Have you ever wondered why the same coffee bean can have such a variable flavor depending on the brewer? It’s all physics and chemistry, says Christopher H. Hendon, Assistant Professor of Computational Materials Chemistry at the University of Oregon. In Smithsonian, he explains: “The variables of temperature, water chemistry, particle size distribution, ratio of water to coffee, time and, perhaps most importantly, the quality of the green coffee all play crucial roles in producing a tasty cup. It’s how we control these variables that allows for that cup to be reproducible.”