A group of thesis student was tinkering near the coffee roasting machine. They were testing the newly modified micro-controller and at the same time evaluating the performance of the whole machine.

The recommended roasting time for most roasting machine is 17 minutes for a specified temperature, +/- depending on desired roasting degree. However, something odd was happening. It was more than an hour and they were still roasting a single batch. I came near and asked what was the problem.

They said, the heating element was not delivering the required temperature. Maybe there was something wrong with the micro-controller program or the heating element lack the capacity.

Before going home, I saw the roasting machine output. A lightly roasted Robusta coffee after over an hour roasting.  I think they need to do some machine revision.

I picked a bean and bit. It cracked well. I picked another bean and it cracked loudly. I picked a handful and munched while going home. Then I realized, light roasted coffee beans are good crackers. Next time, try biting the bean before making a good cup.