To clean a dried coffee stain on a carpet, a person could either use a vinegar and water solution or a dish detergent and water solution. If there was milk in the coffee, it is best to use a laundry detergent that contains enzymes along with another method.
To get rid of coffee on a carpet, the stain should first be blotted. Dried coffee will require a soaking wet towel in order to soak up as much of the stain as possible. Two cups of warm water should be mixed with either 1 tablespoon of dish detergent or 1 tablespoon of vinegar, and then applied to the stain with a white, dry cloth. The stain should be blotted until it is completely cleaned.