Canning tomatoes is one of those extreme controversies in the canning world. Forever, conventional wisdom stated that tomatoes were acidic enough to be canned on their own without added acid. Maybe that was true at the time, maybe it wasn't but a lot of people bought into it and very few of them died. A recent article I read actually said that the prevalence of heirloom tomatoes in the 70s introduced a lot of less acidic tomatoes into our diets and gardens and todays tomatoes are actually less acidic than those of days gone by. Whatever the case may be, the USDA recommends adding 2 tbsp lemon juice or vinegar or 1/2 tsp citric acid to each pint of canned tomato product (half that for pints).
I can't say I follow those guidelines to a T, but I come close and I'm comfortable with my canned tomato products. The USDA link above has all of their tomato guidelines tho, if you've got any questions.
Anyways, I brought home a half bushel of tomatoes on Thursday with the hopes of making as much spaghetti sauce as I can from them. My usual process is to chop'em up a lil and toss them raw into the food processor. Put them in the pot with some garlic and spices and wait forever for the liquid to boil off. It works and produces tasty sauce, but this week i found a MUCH easier method.
1. Dig out your Roasting pan or electric roaster and preheat the oven/roaster to 350.
2. Halve/Quarter your tomatoes and toss them in the roaster (with a SMALL ammount of garlic & onions if you like, tho technically thats against regs...but NO OIL)
|I happen to own the mother of all church-lady roasters and it was full to the brim!|
4. Once the tomatoes have given up most of their juices, strain and blend.
5. If you're happy with the consistency, planning on using the "add acid to the individual jars" method, and planning on plain sauce, then you can just fill sterilized jars and process 35 min for pints, 45 for quarts.
6. Personally, I like to add basil, vinegar, and salt & sugar to adjust for the vinegar (and maybe cook down a little extra liquid) before I fill and process.
It was INFINITELY easier, if you ask me and produced slightly more flavorful sauce. (8 quarts of it).