Everyone’s “perfect” cup of coffee looks a little different, but five mathematicians are working to better understand what influences the final product to make the “perfect” cup of drip coffee. Their study will be published this week in the SIAM Journal of Applied Mathematics.
Previous studies have involved the math behind coffee extraction, but there has been little done on the coffee extraction specifically from drip filter machines (hot water over ground coffee in a filter), BBC reported.
During the drip filter process, gravity pulls water through the filter, which extracts coffee solubles from the grains composed of more than 1,800 chemical components, according to the SIAM Journal of Applied Mathematics website.
"Our overall idea is to have a complete mathematical model of coffee brewing that you could use to design coffee machines, rather like we use a theory of fluid and solid mechanics to design racing cars," Dr. William T. Lee, one of the mathematicians involved in the study, told BBC.
Going in with the knowledge that grinding beans too finely could result in over-extracted and bitter coffee, the study looked into the effect of coffee grain size and the final coffee product. The study will be able to help coffee-drinkers think of the coffee extraction process by how much coffee they want coming out of the beans based on grain size. It could also be used to optimize coffee machines, from an industrial standpoint, for a certain size of grain.
"What our work has done is take that [observation] and made it quantitative," Lee said.
A potential next step involves changing the shape of the coffee bed while water flows through the filter.
"The shape of the coffee bed is deformed as you brew the coffee. When it goes in first, it's sitting flat at the bottom of the filter, but at the end of [brewing] it's coating the walls of the filter. This also seems to play a role in how the coffee tastes," Lee added.