As long as it has closed is it OK?

No, they still need to be processed. Sometimes the product and jar are hot enough to cause a lid to seal "pop" but it is a weak seal and the contents of the jar have not been sterilized.

With the exception of a few products (like jams), the point of the processing is to thoroughly heat the product in the jar to the correct temp needed to kill bacteria, not just to seal the jar. ;)

Dave

wouldn't it be better to fill only as many jars as your canner will hold ... cover and move the pot off the heat or turn it to Xtra low. Then after processing the first batch, reheat, fill jars and proceed to process the second batch.

If you allow the leftover jars to cool, you could experience thermal shock and breakage when processing.

When processing sauces and relishes, if I have a half pint or so left, I'll jar it, put it in the fridge and use it within a few weeks.

Excellent point, Kay - one I have never given much thought to till you brought it up. Thanks! ;)

If we are talking a long processing time for the first batch or with pressure canning when you have to add on the heating up and cooling down time, those waiting jars will have cooled quite a bit. So waiting to fill them with hot product would likely be better.

Most of the things I do have short BWB processing times - like 20-30 minutes or less - so I do go ahead and fill those and let them wait. But if the product processing time is much longer than that or if it is something that needs pressure canning, I think you are right. Waiting to fill those left-over jars might be best.

Be an interesting opinion survey.

Dave

another concern: the flats are supposed to be used only once. I'm sure that even if they "pop", when you process them, the "stuff" will soften enough to allow the air to be vented. After processing, will that "second" seal be weaker?

Thanks for your insight. I usually only have a bit of salsa or jam left and I need the pot to start the next batch - keep the assembly line going - you know. It is strange that you mention jam. today I opened a plum/peach that WAS sealed - but there was mold on the top - that is what got me wondering about the "is any seal as good as a processed seal issue". and that WAS jam - I think I processed all the jams too - so it doesn't make sense. I have processed everything else - I had one jelly size (tiny) jar of hot pepper jelly that sealed on its own and I marked the lid - so I can see if there is any difference.

As soon as these sealed jars are put into the HWB they will unseal as the pressure in the jar rises and will seal again when removed from the canner. It is not wise to put hot product into jars until ready to process. I do it sometimes with raw packed tomatoes as every thing is at room temp when canned. Also, while waiting, the hot contents cools down and the HWB timing will be way off.

OK then another question - Why is the rule of thumb that jars can be reprocessed within 24 hours?
Obviously they have been full of food for some time - yet I have seen it written on this forum and other places - within 24 hours is OK.

I assume people reprocess because the jars did not close - so they will be at room temperature by then.

HMMMM?????

If reprocessing within 24 hrs. the contents must be reheated if the instructions were to fill jars with hot product. If you are going to reprocess a quart of raw packed tomatoes you wouldn't need to heat but I would anyway just to be sure nothing developed in that jar in the 24 hrs. I'd much rather put in frig and use up.

Ok thanks Shirley - I thought you just reprocessed the jars - I didn't know you had to heat it up again.

I think I am clear on this stuff now.

important that you use a new flat when reprocessing.

This has happened to me too. I always process them the same way. Most of the time, they pop back out during processing, and will be the first to pop back in while cooling after processing.

Hi pickles - here is a link to basic canning info - no recipes - that explains all the "whys" and "how-tos" and safety points. You have posted some assumptions that aren't really safe to hang on to ;) so I thought you might want to check this out.

It is good for all of us to review this info once in awhile, not only because the rules change, but because it explains in detail all the important points that aren't included in the recipes. The recipes just assume that we already know all this stuff - like how to re-process, how to evaluate seals, storage, prevent mold, temperature requirements, etc.

Be safe in your canning.

Dave

Here is a link that might be useful: NCHFP - Basic Canning Guidelines

thanks Dave
I just want to say that I have been canning for over 20 years (not every year though) and I follow books and recipes - but always wondered about a seal that closes before processing.

Just to throw some fat in the fire - I am reading the link that Dave suggested and read this:

Reprocessing unsealed jars

If a lid fails to seal on a jar, remove the lid and check the jar-sealing surface for tiny nicks. If necessary, change the jar, add a new, properly prepared lid, and reprocess within 24 hours using the same processing time. Headspace in unsealed jars may be adjusted to 1-½ inches and jars could be frozen instead of reprocessed. Foods in single unsealed jars could be stored in the refrigerator and consumed within several days.

See - it doesn't say to reheat the food and then reprocess it as Shirley wrote. I would not have figured you were supposed to reheat AND reprocess from this info.

Confusing.....

Not really "fat in the fire" as it is 2 different things. ;)

Shirley's point was for those recipes that call for hot packing. If the contents of a hot-pack recipe have been allowed to cool, as they would within 24 hours, then the contents have to be reheated, packed in new jars with new lids and reprocessed.

Recipes that are cold packed, raw packed, or hot packed recipes that are immediately reprocessed don't have to be reheated contents-wise.

EX: stewed tomatoes. They have to be hot packed. If I pack them and process them and one jar doesn't seal. I can

a) immediately re-process the jar.
b) if I can't immediately reprocess it, I can refrigerate it for up to 24 hours, then reheat and repack the contents in clean jar with new lid and re-process it.
c) put it in the fridge and eat it within several days,
d) freeze it.

Hope this help clarify. ;)

Dave

Dave, Thanks. You said it best.

Pickles (the poster, not the product), hi. For reprocessing, while I have the contents dumped in the pot, I wash the jars again, and yes, new lids of course.

For your situation of having a jar's worth left and wanting to start a new batch, if it's a new batch of the same thing, why not save it in a bowl and then when the second batch is ready, add the jar's worth back in, heat a few more minutes, and then fill all the jars? With jam I would just put the jar in the fridge to avoid having it set and then reheat (except with no-added-pectin jams, I guess you could leave those on low heat in a small pot on another burner while making the next batch). Actually with jam, I personally would feel comfortable doing open kettle (just letting it seal) and clearly marking that it's only for myself and that I will use it first--in which case, I would just put it in the fridge anyway.

When you found mold in a jar, was it fuzzy, or was it just black stuff? Sometimes canned products will get black stuff on the lid, but it's just a dried-out or oxidized version of what's in the jar. If it was really mold, it is probably a bad seal. I had some peaches that no matter how many times I washed the outside of the jar, mold would grow along the threads. Never got inside, but sure was unappetizing (kept those for myself also).

Melissa