Over past decades, it was coffee and even more coffee which helped us through maths. But a sunny morning mid-January in 2020 reversed that when some ingenious mathematicians used maths and even more maths to help us find the perfect Nespresso.
January 22nd 2020, to be precise, is the day which made history. It is the day when Cameron et al published their now-already-landmark-paper entitled “Systematically Improving Espresso: Insights from Mathematical Modeling and Experiment”. We felt immediately drawn to this work, being scientists ourselves.
In essence, these curious scientists from Portsmouth University, UK, went about optimising coffee through a rich body of … mathematical equations. Said equations model the physical and chemical processes taking place in the bed of coffee as water is pressured through whilst making the (N)espresso.
The initial models predicted the obvious, i.e. the finer the coffee grind, the larger the portion of coffee that dissolves in the water. However, reality had other ideas: when tested with a real coffee machine in a real coffee shop in real life, they found that at very fine grinds the particles get so small that they really clog up the bed of ground coffee with water not being able to penetrate the grind.
Now, equations predict that the extraction yield from different areas of the coffee bed can clog up each time. And that specific variability makes the different flavour we experience with each cup, where a higher extraction yield gives a bitter cup, whilst lower yield gives a more sour taste. To make the taste reproducible, so argue the authors and their maths, the coffee particles ought to be just large enough that the flow is uniform and predictable, but as small as they can be to maximise the surface area.
Grinding coarser coffee not only means a more consistent coffee taste, but also allows the coffee industry to save up to 25% coffee mass and significant water. A win-win, clearly. And, it turns out, we at Moving Beans had discovered that already by total accident more than a year ago. As a result, our compostable Nespresso-compatible capsules are filled with medium-grind coffee.
Maybe that’s why we have had consistent feedback that our coffee tastes great?