Well, not so much an ode as a diatribe...Ode to Soap just sounds better than Diatribe on Soap...
I'm a bit of a soap junkie. About 3 years ago I used handmade soap for the first time and I've never gone back. It smelled better. It felt better on my skin. The lather is less bubbly, but it's thick and luxurious. I knew there had to be some difference between this soap and store-bought soap...turns out, there is.
Soap cleans as an emulsifier. That's a fancy word to describe a natural molecular process that's pretty incredible. If you've ever tried to rinse an oily pan or wash grease off your hands, you know you can't do that with just water. Oil, including oil from your skin, does not dissolve in water, so water won't wash it away. Emulsifiers have molecules that have one side that attracts oil and one side that attracts water. So it forms teeny molecule balls that surround oil molecules, with the oil-loving side inside and the water-loving side facing out towards the water. Neat, huh?
Many store-bought soaps, especially liquid soaps, are not actually soap. They are detergents, which don't contain emulsifiers. They use surfactants, which work in a similar way and reduce the surface tension of water. The thing about detergents is that they usually contain ingredients derived from petroleum by-products. It's pretty easy to tell if your soap is really a soap. The only FDA labeling requirement for soaps is that they say, well, SOAP. So, if it says soap, it's soap. If not, it's not.
Commercial soap also usually contains some questionable ingredients: parabens, sulfates and triclosan, to name a few.
Another big difference is a big difference! Soap-making is a chemical process that produces glycerin. The glycerin doesn't completely wash away. It stays on your skin, pulling moisture out of the air and keeping it close to your skin. It is moisturizing by nature. When soap is made in factories, they generally pull out a portion of the glycerin to sell or to use in other products, like the lotion they make to moisturize your skin since your soap is drying.....hmm......
Another difference is that most handmade soap is "super-fatted." Because soap-making takes lye, and lye is caustic, soapers will add extra fats - olive oil, coconut oil, cocoa butter, etc - to make sure that there's no leftover lye in the mix. What that means for you is extra moisture, usually 2-7%, build right into the bar.
Besides all the science stuff, I also like the fancy shapes and incredible scents and additives (oatmeal, honey & shea, anyone?) and I like the idea of supporting small-scale producers.
I've since moved on to making my own soap, but I still love to try out other handmade soaps...and body butters, and sugar scrubs, and clay masks, and bath teas.....And I highly recommend that you do too : )