Just how many will fit. Of course, you don't want to cram them in tight, but just as long as they comfortly fit.If they just barely touch, that is OK.
Most canners will hold the amount listed in the directions.

Agree that the jars touching is 'normal' and no problems. Most of the recipes are based on what the average canner (Presto 23 quart) will hold and that is 7 quart jars. But obviously if you have a bigger or a smaller canner - some will only hold 4 quart jars and some will hold 20 quart jars - you adjust the recipe accordingly.

The important issue is that to qualify as a pressure canner it must hold a minimum of 4 quart jars.

Dave

I BWB in my stockpots, so for me a "load" is what fits. I use smaller pots if I have a smaller load, sometimes as little as four 1/2 pints.

I put in jars so the fit and don't have enough room to fall over. They move around in the canner so even if you space them out carefully, they won't be that way when you open it up. If you have a rack with holding spots, you can keep them apart, but with just a bottom rack, if there is room for them to crowd together and then have room for one to tip over, seems like that is just what they do.

I now always add jars with water (no lid) to fill any "empty" spaces if I don't have a full load.

Like Digdirt said, for PC you need a pot big enough to hold 4 quart jars - usually about 10 qt liquid capacity.

As for the PC, can I stack the jars? If so, do I need to add additional water?

Thanks!
Michele

I find the capacity also changes with the jars. For example, I may not be able to fit in as many wide-mouth jars as narrow-mouth or I may be able to stack Kerr pints, which are shorter, but not Ball pints.

It really depends on the canner and its design.

Carol

Thanks, all. It looks like 9 pints fit comfortably if I use a rack without the little dividers. Here I gooooooo.........

Kathy

You PC should have come with the standard flat rack in it. That is what the jars sit on. Looks like a flat metal plate with holes in it. Please don't confuse the jar holder that one finds in a BWB with the pressure canner rack. Totally different things.

Dave

I put 8 quarts, not 7 in my pressure canner and now I can't get them out. They are too close. What can I do to get them out?

Wow, that is a problem I've never encountered. When I have two glasses stuck together I put ice in the top one and dip the bottom one in warm water. Since liquids expand when cold, maybe you could fill the canner with hot water and see if you can wiggle them out.

Good luck!

Annie