This year in the garden I grew luffa gourds, which resulted in an abundance of homegrown luffa sponges. Eager to find ways to use my homegrown sponges, I discovered slices of luffa sponges can be submerged into handmade soap and used to provide natural exfoliation while washing. As I began to dig into soap making methods, I discovered that making homemade soap is an art! Soap makers create intricate designs and custom fragrances. They create blends of unique oils and butters. I envision creating soap with products that we will grow on the farm: milk, lard, tallow, honey, and of course luffas. However as I begin this journey into cold process soap making, I’m going to experiment with some common ingredients to learn this new craft.
Word of Caution
Making homemade soap requires the use of lye also known as sodium hydroxide. Sodium hydroxide is a caustic solution that can cause burns to the skin, eyes, lungs, and digestive system. Lye requires safe handling by responsible adults. Follow all safety guidelines and use the required safety equipment while making homemade soap. See the Useful Information section of this post for more information.
Soap Making Methods
There are four main methods of soap making: melt and pour, cold process, hot process and rebatch. While melt and pour is probably the easiest for a beginner, I wanted to dive right in! In a nutshell, soap is created when fats and oils are mixed with lye to create a chemical reaction called saponification. For my fellow science nerds, the definition of saponification is:
Saponification is a process by which triglycerides are reacted with sodium or potassium hydroxide (lye) to produce glycerol and a fatty acid salt called “soap.” The triglycerides are most often animal fats or vegetable oils. When sodium hydroxide is used, a hard soap is produced. Using potassium hydroxide results in a soft soap.Anne Marie Helmenstine, Ph.D.
I choose the cold process soap method which allows for the use of fresh ingredients, such as milk and honey. It also does not require the use of heat to prepare the soap mixture. While all the soap making methods have their pros and cons, it’s truly a personal preference as to which method you choose. Cold processed soap is the most popular beginner soap making method.
Soap Making Equipment
When making soap, it’s best to use equipment that is dedicated to soap making. While I wanted to have the equipment I needed to create soap, I didn’t want to invest a lot of money in a hobby that I might not continue. I can certainly see the benefits of making our own soap with farm fresh materials. Additionally, it is a way to create revenue on the farm in the future with products that we are producing in abundance.
Safety equipment is one area that can not be skimped on. A good pair of safety goggles is needed to protect your eyes. Additionally, rubber gloves are needed to protect your hands. It’s also important to wear a shirt with long sleeves, long pants, and shoes to protect your skin.
Be sure to work in a well ventilated area. Since we live in an RV, an enclosed space with poor ventilation, I opted to make my soap outside to best protect us from fumes caused by the saponification process.
Mixing Bowls and Containers
While you can use certain grades of plastic bowls, I purchased stainless steel bowls that will be used when mixing my lye mixture. Due to the intense temperature, the bowls must be heat safe. Glass bowls should be avoided, as they can crack or break during saponification.
In the future, I would like to add a large spouted measuring cup for measuring oils and butters. I found it messy to pour the melted oils without a spout. Since the lye mixture will not be added to this container, it can be glass or plastic, however, it’s best to choose a microwave-safe container. My plan was to melt my butters and oils on the stovetop creating a double boiler with my stainless steel bowl. However, I opted to use the microwave to speed up the process. A microwave-safe bowl is necessary, as stainless steel can not be used in the microwave.
Additional bowls or containers will be needed for measuring essential oils, additives, or mixing colorants. I sacrificed a couple of canning jars for this purpose. I have marked them with an X in permanent marker to identify them as soap making jars.
Finally, molds are used to mold the soap into shapes. Larger loaf-type molds can make large blocks of soap that are cut into bars. For my soap making, I am using round molds to place a luffa into each bar of soap.
Measuring and Mixing Tools
No matter what soap making methods you choose, a good food scale is essential. Each ingredient needs to be measured accurately. Choose a scale that you can change the unit of measurement. I measured in grams when making my soap. You also want to be able to tare the scale, to disregard the weight of the container.
I purchased a silicone spatula and a stick blender for soap making. Both will be used when measuring thick butters and mixing the soap mixture during saponification.
A thermometer is needed to monitor the temperature of the lye mixture and also the melted oils. The preferred soap making temperature for non-milk-based soaps is 120 to 130 degrees. When using milk, the best temperature is around 70 degrees. The oils should be within 10 to 15 degrees of the lye mixture. I found this to be a challenging part of the process, as I struggled to manage my timing well with preparing the oils and mixing the lye solution.
Choosing a Recipe
Finding a soap recipe was more difficult than I expected. Many YouTube videos that I found did not include a recipe. Specifically, I was looking for a goat milk soap recipe that included honey. I eventually found a wonderful video by Holly from Holly’s Soapmaking. Holly does a wonderful job of explaining the process of soapmaking with good instructions and an excellent video for cold-processed soaps. As a bonus, she shares her recipe in every video. Holly introduced me to SoapCalc.
