Early on in my soapmaking journey, a friend I’d gifted some soap complained that one of the bars didn’t lather anymore. She said she really gave it a good workout 😀 but nothing happened.
At that time I chalked it down to hard water in her area and rested the matter. Recently…well over a year later… it registered in my mind as I was doing lathering tests what may have happened.
Handmade soap is usually made with a little (or a lot) of extra oils that’s not turned into soap. Not to mention all the natural glycerine that’s produced in the process. So for example my 100% coconut oil soap has 20% of ‘unsaponified’ oil in the bar. When I leave it unused for a few days, when I pick it up again it feels a little slick and I have to lather it under running water to get the luxurious dense lather that’s normal for that recipe! Other soaps with less oil lather up much quicker though.
Just thought to note this here for reference!