Maintaining clean coffee machine cannot be stressed enough. If all espresso machines were cleaned regularly, espresso quality would increase several fold and create a larger market demand for espresso drinks. Cleaning a coffee machine is equally important as buying good beans, roasting properly, and blending well.
Cleaning Coffee Machine
Although most porta-filters are black inside, when properly cleaned they will have a shiny metallic surface. After one day of not cleaning the porta-filter coffee oils will accumulate, go rancid, turn black, and ruin the espresso. If your espresso comes out thin, white, and rancid tasting this is usually the problem. If the espresso does not pour as it should, try cleaning each of the coffee machine parts thoroughly. It is important to clean the porta-filter, basket, and screen heads hourly by quickly scrubbing with a small piece of a green Brillo pad. Scrub thoroughly, but quickly to avoid cooling the group head or the porta-filter too much, and rinse thoroughly. While scrubbing the porta-filter, back flush the group head for 30 seconds with the blind basket in place and a teaspoon of TSP. Follow with at least 5 rinsing cycles. If you have never cleaned your porta-filter before, place it upside down in a milk pitcher, fill the pitcher with water covering only the metal, add a couple teaspoons of TSP, and boil the water using the steam wand. Scrub periodically. This should get out the worst rancid coffee oils. If all else fails order a new porta-filter. You will be amazed with the results by simply focusing on coffee machine cleanliness. In fact, try an espresso before and after cleaning. The difference in cup quality should be the only reminder necessary to convince you that coffee machine cleaning should be a regular part of your espresso routine.