Coffee bean roasting process - with two separate drying stages using fluidising gases at differing temps. and velocities

摘要

Continuous dry rotating of green coffee beams is effected by progressively and continuously moving and agitating dry green coffee beans in a fluidised bed successively through first and second separate roasting chambers. In the first chamber the beans are contacted with a dry high velocity gas which fluidises the beans. The gas temp. is 440-470 degrees F. This effects a partial roasting of the beans and expansion of the cellular structure. In the second chamber the beans are contacted with an independent dry roasting gas stream which fluidises the beans. This gas stream is at a lower velocity and higher temp. than the first stream. This stabilises the open structure of the beans and darkens them without burning them. The temp. is 515-545 degrees F. The beans are finally cooled. Method produces a high soluble solids yield, low density, roasted coffee prod.