Q. How (and how often) should I clean my coffee maker?
A. An old wive's tale suggests that one should leave a coffee pot with the oils from the last pot in it to season it. However, all this does is taint the fresh coffee and mix the old oils with the new, making a bitter brew and contaminating the flavor.
If you use your coffee maker once a day, it's best to clean it weekly. Run a full pot of half vinegar/half water through your coffee maker, which will loosen hard water deposits. If your pot is especially dirty, you can repeat this step if you like, but its recommended you use a new batch of cold water and vinegar. Then run clean cold water through the pot. Repeat until vinegar smell fades. This may take three or four times.
Clean filter basket and pot with soapy water. Don't forget to clean the pot lid. The lid picks up a lot of oils. Clean the water reservoir with a clean cloth, to get any water deposit build-up.