Can I use a regular bath canner for 1/2 gallon jars or is a special sized one required?
There's also a Harvest Forum (for canning, etc.) -- you might try there if you haven't already....
Here is a link that might be useful: GardenWeb Harvest Forum
DON'T DO IT!!! DON'T DO IT!!! DON'T DO IT!!!
I apologise for the shouting caps, but I really don't think you should EVER use a container larger than a one-quart jar. The USDA currently only recommends using a 1/2 gallon jar only for juices, and only very acidic ones at that. (I don't know what their definition of 'very acidic' is, though.) You wouldn't want to use a 1/2 gallon jar for any solid foods: no vegetables, and certainly NEVER any low acid foods which would require a pressure canner.
The rationale for this policy is simple: a boiling water bath only kills botulism spores in an acidic environment. You need both heat AND acid. Given the mass of the jar, it's quite possible that the heat won't penetrate the inside of the jar sufficiently well enough to kill the botulism spores.
Lest you think I'm a nervous nellie about food, I'm not, really; I love good raw oysters (if I know the source), and I eat ethnic foods on vacation in restaurants whose sanitation might be a bit questionable. But you don't mess around with botulism. I'm a pretty experienced canner--I make and can all my own chicken broth, for instance, and it's a heck of a lot better than any commercial product. You can follow USDA guidelines for processing that and be fairly well assured that the product won't kill you. But if they recommend against something (as they do concerning the 1/2 gallon jars) I'm certainly not going to pretend I know more than they do.
Let's see: using a 1/2 gallon jar, that means I only have half as many jars to fill, process, store and clean prior to re-use. The downside is a more-than-negligible chance I could get botulism.
And botulism isn't like ordinary food poisoning where you have wicked gastroenteritis with vomiting and diarrhea, but usually pull through with enough fluids. The botulism toxin causes paralysis, and you stop breathing and DIE.
Please do this: do a Google search using these terms: "1/2 gallon canning jars food safety", and also check out the link below on botulism poisoning. If you STILL decide to use the larger jars, all I can say is: make sure your will is in order! :)
Here is a link that might be useful: botulism
Apple and grape juices are the ONLY thing the conservative US Govt. considers suitable for using.
Let me tell you I was raised on a farm and that was about all the size my mother and neighbors used as a quart wasn't large enough for a meal, and I never heard of anyone getting sick form using 1/2 gallons. They all always washed and sterlized them before using. I am now passed 70 years old and never heard of such a thing.
A little OT... I'd love to come across those half-gallon jars for storage of dry stuff. Found a whole care of 1.5 quart jars at a yard sale (for CHEAP) and scooped them up for storing things like rice, small pasta, grains.