Dear Ladies and Gentlemen of Arcom,

I have a terrible time with jars breaking while in the caner.  I believe I am doing everything correctly, but I will have a jar or two break at times. Here is my method: (doing raw pack pork today)
I put three quarts of water and a little white vinegar in the caner. (Presto)
Heat that up, not boiling, and then add my jars into the caner on a spacer plate (second batch I had one crack while initially putting it in the hot water...)
Bring the temp up to vent steam and then for 10 minutes let the steam vent.
Put on my weight ( I have one of those rocker weights) 10lbs.  It holds it around 11 lbs.
Run 11 lbs. for 90 minutes.
Take off heat and let pressure release on its own.  
Remove jars and let cool in a non drafty area.  
I used to use a glass cooktop and then switched to gas cooktop thinking that was the problem with breakage, but today with the gas (first time) I had two jars break.  
Jars are new.
ETA:  I also have one of the torque wrenches so I don't ape tighten the hell out of the lids.  I wonder if it is a head space issue.  I am right around an inch from the top of the rim.

What could be the problem?  Should I warm the jars up first?  The meat was a little cold when putting in jars, but the first batch I put the jars filled with meat in the oven at a very low temp just to heat up the jars and that is the only time I have done that and I had one break.  And, that was when the caner was cooling down, I heard it snap...

Frustrating and wasteful it is!!

Any help will be appreciated.

Who makes the jars? China crap or old skook mason jars

Good 'ole Ball widemouth, Made in USA.

Hmm. Ive had the China junk do just like you said,,couldnt put really hot stuff in them..dont know about the Ball or Mason ones, ive had good luck, but these were older jars. not new

When doing raw pack meat in a pressure canner, I was taught to run the jars through the dishwasher on hot and time it so that the cycle finished about the time the water in the canner was boiling.

I suspect that the temperature shock is the source of your cracks.  Try the dishwasher trick and see if it helps.

Wow, sorry to hear this.  How old are these jars?  I have only used Ball jars from 8+ years ago or so an have not had any issues like you describe.... I'd be curious if there is possibly a problem with newer jars.  From your description, it doesn't sound like the problem is your canning method.

It should be easy to pre-heat the jars in a water bath.

You might try leaving a bit more headspace also.

I find the only time I have quart jars break is when I put them directly into boiling water, regardless of pre heating or hot packing.  I do not have a problem putting them in my pressure cooker when the water gets up to 130 and the recipes turn out fine.  I use Ball jars, lids, and the torque wrench.

During my last canning session I had a brand new Ball Qt jar break going into the water to sterilize. the only thing i could think of is I let it cool down too much before I set it in the hot water.

Normally I go from the soap -> hot rinse ->water bath for boil to sterilize ->pack -> boil/pressure seal.

Yeah guys, those rings don't have to be tight.  just enough to make the seal on the lid touch the glass.  I'd say your shocking the glass and causing them to crack.  Either heat the jars up to a higher temp (slowly) or put them in the pressure cooker that has lower temp water.  
Overtightening the rings puts stree on the glass which will make it break easier.  Just like the old "Visions " cookware.  Off the stove and in the sink was always a bad idea.  Learned that the hard way.

I think next I will try a bigger head space.
Heat the jars up before packing and putting in water.


Thank you all for the replies!!

I used Mainstays regular mouth lids for the first time last night and put them on finger tight with Ball lid tool.  Once the water got rolling the lids developed a pinch in them because they were on too tight.  I pulled them out and put the lid on just barely and it went away and they sealed just fine.  I have not noticed this with Ball Lids.  Note to self; don't buy cheap lids.

Did you have any break?

I've broken a couple canning green beans because I over-tightened them, finger tight only.  As others have said make sure the jars are pretty warm before you start.  I usually take one out of the dish washer at a time.  It's a bit slower process but it assures the jars are warm/hot when they hit the water.

That's the problem.

Put the jars in and then start heating the water.
The jars are getting cold shocked and breaking by hitting the hot water.

I heat my jars in the oven set on 180.

Dish washer cycle or 200 in the oven works well.

None last night.  I have never had a pint break on me, just quarts.  Most of the ones that have broken do so when they enter the water and I could hear it crack.  It very well could be how the new jars are made.

Yep, preheat jars and don't put them in canner with hot water. I learned that one the hard way (more than once). I keep my jars full of hot water prior to filling them with whatever I'm canning and make sure the water in the canner isn't significantly hotter than the jars.

Don't think I've ever broken jars due to screwing the rings on too tight, but I only finger tighten them, never crank them on.

Temp shock.

The new Ball Mason jars in the green boxes with the zinc lids are crap.  They are still made in the USA, but they break all the time.  Makes me sick.

I looked in the Ball Complete Guide to Home Preserving and could not find anything about raw packing meat.  

I agree with the others, and think your problem is temp shock, not the cans.  When we did meat a while back, we hot packed.  Heated up the meat in the oven until just browned but very rare, and packed in hot cans from the hot canner water.  No issues, and plan to do the same this fall with deer and antelope should I be successful.  

I would go back and re-read the instructions on what to do.  If you do that, you should have no problems.

Lids are too Tight.

Lids should be loose till they come out.

Thanks for the advice.  I will barely put the lids on next time.  

Appreciate the help all!!

I've had ZERO jars break by ignoring some of the old methods of preheating.

I sterilize my jars by washign well in hot soapy water, rinse them out with cold water and allow them to dry upside down on a towel.  

While they are upside down I cut up the meat and place it in the jars.  

I cold pack the jars then place the lids on finger tight.

I put hot water from the tap in the canner, and place the jars in the water, then I turn on the heat for the canner.

By the time the water is ready to boil the jars have all warmed up evenly and I place the lid on the canner.

The thermal shock is the leading cause of cracking.

TRG

It's still a problem if you are cold packing jars.  180 to meat (40 degree) temp back to boiling temp.

TRG