How to Make Soap - A Beginner's Guide - Public Goods

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How to Make Soap – A Beginner’s Guide

While plenty of store-bought options exist, making soap at home is a fun and highly satisfying experience! Keep reading on to find out how to make homemade soap yourself.

Image of homemade soap

Making soap at home is not only a fun and educational process, it’s also an easy way for you to control the ingredients that go into your suds. While store-bought options can contain a variety of chemicals and toxic fragrances, you only need a handful of ingredients and some patience to make all-natural soap at home. It may seem difficult at first, but after a few attempts, you’ll be a soap-making machine and all your friends will have the cleanest hands.

Before we get to the actual recipe for making soap at home, it’s important to understand the basics of how modern soap is made.

Soap-Making Process

In truth, not much has changed since soap was invented around 2800 B.C. Sure, the specific ingredients are different, but the general concept remains the same. At its core, solid bar soap contains fats or oils mixed with a caustic substance or alkali. While the ancient Babylonians boiled wood ash with fats, in modern soapmaking, the alkali is called sodium hydroxide—more commonly known as lye.

The Basics of Soap-Making

To make soap, a very specific amount of lye and oils or fats are combined. As they mix, heat is naturally released, causing a chemical reaction that turns the ingredients into soap over time. This reaction is called saponification and it requires lye in order to occur. However, you don’t need to rely on the natural heat output to induce saponification.

Hot Process vs Cold Process: There are two major methods for making DIY bar soap at home: hot process and cold process. The cold process relies on heat naturally generated by the saponification process to make soap. It takes up to six weeks for the soap bars to cure.

The hot process, however, takes advantage of external heat to speed up saponification. This methodology gives you a final product in 24 hours and is generally easier for beginners, so we’ll focus on hot-process soap-making for the rest of this article.

Truth and Lye

As we covered above, saponification—and therefore soap—is not possible without lye. However, lye is a caustic chemical that can irritate the skin, eyes, and respiratory system. So, it’s understandable that some people are concerned about including it in DIY soap recipes. They fear that lye can remain in the final product, posing a risk to their health.

But this is a myth. When soap is made properly—using the correct ratio of lye to oils—there is no lye leftover in the resulting soap. Instead, every single lye molecule reacts chemically to fat molecules, and both convert to soap plus glycerin.

Lye will pose no danger to you or your health as long as you follow safe practices while handling it during the soap-making process. To have fun and end up with a well-balanced bar of soap, follow these safe practices for handling lye.

  • Make sure that your lye ratio is correct. If you’re unsure, use an online lye calculator to find out.
  • Never add lye to base oils that are hotter than 180 degrees Fahrenheit.
  • Always add lye to water. Never add water to lye.
  • When adding lye to water, do not touch the container or breathe the fumes.
  • Do not allow lye to come into contact with tin or aluminum.
  • Always work outdoors or in a well-ventilated area when using lye.
  • Always wear appropriate safety gear including a pair of goggles, an apron, long sleeves, and rubber or latex gloves.

Infinite Customization

One benefit of making soap at home is that you know exactly what goes into it. Store-bought soaps often include synthetic fragrances or even rely on chemical detergents instead of lye. But when you’re the cook, you can make your soap as natural as you want to. For example, imbue a lovely scent and even healing properties with quality essential oils, use natural ingredients as colorants, or top your bars with dried flowers and herbs to add a layer of beauty.

Image of people making homemade soap

Homemade Soap Making Supplies

Here is a list of everything you need to gather before you start making soap. Chances are you already have most of these things in your kitchen!

Soap-Making Tools

First, collect the tools you’ll need to make soap at home. There’s nothing particularly exotic on this list, so start raiding the kitchen to prepare!

  • Slow cooker
  • Container for measuring lye (NOT aluminum or tin)
  • Container for mixing lye and water (NOT aluminum or tin)
  • Digital food scale
  • Silicone spatulas (that haven’t been used)
  • An immersion blender or a whisk (NOT aluminum construction)
  • Thermometer (that hasn’t been used)
  • Silicone molds
  • A sharp knife

When choosing containers to handle lye, avoid using tin or aluminum materials. These can be unsafe when coming into contact with lye. A kitchen scale is also very important. In order to get the right lye ratio, all ingredients including oil and water must be calculated by weight, not by volume.

