As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR RETURN, AFTER TAKEOFF THE ODOR OF SMOKE WAS NOTICED BY SEVERAL PASSENGERS AND CREW. THE COCKPIT CREW DETECTED HOT AIR COMING OUT OF THE AIR VENTS. ODOR DISSIPATED SHORTLY THEREAFTER, UPON INSPECTION FOUND EVIDENCE OF COFFEE CONTAMINATION IN RT ACM. CLEANED ACM. OPS CHECK NORMAL. AC OK FOR SERVICE AMM 21-51-00. (K)