What is Cold Process Soap? Get the Facts Here!

By Marsha Harrison

Fact-checked by Kia Lowe

what is cold process soap

The cold process method is one of the ways to create a natural and homemade soap minus the use of external heat.

Not only does it require the least amount of equipment for DIY enthusiasts looking to get started on their soap-making journey. It also allows you the most control over what exactly goes into your product.

If you want to know the essentials of what is cold process soap all about, continue reading below.


What is the Cold Process Method About?

Cold process soap is sometimes called CP soap. Cold process is essentially a soapmaking method without the use of external heat.

In the cold process method, the natural glycerin that’s created from the chemical reaction of combining lye and oils remains in the finished product, making a milder and more nourishing soap.

What Does Cold Pressed Soap Mean?


Cold press soap is often used interchangeably with cold process soap. While they are both related, they are distinct from one another.

Cold press refers to the method of extracting oils which are then added to the lye to give a pleasant scent or provide additional benefits. The cold process, on the other hand, deals with the actual process of creating soap.

What Are the Benefits of Making Handmade Soap?

  • The most obvious benefit is that you can create a soap that is as natural as possible since all ingredients are non-toxic and organic.
  • You can add essential oils if you want more than just a clean-smelling bar of soap.
  • You will know exactly what’s in your soap, which is especially important for people with allergies or sensitive skin.
  • You can also control how much lye goes into your batch of cold process soap. This helps keep your pH in check and creates a milder bar of soap than store-bought products, which tend to have high alkalinity.

What is the Cold Process of Making Soap?

The cold process method is also known as cold water saponification – this refers to the chemical reaction between your oils and your lye.

The resulting reaction produces glycerin, which gives your soap its moisturizing properties. If you’re a beginner at soap crafting, don’t worry since you don’t have to be a chemistry expert to get started.

Step 1: Get Your Materials Ready


  • The first things you’ll need before mixing your ingredients are a pair of protective gloves, safety goggles, and long sleeves. This is because you’ll be handling lye, which can burn your skin and eyes if not handled properly.
  • You want to work in an area with good ventilation, as you’ll be working with lye fumes while mixing your ingredients.
  • Prepare your ingredients. The most basic ingredient you will need is lye. You will also need a variety of additives such as essential oils, colorants, and herbs for scenting your soap.
  • Don’t forget your equipment, such as a digital scale; heat proof containers made from stainless steel are best; spoon and spatulas; and of course, molds made from silicone are the top picks.

Step 2: Mixing Your Ingredients


  • Once your ingredients are all ready, you can start mixing. This involves adding lye to water in a heat-proof container and mixing until it dissolves completely.
  • At this point, there will still be some undissolved solids that need to be removed from the mixture before cooking can begin (these are called “lye crystals”).
  • To remove these crystals, leave your mixture alone for several hours, so they settle at the bottom of your container.
  • Next, you’ll need your fragrances and colorants. You can purchase them from various stores online or at craft stores near you.
  • It’s optimal to use organically sourced ingredients and high-quality essential oils to avoid adverse reactions. They should be used in moderation as well.
  • Stir well until you achieve trace, which is when the oils and water are emulsified, and the consistency is thick like a pudding.

Step 3: Molding and Setting


  • Once everything is mixed together, pour it into your molds of any shape or size you like.
  • Use plastic wrap or wax paper around each mold until all of the soap has been poured into each mold.
  • Let this sit overnight before flipping over onto a cutting board or some other flat surface where they can sit overnight until they harden up completely.
  • After at least two nights of letting your handmade cold process soap solidify, you can cut it into bars.
  • Leave the bars to cure in a well-ventilated space for at least four weeks. Afterwards, you’re all set to go.
  • Note: The resulting soap should be able to take a bit more of a beating than liquid hand soap, but it’s not as tough as bar soaps that have been cured for months or years.

Considerations for Making Saponified Soap

The first consideration is the cost factor of ingredients. The more exotic the oils, butters, and herbs you use, the higher your costs will be. If you want to make an all-natural, organic bar of soap, you will have to pay more for your ingredients.

Let’s not forget the equipment you’ll need, but since they’re a one-time purchase, you can save more in the long run, especially if you can repurpose unused equipment.

Frequently Asked Questions


1. Cold Process Soap vs Hot Process Soap

  • Hot process soap is another handmade soap that does not require any waiting time between mixing the ingredients and pouring them into molds.
  • Hot process soaps are usually quicker to make than cold process soaps but also don’t have as much flexibility regarding ingredients (e.g., you can’t add extra oils or butters).
  • Hot process soaps do not produce as hard or long-lasting bars. However, they can be used in place of a cold process when making certain recipes like swirls or embeds.

2. Cold Process Soap vs Melt-and-Pour Soap

  • Melt-and-pour bases are premade soap bases that can be melted down and molded into any shape you want.
  • But this process doesn’t let you control the ingredients that go into your soap, and they often contain synthetic foaming agents, parabens, and other unnatural ingredients.
  • The cold process method offers a beautiful array of natural ingredients that can add color, scent, exfoliation, and more to your soap base.

3. Cold Process Soap vs Milled Soap

  • Milled soap takes cold processed soap a step further by milling the leftover bits of excess oils into tiny flakes (or powder).
  • These flakes are then added back into your batch of CP soap to give it extra nourishing properties.
  • The resulting bars are harder, often containing no glycerin, and they will break into smaller pieces if dropped on the floor. The hardness also means they can be used as body scrubs or exfoliants.


Now that you’re all caught up with what is cold process soap about, you see why more people are starting to realize that the cold process is the way to go.

It allows you to customize your soap in a way that ranges from simple aesthetic choices like color and fragrance all the way to adjusting the ingredients going into your soap depending on your skin type and overall health.

There are plenty of recipes and tutorials online for you to check out, so you can customize your own batch of soap for a special occasion, too.

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