Common Defects
Some major roasting defects occur as a result of external events, like earthquakes and power outages. Other defects are the result of operator errors, such as double charging the roasting drum, which occurs when the operator accidentally loads a second batch of green beans into the roaster while a first batch is already being roasted. Such a mistake can create hours of sorting and selection after the fact. Another common operator error is accidentally over-roasting and burning the beans, to the extent that even the stoutest operator cannot claim that it was a very special French Roast. Some of these errors, such as earthquakes are obviously not preventable, so you have to just throw away that batch and
start over.
impeller, which will allow the beans to cool slowly and securely in the drum, thus preventing major heat build-up and reducing the risk of roaster fires. Furthermore, developing clear roasting and operating procedures, as well as repeating monthly fire and emergency drills, can help roaster operators respond quickly and intelligently in case of unexpected events.
The second category of defects, called minor defects or roasting taints, occur when an operator does not calibrate the roasting machine adequately for the beans being roasted. Although these defects are not as detrimental to the completed cup of coffee, they do occur more often than operator errors and are more complicated to correct.
In the beginning of my coffee career in the United States, I met a client from Hawaii who brought me his newest crop of coffee beans, freshly picked from his Kona coffee trees. He asked me to design
However, most of the aforementioned errors can be prevented relatively easily. For example, I would recommend installing a back-up generator that automatically turns on in the event of a power outage. In this case, the generator can provide emergency power to the drum drive motor and the roaster