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Aroma Chemistry

What Causes the Smell of New & Old Books?

Aroma Chemistry - The Smell of New & Old Books v2

Everyone’s familiar with the smell of old books, the weirdly intoxicating scent that haunts libraries and second-hand book stores. Similarly, who doesn’t enjoy riffling through the pages of a newly purchased book and breathing in the crisp aroma of new paper and freshly printed ink? As with all aromas, the origins can be traced back to a number of chemical constituents, so we can examine the processes and compounds that can contribute to both.

As far as the smell of new books goes, it’s actually quite difficult to pinpoint specific compounds, for a number of reasons. Firstly, there seems to be a scarcity of scientific research that’s been carried out on the subject – to be fair, it’s understandable why it might not exactly be high up on the priority list. Secondly, the variation in the chemicals used to manufacture books also means that it’s an aroma that will vary from book to book. Add to this the fact that there are literally hundreds of compounds involved, and it becomes clearer why it evades attribution to a small selection of chemicals.

It’s likely that the bulk of ‘new book smell’ can be put down to three main sources: the paper itself (and the chemicals used in its manufacture), the inks used to print the book, and the adhesives used in the book-binding process.

The manufacture of paper requires the use of chemicals at several stages. Large amounts of paper are made from wood pulp (though it can also be made from cotton and textiles) – chemicals such as sodium hydroxide, often referred to in this context as ‘caustic soda’, can be added to increase pH and cause fibres in the pulp to swell. The fibres are then bleached with a number of other chemicals, including hydrogen peroxide; then, they are mixed with large amounts of water. This water will contain additives to modify the properties of the the paper – for example, AKD (alkyl ketene dimer) is commonly used as a ‘sizing agent’ to improve the water-resistance of the paper.

Many other chemicals are also used – this is just a very rough overview. The upshot of this is that some of these chemicals can contribute, through their reactions or otherwise, to the release of volatile organic compounds (VOCs) into the air, the odours of which we can detect. The same is true of chemicals used in the inks, and the adhesives used in the books. A number of different adhesives are used for book-binding, many of which are based on organic ‘co-polymers’ – large numbers of smaller molecules chemically chained together.

As stated, differences in paper, adhesives, and inks used will influence the ‘new book smell’, so not all new books will smell the same – perhaps the reason why no research has yet attempted to definitively define the aroma.

An aroma that has had much more research carried out around it, however, is that of old books. There’s a reason for this, as it’s been investigated as a potential method for assessing the condition of old books, by monitoring the concentrations of different organic compounds that they give off. As a result, we can be a little more certain on some of the many compounds that contribute to the smell.

Generally, it is the chemical breakdown of compounds within paper that leads to the production of ‘old book smell’. Paper contains, amongst other chemicals, cellulose, and smaller amounts of lignin – much less in more modern books than in books from more than one hundred years ago. Both of these originate from the trees the paper is made from; finer papers will contain much less lignin than, for example, newsprint. In trees, lignin helps bind cellulose fibres together, keeping the wood stiff; it’s also responsible for old paper’s yellowing with age, as oxidation reactions cause it to break down into acids, which then help break down cellulose.

‘Old book smell’ is derived from this chemical degradation. Modern, high quality papers will undergo chemical processing to remove lignin, but breakdown of cellulose in the paper can still occur (albeit at a much slower rate) due to the presence of acids in the surroundings. These reactions, referred to generally as ‘acid hydrolysis’, produce a wide range of volatile organic compounds, many of which are likely to contribute to the smell of old books. A selected number of compounds have had their contributions pinpointed: 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. Other aldehydes and alcohols produced by these reactions have low odour thresholds and also contribute.

Other compounds given off have been marked as useful for determining the extent of degradation of old books. Furfural is one of these compounds, shown below. It can also be used to determine the age and composition of books, with books published after the mid-1800s emitting more furfural, and its emission generally increasing with publication year relative to older books composed of cotton or linen paper.

Furfural

So, in conclusion, as with many aromas, we can’t point to one specific compound, or family of compounds, and categorically state that it’s the cause of the scent. However, we can identify potential contributors, and, particular in the case of old book smell, a number of compounds have been suggested. If anyone’s able to provide further information on ‘new book smell’ and its origins, it would be great to include some more specific details, but I suspect the large variations in the book-making process make this a tough ask.

In the meantime, if you can’t get enough of that new book or old book smell, you might be interested to learn that the aroma is available in perfume form.

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179 replies on “What Causes the Smell of New & Old Books?”

The digital age has indeed arrived so on that note the smell of books will be forgotten like old VHS

Either that… or like the idea of “smell-o-vision” there will be vaporizers built into the next gen of e-readers. To give that real book feel.

That said. Print isn’t dead, or even dying. Passing a book along in bound form is still easier than sharing an ebook with your friends.

So what will new books printed today smell like 50-100 years from now? Different than how old books smell today?

