One coffee drinker's perfect brew may be another drinker's battery acid. For this reason, and presumably others, mathematicians are zeroing in on the equations behind the taste of drip coffee. From a report on BBC:Composed of over 1,800 chemical components, coffee is one of the most widely consumed drinks in the world. The work by Kevin Moroney at the University of Limerick, William Lee at the University of Portsmouth and others offers a better understanding of the parameters that influence the final product. It had previously been known that grinding beans too finely could result in coffee that is over-extracted and very bitter. On the other hand not grinding them enough can make the end result too watery. "What our work has done is take that [observation] and made it quantitative," said Dr Lee. "So now, rather than just saying: 'I need to make [the grains] a bit bigger,' I can say: 'I want this much coffee coming out of the beans, this is exactly the size [of grain] I should aim for." Dr Lee says he sets his grinder to the largest setting. By doing so, he says: "The grains are a bit larger than you get in the standard grind, which makes the coffee less bitter. Partly because it's adjusting that trade-off between the stuff coming out of the surface and stuff coming out of the interior. When things are larger, you're decreasing the overall surface area of the system. "Also, the water flows more quickly through a coffee bed of large grains, because the water's spending less time in contact with the coffee, helping reduce the amount of extraction too. "If it's bitter, it's because you're increasing the amount of surface area in the grains. Also, when the grains are very small, it's hard for the water to slide between them, so the water is spending a lot more time moving through the grains -- giving it more time for the coffee to go out of solution."