Tomato Conserve
adapted from The Art Of Simple Food II by Alice Waters
yield: approximately 4 1/4 pint (4 ounce) jars
preparation time: 4-6 hours, depending on tomatoes
5 pounds ripe tomatoes, preferably organic (see notes about tomato varieties)
2 tablespoons olive oil
1/2 teaspoon salt
Preferred special equipment: A food mill, though a strainer can be used.
Preheat oven to 300 F.
Wash and core the tomatoes. Slice them into large pieces and place in a large pot with olive oil and salt.
Bring tomatoes to a boil, stirring. Turn down to simmer and cook for five minutes, stirring.
Place food mill or strainer over large bowl. Put tomatoes through finest screen of food mill or the strainer. Tomatoes will be very liquid, with a few seeds. That’s okay. Carefully decant into rimmed baking dish and place in oven. I used an 11×13 glass baker. Stir every 30 minutes. Tomato puree will start to cook down rapidly. Stir tomatoes in from edges every half-hour or so.
After about two hours, mixture will have thickened and reduced considerably. From here, watch closely. You may need to transfer the mixture to a smaller pan to avoid burning at edges.
As mixture thickens and gets closer to being done, you will need to gradually decrease oven temperature by 25-degree increments. Test for this by dragging a heat-proof spatula or wooden spoon through the conserve. If it leaves a clear “path” before slowly filling in, it’s time to start turning the temperature down. Another simple way to know is no amount of stirring from the outer edges prevents burning.
What I did:
Hour three of cooking: oven temperature: 250F. Transferred conserve to 9×13 pan
Hour four of cooking: oven temperature: 225F. Transferred conserve to 11×13 baking sheet (thick enough that no “sides” on a pan required)
Hour five of cooking: oven temperature: 200F: conserve ready. Mixture thick, left wide channels that did not close when spatula drawn through it.
Sterilize 5 four-ounce jars (just in case, you will likely use four). Pour mixture in to fill line; don’t overfill. Seal with layer of olive oil. Screw lids on and refrigerate. Top up with olive oil after each use.
Notes: Roma tomatoes are drier and will cook more quickly. They aren’t available in Northern California as I write (early August 2016). Waters notes Romas will taste sweeter, while other varieties of tomato, which have more water, will taste more acidic but still delicious. I used Early Girl, which took 4 1/2 hours total cooking time. They’re wonderful.