Mama Buzz expressed an interest in trying out my ferments, which led to pondering and discussion about how to safely ship foods that, if left at room temperature for any length of time, will create CO2.
My experimental solution was to screw canning rings over 4 layers of plastic wrap. I figured the wrap could bulge, or even break, if gas built up, sparing the glass jar from breakage. Mama Buzz received the box and said, “nice job with ferments…plastic wrap was a good idea, they are all bulging but not broken.” Yay!
Mama Buzz asked for a zippy bag for each jar to confine any leaked food. This turned out to be an excellent idea, since some of the jars dribbled a bit. Those rings are designed to hold the cap on, not make a seal. Plus I jammed 4 layers of plastic wrap in the screw spaces. It would be surprising if there had not been some dribbling.
The jars then got wrapped in mini bubble pack. I’ve shipped my canned fruits this way many times without any problem. Nine of these size jars fits into the large Flat Rate Priority box, which costs $17.90 to ship. There is some space top, bottom and on the sides, so I always put more bubble pack all around and have never had a jar break during shipping.
I did have one jar split open one time, but that was my own dumb fault. I sent a jar of my home-made mouthwash (essential oil hydrosol) and forgot to leave 1″ headroom. It froze in shipping, which split (but did not shatter) the jar and leaked some wet into the box. Hence, Mama Buzz’s wisdom-borne-of-experience regarding zippy bags. 🙂