Everything You Need To Know About Hot Process Soap Making

In the past few years, hot process soap making has become a major trend for those looking for a more cost-effective and natural way to care for their skin. With people growing more conscious of the ingredients in skincare products, hot process soap has become a go-to choice for many. Hot process soap makes it possible to create solid bar soap, liquid soap, and cream soaps customized to match individual needs. 

Are you interested in giving hot process soap making a try? This article is here to help you explore the wonderful world of soap crafting! We will discuss the different kinds of soaps you can make with the hot process technique and provide some helpful tips for newbies. So let’s get started!

Learn how to make hot process soap

There are several variations of the hot process method, including the “direct hot process” method, which involves mixing lye and oils together and cooking the mixture until it reaches a liquid consistency, and the “crockpot hot process” method, which involves cooking the soap mixture in a crockpot or slow cooker.

Hot process soap in mold

Hot Press SOAP or Hot Process SOAP

The hot process method is a method of making soap that involves mixing lye and oils together and cooking the batter until it reaches a thick, pudding-like consistency. This method is “Hot Process“. Many people often refer to it as hot press and depending on the circle you are in you may be chastised by more seasoned soap makers for mixing up the terminology. Have no fear, after reading this article you will have it for sure. The reason it is referred to as a process is because you us a series of steps to complete the soap making process. There is no such thing as hot press soap but we know what you mean if you have said this.

The bottom line is either term means you are using external heat to make your soap. It involves the use of external heat to accelerate the saponification process, which is the chemical reaction that occurs when lye and oils mix together to form soap. This chemical reaction is Saponification.

Four hot process soap methods

There are a few different variations on the hot process soap-making method.

  • Crockpot method: This involves using a crockpot to heat the soap mixture. The soap mixture cooks on low heat until it reaches the desired consistency.
  • Oven Hot Process; For oven hot process soap making, the mixture is heated in the oven. The soap mixture is put in a baking dish or loaf pan and then slowly cooked in the oven until it saponifies and reaches the consistency you want.
  • Hot process microwaving: This method consists of heating up the soap mixture in the microwave.
  • Hot process double boiler method: In this technique, the soap mixture is in a heat-resistant container and placed in a pot with simmering water, which warms the mixture until it reaches its desired texture.

Hot Process Technique

You can make your own hot process soap at home using these easy steps.

  1. Gather all of the necessary ingredients and equipment. You will need lye, water, oils, a pot or crockpot, a stick blender, spatula, soap mold and any fragrances, additives or colorants you want to add to your soap. Make sure you have a well-ventilated area to work in and protective gear such as goggles and gloves.
  2. With goggles and gloves on Mix the lye and water in a well-ventilated area using a heavy duty plastic container. following all necessary safety precautions. Mix the lye solution in a heavy duty plastic container, as lye can react with metal and cause the mixture to become contaminated. When making your lye solution, pour the lye into the water. Never pour the water into the lye.
  3. Heat the oils in a pot or crockpot until they are melted. You can use a stovetop or microwave to heat the oils.
  4. Carefully add the lye solution to the oils and stir until the mixture reaches trace, which is the point at which the soap mixture thickens and begins to resemble a thin pudding.
  5. Cook the soap mixture in the pot or crockpot until it reaches a thick, pudding-like consistency. You can use your spatula stir the batter every thirty. The cook time will vary depending on your pot and the amount of heat.
  6. Once the soap has reached a consistency that resembles that of vaseline, it has completed the cook process.
  7. Allow the temperature to drop to about 120 degrees Fahrenheit and mix in your fragrance or essential oils.
  8. Scoop the soap mixture into a mold and allow it to cool and harden.
  9. Remove the soap from the mold after about 24 hours and cut it.
  10. Allow the soap to cure for 4 weeks weeks before using it. During this time, the soap will continue to harden and become milder.

Types of hot process soap:

All types of soap – solid, liquid, and cream – offer their own distinct characteristics and advantages. With hot process, there is more versatility to make soap than any other method. By making small tweaks to the recipe, you can end up with an entirely different outcome.

  • Bar soaps normally have a long shelf life and are used on the face, body or hands and are typically used with a washcloth or sponge. This is made with sodium hydroxide.
  • Liquid soaps are convenient and easy to travel with. This is made with 100% potassium hydroxide. although some makers will add a small percent of sodium hydroxide as part of the lye solution.
  • Cream soaps are known to be moisturizing, gentle on the skin and is often applied with the fingers or a brush. This is made with a dual lye solution consisting of sodium hydroxide and potassium hydroxide.

One Process Different Final Products

To make bar soap, the basic process is to mix together oils and a lye solution, which causes a chemical reaction called saponification. The mixture is then poured into molds and left to harden. Once the soap has hardened, it can be removed from the molds and cut into bars.

To make liquid soap, the basic process is similar to making bar soap, but with some additional steps. The mixture of oils and lye is heated until it reaches a certain consistency, which is typically thicker than the mixture used for bar soap. Potassium Hydroxide is used instead of Sodium Hydroxide to create a liquid soap instead of bar soap. After the soap completes saponification it is diluted with distilled water. After that, the mixture is then poured into bottles and left to sit for a period of time to thicken.

