Water bath canning of tomatoes requires 2 TBL lemon juice per quart, 1 per pint. Citric acid can also be used, though I don't know the amount required. If you pressure can, you don't need either.

I don't bother with removing any of the juice before heating them to can. When I put the toms in a jar, I try to get mostly tomato in the jars. Set the leftover pot juices and tomato bits aside.

When I blanch and peel the tomatoes prior to canning, I save the tomato skins in a separate bowl. The skins get combined with the leftover pot juices and processed through either a Foley food mill (used that for years)--of a Victorio type strainer. A surprising amount of pulp clings to the skin. This juice then gets reduced into sauce that I can in mostly 8 oz & 12 oz jars, i.e., small amounts that you would normally use in a recipe. Alternately, you could freeze it but I never seem to have extra freezer space. I usually reduce by at least half but that's your choice...reduce it less for 'juice'. Sauce or juice works equally good for soups, chilis, etc.

If I had a larger garden and a longer growing season I prolly wouldn't go to all that bother to wring every last bit out of my tomatoes.

I always have several different varieties of tomatoes and they all get processed together. The 'juiciness' of a tomato depends on the variety and growing conditions as you prolly know.

The only time I try to separate the seedy glop from tomatoes prior to heating is when I make salsa.

Sure you can! I run mine through the meat grinder, cook, and then can.

NCHFP and Ball Blue Books both say add the lemon or citric acid whether boiling water bath or pressure canning is used for the processing so I do...

"has not been a properly researched process for pressure canning of low-acid tomatoes without added acid, so the available process times still require the addition of acid same as if they are being processed in boiling water."

Thank you, everyone!!