To make it as easy as possible to roast consistently, choose just one or two batch sizes to work with. The maximum batch size depends on your burner capacity, while the minimum batch size depends mainly on the correct placement of the temperature probes.
The amount of weight lost during roasting depends on how dark you roast. To account for weight loss when working out how much green coffee you need to roast, divide the amount of roasted coffee you want to produce by the expected yield.
Warm up the roaster sufficiently to ensure consistency. Idle it at 20°C (40°F) above charge temperature for 20–45 minutes and then at 5°C (10°F) for a further 10 minutes.