Prep 20 mins
Cook 55 mins
A chunky jam with a sea-green hue and sweet tart flavor that might lead some to guess incorrectly that the dominant fruit is kiwi. The recipe comes from Rosetta Costantino in her book "My Calabria". Tomatoes used in this jam should be green and firm with no sign of red blush.
- Core the tomatoes, halve them, and dig out the seeds with a table knife. Cut the tomatoes into 3/4" cubes (or smaller if you like).
- Put a small plate in the freezer. You will use it later to test for doneness.
- Place the tomatoes in a heavy 6-quart pot with the sugar, lemon zest, and lemon juice. Stir well, then bring to a boil over moderate heat. Reduce the heat to maintain a slow simmer and continue cooking until the tomatoes become translucent and the syrupy liquid thickens considerably, about 40 minutes, stirring occasionally to prevent the jam from sicking. (Note: towards the end keep an eye on it so it doesn't burn). When the jam reaches 215 degrees F (102 degrees C) on a candy thermometer, remove the chilled plate from the freezer and spoon a little jam onto it.
- Return the plate to the freezer until the jam is cold. Test it for doneness (my note: prod it with your finger, if it seems to be developing a surface skin and solidifying it is ready), and if the jam is still too runny, continue cooking it. Otherwise remove pot from heat.
- This will produce 2 pints or 4 half-pints worth of jam that can be processed via Water-Bath Canner. Fill jars to 1/2" below the rim to allow for appropriate headspace. Process the jars in the canner for 15 minutes.