SoapCalc is a lye calculator that is used to create soap recipes. Soap making is chemistry! It’s vital that ingredients are accurately measured to ensure success. Any variation in your ingredients changes the outcome of the recipe. SoapCalc takes into consideration the exact specifications of my soap and the makeup of the fatty acids in each oil. It allows the home soapmaker to make adjustments to types of oils, and fragrances and adjust the recipe to fit the available soap mold. Best of all, it does the math for you!
The Lye Base
For my lye base, I chose to use goat’s milk. Goat’s milk makes an excellent base for soaps, as it naturally contains saturated and unsaturated fats. The saturated fats increase the lather production of the soap, while the unsaturated fats have moisturizing and nourishing properties. It also naturally exfoliates the skin due to the lactic acid in the milk. Since lye heats up when it is mixed with liquids, it’s best to freeze the goat’s milk to help prevent burning the milk. I also placed my lye bowl in an ice bath to further help control the heat created when the lye is dissolved into the milk.
Take extra caution when working with milk. Since the milk is not a clear liquid, it is harder to tell if the lye is completely dissolved. Undissolved lye is irritating the skin and can burn. I watched the edges of my bowl for telltale signs of undissolved lye in the lye solution.
The Fats: Butters and Oils
Traditional soap making methods made soaps with animal fats. However, we now have an abundance of oils and luxurious butters available to us. Soapmakers can create custom recipes with exactly the qualities that they are seeking. The oils and fats included directly affect the lathering ability, cleansing properties, hardness of the soap, and speed of saponification. Soap makers can choose oils based on affordability, accessibility, and environmental and ethical considerations. I have to admit, choosing oils is highly scientific!
As a new soap maker, I followed Holly’s guidance regarding a blend of butters and oils. As I become more proficient, I will be able to use SoapCalc to make adjustments to recipes to the fats and butters I choose.
SoapCalc automatically calculates the fatty acids in each oil. The fatty acids in the oils and butters you choose define the soap’s hardness, cleansing, conditioning, and lathering properties. SoapCalc helps soapmakers achieve the optimum balance of oils to achieve the qualities they desire in their soap. Then SoapCalc automatically calculates the SAP (saponification) values of your oils to determine the exact amount of sodium hydroxide that will be required to achieve saponification.
Olive oil is the most common oil used in soap making. It makes hard, long-lasting bars of soap that are suitable for all skin types. There are different types of olive oil that have an effect on trace during the soapmaking process. Olive oil is high in oleic acid which contributes to the conditioning, moisturizing, and lathering of your homemade soap. Castile soap uses 100% olive oil as an oil base.
Coconut oil produces hard bars of soap with a fluffy, stable lather. It’s an affordable oil and easily accessible. The solid oils help produce a hard bar of soap. Coconut oil can be drying to the skin, so it’s generally used at no more than 30% of the oil blend. People with sensitive skin will prefer coconut oil to be limited to only 15% of the oil. In the recipe I am using, Holly limits the coconut oil to 23% of the oil weight.
Shea butter is a very popular addition to soap making. It comes from the nuts of the African shea tree. It is a luxurious oil that has 4 to 9% unsaponifiable. That means that a portion of the oil will not be saponified or made into soap. The additional fats add to the superfat percentage of the soap batter. While some oils can strip the skin of its natural oils, superfats are nourishing to the skin.
Cocoa butter is used in many skincare products due to the many benefits it provides to our skin. . It is a non-greasy, but moisturizing butter that is healing to the skin. It prevents dryness and is often used to reduce scars and help reduce the effects of aging. This hard butter can cause soap to be brittle so it should be used sparingly in soap making. It also takes the longest time to melt, so melt it first.
Avocado oil is known for its moisturizing qualities and it is rich in a variety of vitamins that are nourishing to the skin. It provided medium lather and mild cleansing properties. Avocado oil also contains a high number of unsaponifiables which means it adds to the superfats of your soap-making recipe.
Castor oil contributes beautiful lather to a homemade soap recipe. It is recommended to use 5 to 8% of the total oil weight, as it can become sticky if used in excess of 10%. Castor oil is a humectant, which means it attracts moisture to your skin. This helps the skin retain its moisture level and prevent dryness.
The Cold Process Soap Making Method
I will admit, I was very nervous about making cold processed soap for the very first time. Soap is made with lye also called sodium hydroxide or caustic soda. Lye is a dangerous chemical that can cause severe burns. When lye is mixed with liquids, it created an exothermic reaction which means it heats up. The chemical reaction of the oils and lye can cause temperatures to soar to 200 degrees.
