Over time, any well used espresso machine will develop some sort of hard-water deposits, oily residue of coffee, and possibly bacteria and impurities. Any of these may render a rancid flavour to your coffee and it's not an uncommon problem.
Ensure your coffee machine is healthy on the inside by regular cleaning. Besides extending the life of your espresso machine, it will improve your coffee's taste!
Glory Coffee carries a selected range of cleaning produces for commercial and domestic espresso machines to help you with all the cleaning needs.