Mathematicians look for the best way to make a good cup of coffee


Coffee is one of the most consumed beverages in the world and is also a favorite. When we drink coffee, we are not aware that this beverage consists of more than 1,800 chemical components, taking into account this factor and others, a group of mathematicians tried to calculate the best way to extract coffee from the grains in order to produce the Perfect coffee.

This research was published this November in the journal SIAM Journal on Applied Mathematics, and should help coffee consumers make a great cup of coffee, and machine producers improve their equipment so that they already produce coffee better quality.

According to Kevin Moroney of the University of Limerick in Ireland and William Lee of the University of Portsmouth in England, the size of the coffee beans and the way it is filtered are essential factors for the final result as well as the temperature of the coffee. Water, which should be between 91 and 94 degrees Celsius.

“Our idea is to create a complete mathematical model of coffee preparation that could be used to design coffee machines”, Lee told the BBC. “It’s a bit like the theory of fluid and solid mechanics is used to create racing cars”.

For the development of this study, mathematicians analyzed “the effect of grain size in the way coffee leaves the machine filter”, the grains are placed in the filter and then the hot water dissolves.

“The most surprising part is that there are two processes to extract coffee from the beans”, William Lee explained. “There is a very rapid process in which coffee is extracted from the surface of the beans and there is a slower process where the coffee leaves the inside of the beans grains”.

“In principle, the concentration of coffee depends on the relationship between the rapid extraction of coffee from the surface of the beans [called the first extraction]and the speed at which water absorbs coffee”, said Kevin Moroney, according to the Huffington Post. “The second extraction is determined by slower diffusion as the water penetrates deep into the larger grains”, he added.

It has been found that coffee extracted from very small grains is bitter and from very large grains is watery. Mathematicians want to be able to quantify this view, “Instead of saying” I have to have bigger grains, “I might say “I want to have this amount of coffee coming out of the beans, I need grains exactly the size X”.

The researcher at the university said that the larger grains are of superior quality because they make the coffee less bitter. “When they are larger, the total surface area has decreased and water flows faster between the grains”, said Lee. In this way, the amount of coffee extraction is also reduced.

“For industrial applications, we expect coffee machines to be optimized to support grains of a certain size”, he added. For now, the search for the perfect coffee is not over, researchers want to look at how best to add water to the grains and how the grains create the filter after it is used.

Adding water to the grains in a single jet placed in the center, like a faucet, or by several jets, like a shower, “has different effects on the coffee”, explained the mathematician Lee.