How does the coffee go brown? All kinds of foreign elements may be added to the coffee during roasting. - Sugar may be added for a more uniform roasting and a deeper colouring of the beans. This is done mainly to mask inferior quality. - Fats are allegedly added to keep the aroma in the beans for a longer time. Fat is poured onto the coffee in the roasting drum at a high temperature and deposits a film around the beans. It gives the beans a shiny look, but it also makes the coffee hard to digest. Again, this is done mainly to camouflage inferior quality. - Water. When coffee is roasted at a temperature of about 240°C, it is extremely important to cool the beans off immediately afterwards. That is why water is sprayed into the hot drum. The water evaporates immediately, and this conversion from liquid into gas consumes sufficient calories to bring the temperature down. But while they are cooling down, the beans also absorb a lot of moisture. This results in a weight gain of up to 5%. In addition to saving time by roasting more quickly, water-cooling means an easy extra profit for large companies with a turnover that runs into millions. And the consumers end up paying for the added water.