Soap is a salt of a fatty acid. It is used for cleaning and lubricating products. It is a vital ingredient in every household, widely used for washing, bathing, and other types of housekeeping. It is used in industries as a thickener, a component of lubricants, and as a catalyst. The chemical formulation of soap reacts with the dirt, grime, and oils to take them away from the fabric’s surface with running water.

Soap making is more than just chemistry. Many hobbyists take it as a profession and come forward with new innovative ideas and better techniques for making it. Soap is made by mixing fats and oils with a base. Different methods are available using which hobbyists can make soaps.

How is soap made?

Saponification is the process of making soaps. It comes from the root word “Sapo” which means “turning into soap”. It is an exothermic chemical reaction in which the salt of fatty acids and oils react with lye. It takes about 24 to 48 hours. The process can be sped up or slowed down by controlling the heat. Saponification can be done using the hot process and cold process, melt and pour process, and rebatching process methods. After saponification, a soap needs a curing time of four to six weeks, i.e., it is left to air dry for this time. It allows excess water to evaporate out of the soap. Then, soaps are stored in different packages, keeping in view the fragrance each soap carries.

Both hot process and cold process soap making have three common steps: preparation of lye solution, preparation of oil, and mixing both till emulsion takes place.

Hot process method

Most soap-making factories use this process. It is simple and easy; so, it’s widely used in small-scale factories all over the world. In this process, glycerol remains in the product and saponification carries on for many days even after the soap is poured into molds. The reaction happens in the kettle at a high temperature.

Hot process soap often has a more rustic look and texture. It’s also the go-to method for transparent or moisturizing soaps. Interestingly, soap that retains natural oils and emollients shares some formulation similarities with butter in how it softens and nourishes.

Cold Process method

Handmade soaps are generally made using the cold process method. It uses the technique of ‘super fatting’. In this process, excess fat is used and the glycerol that remains acts as a soap-softer and moisturizing agent. Glycerine (glycerin) is added to make the soap softer. Superfatted soap is more skin-friendly. The only con is that it leaves the skin a little greasy. For added fragrance, essential oils are added to the soap. To increase the exfoliation property of soap, sand and pumice are also added. Compounds like triclocarban can be added to give anti-bacterial properties to the soap.

For small businesses and handmade product sellers, understanding soap types is as important as choosing the right commerce platform to market your creations effectively.

Additives

  • In the hot process, fragrances and essential oils are added to the soap after it is heated.
  • Fragrances and essential oils are added to the soap in the cold process before molding begins.

Time required

In the hot process, the soap is heated using the double-boiler technique on low heat, 140-176 degrees Fahrenheit. Heat is turned off when soap reaches its gel phase in 1-2 hours. Then, additives like colourants and essential oils are added. The soap is poured into molds. It is unmolded after cooling down and left to air dry for a week or two. It is a comparably short process.

In the cold process, the soup takes 24-48 hours to set in after it is poured into molds. As the molds are insulated, so they act as a heater to make the process speedy. Then the soap is unmolded and left to cure for about 2 weeks before final packaging. This process takes longer than the hot process.

Transparency

The hot process is used to make transparent or liquid soap as the soap passes through its gel phase when it is heated. This gives a more ‘rustic’ appearance to the soap because of its less smooth texture.

Cold process can’t make fully transparent soap. It is used to make cream soaps and whipped soap that floats on water! It allows the maker to customize every ingredient to suit his/her personal preferences. As the cold process soap is opaque, so glitter does not work in it. Still, the maker can add glitter on top. So, it allows more creativity.

Additives

The hot process uses fewer additives as the soap maker has to add them after taking off the soap from the heat. But, attention is to be paid that the soap’s temperature does not exceed the flash point of certain additives like essential oils, or they will evaporate.

The cold process uses more additives, but their essence gets away more easily than the soap made with the hot process.

Which process to choose?

Hot process and cold process have their pros and cons. The cold process takes less time and effort for saponification, but takes ages to cure. Sideways, hot process takes time, effort, and technical knowledge, but is ready to use once unmolded. One thing is sure, both processes provide an equal quench of thirst for curiosity and creativity and give immense satisfaction to the maker.

Crafting Soap: A Personal Journey of Creativity

Soap making is not merely a chemical reaction — it’s a thoughtful, even therapeutic process that makes you feel connected to the products you use daily. From selecting natural oils to testing fragrances and textures, it’s a hobby that’s worthy of your patience and creativity. Unlike mass-manufactured bars, handmade soaps are imbued with your personality and love.

When you craft soap through the cold process technique, you’re not merely combining ingredients — you’re creating a personalized experience. You choose what comes into contact with your skin. Whether lavender for relaxation or oatmeal for scrubbing, each ingredient has a specific role. That choice makes each batch personal and special.

The hot process, however, rewards you more quickly. It’s perfect for creatives who need something effective, quick, and homespun. The rubbery feel, the fragrance trapped at just the right moment — it all is like orchestrated artistry. And once unmolded, it’s ready to use, eliminating weeks of cure time.

Both processes have something unique to give. Cold process allows for design and aesthetic expression, whereas hot process prefers function and efficiency. The secret is knowing what you desire from your soap. Do you like to see swirls spring to life in a loaf? Or would you prefer a rich, skin-nourishing bar without delay?

Whichever you prefer, soap making anchors you. It puts on the brakes. It provides something useful for your hands to do and something constructive for your brain to work on. There is nothing quite as satisfying as to hold in your hand a piece of soap that you made yourself from scratch — created with intent, fragrant with thoughtfulness, and employed with pride.