Hot Process Soaps: Ugly Duckling or Beautiful Swan?
There are many ways to make your own soap, and two of the more popular methods are cold process and hot process. Most of the lovely swirly soaps that many people make use the cold process method, which as the name implies, uses a batter that is cool (about 100 degrees) and turns into soap (saponifies) over an extended period of time. You should wait 4-6 weeks for the soap to fully cure, and if you like to make colorful soaps, one must be wary of some fragrance oils as they can cause all sorts of trouble by making the soap batter too thick to pour. So, if you have a fragrance that you really want to use and it acts up in cold process, there is another option. Hot process. Again, as the name implies, the soap is made at a much higher temperature (in a crockpot at closer to 200 degrees) and the cure time is substantially shorter. However, the batter is gloppy like mashed potatoes or peanut butter and cool swirly patterns are much more difficult. I set out to see if I could make a few hot process soaps that actually look really nice, and will continue on this quest. I first got the courage to try the hot process technique after reading this inspiring post from the amazing Soap Queen. My first hot process soap was very functional, but not much to look at. It is a conditioning and moisturizing soap made with goat milk and finely ground oatmeal. Unfortunately, when you put it next to the cold process soaps, it looks a little boring.
Up next, I tried a gradient style soap similar to the Soap Queen's lovely soap. This Blackberry & Sage scented soap smells amazing and was my first hot process soap to sell out.
Next, I tried a tri-color soap with natural colorants (paprika for red and nettle powder for green) scented with a Ginger Patchouli fragrance. I layered the colors for a rustic striped look. One thing to know about hot process soap. When you add the fragrance to hot soap batter, it can make your entire house smell of that fragrance. I learned with this soap that my husband really does not like patchouli and made me promise to never make this soap again (I am almost sold out so I will have to break this promise but will wait for a night when he is out of town).
A two-color gradient is a nice way to create a visually pleasing soap with hot process.
The last in my series is another inspired by the Soap Queen. I attempted the color gradient with a layer of mica separating each layer, and I really love this soap. It certainly helps that it smells fantastic too!
The one thing to pay attention to when using fragrance in hot process soap is the flashpoint of the fragrance. That is the temperature at which the fragrance burns off or essentially evaporates. I recommend avoiding fragrances with a flashpoint <150F but if you cooled your soap to lower you could get away with it (and potentially have even more of a gloppy batter though but that is another matter).
If you have ever made hot process soap, please feel free to share your experiences in the comments.
The soaps in this post are available in my Etsy store until they end up in their new homes.