Coffee beans sing distinct tune

Crackling sounds could be key to automated acoustic roasters

CUP OF JOE  As they roast, coffee beans emit a chorus of crackles that begins with low, loud noises and ends with quick snaps that sound like Rice Krispies in milk.  

Preston S. Wilson/UT-Austin

Listen to the audio

The snap-crackle-pop of coffee beans could tell automatic roasters when to turn down the heat.