Just like food, soap has a shelf life.
Here's where it gets tricky though. After a year, your handmade soap can still be used and it will work just fine, it may however, not smell quite as strong as it used to and in some cases it may smell not as good. However that doesn't mean the soap has expired or turned rancid, it's still soap and will continue to clean and fight germs. For the oils in the soap to go rancid, if properly made and stored, could take several years.
Being a soap maker, I use all my older bars. I am currently using a bar of soap in my spare bathroom that is close to 3 years old. It works fine and smells good. I've kept it stored in a cool, dry environment until using it to extend the shelf life.
So, how can you tell if that bar of handmade soap you found in the drawer in your bathroom is still good? Let your nose guide you! Does it smell good? Does it have no smell? Then put it in your shower and use it. If it smells rancid then toss it.
Recently I became aware of a new use for my dish soap and would like to share it with you; it makes a wonderful spot remover for clothing! Get the dish brush wet and rub it over the dish soap. Then gently rub it over the spot on your clothing and toss it in the laundry (with my new laundry soap of course)! Give it a try and perhaps you'll find that spot remover will be one less plastic bottle to buy!
I've received a number of inquiries on if I have an unscented variety of my conditioner bar. As of this year I can now answer that question with a yes! The bar is rich in cocoa butter so there is still a faint scent, however, no essential oils are added to the unscented variety.
Finally, I want to mention a new color finish to my shave scuttles. Desert Rabbit ceramics is supplying me with a beautiful matte finish dish! Right now I only have it in black but I've been told I'll soon be able to stock matte finishes in other colors and in the popular soap dish! Look for this addition this spring!