I use glass canning jars in the freezer on a regular basis. The straight-sided ones are the best, but I have used the ones that aren't straight and I have used wide mouth quarts, as well. Over several decades, I've had only two jars break but I accidentally bumped them together in the freezer after they were frozen. They do take up more space, and you do need to leave room for expansion, as Dave said. I store some things in plastic, but prefer glass and think they maintain food quality better. Plastic can lose a seal or get torn. I don't have a food saver, so my freezer ziplocks aren't as good as the food saver bags.

You need to dump them all if this jar was sealed and so are the rest. It would most likely be in all the jars of that batch if that is the case. Mold has mycotoxins. It is linked to some kinds of cancers and arthritic conditions. Never eat anything with mold other than cheese that is supposed to have a healthy type of mold. What you are seeing is just the tip of an iceberg. The whole food is full of mold. Bread is the same way, any food that shows signs of mold. It is spoiled food. Did you have it at a full boil when it went into the jars ? Did you properly can them in a boiling water bath canner ? Did you use the right size of jar that is called for and not a larger jar ?

Marcia, I really recommend against trying to take a glass jar as carry-on. I have had a jar of homemade jam I was taking to my elderly, ill mother-in-law confiscated. (That batch had a nice, solid set, so I tried to argue it wasn't a gel and in the plaste test hadn't spread, but the agent said even the fact of it being in a glass container made it potentially dangerous. He had the good grace to be apologetic about it, at least.) I've shlepped across Europe car-free and budget-tight, too, and can imagine your dilemma. If it were me, I would cruise the dollar stores for a plastic box that would fit the jars, to give hard sides without adding a lot of weight. I'd pack them in it with lots of paper and a ziplock. A good buffer of wadded paper is better than clothes, though it's hard to devote the room to it, I know. But if something DOES break, paper is the best defense agains broken glass (which can slice your ziploc otherwise), AND it is more likley to be seen by the airport goons as packaging that needs to be replaced than clothing is [even though, as you say, a jar in a sock is obviously there for its protetction]. Your chances are better of your checked backpack avoiding de-packing and getting badly re-packed than of getting a glass jar of something through security and on in your carry-on. As for brining the liquor back, maybe you can buy it at the duty-free at the departing airport? Though I have successfully brought bottles of wine home in a checked backpack, wrapped in paper and a ziplock, then wadded up in cloths & placed in the centre of the backback. If the store you buy it in can supply a sturdy box, though, so much the better.... Good luck, in any case! I love the idea of bringing some homemade goodies to your overseas friends and can see why you'd want to do it despite the hassle. Good luck and have a great trip.... Zabby

Hi Eleena: Yes, the reason I want THESE is due to their shape and appearance. I wanted to serve mousses', puddings, layered desserts, etc. in them because the Spega jars are soooo attractive whereas the Ball-ones are more utilitarian. I HAVE purchased the Weck ones now, which are almost as cute but still have my eye out for Spega, too, if not too expensive.