To make cream soap, the basic process is also similar to making bar soap, but with some variations. Recipes are formulated with ingredients like glycerin and stearic acid. This mixture is heated and emulsified using an emulsifying wax, and then poured into containers and left to cool and thicken.

It is worth noting that making any of these types of soap requires precise measurements, safety precautions and some level of experience. It is also important to research and follow proper recipes and instructions to produce a safe and effective soap.

The benefits of taking a live soap school class:

For expert guidance and support, get on the waiting list for our Advanced Soap Making Program: Mastering Hot Process Soap Making- from Solid Bars to Liquid and Cream Soaps. This program isn’t just theory; it’s hands-on. Our online program includes live lessons, video lessons, resources and a supportive community. This allows you to learn from the comfort of your home and at a pace that suits you.

Additionally, you have the chance to ask questions and receive feedback from a professional certified soap maker during our live lessons, something that can be worth its weight in gold in helping you hone your abilities. In this class, you will learn how to make hot process soap and create a range of products such as solid bars, liquid soaps, and cream soaps.

One major benefit to Live Soap School is being able to gain knowledge and develop with the help of a supportive community of fellow students. This is your opportunity to connect and interact with other students who are also studying; you can provide each other with tips, techniques, and ideas. Connecting with others offers invaluable feedback and support while you are developing your soap making skills. Having a supportive group of other students and a certified soap maker, you can trust that you will be helped as you study and progress as a hot process soap maker.

Tips for making hot process soap at home:

Making soap in crock pot
  • Making hot process soap at home can be a fun and rewarding experience, but it is important to take safety precautions when handling lye. Lye is either the sodium hydroxide or potassium hydroxide used to make soap. It is a very caustic substance that can cause serious burns if not handled properly. In fact I have gotten a lye burn on my foot wearing crocks in the soap studio and arms by accidentally brushing my arm with raw soap batter on my glove. Always wear protective gear such as goggles, gloves, closed toe covered shoes and long sleeves when working with lye. Make sure the area you are working in is well ventilated and keep children and pets away.
  • Never walk away from a pot cooking soap. You may have heard the term volcano. This occurs when the temperature gets hot and the soap creates a volcanic like eruption and the soap boils out of the pot. This can be avoided by maintaining a temperature below 150 degrees Fahrenheit. If the soap starts to climb up the sides of your crockpot, use a whisk to stir quickly to release the air.
  • Hot process can be more forgiving than cold-process soap with fragrance oils as it is added after the soap has cooked. Just be sure that you are testing your fragrances and essential oils in small batches to achieve the desired outcome and monitor any impact it may have on your soap. Additionally be sure to follow the IFRA standards on the proper usage rates.

Video Demo of Hot Process and Cold PRocess

If you need help deciding which method is right for you, check out this Facebook live in which we made both hot process and cold process soap. We also included a discussion on the differences between the two.

Free Hot Process Soap recipe

Here is a hot process soap recipe that is moisturizing and conditioning with lots of lather:


  • 8 oz. coconut oil
  • 8 oz. olive oil
  • 4 oz. avocado oil
  • 4 oz. castor oil
  • 6 oz. distilled water
  • 2. 8 oz. sodium hydroxide
  • Optional: Essential oils or fragrances for scent


  • Begin by weighing out your ingredients and preparing your workspace. Put on gloves and goggles to protect yourself, and make sure you have all the necessary tools, such as a digital scale, a stick blender, and a large, heat-resistant container for mixing.
  • In a separate, heat-resistant container, carefully weigh out the lye and slowly add it to the distilled water, stirring constantly until the lye is fully dissolved. Set this mixture aside to cool.
  • In a large, heat-resistant container, melt the coconut oil, olive oil, avocado oil, and castor oil.
  • Once the oils and the lye mixture have both cooled to around 130-140°F, slowly pour the lye mixture into the oils and use a stick blender to mix the two together.
  • Blend the mixture until it reaches “trace,” which means that it thickens to a consistency similar to that of a thin pudding. This process usually takes around 5-10 minutes.
  • Once the mixture has reached trace, put the lid on and allow to cook until it gets to a vaseline like appearance.
  • Pour or scoop the mixture into a soap mold and let it sit overnight.
  • Once the soap has hardened and cooled, remove it from the mold and cut it into bars with a knife. Allow the bars to cure for 4-6 weeks in a cool, dry place before using.
  • Lather up with your handmade soap.

Next Steps:

There are several variations of the hot process method, including the “direct hot process” method, which involves mixing lye and oils together and cooking the mixture until it reaches a liquid consistency, and the “crockpot hot process” method, which involves cooking the soap mixture in a crockpot or slow cooker.

Regardless of the specific method used, hot process soap is made by mixing lye and oils together and cooking the mixture until it reaches a desired consistency. The resulting soap can be a solid bar, a liquid, or a cream, depending on the ingredients and methods used in the soap-making process.


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