Why does my coffee taste bad in my Keurig?
Also question is, how do I get rid of the nasty taste in my Keurig?
The most effective way to descale the Keurig is to use vinegar; white vinegar is a disinfectant, deodorizer and acidic enough to dissolve most buildup inside the machine. Empty the water reservoir and fill it with 48 oz of white vinegar. Run the vinegar through the Keurig until the reservoir is empty.
Subsequently, one may also ask, why does my coffee suddenly taste metallic?
Tap water that's treated with extra minerals can add a metallic taste, and in turn make your coffee's flavor seem a bit off as well. If you know your water is treated with calcium and magnesium, it might be in your best interest to use bottled or filtered water when brewing your coffee.
Run the machine: Start the brew cycle without inserting a K-cup. Repeat until reservoir is empty, discarding the mug contents after each brewing cycle. This process will help remove lime and scale buildup. Keurig recommends descaling your brewer at least every 3 to 6 months depending on your water source.