ERRORS IN ROASTING DEFECT

1. Scorched:

– Main causes: Heat supply is too large, roasting too fast, drum speed too slow or too fast.
– Fix: Roast slower, set the gas level down, adjust the drum speed accordingly.

2. Tipped

– Cause: The charge point is too high, the coffee bean has a high moisture content, and the kernel structure is too soft.
– Fix: Low charge, low gas drying stage (low ROR), re-dry the beans to reach the best 12% moisture

3. Under-developed

– Cause: Roasting has not reached the ripe temperature of the coffee (usually the first burst point will be the beginning of the roasted coffee), this error will cause a grassy, sour or acrid taste of young fruit.
– Fix: Put the coffee out at a higher temperature.

4. Baked – Slow roast

– Usually roasting over 30 minutes will be called slow roasting, depending on the type of coffee, depending on the roasting machine.
+ Cause: Roasting too slow, heat loss during roasting causes bland, tasteless, grainy smell.
+ Fix: Increase gas evenly for each roasting phase to shorten the roasting time

5. Fast roast

– Usually roasting less than 15 minutes will be called quick roasting, depending on the type of coffee, depending on the roasting machine.
+ Cause: Excessive gas level during roasting (ROR is too high) will cause errors such as sourness of unripe fruit, undeveloped flavors inherent in coffee beans, poor quality.
+ Fix: Reduce gas evenly during the stage to make sure the batch is not too fast or too slow.

6. Burnt

– Cause: The temperature at the end of the roast is too high, causing a bitter, burning taste.
– Fix: Finished roasting the curry at a lower temperature.

7. Young green (Quakers)

– Cause: Because the beans from the green coffee cherries when harvested are not ripe but picked green, roasted will have the taste of grains and wood.
– Fix: Pick ripe beans or remove green fruit during preliminary processing.