How Do You Test Soap Recipes?

[ScentimentallyYours]

How does everyone test/compare soap recipes in finished bars?

I have participated in soap exchanges with five other people who sent fabulous bars. They look and smell wonderful. I would like to test the qualities of some of the bars, but I’m not really sure how to compare them.

I would start with the look and feel of finished bars. Some are cold process, some hot process, and I have had them long enough to compare how the finished bars have aged.

My conundrum is comparing the other qualities during use that I read about all the time on SMF. Do I cut small pieces off of a dozen bars and compare wet soaps all at the same time? It makes it easier to control variables, such as the same temperature water for each soap. Side-by-side also may improve the ability to recognize differences in lather, such as quality of bubbles and feel of the soap. I’d also like to know how to test for longevity without using the whole bar up.

On a couple of my bars I put small pieces in warm water and let them dissolve. When the soapy water cooled, the molecules had all arranged themselves and turned the liquid into a gel. It was pretty cool! Small pieces aren’t great for testing longevity, but maybe larger pieces of the same weight would work.

I plan to make soap today and then use suggestions to test the beautiful soaps already in my house. Advice appreciated!

 

[Firefly24]

@ScentimentallyYours I have read that handmade cold processed soap can go rancid just after a year of curing. I make soap with butter & oils like most of us here. When I cut a loaf of soap, I cut pieces to specifically test prior to selling. I keep a notebook and write down all the millions of details specific to that batch.
When I am using it to test, I check for bubbles, lather, creamy, and moisturizing. I also make notes of the scent. When I use a bar in the shower, vs. using a bar at the sink, the longevity is no comparison as the soap at the sink gets much more use.

This is a great question, and I hope to hear what other people on here do too.

 

[Mobjack Bay]

In this long thread on testing I focused on how using different oil and fat combos affected lather qualities when the major soap properties were held constant. In other words, if users are given three soaps, one made with lard, one made with soy wax and one made with cocoa and shea butter, and the soaps have the same calculated properties (bubbly, cleansing, longevity, etc.,based on the amounts of lauric+myristic vs. oleic vs. palmitic+stearic) can they tell them apart (perceive significant differences in lather qualities)? The answer is complicated. The results seemed to be influenced by what people like as well as the recipe. For example, soap-maker testers gave high marks to the bars they thought bubbled the best, while some non-maker testers gave the highest marks to bars that they thought made the creamiest lather. How a bar is handled during use, water hardness and water temperature all seemed to affect testing in my experiment. The thread includes a lot of discussion of how to test lather. Another testing thread by @dibbles focused on how aloe, sugar and sorbitol affect lather. This thread by @Shirley-D looked at how changes in palmitic to stearic ratios affected lather.

edited for clarity