When sediment from water builds up inside your machines, or the oils from beans get rancid inside your grinder or machine, you're going to start tasting some pretty funky coffee. Exorcise the ghosts of brews past with some simple cleaning techniques you can do every once in a while. Everything will just taste (and look) so much better.
• Clean stainless steel travel mugs, thermoses, and carafes with baking soda, white vinegar, and a scrub brush.
• Clean auto-drip machines by first running a solution of equal parts white vinegar and water through the brewing process. Then run plain water through it.
• Clean your coffee grinder regularly with a brush like this one from Amazon ($10), and every once in a while grind up white rice in there to absorb the oils.