Espresso Coffee Is Made by Forcing Hot Water under High Pressure through a Compacted Bed of Finely G (image) Society for Industrial and Applied Mathematics Share Print E-Mail Caption (a) Espresso coffee is made by forcing hot water under high pressure through a compacted bed of finely ground coffee. (b) Drip filter brewing involves pouring hot water over a loose bed of coarser coffee in a filter. In either method water flows through the bed, leaching soluble coffee components from the grains. Any undissolved solids in the fluid are filtered from the extract as the liquid leaves the filter. Credit Image credit: Kevin M. Moroney Usage Restrictions Must include credit to Kevin M. Moroney Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.