Wondering why your coffee tastes burnt? There are three culprits behind this unpleasant taste.
Over-roasted coffee happens when the roast profile heats up too quickly. While some of us love a great dark roast, too much of a good thing can end up tasting bitter and/or burned in the cup.
Coffee that's stale (i.e. spoiled, or over a week or so past roasting for dark coffees) will also taste burnt. Avoid this by using fresh beans or freshly ground coffee.
Once brewed, the heat plates on most drip brewers are a flavor killer (which is why overheated coffee is so highly prized at gas station cafes). You want to keep your coffee warm, but prolonged exposure will literally cook the coffee, producing the ultimate in burned coffee taste. Don't leave your coffee pot on the heater all morning!