I received a challenge from a customer this summer. She asked if I could try making a grapefruit soap scented with essential oil. I've used it in the past and the scent utterly vanished after a month or so. I did some research and asked other soapers for advice and this is what I came up with for my second attempt.
1) Clays and/or cornstarch in the soap will help the scent to "stick."
2) A touch of other essential oils, like benzoin, litsea cubeba (may chang), and patchouli may also up the "stick" factor.
I'm not quite certain about the actual definition of "sticking"--does that mean the scent remains the same strength as when added, or to a lesser degree? I would be happy with even a faint grapefruit-y smell.
So now I wait. And sniff. Every time I walk by the bars I sniff them. And I exhale happily, because they still smell like grapefruit.
Does anyone have any experiences with getting essential oil scents to survive saponification? Or any advice for me for next time? I'm anxious to learn!
P.S. A year (plus) later--After some time, I realized that I was smelling litsea, not grapefruit. I forgot to document when exactly I noticed the grapefruit scent faded, but it did indeed, and it was soon enough that I will avoid using it in soap in the future. So sad.