Your handmade soap needs to breathe!
The best place to keep handmade soap is in a shower caddy. That will keep it out of direct water and will give it air flow. If you don't have a shower caddy, you can also get a soap tray (from us!), which will also give it sufficient air flow.
When we were making this video, my friend who edited it said, "How did you change the expression on the little soap's face?" The truth is, that poor soap was so mushy after only two days of sitting in water that I was able to wipe away his sad expression and replace it with a happy one. While that sounds like a wonderful life tool, it means this poor soap only had a couple more weeks of life in it before it deteriorates to nothing.
Keep your soap for a long time by keeping it dry!