[…] 6 June 2014 Thoughts in early June: Is there a Chance a day can be a good day or at least a moderately fine day when said day starts with a honey bread (face down of course) on nice and fresh trousers? Has anyone ever researched the correlation of the average cleanliness of a house in times when the tax returns need to be filed? And finally, and here I have got an answer, what causes the smell of new and old books? […]

[…] Compound Interest: Everyday Explorations of the Chemical Compounds provides this infographic about the smell of books, and a full discussion, with references, of what’s going on when books release their odors. This subject constantly fascinates me. Previous posts are Smell of a book and Smell of a book, 2. […]

[…] Compound Chemistry reports that hints of almond are created by benzaldehyde, while vanillin emits notes of vanilla. Sweet smells come from toluene and ethyl benzene, and 2-ethyl hexanol produces a light floral fragrance. Additionally, the book can also retain some odors it has been exposed to during its history, such as smoke, water damage, or pressed flowers between the pages. […]

[…] Compound Chemistry รายงานว่ากลิ่นอายของแอลมอนด์นั้นถูกสร้างมาจากสารเบนซัลดีไฮด์ (benzaldehye) ในขณะที่สารวานิลลิน (vanillin) เป็นต้นเหตุของกลิ่นวานิลลา กลิ่นหอมหวานมาจากสารโทลูอีน (toluene) กับเอธีลเบนซีน (ethyl benzene) และสาร 2-เอธีล เฮกซานอล (2-ethyl hexanol) ผลิตกลิ่นหอมดอกไม้บางๆ นอกจากนี้หนังสือยังสามารถที่จะเก็บรักษากลิ่นบางชนิดซึ่งมันได้รับในช่วงอายุการใช้งานของมันไมว่าจะเป็น ควันบุหรี่, กลิ่นน้ำจากการเปื้อนน้ำ, หรือกลิ่นดอกไม้ที่นำมาคั่นระหว่างหน้าหนังสือ เป็นต้น […]

[…] Everyone’s familiar with the smell of old books, the weirdly intoxicating scent that haunts libraries and second-hand book stores. Similarly, who doesn’t enjoy riffling through the pages of a newly purchased book and breathing in the crisp aroma of new paper and freshly printed ink? (Compound Interest: “What Causes the Smell of New & Old Books?”) […]

[…] Compound Chemistry reports that hints of almond are created by benzaldehyde, while vanillin emits notes of vanilla. Sweet smells come from toluene and ethyl benzene, and 2-ethyl hexanol produces a light floral fragrance. Additionally, the book can also retain some odors it has been exposed to during its history, such as smoke, water damage, or pressed flowers between the pages. […]

Is this available as a poster? I would love to put this on my wall (being both book-obsessed & a perfumer). 🙂

Hi, sorry for the delayed reply! It isn’t currently available on the poster store – it uses a public domain image of books, and I’d need to check whether the licensing terms of that image would allow for its use in a commercial product. Until then, the PDF file is available at the bottom of the post, though, so if you have the resources to print it yourself, that could be a possibility?

[…] As a life-long bibliophile, I have always found the scent of old books, antiquarian bookshops and libraries intoxicating. And who doesn’t love the smell of a brand new book? The infographic below explains just what causes those wonderful aromas. If you won’t to learn more about the chemistry behind book smells, check out the Compound Interest chemistry website here. […]

[…] – rather, it’s a complex mixture of chemicals that, combined, give the recognisable smell. What Causes the Smell of New & Old Books? Click to enlarge Everyone’s familiar with the smell of old books, the weirdly intoxicating scent […]

[…] Compound Chemistry reports that hints of almond are created by benzaldehyde, while vanillin emits notes of vanilla. Sweet smells come from toluene and ethyl benzene, and 2-ethyl hexanol produces a light floral fragrance. Additionally, the book can also retain some odors it has been exposed to during its history, such as smoke, water damage, or pressed flowers between the pages. […]

I’m so confused. I’ve worked in libraries for years, and I HATE the smell of old books. I really don’t understand why anyone likes the smell, or where the heck you’d get vanilla, almond, or anything sweet out of it. To me, old books smell like nasty crumbling leather, years of settled dust, a bit of wood pulp, and mildew.

New books, on the other hand, smell amazing…which I’m going to attribute to the vinyl acetate, and whatever chemicals are in the paper (especially shiny, good quality paper).

[…] They have interesting real world chemistry examples of what is actually going on with the things you observe in real life.  Today, on world book day (not sure who decides on these days), you can learn about the smell of old vs. new books. […]

[…] “Compound Chemistry” izveštava da se dašak badema može stvoriti i od benzaldehida, dok vanilin emituje aromu vanile. Slatkast miris potiče od toluena i etilbenzena, a 2-etilheksanol stvara lagan floralni miris. Pored toga, knjiga isto tako može i pokupiti mirise kojima je bila izložena tokom svog veka, kao što je dim, oštećenja od vode ili presovani cvetovi čuvani među stranicama. […]

[…] Compound Chemistry reports that hints of almond are created by benzaldehyde, while vanillin emits notes of vanilla. Sweet smells come from toluene and ethyl benzene, and 2-ethyl hexanol produces a light floral fragrance. Additionally, the book can also retain some odors it has been exposed to during its history, such as smoke, water damage, or pressed flowers between the pages.  […]

[…] TAPoR – Text Analysis Portal for Research. Image Sort Visual Learning Tool – About. Organizers. Shom.pdf. Circles-of-Life-c-Martin-Krzywinski-Circles-of-Life-2014.png (PNG Image, 3839 × 5905 pixels) – Scaled (9%) Home – Visual Thinking Strategies. Visual Thinking. DataVis.ca. What Causes the Smell of New & Old Books? […]

[…] and if you are more into textual informations, here is the link for it from great Martha Stewart :http://www.marthastewart.com/265… step 2: Now that is beautiful looking, open the pages smell them. I mean have you smelled pages of a new book. I hope your friend gave you brand new book. Although old ones also smell good. and yeah, while you are at it, learn about the reason behind that amazing smell,and ME(the awesome guy) will provide you link for that too : What Causes the Smell of New & Old Books? […]

[…] step 2: Now that is beautiful looking, open the pages smell them. I mean have you smelled pages of a new book. I hope your friend gave you brand new book. Although old ones also smell good. and yeah, while you are at it, learn about the reason behind that amazing smell,and ME(the awesome guy) will provide you link for that too : What Causes the Smell of New & Old Books? […]

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