Did you know that you are never, ever supposed to use soap to clean a coffee maker? Soap will leave residue and make all of your coffee taste...soapy. There certainly is no need for you to clean your coffee maker every time you use it, but you should clean it about once per month. Coffee has oil in it and over time this oil can build up in your coffee maker and give your coffee a weird flavor. If you live somewhere with hard water, you probably need to clean your coffee maker even more regularly. Otherwise you could end up with calcium deposits swimming in your cup. Fortunately, your coffee maker is probably one of the easiest things to clean in your entire kitchen. In fact, it's almost self cleaning, just like the oven.
If your coffee maker is just somewhat dirty, or it looks fine but you would rather be safe and start cleaning it before it turns gross, clean it with vinegar. Specifically, use regular white vinegar to clean your coffee maker. Vinegar can be used to clean almost anything in your home, including your stinky dog and your kids. Vinegar is highly acidic and will kill most mold, bacteria and germs. Yet it is also environmentally friendly. It is a gentle cleaner and will not harm your coffee maker like harsh chemical cleaners might. Vinegar will even remove soap scum, so if you mistakenly tried to clean your coffee maker with detergent you still might be able to get that soap taste out. To clean your coffee maker with vinegar, start by mixing a solution of half vinegar and half water and add that to the coffee maker's reservoir. Make sure that there is no filter in the coffee maker and turn the coffee maker on. Let a few cups run through, then turn it off in the middle of the cycle and let it sit for an hour. Start the coffee maker again and allow it to complete the cycle. Throw the vinegar mix out and run plain water through the coffee maker several times until it no longer smells like vinegar.
If your coffee pot is really dirty and full of coffee stains, the vinegar rinse alone might not get it clean. You might need to step up your coffee machine cleaning game and add another common household cleanser: baking soda. If your coffee pot is totally filthy, then add about one teaspoon of baking soda and enough vinegar to mix up a paste. Then, using a toothbrush or other plastic brush so that you don't scratch your pot, gently scrub away at the coffee stains. You may be tempted to try steel wool or something tougher, but this could scratch up your pot. You shouldn't need anything like that, though. The vinegar, as an acid, should break down the stains. The baking soda will act as an abrasive and will scrape those weakened coffee stains right off. You can rinse the vinegar and baking soda out of your coffee pot with warm water.