The roasted coffee beans: coffee is roasted and most important step to extract properties of Coffee. Out whether a fragrance. The mellow flavor and mellow out to the usual roasting heat 180-240 degrees Celsius for about 10 -20 minutes duration, temperature and duration of use will affect the aroma and taste of coffee. A Light intensity of the roasting. Can be divided into more than 12 levels and aroma, but a simple explanation will be 3 groups to understand the basics.