Whats the best way to clean the inside of a coffee maker?
Just a soft sponge and dishwashing liquid – wash and rinse well after each use; keep your coffee maker disassembled to let dry thoroughly in between uses. No additional cleaning should be required, under normal conditions. If you use your coffee maker regularly, your coffee will become better and better; if not using it for a while, throw away your first batch.
I assume you mean “hard water stains”, as opposed to genuine dirt. A few years ago, I lived in a rural town that relied on well water. It was OK to drink, but it was extremely “hard”, and it literally killed two coffee machines. Someone recommended that I try a product that contains sulfamic acid. I had already tried the white vinegar trick; the problem is, the acid in vinegar isn’t concentrated enough. There are a number of coffe maker cleaning products that contain sulfamic acid…some are in a liquid form, and some come in a dry powder that you add to water. The one I like best is called “Dip-it”. Just remember to treat your coffee maker at least once every two months. And I always brew an extra pot of plain water (one more than the directions say) through the machine.