Curing handmade soap is a process in which freshly cut bars of soap are left to dry out in the open for a period of 4-6 weeks. Essentially, during this time, water evaporates making the soap harder and long-lasting in the shower. Also, chemically, the final leg of saponification takes place, making soap totally lye free. The pH of the soap reduces to a level where it becomes much gentler and nicer to use.
Curing handmade soap in a well ventilated, cool, dry area is essential for product quality and increased shelf life. Line up the soaps in a row and stand them on their edges making sure that they don’t touch each other. Soaps can be cured in slotted plastic trays, cane/bamboo baskets, or on wooden shelves. Curing soap on a stainless steel metal rack is more ideal than on aluminium racks because aluminium reacts with lye.
Time for curing handmade soaps may vary
Distilled water is used in soapmaking as a solvent to dissolve lye. And this water evaporates out from the soap during the curing time. Using more water will yield a softer soap on cutting and will require a long time to cure. Using less water will make a firmer soap on cutting and will cure much faster. Regardless of the water used, it is better to let soaps cure for a minimum of 4 weeks. However, there are exceptions for curing time. Hot process soaps cure much faster and high/pure olive oil soaps such as Castille & Bastille soaps do well with an extended cure time, sometimes ranging from 4-12 months.
‘Sweating’ soap!
When the humidity is particularly high during monsoons, you may find tiny beads of liquid on the soap. Although it resembles ‘beads of sweat’ It is not actually sweating but the opposite of it. Cold process soaps form a substantial amount of glycerin during the saponification process. This glycerin is what provides moisturizing properties to the soap together with the oils. Glycerin is also a well-known humectant, which means that it has the tendency to draw and retain moisture. So, when humidity is high, the glycerin naturally pulls atmospheric moisture to the soap and appears like ‘sweat’. Sweating can be a messy issue when curing in humid weathers. The best advice is to simply let the soaps harden at room temperature. Using a dehumidifier is another option. If its any consolation, the moisture usually dries out once the humidity recedes!
Storing Handmade Soaps
Even after curing, handmade soaps do well when stored in plastic bins with holes, in open cardboard boxes or left exposed on shelves. Make sure metallic shelves are 100% stainless steel and not aluminium. Any other metallic surface needs to be lined with baking paper first to avoid oxidation due to contact.
Do not store soaps covered in plastic wrap or in air-tight containers. Handmade soaps need to breathe – always!
Have I covered everything you need to know about curing and storing handmade soaps? Let me know if you have any additional questions in the comments below! Always happy to help!