When it comes to making natural soap, it's pretty simple, there are really only two basic methods - cold process and hot process - and the names do describe the main difference between the two.
With both of these methods, you take non-soap raw ingredients and through the miracle of chemistry, create a new substance, Soap. The main difference is that hot process soap is made with added heat while cold process soap generates its own heat through the saponification or soapmaking reaction.
There are other ways to recreate soap, such as rebatching or using a melt & pour base. Sometimes, a dried powdered goat milk like substance is used in rebatched and melt & pour soaps to mimic the fresh sustainability sourced goat milk used in our cold processed soaps. Don't Be Fooled! Hot process and cold process methods are the only ways to make soap from scratch with the natural, purposeful ingredients you desire.
When soap is created with the cold process method, the first step is choosing which blend of fats, butters, and oils to use in the formula. These are chosen based on the desired qualities of the finished soap. Sometimes you want something really cleansing with out much superfat, like a Laundry Soap. Or you may want something incredibly gentle, like a Goat Milk Castile Soap made with only Olive Oil and Goat Milk.
Once the oil blend is determined, a lye calculator is used to determine how much lye and liquid is needed. This is fairly simple when it comes to how much lye to use. But it's a little more complicated when it comes to determining the amount of liquid. Especially if using goat milk, as the cream adds to the soap's superfat percentage and requires experimentation. Plant Based milks are also an option.
Testing is key to determining the amount of goat milk or plant based option to add. If too little milk, then the full benefits of adding the milk is not met. If too much milk, then the bar of soap doesn't last very long and melts away far too quickly. It was only through extensive testing over years of making soap, that the perfect amount of milk to produce a longer-lasting bar of natural soap was found.
Once a formula is determined, it's time for Saponification. The cold process method looks something like this:
After carefully measuring and melting any oils/fats that aren't liquid at room temperature, the milk and lye solution is carefully added. Any additives are included and mixed until it starts to thicken, a point called trace. Before the soap sets, it is poured into molds and left to sit overnight. The next day the soap is unmolded and cut if needed.
The curing process for simple coconut oil based cold process soaps takes 3 to 4 weeks in a well ventilated area. The longer the cure the harder the bar, the longer the bar will last. Historically, castile soaps are given a year to completely cure before use.
As the name implies, the cold process method purposely does not add any heat to the soaps to speed up the curing process. Many soapmakers add heat during this time because it speeds up the saponification reaction and makes the soap ready to be used in a shorter time period. This heat however affects any additives that may have been added to the goat milk soap. Patience is a Virtue.
During the cold process curing time, the saponification reaction is continuing. While much of the reaction occurs within the first 24 hours, which is why the soap can be unmolded and cut at that point, it does continue for a few weeks. While the soap sits, seemingly doing nothing, not only is water evaporating which helps the bar to be firmer and last longer, but the last of the lye is continuing to react with the oils that create soap and glycerin. By the time a few weeks are up, there is no more lye left. To cure, you want to place your soap in an area out of direct heat / sunlight where it can get airflow. Do not put it in a sealed container.
An important by-product of the cold process soapmaking method is glycerin. The glycerin that is produced by this method is perfectly in balance within the soap. Most commercial soap manufacturers regularly remove the glycerin from their soap and sell it because it is a very valuable by-product. This can cause commercial soap to be more drying because the naturally occurring glycerin has been removed and often added to expensive moisturizers.
Glycerin works well with your skin because it is a humectant. A humectant attracts moisture. But it is important that the glycerin be in balance. If you use too much glycerin, it can actually pull too much moisture out of your second layer of skin which is why you should never use straight glycerin on your skin. In cold process goat milk soap, there is naturally occurring, not synthetic, glycerin.
Granted, this has been a fairly simplistic description of soap making, but it covers the basics. Natural soap made with the cold process method as opposed to hot process, produces a superior bar of soap, in my opinion. Once you feel the difference natural soap makes on your skin, you'll be a believer too!
JD
Side Note: This blog post focuses on the process of making soap, not specific properties of any soap itself, as those would fall under the purview of the FDA as cosmetics or drugs.
This blog post aims to inform it's readers about soap, highlighting the care and craftsmanship involved in creating this natural and luxurious product.
