While you don't need to clean out the entire machine every time you make a pot of coffee, you definitely need to clean out the pot and the filter holder. If you use a reusable metal or mesh filter, it should be thoroughly washed before being used again. Otherwise, leftover residue from stale coffee will be noticeable in the next brew.
Easy Soap, But Soap
Don't simply rinse your coffee pot out with water. Coffee contains strong oils that can only be washed away with mild soap. Refrain, however, from using too much and make sure you rinse it out thoroughly to avoid a soapy taste on your next pot of coffee.
Remember, even if you're dumping out one pot and simply throwing on another, the leftover oils from the previous pot of coffee can taint the next brew and negatively affect the taste. So, wash your pot with gentle soap after every use.
Clean the Machine Every Few Uses
You should give your coffee machine a thorough cleaning at least periodically. Doing so will prevent the build-up of calcification, lime or other mineral deposits and keep the machine running at peak capacity.
Do a basic weekly cleaning by running a pot of water and vinegar or water and lemon juice through the machine once and following it up with a plain pot of pure water.
Then, once every few months or once a year, depending on how hard your water is, get rid of mineral deposits using a coffee machine descaler or decalcification solution.
Replace the Water Filter
If your coffee machine has a built-in water filter, be sure to replace it as needed. A dirty water filter can taint every pot of coffee and deposit dangerous molds or bacteria that have built up inside the filter unit. This caution is no different from the changes you would make on any other water filter - for instance, in your refrigerator.
Replace Your Filter
If you use a reusable metal or mesh filter, consider replacing it about once a year. While metal or screen filters are designed to be washed and reused, fine grounds residue can get stuck inside. This not only clogs the filter, but can also affect the overall taste of your coffee.
If the flavor of your coffee is important to you and you don't want it to taste like it was made by a local auto shop, then some level of reasonable and minimal care must be given to your coffee maker.
Keeping a clean coffee machine benefits you two ways - your machine will last you much longer and your coffee will taste great pot after pot. Remember, wash it after every use, use gentle soap, rinse well, decalcify the machine regularly, and replace the water filter and your grounds filter on a systematic basis.
