Mailing home canned foods
Hi, just wondering if there really is any safe way to mail home canned foods? I have made an assortment of fruit items and canned them in a water bath canner - using all verified recipes and adjusting boiling time for my altitude. I want to mail some to my friend, but as she lives in Alaska I'm sure the mail will be taken in on a plane and that seems like a lot of pressure change. I intend to put each jar in a ziplock, wrap it in bubble wrap, lable the box "fragile", etc, but my main concern is that the seal will open in the process of changing pressure. Or it will open and re-seal as the plane goes up and then down. I know planes are pressurized, but maybe not the cargo hold? Or even if it is pressurized, I think they pressurize the cabin as if you were at 7,000ft or something (don't know that for sure). I canned my food at 3,000 ft, so that's still a big change. Let me know what you think, or if there is any actually research done on this. Thanks!
You sound like you have done all the right things to make sure your canned products are safe and good quality!
Unfortunately, we don’t have good research about shipping jars of canned food in high elevations or unpressurized cargo areas. It does seem that there is a risk of jars unsealing during dramatic changes in pressure. A fairly tight ring on the jar could help reduce the likelihood of this. The recipient should check the jars immediately for any signs of broken seals or damaged jars. The acidity in the fruit does allow some time before the spoilage (mold or fermentation) would begin, so immediate refrigeration upon arrival would help preserve the contents if the seal had broken. There is not the major food safety risk of botulism and some other dangerous bacteria associated with fruit products like there is with vegetables and meats.
Placing the jars, in bubble wrap in sealed plastic bags is a good idea in case of breakage. You might try it first with jams and jellies that will not leak if the jar does come unsealed or gets cracked.
You might also check with your local post office. I didn’t see any guidelines on their website, but someone there might have some suggestions or experience to share.