How to Roast Your Own Coffee Beans ?
A typical roasting profile for coffee beans starts from an ambient temperature to a peak of between 205°C (400°F) and 250°C (480°F) over a period of 4 to 20 minutes. The beans are then rapidly cooled. The times spent at various temperatures and the peak temperature greatly affect the flavor and the color of the roast. Rapid cooling of the beans is necessary to prevent substantial loss of flavor. Professional commercial roasting equipment is usually automated and well instrumented.
Home roasting of green coffeee beans is a popular practice. You get the freshest possible coffee with the aroma intact. Since storage affects coffee flavor coffee flavor you can roast just the amount required. With modest equipment, experience, and skill you can produce good results. The simplest way of roasting green coffee beans is to stir them in a flat pan over a high heat. This method produces coffee beans with a variety of roast levels as it is almost impossible to achieve a consistent roast merely by stirring.
Common DIY roasters include hot air popcorn poppers, stove-top popcorn poppers and barbecue roasters using home made steel drums suspended and rotated over burners. Some home-built roasters are based on stir-arm popcorn poppers coupled with convection ovens. Modified home bread-making machines are also used to roast the beans with the high temperatures needed for coffee roasting provided by heat guns.
Home roasting produces relatively small amounts of aromatic coffee and often the slow cooling abilities for the freshly roasted beans can dull or flatten flavor. Coffee roasting produces smoke and fumes and should be done in a well-ventilated area. If coffee is roasted outdoors the ambient temperature needs to be monitored because it can affect the roast temperature. The appropriate degree of roasting depends upon the variety of coffee bean being roasted and the style of coffee required. A typical roast takes around twenty minutes to complete.