Date: 201912
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Parked
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Deviation / Discrepancy - Procedural Security; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Hazardous Material Violation
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: We accepted Aircraft X in ZZZ to perform flight from ZZZ-ZZZ1. The aircraft was catered for both legs in ZZZ. However; we did not eat during the short flight from ZZZ-ZZZ1. During cruise from ZZZ1-ZZZ2; the FO (First Officer) went to the galley to retrieve a sandwich. Upon removing the large black catering bag from the top cabinet; he noticed a white bottle in the very back corner. Once he picked up the bottle he realized it was a CVS rubbing alcohol 91%. The bottle was unsealed and almost full. He brought what he had discovered to my attention. We talked about the pre-flight safety inspection. I asked if he remembered looking behind the catering bag. He could not recall. After we talked about it; we both realized that this was easy to miss due to the following factors:1. When we check the catering inside these bags; we usually pull the bag to the edge of the cabinet; open it and check the contents. Most times the bag is not placed on the floor. After checking the catering contents the bag is pushed back into the cabinet and the door is closed and latched.2. We have many different caterers. The food is packaged differently into a large variation of containers.3. Our aircraft has many different galley configurations. Some only have cabinets; while others have a combination of cabinets and chiller. Some have ovens; others do not. At the end of our conversation we came to the following conclusion. We need to be more cautious and take our time performing our safety checks.Once we blocked in I immediately requested a GSC. A few minutes later GSC [name] showed up. I explained everything in details and he took possession of the bottle. He informed us that he would inform his supervisor and investigate the matter. I left the airplane and headed to the sort building. I wanted to share this with our local supervisor. He was not present; but my FO contacted him over the telephone and also informed him of what had transpired. My FO and I left the sort and went to the hotel. Suggestions: After the fact; my FO and I agreed that we must mitigate the risks mentioned above by being more cautious during the pre-flight safety inspection. Also; it becomes very difficult to control all safety barriers once we have performed pre-flight safety duties and there a numerous personnel coming in and out of the flight deck and galley area.


Second narrative: [Report narrative contained no additional information.]


Synopsis: B767-300ER flight crew reported finding a bottle of alcohol 91% (Hazmat class 3; flammable liquid) in the crew catering container. Event was reported to GSC at destination.