Here's a science Monday factoid for you: Lilac essential oil. Does it exist?
Answer: not really. It doesn't respond well to steam distillation, and the yield is so tiny that REAL lilac essential oil would cost a few thousand dollars per ounce IF you can find it which mostly you can't.
The good news is that synthetics have become increasingly more sophisticated over time, even in the time I've been making and selling soap. I have sniffed my way through probably a hundred different lilac fragrance oils, and have happily settled in with one that smells like my mom's yard did when I was five (both white and purple lilacs.)
This brought to you by demolding and cutting lilac soap. 