Researchers explore the role of uneven coffee extraction using a simple mathematical model. They split the coffee into two regions to examine whether uneven flow does in fact make weaker espresso. One of the regions in the model system hosted more tightly packed coffee than the other, which caused an initial disparity in flow resistance. The extraction of coffee decreased the flow resistance further. Understanding the origin of uneven extraction and avoiding or preventing it could enable better brews and substantial financial savings by using coffee more efficiently.