Automatic coffee makers are a very common small appliance in many American homes and offices. These devices are produced by countless manufacturers under different brand names, and they come in various sizes, colors and features. Over time, oils from beans, residue and even lime scale can build up in the pot, hot plate and filter basket. Fortunately, with the help of hot water and citric acid, the common chemical found in lemon juice, you can restore the cleanliness of your automatic coffee maker.
Boil one cup of hot water on the stovetop or in the microwave.
Add approximately 2 tablespoons of citric acid to the hot water and stir until it is dissolved . If you can't find citric acid at a local store, then mix equal parts lemon juice with the boiling water and stir.
Pour the mixture into a large measuring cup and fill the measuring cup with cold water until the quantity reaches the 4-cup marker.
Pour half of the mixture into your coffee maker a turn on your machine so that the mixture runs through the coffee maker and into the pot. When the mixture has finished running through the machine, discard the mixture that is now in the pot.
Fill the coffee machine with another pot of clean water and run the brewing cycle again. Citric acid is not toxic, but you want to flush the citric acid out of the machine to avoid any taste of bitterness or sourness in your next pot of coffee. Once the clean water has run a full cycle through your machine, discard the water.
Wait for the machine to cool. When it is cool, you can use the other half of the mixture to clean the hot plate, filter basket and inside of the coffee pot. Wet a clean rag or sponge with the mixture and thoroughly scrub away any coffee residue or lime scale.
Rinse the parts that you cleaned with a clean, wet rag, and allow the machine to air dry.