Soap orders by soap by the loaf are cold processed soaps. Cold processed soaps need time to cure and age before they can be labeled and soap. The Hot Process method of making soap does make for a bar that can be sold right away but their texture is not the same as cold process. Cold process soaps and usually smooth and hard bars of soap.
The reason why the bars need time to cure is simple. We mentioned hot process above. This is when the soap maker continues to cook each batch of soap over a heat source, speeding up the process of the saponification process (the lye) and continues to evaporate the wax. With cold process soaps, such as you find at soap by the loaf, nature takes care of the curing process merely by letting the soaps sit out in the open.
When the soap is made, the fatty ingredients (coconut, olive, shea, soybean) and blended with sodium hydroxide (lye) along with essential oils and color and spices or herbs. When the lye (diluted in water) mixes with the molecules of the fatty oils – the end result is soap. However, the soaping process, known as saponification, continues over the next couple of weeks. As the bars of soap are allowed to sit out in the air, the lye works its way out of the batch and the water continues to evaporate.
A bar of soap CAN be used after only two weeks of curing. It won’t hurt you. But, softer soaps melt away quicker in the shower or tub. When your bars of soap are allowed to cure a few four to six weeks, the end result is a very hard bar of soap. The basic rule is – the longer it sits, the harder it gets and the longer it lasts.
When you receive your soap loaves and have cut them into bars, spread the bars out a bit. A small space between each one is enough to allow air to reach all sides of the bar. But when the bars are crammed against each other it makes it harder for the water in the bars of soap to evaporate. Keep them at room temperature. Basically, a temperature that is comfortable to you under normal living conditions – not too hot and not too cold. Some customers with little space have even told me that they place the bars on trays and slide the trays under the bed with a small fan running in the room when they are at home. Shelves in the laundry room work well as a curing space for you soaps too. No other options? Clean off a shelf in your closet. True, there won’t be as much air circulating in there but the soaps will still cure and your clothes will smell amazing.
Another reason why some soaps need a longer cure time has to do with their ingredients. Soaps that contain honey tend to feel more ‘oily’ in the beginning. If you label your honey soaps too soon it will leave an oily mark on the label.
If you follow the simple rules of how to cure your soap, it will make all the difference in the response you get from customers. Their bars will last longer and they will come back for more. After all, you wouldn’t want to buy cheese that hadn’t been aged properly. Curing soap is similar.