Can Sealed Jars Survive Air Travel? How To Pack Them Safely

If you're a frequent traveler, you probably know the rules about flying with liquids or gels. The TSA is unlikely to let you through with a sealed jar as the contents will usually be over 3.4 ounces (or 100 milileters). But even if your jar contains less than that, an agent is bound to pick it up when it goes through the scanner, and depending on what's inside, will pull you out of the line to deal with it. If you're wondering what the reasons are, one of the more, say, explosive ones is that sealed jars can pop inside a plane due to pressurization.

When a plane gets up to 35,000 feet, the pilots will adjust the cabin pressure to the equivalent of 6,000 to 8,000 feet in the air. The change in pressure is the reason why your ears feel so weird up at altitude, but it can also be why your sealed jars crack and leak. Unlike air, liquid can't expand. So when cabin pressure changes, the air inside the jar also balloons up and pushes outward. If the container is too weak, it's going to pop. Usually, a broken container simply leaks and doesn't burst catastrophically (it won't cause an in-flight emergency), but it's sure to be messy. That delicious honey you bought on holiday, or special preserves you're taking to a friend may end up all over everything.

Problem is, even if you checked in the jar, it will still go through the same thing in the cargo hold, which is pressurized to the same level as the passenger cabin above (this is why you should never pack carbonated drinks in your checked luggage). So unless you want your clothes to be peanut butter-scented, you'll have to be very smart about how you pack your sealed jars.

Resealable plastic bags are your best travel buddies if you regularly travel with liquids. One option is to empty the jar's contents into the bag, squeeze out as much air as you can (then there's no air to expand), and seal up the bag. That's it — no need to worry about anything bursting. 

But if you don't want to tinker with the jar in any event, there's an even simpler trick: Just put the whole thing inside a protective plastic bag. If it does burst, at least it's not going to ruin everything else in your checked bag. For especially smelly or liquid stuff (such as beers and wine), double-pack it in plastic bags. Better safe than sorry.

And our last tip is if you've bought jars of produce after going through security, take those sealed jars with you onto the seat (in a plastic bag) and don't put them in the overhead cabin. It's for the same reason that you shouldn't put a water bottle up there. Things get thrown around a lot, not just during boarding and deplaning, but also up in the air, where there can be turbulence. The pressure plus the roughness may well break your jar.