What does the Air-to-Bean ratio (ABR) refer to in the coffee roasting process?

The Air-to-Bean Ratio (ABR) is an important concept in the coffee roasting process that refers specifically to the ratio of hot air to the batch size of coffee beans being roasted. This ratio plays a crucial role in how evenly and effectively the beans are roasted, as it affects heat transfer, energy efficiency, and the overall development of flavors within the coffee.

A higher Air-to-Bean ratio allows for more hot air to circulate around the beans, which can lead to a more uniform roast and the ability to roast larger batches of beans effectively. Conversely, a lower ratio might benefit smaller batches but can lead to uneven roasting if not managed carefully.

Understanding and optimizing the Air-to-Bean ratio is essential for achieving the desired roast profile, influencing factors such as the development of acidity, sweetness, and body in the final cup. Thus, the focus on this ratio highlights its significance in balancing heat application with the mass of the beans being roasted, ensuring that the roasting process brings out the best flavors in the coffee.