# Coffee Roasting Acoustics Article



## BenjaminPiper (Jul 22, 2014)

I came across this today when I was reading through some Journals for work.

http://scitation.aip.org/content/asa/journal/jasa/135/6/10.1121/1.4874355?TRACK=Gallery


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## 4085 (Nov 23, 2012)

The trouble, as I see it, is that different beans produce a completely different sound and intensity. Some are like machine guns, others you nearly miss


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## BenjaminPiper (Jul 22, 2014)

That's interesting. Do you notice that the different sounds often match with particular flavours?


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## 4085 (Nov 23, 2012)

No, not at all. The different sounds come from the fact that all beans have different size and density and perhaps other charachteristics. I have never thought about tying in sound to flavour, but to do that, you would really have to roast one bean variety only and set it up so that the voltage remained constant etc etc. Not easy to do for a home roaster but perhaps those with a bit of professional experience might wade in


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## BenjaminPiper (Jul 22, 2014)

Perhaps then the sound of the roast could be linked to some of the quality parameters. The spread of frequency content could indicate the variation in bean size for instance, although the paper gives the impression that the gasses and moisture inside the bean really define the sound of the first crack.


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