Coffee beans for a Mr. Coffee automatic drip coffee machine should be ground to a medium grind with a slight variation depending on the design of the specific machine. Along with water temperature and bean type, the grind of the coffee is one of the strongest influences on flavor.
Mr. Coffee coffee makers with flat-bottomed filters should use medium grounds with a texture similar to coarse sand. Compared to flat-bottomed filtered machines, cone-shaped filters require coffee grounds that are finer but still medium ground. Coffee beans should be ground as close to brewing time as possible to avoid losing their oils, which produce flavor. Within one minute after grinding, a coffee bean has lost most of the carbon dioxide that releases the bean's flavors.
Shortly after the grind, the beans lose up to 60 percent of the aroma, and even refrigerating or freezing the grinds does not keep the beans fresh and flavorful. The perfect grind for the coffee maker also depends on personal preference. Individuals should try different grinds in the medium-sized range for a Mr. Coffee coffee machine to see how strong they want their coffee. If the coffee is too bitter, the user should try a coarser grind, while a finer grind can be used to correct a flavorless coffee.