Soap-Making Ingredients

For the purposes of this article, we will focus on making DIY soap using plant-based fats, specifically coconut oil and olive oil. However, other oils and animal fats will work as well. For the following recipe, you’ll need:

  • Coconut oil (20 oz)
  • Olive oil (10 oz)
  • Distilled water (9 oz)
  • Sodium hydroxide aka 100% pure lye (4.78 oz)
  • Essential oils of your choice
  • Colorants (if desired)
  • Dried herbs or flowers (if desired)

You can easily scale this recipe to make more or less soap. However, it is extremely important to make sure the lye ratio of your soap is correct for your health and safety. Use a lye calculator to dial in the lye ratio when scaling this recipe.

Image of someone adding flowers to homemade soap

How to Make Homemade Soap

Let’s start making soap! But before going homebrew chemist in your kitchen, take a moment to prepare your mind and space. Soapmaking can be a meditative activity, so there’s no need to rush!

First, put on your safety gear for handling lye to ensure the process goes smoothly. Next, precisely measure out your ingredients using a digital scale so they are easy to reach during the process. We measured our lye down to the hundredth of an ounce (4.78 oz) to leave absolutely no room for error in our final product.

Soap Cooking Instructions

  1. Turn your crockpot on low and add the coconut oil. As it melts, prepare the lye solution.
  2. Add the water and lye to the non-aluminum container. Carefully and slowly pour the lye into the water, gently mixing with a spatula as you go. It will heat up and create fumes, so do this step outdoors if possible. Always work in this order and do not pour water into lye as it is unsafe.
  3. Allow the lye and water mixture to cool until it is below 100 degrees F. This process can take 30 to 40 minutes. Place your container outside to both speed up the cooling and minimize the fumes you breathe.
  4. Add the olive oil to the slow cooker once the coconut oil has completely melted. Allow the oils to heat up until they are between 90 to 100 degrees F.
  5. Pour in the cooled lye solution. When the oils and the lye solution are both around 90 to 100 degrees F, combine them by pouring the lye into the fats. Go slowly to avoid splatter and mix with the spatula as you pour.
  6. Stir the mixture using an immersion blender. If you don’t have an immersion blender, you can use a whisk in a pinch. The important things are to make sure your tools do not contain aluminum and to avoid creating air bubbles as best you can.
  7. Continue mixing until the ingredients have reached a trace. This is when everything has been combined and there are no air bubbles left.
  8. Cover the slow cooker and cook the trace for 1 hour. Check periodically for bubbles every 15 minutes and gently stir them away if necessary. Your soap will go through many changes during this time, so don’t worry if you witness it rising and falling or taking on a gel-like consistency.
  9. Mix in your fragrance oil if you are using any. See the section on adding scents, below.
  10. Let the soap mixture cool until it drops below 180 degrees F. Once the mixture has cooled adequately, it’s time to pour it into your molds and allow it to set.

Setting and Molding Soap

Now it’s time to pour your concoction into a mold to let it cure. What you pour your soap in is up to you. You can use a loaf mold with the intention of slicing up rectangular bars after it hardens or buy specific silicon molds meant for soap. Or, you can get creative and use a silicone tray for large cocktail ice cubes to make fun-sized soaps as gifts. Whichever way you go, remember that standard bars of soap are 3.5 to 4 ounces.

If your soap is too thick to pour, you might have to spoon it into your mold. That’s ok. When all the soap batter is in your molds, glide a spatula over the top of the molded soap to smooth out the top, and then let it sit overnight. After 24 hours, your soap will be ready to unmold, slice, and use, however, we recommend letting it set for a full week as it will continue to harden and create a higher quality product.

When you are ready to unmold and use your soap, it should be completely cool and hard to the touch. If you are having trouble popping your soaps out of their molds, there may still be moisture in the soap. Let it sit a few more days and try again.

Adding a Scent

One of the most fun and creative ways to experiment with making soaps at home is to add a custom scent with a natural fragrance. We recommend using essential oils, which deliver a noticeable but refined smell that is pleasant without being overbearing like synthetic fragrances can be.

As a good starting point, use around 2 tablespoons of essential oils to add fragrance to this recipe. If you find the smell is too faint or too strong for your liking, you can adjust as needed for your next batch. Think about which smells you enjoy before mixing them and try to use only complementary smells. For example, orange and lemon essential oils would go well together, while rose geranium and peppermint probably would not.

An important thing to remember is that adding additional ingredients can change how your soap comes out. It is smart to add just one fragrance or colorant at a time and test to see how the recipe reacts before making additional changes.

Image of someone cutting homemade soap


This beginner-friendly recipe is only the tip of the soap bar. If you had fun with it, keep experimenting with different colors and essential oils to get really creative with the soaps you make. If you’re looking for another DIY recipe or all-natural household tips, keep it right here on our blog. For example, try making fall-scented candles next.

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