oils available to use in soap-making, the most common being olive oil, palm oil, coconut oil, and castor oil. Each type of oil has its own saponification value, which indicates how much lye it takes to turn one ounce of that oil into soap. The numbers are precise and should be followed closely to avoid ending up with a caustic, lye-heavy soap, or inversely, an oil heavy soap that is soft and prone to spoilage.

Also, each oil brings its own characteristics to soap - values such as bar hardness, cleansing and conditioning abilities, bubbliness and creaminess of the lather, etc. It would seem that no one oil has the perfect combination of these properties, which is why most soap recipes call for more than one type of oil.

In addition to the basic soap components, many soapers prefer to add fragrances, colors or other additives such as oatmeal, sea salt, rose petals, lavender, or any number of other ingredients which may affect the beneficial properties of the soap, or they may be purely for aesthetic value. The combinations and options are limited only by your imagination, and this is what so many soapers enjoy most about their hobby - being creative and trying out new things. Whatever options you try, it is always a good idea to do a little research beforehand to learn as much as you can about any adjustments that may need to be made to the recipe or the process.


The Process:

The basic soap-making process is really quite simple, but it is important that it is followed closely. To ensure success, measurements of all ingredients should be precise. All measurements in a recipe are by weight, therefore an accurate kitchen scale is a must. Always place the empty bowl or container on the scale first and "tare" or bring the scale to zero before adding any ingredients. Also, "tare" the scale between ingredient additions to avoid having to do the math of adding up the weights each time.

Step 1

  • Safety first! Put on your safety glasses, rubber gloves, and dust mask.
  • Using a stainless steel spoon to scoop it, carefully weigh the sodium hydroxide (lye) into a clean, dry container. A disposable paper cup is ideal.
  • In a seperate large measuring cup, weigh the water.
  • Carefully add the lye to the water and stir it well with a stainless steel spoon to ensure all the lye is dissolved.
  • Set the lye water aside in a safe place to allow it to cool.

Step 2

  • Weigh the hard oils such as coconut and palm oils into a large bowl, then melt them. This can be done in a microwave or in a double boiler on the stove.
  • Weigh the liquid oils into the melted oils, then give them a few stirs to mix them.

Step 3

  • When the lye water has cooled to within about 5 to 10 degrees (F) of the oil mixture, carefully add the lye water to the oil mixture. Give it a few stirs with a spoon.
  • Place the head of the stick blender deep into the mixture. To avoid air bubbles in your soap, when you stick the blender into the mixture, do so with the head on an angle as it goes in to avoid an air pocket which may be trapped under the head. Once the head is completely submerged under the mixture you may now turn it on and begin mixing your wonderful concoction! You will almost immediately notice that the mixture loses its transparency, changes color somewhat, and begins to thicken. Saponification is already starting!
  • Keep mixing. Go deep with the stick blender and scrape down the sides of the bowl with rubber spatula to ensure all ingredients are fully blended.
  • Mix until "trace" is reached. Trace refers to the point when the mixture is thick enough that when you lift your blender out and allow it to dribble onto the surface, the dribbles leave a slight mark on the surface.

Step 4 (Optional)

  • Once trace is reached, this is the time when any colors, scents or other optional ingredients are added to the mix.
  • Mix these in well with your stick blender. If trace has been lost because of the addition of these ingredients, continue to mix until trace is reached again.

Step 5

Pour the soap mixture into your mold(s). A mold can be anything from an old shoe box lined with parchment paper, to an ornate silicone mold purchased from a soap making supplier. The choice is yours, but just be sure that whatever you use, that you will be able to get the hardened soap out of it again!

Next Steps

After 48 hours, the soap can be removed from the mold and sliced if necessary. The tools used for this can be anything from a dough or pastry cutter, a long kitchen knife, a wire cheese cutter, to a professional soap log cutter which can slice the entire soap log into uniform sizes all at once. If a knife is used, for appearance purposes only, it is recommended that the blade not be serrated, as this could leave drag marks on the bar.

Finally, place your soap bars on a rack in a well ventilated area, out of reach of young children, and allow them to cure for 4 to 6 weeks. During the curing phase, the bar will harden as the liquids evaporate and the pH levels will neutralize to a level that is safe to use on your skin. Patience is definitely a virtue here as you will surely be anxious to try it out sooner. Don't do it! Until the soap is fully cured, the pH levels will be too harsh for use on skin and the bar will be soft. Mark the date on a calendar and give it the time it needs, so you can fully enjoy your creations!

Ready to give soap making a try? Start with a Basic Cold Process Soap Recipe!



The need to take safety precautions cannot be over-emphasized. Please read through all instructions before starting. Once you are familiar with the safety measures and have read through and understand the entire soap-making process, you can let the fun begin!

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Grow My Goodness! accepts no responsibility for your success or lack thereof in the garden, the kitchen or bath. Information contained in this website is obtained through personal research, and mostly from trial and error. It is for your enjoyment only and is not a replacement for good common sense and sound medical advice. Your health is your responsibility. Eat your veggies, exercise daily, get plenty of rest, and visit your doctor annually.
Oh, and a glass of wine here and there might not hurt either!

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