Adapted from Preserving Italy by Domenica Marchetti
Special Equipment: 4-inch square of cheesecloth; length of kitchen twine; instant-read thermometer; 2 sterilized ½-pint jars and 1 sterilized 4-ounce jar (with their lids); basic water-bath canning equipment
Please read safety and water-bath canning instructions before beginning the recipe.
- 1 pound Tropea or standard red onions, cut into small dice (the amount of onions used will vary by their size)
- 2 cups granulated sugar
- 1 cup full-bodied red wine
- ½–¾ teaspoon fine sea salt
- 10 whole peppercorns
- 1 whole clove
- 1 bay leaf
- 1-inch piece of vanilla bean
- ½ cinnamon stick
- 2 tablespoons red wine vinegar
- Have your canning equipment and water bath ready.
- Combine the onions, sugar, wine and salt in a heavy-bottomed pot. Use the cheesecloth to make a sachet containing the peppercorns, clove, bay leaf, vanilla bean, and cinnamon stick and tie securely with the length of kitchen twine. Place the sachet in the pot with the onions and other ingredients.
- Bring the onion mixture to a boil over medium heat, stirring to dissolve the sugar. Lower the heat so the mixture simmers, stirring often until the jam is thick and registers 220°-225° on the instant-read thermometer. You should be able to drag a visible path along the bottom of the pot using a silicone spatula once the onion mixture has finished thickening. Stir in the vinegar and remove from the heat.
- Ladle the jam into the sterilized jars, leaving ¼-inch headspace. Wipe the jar rims with a clean, damp cloth, if necessary, place the lids on, and screw the bands on the jars until fingertip tight. Process in the boiling water bath for 10 minutes. Remove the jars from the water bath and set them upright onto a clean dish towel in an area of the counter where they will not be disturbed. Let them cool completely to room temperature.
- Store the jam in a cool, dark place for up to 1 year. Once opened, refrigerate the jam and consume within 6 months. If any jars refuse to seal properly, store them in the refrigerator and consume those first.