Alkalization and roasting are perhaps the two major steps that contribute to the flavour and colours of the resultant semi-finished products (except for cocoa butter). During alkalization alkali solution is added to the nibs and processed in a pressurerized vessel to change its colour (range from reddish to dark brown) and pH. In the roasting process the cocoa nibs (natural or alkali treated) are roasted at high temperatures (120-150°C) to further develop the aroma and the typical chocolate flavour.