During saponification, the fats and oils (acids) are transformed into soap when they are combined with the lye mixture (the base). The chemical reaction creates self-generated heat and neutralizes the acids and bases during the process. The end result is soap.
When making cold processed soap, the saponification process takes several days to complete. As the oils and lye are mixed saponification begins. The batter begins to emulsify or thicken. This thickening is called trace. Trace looks like trails of thick soap mixture on the surface of the batter when drizzled off of the spatula or immersion blender. Soap makers mix soaps to different levels of trace for different artistic purposes.
Additives Used in Soap Making
Once the lye mixture reaches the desired trace or thickness, soapmakers can add fragrance oil, pure essential oils, and other natural ingredients to the mix. Ingredients like, honey, oats, poppy seeds, coffee grounds, and even flower petals are commonly added to homemade soaps. New soapmakers should be aware that some additives can accelerate trace. Hand-mixing these additives rather than using a stick blender can help.
Adding Honey to Soap
Honey adds a sweet aroma to the soap as well as acts as a humectant, which means it helps retain moisture in the skin. Honey also has antibacterial properties which is an added benefit of adding to soap. However, since honey contains sugar, it does accelerate trace in soapmaking. It’s best to thin honey with a small amount of distilled water to help mix it in thoroughly in the soap mixture. Only about 1 teaspoon of honey is added per 500 grams of oil.
Oatmeal contains an element called beta-glucan colloidal which helps protect the skin. Additionally, oatmeal acts as a natural cleanser and exfoliate. Oatmeal also has natural anti-inflammatory qualities that can help soothe the skin. In my recipe, the oatmeal was ground to a powder, but it can be added at a thin trace to help suspend the oatmeal in the soap mixture.
Fragrance has a way of stimulating our senses. Soap makers can add natural fragrances using essential oils or any type of perfume they desire. I choose to add only essential oils to my soap, trying to keep as natural as possible. I used the fragrance blend recommended by Holly at Holly’s Soapmaking. While I like lavender, I was not thrilled with Patchouli. This essential oil was added at only half a part but still is a powerful fragrance. I opted to leave it out of my second batch. My next batch will be fragrance-free for those with sensitivities to fragrances. I am a little concerned that the silicon molds have absorbed some of the fragrances, so I will see how successful it will be to create a fragrance-free soap.
Creating Bar Soaps
After adding any additives, the soap mixture is poured into a silicone mold. Saponification continues in cold processed soap making even after the soap is poured. The mixture will continue to heat up and enters what is called gel phase. Depending on your end goals you may want to encourage gel phase by insulating the mixture. Soap that completes gel phase creates bright, vibrant colors and will be more transparent soap.
In some cases, you may want to cool the mixture by putting it in the freezer or refrigerator. When working with goat’s milk, I want to cool the mixture since gel phase can scorch the milk. My goat milk soap was put into the freezer for five hours and then moved to the refrigerator for 24 hours. Once the soap is fully cooled, it is removed from the fridge. After two additional days of curing at room temperature, the soaps are removed from the molds and will be allowed to cure for 6 weeks.
Why Does Soap Need to Cure?
Saponification continues for 24 to 48 hours after the soap has been mixed. Saponification is different than curing. Soap is cured so it can dry completely. Soap can be used before it’s fully cured, but it will melt quickly if left in the shower. It also continues to neutralize during the curing process becoming more gentle on your skin.
Dry soap equals harder soap. I could tell the difference in my soaps made only one week apart. The new soap was lighter in color and softer, while the soap only one week ahead of it was drying a darker color. Soap is dried by placing it on a rack that has good airflow around all sides of the soap. It needs to be kept away from animals and children through the curing process. The curing time is different for different kinds of soaps. Soaps made with high amounts of olive oil will take much longer to cure. My goat’s milk soap will cure for 6 weeks before I can give it as a gift or use it at home.
Am I Hooked on Soap Making?
I have found soap making very enjoyable. My long-time followers know that I am a bit of a science nerd. It’s mind boggling to me how centuries ago they discovered they could take ash and fat, both dirty substances, to create soap!
Soap-making truly is chemistry. I feel like such a scientist all decked out in my goggles, weighing my ingredients on a scale and watching saponification turn milk and oil into soap! I have to admit though, despite my initial hesitation and nervousness regarding soap making, it wasn’t scary at all.
About the Author: Barbra-Sue Kowalski grew up on a small hobby farm. She was always drawn to farm life, however, she was stuck in an urban life far from her roots. Barbra-Sue was a single mom for 13 years, raising her 3 children on her own. She met Philip in 2018 and they married in 2021. Between the two of them, they have 5 grown children and 4 grandchildren. These empty nesters are following their dreams! As they both turn 50, they are building their off-grid homestead to live the life that they dream about. Learn more about Philip and Barbra-Sue here. Contact them here. To leave a comment on this post, please scroll down.