Ask an avid reader what their favorite scent in the world is, and the answer is almost immediate: the intoxicating smell of old books. Whether you’re taking a good whiff in an indie bookstore or breathing in the delicate pages of an ancient volume at a local library, there’s no denying that old books smell damn good.
But why exactly is that?
Well, thanks to Andy Brunning, a Cambridge chemistry teacher who devotes his free time to debunking complicated chemistry, you don’t need a master’s degree to find out.
If you go into your local Barnes and Noble and sniff a few different volumes, odds are they all smell a little bit different. This is because each individual publisher has different preferences when it comes to paper, ink and book binding materials, which means that the chemical compounds found in new books are extremely varied. This, in turn, leads to each individual title having a slightly different scent, making the exact smell of new books difficult to pinpoint.
Old books, on the other hand, have a much more easily identifiable smell. Most old books have choice amounts of the chemicals cellulose and lignin in them, which both contribute greatly to the amazing aroma of aged books. When lignin, which is also responsible for the yellowing of old pages, and cellulose break down, they react and produce several volatile organic compounds (AKA scents). For instance, the breaking down of these chemicals can produce benzaldehyde, which gives off an almond-like scent, vanillin, which gives off the aroma of vanilla, and two-ethyl hexanol, which is slightly floral.
Although each book has a slightly different chemical composition, it is the combined chemical degradation of these chemicals that produce the intoxicating scent of aged volumes that we all know and love. So the next time you get a dirty look from a librarian for smelling an aged Hemingway, just remember this haughty retort: “I’m just examining the chemical breakdown of cellulose and lignin — *breathes deeply* — which seems to be coming along quite splendidly.”