I started making soap in September 2014, and still have several bars of every batch I have ever made. I use EOs to scent the soap. Almost every single scent has completely disappeared. Even soaps I only made 2 months ago have pretty much lost their perfume. Lavender seems to stick around the longest but even that is pretty faint now. I have always just use the default fragrance amount on soapcalc. Anyone have any advice? Do I need to add something to the soap? Do I need to use more EO? Or a specific grade? Is there a perfect period to cure soap when it's cured enough but hasn't lost its scent? Should I switch to synthetic FOs?