Adapted from The New Portuguese Table, by David Leite. Makes about 2 (8-ounce) jars.
Course Pickles, Jams, Preserves
Diet Gluten Free, Vegan, Vegetarian
Keyword port, tomatoes
Prep Time 20minutes
Cook Time 1hour30minutes
Total Time 1hour50minutes
2 (8-ounce) glass canning jars with new lids and bands (When canning jam, I always add one 4 ounce jar + lid + band as back up for any extra. It’s just a thing I do, but I almost always need the extra.)
Combine the tomatoes and any accumulated juice, the sugar, cinnamon, zest, cloves, and port in the 4-quart saucepan. Bring to a boil over high heat, skimming any foam that accumulates on top. Lower heat to medium-low and simmer, stirring occasionally. As the jam thickens, stir more frequently, at least 1 hour.
Test the jam to see if it’s ready to can. Put a small plate in the freezer for about 10 minutes, then dollop a spoonful of jam on top and put in the refrigerator for 2 minutes. It it gels, you are ready to can.
While the jam cooks, sterilize the jars, rings, and lids. In the canning pot, add enough water to cover the canning jars by at least 2 inches. Bring to a boil and immerse the jars and the metal bands. Ladle some of the boiling water into a small bowl and put the lids in to soften the rubber.
When the jam is ready, remove from heat and discard the cinnamon stick, cloves, and lemon zest.
Using the jar lifter or tongs, remove the jars from the water, keeping the water boiling. Using the wide-mouth funnel, ladle the hot jam into the jars and leave ¼-inch (6 mm) headroom. Wipe the rims clean with a wet cloth, place the lids on top, and screw on the bands until finger tight (not too tight).
Lower the jars into the pot and make sure they are covered by at least 1 inch (2.5 cm) of water. Once the water returns to a boil, process for 5 minutes. Transfer the jars to a heat resistant surface (I use an old cutting board) and let cool completely.
Listen for the “pop” to indicate the jars have sealed and check the lids to make sure they’re depressed. If the jar did not seal, keep it in the refrigerator and eat within 2 weeks. Properly processed jam will store for up to 1 year in a cool, dark place. Refrigerate after opening.
You can use dry pectin to speed up the setting process, though the flavor will change somewhat because it only cooks for a few minutes instead of an hour. Add the dry pectin in Step 1 and bring to a full rolling boil over high heat, stirring constantly. Add the sugar, stir, and bring back to a hard boil. Boil it hard for 1 minute. Skim off the foam and proceed with canning.