You mean raw pack cucumbers over which hot or boiling brine is poured?

Are the jars being filled hot or room temperature?

Carol

Raw veg over which hot brine is poured. Then jars are sealed and placed in the steam canner.

The batch from the water bath came out fine. But it was only four jars, who knows what might happen next time.

I am doing more raw pack pickled jalapenos later this week. I'll see what happens.

Like Carol said:

Are the jars being filled hot or room temperature?

Raw packed vegetables still go into pre-heated jars, not cold jars.

Dave

Also the thermal properties of water are not the same as steam.

Carol

USDA does not endorse steam canning anyway does it? I remember using a steam steriliser for baby bottles back in the sixties, but haven't seen one since then. I've read if you insist on using them it should be strictly jams, jellies and such. Not even tomatoes. I just want to know if the parameters have changed, not challenging you for using one.

They are still not recommended as a safe method for any foods. Only the boiling water bath for high acid foods and the pressure canner for low acid foods. Steam canners have hot and cold spots, unlike the other canners. There are several reasons why they should not be used.

That is thermal shock when the bottom falls off.

2. The jars are all fracturing at the bottom - it is breaking off in a nearly neat circle from the jar.
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it is breaking off in a nearly neat circle from the jar.
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sounds like quality problem

Were those cracked jars purchased recently, or were old ones ?

Can anybody tell me how much negative/ vacuum pressure is created in pressure canning in, say a quart size jar ?

This post was edited by seysonn on Thu, Oct 10, 13 at 6:17

IMHO the USDA regs are overly conservative and geared toward inexperienced home canners using upredictable or unsupervised methods.

I've done food production in an inspected facility and have a pH meter so most of my canning is actually done hot pack with one piece lids.

I've used the steam canner for 10+ years for jams and cold pack product but since I am having problems and losing jars now I will switch back to water bath.

In most recipes with added acid (salsas, pickles) you only need to process long enough to set the seal (5 min) if you pack at 180F or higher.

Were those cracked jars purchased recently, or were old ones ?

He already said they were used jars. Thermal shock in canning jars has little, if anything, to do with the age of the jar. It is the rapid change in temperature that causes it.

The BWB processing is a gradual warm up of the jars (which are supposed to be warm/hot already anyway) but steam processing is a much more rapid change in temperature. Just one reason why it isn't recommended.

Can anybody tell me how much negative/ vacuum pressure is created in pressure canning in, say a quart size jar ?

Depends on the pressure used - 5-10-15 lbs.

IMHO the USDA regs are overly conservative and geared toward inexperienced home canners using upredictable or unsupervised methods.
I've done food production in an inspected facility and have a pH meter so most of my canning is actually done hot pack with one piece lids. I've used the steam canner for 10+ years for jams and cold pack product but since I am having problems and losing jars now I will switch back to water bath.

In most recipes with added acid (salsas, pickles) you only need to process long enough to set the seal (5 min) if you pack at 180F or higher.

Pickles, assuming a sufficient amount of vinegar is used, I might agree with you. But salsas are a whole different ballgame as they are only marginally acidified.

It is your choice of course, your risks to take. But personal choices that deviate from accepted standards are not methods that should be advocated to others.

Dave

The bottom falling out is thermal shock, not the jars themselves.
There are several types of breaks that occur. Each break looks different and has specific causes. If the reason for jar breakage can be determined, faulty procedures can be corrected so this problem does not occur.

Thermal shock is characterized by a crack running around the base of the lower part of the jar and sometimes extending up the side

Processing times are not just to set the seal. That is not safe to assume only 5 min. is needed. It takes different times depending upon the type of food, the size of the pieces, the density, ph level, etc. It is not a "one size fit all" approach in safe processing. Also, we never suggest anyone use a ph meter to test their own foods. Foods can and will change ph in the jars as the sit. A sealed jar is not always a safe jar of food. I don't know where you are getting your information, but it is not considered safe according to todays safe standards.
Whether you have canned for a long time or not, that doesn't insure that something can't go amiss now. We are dealing with different factors than in years ago. Different varieties of produce, the bacteria counts will be different in different soils, ph is different in different soils,, etc.
If we both grew tomatoes in our gardens from the same original tomato, the ph of those tomatoes very well could be different final ph at your home than mine.
I am assuming by "cold pack" you are meaning raw pack. There are 2 kinds of packs, raw or hot pack.

Now that I am sure the cause is thermal shock, as I suspected, I will adjust my process accordingly.

I was trained in a USDA certified food production facility. I am well aware of how to calibrate a pH meter, measure acidity, and take appropriate steps to ensure safe canning. I use tested recipes that are appropriately acidified.

Use whatever process you feel comfortable and competent in using and enjoy the fruits of the harvest.

That's why I said I wasn't challenging you for using one. It would seem to me that there should be a way to design a steam appliance with consistent enough function to market to the public. I'd use one in a heartbeat if there were. I will often use a pressure canner on items I could water bath because it's such a pain to handle.

The glass breaking in a circle almost has to be thermal shock, and why this failure is so consistent in appearance. If you inspect any canning jar closely, you will see a seam running around the periphery of the bottom. It means your glass canning jars consist of three pieces as you will also commonly notice the seams running down each side. The jars are failing at a joint where the parts have been essentially welded together. Joints are the weakest link in a chain and points of stress during and after the manufacturing process and why glass jars are annealed (heat treated) All four jars fractured identically with failure at the bottom seam. Thermal shock. Caused by your technique in canning or a defect in heat distribution in your device.

We used to use the steam canner for years, so I understand what you are saying, my mother still has 2 Conservos, but we don't use them, more as collectors items now.

