This is the way our friend Maria puts up tomatoes every year. To prove her method is infallible, she brought us bottles labeled as far back as 1972. Bottles over ten years old were still good. To store this sauce she uses any small bottles and sterilizes them. Only top-quality, ripe tomatoes should be used for this recipe. Plum tomatoes are the best.

7 lbs tomatoes
1 T coarse salt
1 cup fresh basil leaves, plus additional leaves for the bottles

Wash and dry the tomatoes, then slice in half lengthwise. Remove the seeds and juice, reserving them for use in soups, stews, etc.
Place the tomatoes in a large stockpot.
Add the coarse salt and the cup of fresh basil leaves.
Bring to a boil, and simmer, uncovered, for 5 minutes, stirring with a wooden spoon.
Press the mixture through a food mill into a large basin and mix well.
Fill washed and sterilized bottles with the tomato puree, leaving a 2-inch gap at the top of each.
Insert a basil leaf into each bottle.
Cap the bottles with plastic-lined caps. (Do not use cork-lined bottle tops.)
Place a rack in the bottom of a large stockpot and place a cloth over it. Wrap each bottle in newspaper and stand in the pot with water to cover.
Cover the pot and simmer for 15 minutes.
Let the bottles cool in the water in the covered pot. When cool, unwrap and store in a cool, dark place.

Source:
Italian Cooking in the Grand Tradition
Jo Bettoja and Anna Maria Cornetto
The Dial Press