Table · field guide
Savory Tomato Jam
Tomato jam is what to make when you are tired of sauce. It cooks down thick and sticky, sweet with a savory edge, and it turns a plate of crackers or a burger into something people remember. Because tomatoes sit on the edge of safe canning acidity, you add bottled lemon juice to every jar. Here is the recipe and the safe way to put it up.
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Why this one works
Jam is a great use for soft or ugly tomatoes that would not make a clean sauce. You cook them down hard, so shape does not matter. About 3 pounds of tomatoes reduces to roughly 4 half-pints of thick jam.
The sugar, vinegar, and spice do the flavor work. The long simmer does the rest, driving off water until the jam mounds on a spoon. It takes patience, but the smell alone is worth it.
Pick and prep the tomatoes
Any ripe tomato works: paste, slicing, even cherry tomatoes if that is your glut. Paste tomatoes have less water, so they thicken fastest. Core the tomatoes and chop them; you do not need to peel them for jam because it all breaks down.
Freshness cue: the riper and sweeter the tomato, the better the jam. This is the recipe for the pile that has gone a little too soft to slice.
Keep it safe
Tomatoes are borderline for water-bath canning, so you must add acid to every jar. Add 1 tablespoon of bottled lemon juice per pint, or 2 tablespoons per quart, before you fill it. Use bottled, not fresh, because bottled has a steady acidity you can trust. You can stir the lemon juice into the batch instead, as long as the amount matches your total jars.
Jams get less headspace than pickles: leave 1/4 inch at the top. Process half-pints and pints for 10 minutes in a boiling-water canner, and adjust the time up for your altitude. Check every jar sealed after 12 to 24 hours, and refrigerate any that did not.
How long it keeps
Sealed jars keep their best quality for about 12 months in a cool, dark pantry. Label each jar with the date. Once you open a jar, keep it in the fridge and use it within about 3 weeks.
One honest caveat: this jam scorches easily near the end when it is thick. Stir often, drop the heat as it reduces, and stay at the stove for the last 15 minutes.
Recipe
Ingredients
- 3 lbs ripe tomatoes, cored and chopped
- 1 1/2 cups sugar
- 1/4 cup 5% cider vinegar
- 1/4 cup bottled lemon juice (plus 1 tbsp per pint jar)
- 1 tsp canning or pickling salt
- 1 tsp ground ginger
- 1/2 tsp red pepper flakes
- 1 tsp cumin (optional)
Method
- Combine all ingredients in a wide, heavy pot. Bring to a boil, stirring to dissolve the sugar.
- Lower to a simmer and cook, stirring often, until thick and glossy, about 60 to 75 minutes.
- Test for done: a spoonful mounds and does not run when dropped on a cold plate.
- Wash jars and keep them hot. Add 1 tbsp bottled lemon juice to each pint jar if you did not stir it into the batch.
- Ladle hot jam into jars, leaving 1/4 inch headspace. Wipe rims and set lids and bands finger-tight.
- Process half-pints or pints 10 minutes at a full rolling boil, adjusting for altitude.
- Cool 12 to 24 hours, check every seal, and refrigerate any jar that did not seal.
Questions, answered straight
Yes. Tomatoes are borderline acidic, so add 1 tablespoon of bottled lemon juice per pint (2 per quart) to make it safe for water-bath canning. Use bottled, not fresh, for a steady acidity.
Drop a spoonful on a cold plate. If it mounds and does not run, it is done. If it spreads out thin, keep simmering and stirring for a few more minutes.
Jams and jellies use 1/4 inch of headspace, less than the 1/2 inch for pickles and relish. Process 10 minutes and adjust for your altitude.