There’s some misinformation going around about how long cold process soap actually needs to cure. A popular supplier has egregiously made a claim that a bar of soap made a week ago or less is ok for sale. While it is safe to use, it is frankly going to be a subpar bar of soap and feel quite harsh and drying on the skin.
Many consumers [and even some soap makers, especially newer] may not understand the importance of curing soaps. The curing process is what improves the quality and longevity of your soap so it doesn’t turn to mush in the shower and lasts longer than a week.
But what is soap curing? In the simplest terms, the curing process is allowing time for the water content in the soap to evaporate, which ultimately leads to a long lasting, hard bar and the best sensorial skin experience.
Side note: Soap curing and saponification are two different things. Saponification is the chemical reaction of the oils and lye [sodium hydroxide] combining and emulsifying, which turns the oils, fats, lipids, and lye into soap. This process is complete within the first 48 hours, where all the lye has been turned in to sodium salts and are rearranging themselves into soap crystals.
A little science fun: What is also happening during the curing process is the crystalline structure of your bar soap is becoming more and more tightly packed, which just takes time. While we think of soap as a solid, it’s actually a mix of salt crystals surrounded by a film of liquid, which is composed of water, glycerin, soluble chemicals, and soap molecules.
A fresh bar of soap is a jumbled mix of fatty acids with that very large liquid phase, larger crystals, and soap molecules. The stearic and palmitic fatty acids found in soap recipes is what creates the lovely bubbly lather, and in the beginning these are a lot larger in comparison to the other fatty acid components. This is why the lather and bubbliness won’t feel as great in uncured soaps.
Time + less water + more soap molecules + tightly packed crystalline structure = better lather and a very high quality bar of soap
On average, it takes about 4 to 6 weeks for soap to cure and for the crystalline structure to be totally transformed. The time it takes soap to cure depends very much on the recipe and percentage of water used in that recipe. [For instance, castile soap, which is 100% olive oil, takes at least a year to cure!] This is why reputable soap makers will cure their soaps for a minimum of 4 weeks, often longer. A properly cured handmade artisan soap should not feel soft or squishy or harsh when you use it.
I take a lot of pride in my soap formulations and has taken me years to perfect my formulas. My soaps will always cure the minimum of 4 weeks so I can bring you the highest quality, long lasting bar of soap. I will never take shortcuts when it comes to your skin because you simply cannot rush artistry. The best things take time, and you deserve the best.
Browse Lather + Soul artisan and crystals soaps here.