A wonderfully flavored canned roasted tomato sauce that is safe to can in a boiling water canner to be shelf stable (adapted from Ball Blue Book's Seasoned Tomato Sauce* and checked by preservation specialists at Oregon State Extension Service)
Citric acid or bottled lemon juicesee amounts needed for different size jars below
Instructions
Heat oven to 425 degrees. Halving all ingredients to work in two batches, divide olive oil, balsamic vinegar (if using), onions, garlic, and dry seasonings between 2 or 3 roasting pans (what you have that will fit in your oven).
Wash tomatoes, remove cores and blossom ends, cut in half and squeeze gently to remove some of the seeds. Place tomatoes, cut side down, on top of ingredients in prepared pans.
Roast for about 40 minutes until most of the tomato skins are puffed and browned. Remove from oven and pluck skins off with tongs (it's okay not to get every bit).
Scrape roasted vegetables into a large stockpot, set aside and repeat the prep and roasting with remaining half of ingredients (unless you are making just a half batch - then just proceed to next step).
Using an immersion blender, whir roasted ingredients until smooth (alternately, you can scrape from the roasting pans into a blender in batches and then add to the stockpot). If you'd like to strain to remove seeds, now is the time for that, too, using a wire mesh sieve.
Bring the smooth sauce to a boil over med-high heat, lower heat and then simmer sauce until it reaches desired consistency, stirring often, about 45 minutes to 1 hour, or more depending on your tomato varieties. You can adjust salt or dry seasonings to taste at this point if you wish.
Prepare a water bath canner, jars, and lids.
Add 1/4 teaspoon citric acid to pint jars (1/2 teaspoon to quarts) OR 1 tablespoon lemon bottled juice to pint jars (2 tablespoons for quarts) and then ladle the hot tomato sauce into hot jars, one at a time with 1/2-inch headspace. Wipe rims, attach lids and place in canner rack.
Process 35 minutes for pints and 40 minutes for quarts (if processing both pints and quarts together, use the longer processing time). Note: start the processing time after canner comes to a full boil and then adjust heat to keep a low boil for the timed amount.
Turn off burner, remove lid and set timer for 5 minutes to let jars rest in canner. Transfer jars from canner to a towel-lined surface and let cool 24 hours. Check seals, label & store for up to a year.
Notes
*The current editions of the Blue Book do not have this exact recipe that is in my 10-year-old book, but it is still considered safe and was okayed by the extension office to use. **The tomatoes aren't roasted long enough to fully roast whole garlic cloves, so you'll want to chop them.***Do not replace dried herbs with fresh, though you can increase or decrease the amounts given and add any other dried herbs you'd like.This recipe can easily be halved or even quartered, depending on how many tomatoes you have.High Altitude Adjustment: If processing at an altitude of higher than 1000 feet above sea level you'll need to adjust the processing time according to this chart.If you have any jars that don't seal (which is rare!), store them in the fridge and use first.