Sweet scent of old books

In trees, lignin helps bind cellulose fibres together, keeping the wood stiff. It’s present in all wood-based paper and as it breaks down, the lignin grants old books that faint vanilla scent.*

A family of compounds have had their contributions to this scent: benzaldehyde adds an almond-like scent; vanillin adds a vanilla-like scent; ethyl benzene and toluene impart sweet odours; and 2-ethyl hexanol has a ‘slightly floral’ contribution.**

Joseph Stromberg in That “Old Book Smell” Is a Mix of Grass and Vanill, smithsonianmag.com [June 18, 2013] ** By Compound Interest in Aroma Chemistry:What Causes the Smell of New & Old Books? compoundchem.com [June 1, 2014]