I've done several rounds of fragrance oil (FO) tests in the past few weeks. I bought at least 30 samples of different FOs from several online sites, all to see which ones might be candidates for selling in the future. I made a one pound batch of my simplest recipe, and poured about one ounce per paper cup at light trace (hence more than one test batch). I used plastic droppers to put in approximately 1.5 ml of FO in each cup, and used popsicle sticks to stir in the FO. That roughly equates to 0.7 ounces per pound of oil. Since I knew the FO's might discolor the soap, I made sure one cup had no FO. Wow! It is amazing how much the FO can change the color of soap. One of the cups was as white as the cup without any FO, while the rest ranged from slightly creamier to dark brown. I knew that vanilla in the FO makes the soap turn various shades of tan to brown, depending upon the concentration of the vanilla, and I found that it doesn't take all that much to turn the soap
brown. Ironically, the "Wedding Cake" scent was the darkest of all. I wanted to make soap cupcakes for my students with that one, but I guess they'll just have to look like chocolate cupcakes! I didn't take a picture of all 30 scents, but I did take a picture of the finalists, showing the range of discoloration.
The soap on the far left by itself has no FO. The darkest is the "wedding cake" FO.
This little experiment taught me that unless I don't care about the color of my soap, it is very important to see how the FO will change it. It is also important to know that the color change can occur over several days - to almost a week, so wait at least that long to determine the final effect.
As for scent, it became apparent that it too, changes over time, again over several days. What it smells like out of the bottle is often not a good indication of what it will smell like once soaped. And several scents changed significantly for the better after a few days.
Lesson learned? Test! Test! Test!
Note: My tests were done with CP soap. Melt and pour is an entirely different animal. I'll get to that sometime in the future.
