Vanillin. Computer model of a molecule of vanillin (formula: C8H8O3). The atoms are spherical and colour-coded: carbon (blue), hydrogen (white) and oxygen (red). Vanillin is a naturally-occurring chemical which is found in tropical orchid (Vanilla sp.) pods, and is responsible for giving them their distinctive flavour and smell. It is also a by-product of paper manufacture and is used in flavouring and perfumes.