Why is the coffee in the filter wet and soppy after extraction?
The dual wall filters create back pressure by forcing brewed espresso through the small holes in the upper layer of the filter and then through the small hole in the bottom layer of the filter (in addition to using barometric pressure from the pump), which helps create a thick, rich crema. Since the water is forced through the filter and then remains on top of the ground coffee in the filter, it’s normal to see wet coffee grounds after extraction. This process is how Breville espresso machines deliver more crema than other machines.
