Full Idea
Aristotelian essentialism is not correctly portrayed as the view that an essential property is such that it must belong to everything to which it belongs at all.
Gist of Idea
Aristotle doesn't think essential properties are those which must belong to a thing
Source
report of Aristotle (Metaphysics [c.324 BCE], props) by Joan Kung - Aristotle on Essence and Explanation VII
Book Reference
-: 'Philosophical Studies' [-], p.377
A Reaction
The view I am arriving at is that essences are rather fluid things, which change their balance and constitution continually. Old people differ essentially from their younger selves. Chemical natural kinds have stable essences, but that is contingent.