I label my soaps with what they’re designed to be used for. It’s not that you shouldn’t or can’t use a soap in another category — it’s soap, not open heart surgery — but the more I learn about how different ingredients in soap work, the more I like customizing for the task at hand. Here’s what I mean:
- home – for cleaning stuff. These soaps usually have substantially more coconut oil in them than body soaps, which when saponified is very good at dissolving oil. Depending on what else they’re for, these soaps might have a lower superfat or lye-discount, making them more alkaline and suitable for (cotton/linen) laundry. Never use alkaline soap on wool or silk.
- hands – for cleaning… hands. These soaps usually have a bit more coconut oil in them than body soaps, which when saponified is very good at dissolving oil. Depending on what else they’re for, these soaps might also contain exfoliating mix-ins like poppy seeds, walnut hulls, or pumice sand.
- body – your basic shower soap. These soaps have something skin-loving in them like shea butter or avocado oil, and they’re mild enough for delicate skin.
- shave – for wet-shaving. These soaps have clay in them for added slip. If ‘shave’ is the only label, the soap was formulated with at least 20% potash for a faster, richer lather. Potash also makes the soap hold on to water for longer though, so those are usually cut into half-size bars to help prevent them getting mushy in the shower.
- hair – for shampooing. Human and animal hair is covered in little scales that are very sensitive to alkalinity, so these soaps are quite mild, whether that’s by using a large percentage of olive oil or castor oil, or a high superfat/lye-discount. If you have hair long enough to tangle, better follow up with a vinegar rinse, diluted 1:5-10 with water. If you’re on well water or know you have hard water, experiment with samples to find what works — hard water precipitates out most of the useful stuff in soap, depending on the recipe, leaving you with chalky, dirty hair. If you’ve never used a hair soap before, I recommend reading up. (I really like humblebee & me for soap-based haircare)[…try those links in order]