As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FLT LVL 270 FROM ATL TO BWI FLT ATTN REPORTED WHITE/GRAYISH SMOKE COMING FROM THE AFT GALLEY ABOVE THE CEILING PANEL. REMOVED GALLEY POWER, SMOKE STILL EVIDENT. DECLARED EMERGENCY INTO CLT. DISCOVERED THE AFT GALLEY LEFT COFFEE MAKER HAS BURNED HEATING ELEMENT AND WAS SOURCE OF SMOKE. REPLACED COFFEE MAKER.