This year I've had more jars break than usual, actually in the last 2 weeks. I've been very lucky each year only breaking 1-2, and this year I'm up to 4. I think it's just the jars' time to go. All canning jars, none of the mayo jars. Plus these were some of the newer jars (only 10-20 years old) versus the OLD ones.

I just watched a PCing live demo on Ball website (sorry I didn't get it in the email and had to call them so posted it late), the Ball expert mentioned that jars are manufactured to withstand 90 degree F temp difference so if you are setting hot jar on room temp countertop OR putting say 70 degree (room temp) jar into 180 degree (simmering) BWB (or steam canner??) the bottom will drop out.

Goes back to ? people have asked multiple times this thread - were jars warm before being filled? Was brine boiling when you poured over the cukes - did the jars crack then? If jars were warm and brine was boiling and jars weren't cracked when you put them in the steam canner it sounds like the steam canner was either 90+ degrees hotter than the filled jars (not likely, that would mean the water was boiling and I imagine you'd burn yourself with the steam when putting the jars in?) or more than 90 degrees COOLER (I don't know how you're supposed to operate a steam canner but it sounds like you should have water preheated, not right out of the tap at 120F or below, b/c your jars should be hotter than that even if raw packing and you are setting them in a couple of inches of water in the bottom of the steam canner?). HTH

She stated raw packed with hot brine.

Yeah, but were the jars warm, how hot was the brine, how hot was the canner?

The only thing not answered was the heat of canner. Hot brine on raw pack isn't usually hot enough to put into a HOT canner, if you can't put your hand in it, it's not HOT.

Chances are the jars were much cooler than the canner's water, and with a steam canner, the water of the canner doesn't matter, since the jars don't sit in the water. Or at least with the steam canners that I've used.

I'd bet it was the jar getting weaker with age.

IMHO the USDA regs are overly conservative and geared toward inexperienced home canners using upredictable or unsupervised methods.
I've done food production in an inspected facility and have a pH meter so most of my canning is actually done hot pack with one piece lids.
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That is how I feel and what I think too.
(Disclaimer : IMO): (
Let me just give you an example( Thing that I have done):

My spaghetti sauce has just about the right consistancey. My big pot is boiling (rack at the bottom and 3-4" of water above rack).
I fill the jars with the sauce, put them in the big pot, put the lids on.
Now how much time do I need ? and what is the purpose here? All I want is to make a vacuum seal after cooling down.

That is why I think that, it is the role of BWB in canning. You have already done your preparation, acidification and cooking. All you want is to create a seal .

Seysonn, you can argue that past the cows coming home and it still doesn't make you correct.

"Processing times are not just to set the seal. . A sealed jar is not always a safe jar of food." LindaLou is a food safety instructor, if you have trouble accepting what other experienced canners are telling you, you can count on her suggestions being accurate. Add to that you look a little silly contradicting her considering her qualifications.

@ morz8 .... I just quoted the OP and said something in that line.
I was not responding To Linda Lou or anybody else. Was I?

Again, I did not contradict anything. I just presented a case example, showing that after cooking and boiling tomato sauce for hours and immediately filling the jars and placing in the BWB, all needed is a seal. I was not talking about PCing that requires higher temperatures for a certain length of time.

Now that you mentioned Linda lou, lets see some of the things she wrote:
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Foods can and will change ph in the jars as the sit. ...
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, ph is different in different soils,, etc..........
If we both grew tomatoes in our gardens from the same original tomato, the ph of those tomatoes very well could be different final ph at your home than mine.
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I didn't respond when she posted that, but the pH in the soil, will not make much difference. What she and I was talking about what the difference of pH of different tomato varieties. Science and people preferences have changed the taste (acidity, pH) of the current tomato varieties. As people have wanted the sweeter taste, the seed developers have given the customers what they wanted, a sweeter tasting tomato.

Most of the hybrids are a sweeter tasting tomato, and lower pH, NOT only the soil. Plus most ground is getting sweeter from people adding amendments to sweeten the soil, therefore raising the pH.

I'm lucky enough to have almost perfectly neutral pH soil.

Taking excerpts out of context doesn't help anyone, neither does arguing.

Yes the officials have to be MORE careful in their instructions, because there are a lot of ignorant people that are trying to teach themselves. The people that were taught by generations have some knowledge, and I feel lucky to have been taught from an early age, but MOST of my generation were never taught at all. I'm 57 and was the ONLY one in my home econ class that knew how BEFORE our teacher taught us back in the 70s. Yes there are improvements, but we all received a basic course.

I've never had a generation that DIDN'T can, we were rich enough to buy 'store bought' food, we grew what we could and found others for the rest.

Marla

I just presented a case example, showing that after cooking and boiling tomato sauce for hours and immediately filling the jars and placing in the BWB, all needed is a seal. I was not talking about PCing that requires higher temperatures for a certain length of time.

No what you "presented" was a personal opinion. Personal opinions have their place but they have little value when it comes to the scientific foundation of safe home food preservation.

You first referenced "spaghetti sauce". But spaghetti sauce is not the same thing as tomato sauce. Plain tomato sauce, if properly acidified, may be safely BWB canned but spaghetti sauce, by its nature, contains additional low acid ingredients such as onions and garlic and pressure canning is required.

You may choose to ignore those lab tested guidelines. It is your risk to take. But to dispute their validity one needs more than just someone's personal opinion for that to be of any use.

Dave

PS: The statements that pH changes as it sits in jars (it rises), that soil pH does affect the pH of the tomato fruit, and that there is very little correlation between fruit pH and sweetness of taste (brix), are all well researched and fully documented.