The acoustics of roasting coffee
What sound does coffee make?
Many of our senses are taken up by coffee; the aromas associated with the beans, the taste of the brewed drink, the aesthetics of the finished product and even the heat – or lack of if you have plumped for an iced version – allows people to ‘feel’ their coffees.
But you couldn’t really ‘hear’ a coffee, not unless you counted your conversation with your friendly barista anyway.
Well, it appears that somebody is looking into the acoustics of the roasting process and working out ways to further refine the art of this dark art which controls so much of the coffees flavour and scent.
Preston Wilson, who normally researches underwater acoustics through his position at the University of Texas, has decided to look into the ‘cracking’ sounds emitted by coffee beans as they are roasted. From his results he is hoping to form an ‘automated acoustical roast monitoring technique.’
Mr. Wilson’s study is widely believed to be the first ever quantitative investigation into the sound of coffee.
As reported in the Journal of the Acoustical Society of America, Wilson noted that he found that towards the end of the roasting process a number of cracking noises were present.
The “first crack” has a higher auditory scale than the “second crack”, as Mr. Wilson explains: “The sound of the first crack is similar to popcorn popping, while the second crack is more akin to the sound of the breakfast cereal Rice Krispies.”
It is hoped that further sponsored tests will follow which could lead to an acoustic blueprint being formed that would form the basis for roasting profiles. By pinpointing the perfect pitches omitted, roasters would be able to micromanage the procedure like never before, cutting out errors and, potentially, reducing costs for those who work in the industry.
Further work will “require a bit of effort,” but what started as a personal project to satisfy his own interest in the area could turn out to benefit everybody associated with coffee, from the roasters right through to the drinker.
picture: Kris Krug (Creative Commons)