Clean Your Coffee Machines Regularly

When you think of the germiest places in your house, you probably picture the kitchen sink or garbage disposal. But your coffee machine's reservoir also tops the list. A study performed by NSF International, a not-for-profit health and safety organization, found that the coffee reservoirs they studied were "loaded with yeast and mold organisms," says Robert Donofrio, PhD, director of NSF International's microbiology labs.

"Hardly any of the volunteers we spoke to cleaned or disinfected their reservoirs. The residual water in that area, plus the fact that it's a humid part of the machine, contributed to bacterial growth." To properly clean your coffee machine, follow the manufacturer's cleaning protocol. If nothing is specified, clean it once a month by adding three or four cups of undiluted vinegar to the reservoir, allowing it to sit for 30 minutes and then running the vinegar through the unit.

Finish by adding fresh water to the reservoir and running the machine through two or three cycles to wash away vinegar residue.