Yes a popper will produce enough heat to roast 200-300g of beans but it wont move that much weight. Its the agitation of the breadmaker that allows the bigger batch sizes.Originally Posted by 3C393E342331292231500 link=1251299776/0#0 date=1251299776
A popper will roast 80g of coffee without any agitation, 100-120g of beans with a little agitation at the start to get get them moving until they shed water and become lighter.
I think (no scientific fact here) that to roast 300g in a "supersized popper" would require a huge amount of air flow to move the beans... bigger air flow means that it also requires more heat added to the airflow to get to the same roasting temperature (of 200C odd). More air, more heat equals more amps and in no time the uber popper would need 3 phase power.
I also think with a better fan the volume could increase a little and with some sort of pulsing on the heater element you could ramp the heat to have more control over the results.
As for facts...
bang for buck, a popper that can be bought for as little as $20 does a fair job of roasting 80-90g coffee and certainly shows the first time user that home roasting can produce some amazing results.