Note: This is a refrigerator jam, meaning that it is not shelf-stable because the jars are not processed after filling. You must store this jam in the refrigerator.
The onslaught of San Marzanos continues here in East Tennessee, forcing us to adopt drastic measures. As freezer space and canning jars dwindle, we find ourselves resorting to a very space-efficient preservation method: tomato paste. Not only does this method help keep us from wasting fresh tomato fruit, it also cuts down on food costs and spoilage. How, you may ask? A not-so-shocking confession: over years and years of making tomato-based sauces, I have probably wasted a little more than half of every tomato paste can I've ever opened. I always wrap the can in a piece of plastic wrap and make a mental note to use it up only to find it, several weeks later, developing a lovely white fuzz behind a jar of miso. Somehow, those little cans manage to contain a slightly excessive amount of tomato paste (excessively tinged with metallic flavors too), and we use tomato paste just seldom enough that the remainder after a batch of marinara almost always gets tossed.
Homemade tomato paste is a bit of a labor of love. It's like apple butter in that you must cook the mixture for hours, run it through a food mill, and then continue to cook it until it reaches "a paste-like consistency," whatever that means. However, like apple butter, the end result is worth it. The flavor is of fragrant, ripe summer tomatoes, but intensified by a factor of ten, thus requiring only a smidgin here and there to elevate dishes that need a little kick. If your usage of tomato paste is similar to ours, this recipe will provide you with enough paste for a little over two dozen batches of tomato sauce!
Freezing the paste in cubes --a favorite method of mine for storing almost any viscous substance from pesto and demi glaze to red curry paste and caramelized onions-- ensures you do not waste your handmade tomato flavor concentrate.
Combine in a large pot:
6 quarts ripe plum tomatoes, washed and sliced
1 large rib celery with some leaves, cut up
3⁄4 cup chopped onion
3 tablespoons minced fresh or 1 tablespoon dried herbs: basil, thyme, marjoram, or
3⁄4 teaspoon whole black peppercorns
12 whole cloves
1 tablespoon salt
One 2-inch cinnamon stick
3 garlic cloves, minced
Bring to a simmer and until the tomatoes are soft, stirring frequently, about 2 hours. Process through a food mill, return to the pot, and continue simmering, stirring frequently to prevent burning. After several hours, when the tomato mixture is reduced reduced by about half, spread the paste to a depth of 1⁄2 inch on a baking sheet or two. Make short cuts into the paste to let air penetrate. Place the paste in a 200°F oven to dry for about 2 hours. Spoon the paste into ice cube trays and freeze. Transfer to zip-top freezer bags, being sure to get as much air out of them as possible (submerging all but the top of the bag in cold water will help get air out). These will keep for at least 6 months, frozen. Toss into sauces as-is; be sure to minimize time the bag stays out of the freezer to prevent frost and weeeping.