How Does Machine Espresso Work? Machine espresso employs precise pressure and mind-blowing filter technology to make the delicious coffee we enjoy. How does it work exactly? Espresso is created by forcing hot water at high pressure through finely ground coffee. The process is similar to that of making drip coffee. https://www.coffeee.uk/products/swan-retro-pump-espresso-coffee-machine-blue-milk-frother