"A good cup of coffee should be smooth and complex. It shouldn't have excessive bitterness, and it shouldn't have off-flavors, like woody, grainy or papery," said Ellen Klosz of Consumer Reports
Among the blends tested include Dunkin' Donuts, Starbucks and long-standing staples like Folgers and Maxwell House.
"None of the blends we tested rated excellent or even very good," Klosz said.
Many well-known coffees rated only fair. For example, Folgers Classic Roast Medium and Maxwell House's Master Blend Mild both tasted grainy and papery.
"We test the coffees black to get the true flavor, but if you normally add cream and sugar, some of the ones we tested would probably be fine," Klosz said.
Those include Starbucks' House Blend and Green Mountain Signature Nantucket Blend - the Medium Roast.
But there are better coffees out there. When Consumer Reports tested 100 percent Colombian coffees, it found several that tasted very good, even when black. Eight O'Clock Coffee 100 percent Colombian is one to try. It's the top-rated Eight O'Clock Coffee.