Preserving a glut of tomatoes at the end of summer is a smart (though messy) move for cooks who want those bright flavors in the depths of January. Roasting the tomatoes before puréeing them adds depth and a subtle smoky flavor — a welcome addition to soups and sauces. Use any kind of tomatoes you like, as long as they are ripe; Brandywines and what are often called Rutgers varieties (Reds, Jersey Reds and Ramapos) work well, as do paste or Roma tomatoes. You’ll need four pint-sized jars (16 ounces each) for purée storage.
In a nonreactive pan, bring purée to a brisk boil for 5 minutes. Ladle hot tomato purée into warm jars leaving 1/2 inch head space, plus room to accommodate lemon juice. If using citric acid, fill to 1/2 inch head space.
06Into every pint jar, add one tablespoon lemon juice or 1/4 teaspoon citric acid. If using salt, add 1/2 teaspoon to each pint jar.
07Wipe jar rims clean with a damp towel. Place lids on jars, screw on rings and lower jars upright into boiling water. Return to a full boil and process for 35 minutes. Transfer jars to a folded towel and let cool for 12 hours. Jars will ping as they seal. Once cool, test seals by removing rings and lifting jars by flat lids. If a lid releases, the seal has not formed. Unsealed jars should be refrigerated and used within three days or reprocessed. Rings and jars may be reused, but a new flat lid must be used each time.