If you want to brew a perfect cup of coffee you have to consult science. A mathematician and a physicist got together to come up with a formula for making the perfect cup of joe. They say the first step is to use coarsely ground coffee beans, which allows for "more efficient extraction" than using finely ground beans. Doing this also means fewer coffee beans must be used. University of Portsmouth has been trialing their new method of brewing coffee at a small coffee shop in the U.S., and says that over the course of a year, the shop has reported saving thousands of dollars due to the ability to use fewer coffee beans.