1 tablespoon bottled lemon juice, or 1/4 teaspoon citric acid per pint (double the quantities for quarts)
Kosher salt to taste
Plum tomatoes are the usual sauce varieties, but one summer, at an engagement party for my good friends Claire and Ben, I got to talking to a couple, Cindy and Nick, from Northern California, who told me about the overwhelming productivity of their backyard heirloom tomato garden. Cindy cooked them into sauce. I was shocked that she would "waste" them on sauce.
"But why?" she asked "Heirlooms have the best flavor. They make the best sauce"
"It was in-cred-i-ble," said Nick.
It turns out Nick and Cindy were right. Because each variety of heirloom tomato has a different flavor profile, the sauce from a mixed batch has the equivalent of a four-octave range. Romas and other plum-type tomatoes, if that's what you have, are also good.
When choosing heirloom varieties for sauce, weight the mix toward red tomatoes over lower-acid yellow ones. Ugly or bruised fruit is acceptable, as long as it hasn't started to develop the acrid smell of tomato rot.
Also remember that, in order to be safely canned using the boiling-water bath, every jar of tomato sauce must be acidified with bottled lemon juice or citric acid. Freshly squeezed lemon juice is not a safe substitute.
- Blanch, peel, crush, and heat the tomatoes. When all of the tomatoes have been added to the pot, gently boil for ten minutes longer, stirring periodically.
- Grint the tomatoes through the fine blade of a food mill or pound them through a chinois. Return the puree to the pot, bring it to a boil, and reduce it by half, stirring occasionally. The gauge progress, stick a wooden skewer into the pot to measure the initial depth, then compare as the contents reduce.
- When the sauce reduces, line up your prepared jars and add 1 tablespoon of bottled lemon juice or 1/4 of citric acid per pint.
- Once the sauce is reduced by half, or to your liking salt it to taste.
- Ladle the sauce into prepared jars, leaving 1/2 inch headspace. Seal, and process in a boiling-water bath for 35 minutes for pint jars, 4o minutes for quarts. Turn off the heat, and allow the jars to rest in the water for 5 minutes before removing.