This is the basic recipe I used, though I usually tweak things a bit as I go along....this time I added the salt and sugar to taste instead of following the recipe and I also added a few baby carrots to the recipe for added sweetness and thickness. This recipe tastes wonderful, BTW, and I can't get enough of it!
http://www.food.com/recipe/moms-best-tomato-soup-canning-recipe-44058
Will be making another batch of this tomorrow. The first batch was one large stockpot, to the brim, and it yielded 7 qt. and 2 pt.
I just removed stems, seeds, and any bad spots and then zipped all the tomatoes down in the blender, along with the cooked down veggies, then returned that to the pot and let that all simmer together for awhile. I added the salt and sugar at the last, before doing the flour and butter thickener. That too was buzzed together in the blender and then added to the soup...that turned the soup a silky texture that it had lacked up to then. It makes a very pretty jar and the texture and taste is incredible! Can't wait to get this out on a snowy, cold day and eat it with fresh homemade bread.
I'd use real butter instead of margarine if you can possibly do so.