Technically, you can put alcohol in a Ziploc bag, but its legality and practicality depend entirely on where you are. In the context of TSA and air travel, you can pack "mini" bottles of alcohol (50ml/1.7oz) in your quart-sized Ziploc bag for your carry-on, provided they are under 70% alcohol by volume (140 proof). However, it is a federal violation to consume your own alcohol on a plane; it must be served by a flight attendant. For checked luggage, you can pack larger quantities in Ziploc bags to prevent leaks, which is actually a recommended practice for frequent travelers. In a public or outdoor context, many people use Ziploc-style "flasks" or heavy-duty plastic bags to sneak alcohol into festivals or stadiums, but this is usually against the rules of the venue and can result in confiscation. If you are simply using a Ziploc bag to keep a bottle from leaking in your suitcase, it is a smart move; however, if you are pouring liquid alcohol directly into a bag to drink from it later, be aware that high-proof alcohol can eventually degrade certain types of plastics, potentially leaching chemicals into the drink. Always ensure the bag is a "freezer grade" version, as these have thicker seals and are more resistant to punctures.