INGREDIENTS
2 pounds (1 kg) red onions, quartered and thinly sliced
½ cup (125 mL) red wine vinegar
1 ½ (375 mL) cups port wine
2 tsp salt (10 mL)
1 tsp (5 mL) ground black pepper
1 tsp (5 mL) mustard seeds
1 cup (250mL) cold water
3 tbsp (45 mL) Ball ® Low or No Sugar Needed Pectin
½ (125 mL) cup sugar
Prepare jars and lids for canning
Combine first 6 ingredients in a medium saucepan. Cook over medium heat 15 minutes, or until onions are translucent, stirring occasionally.
Stir in water and pectin. Bring mixture to a full rolling boil that cannot be stirred down stirring constantly.
Add sugar, stirring to dissolve. Return mixture to a full rolling boil. Boil hard for 1 minute, stirring constantly.
Turn off burner and remove from heat. Ladle hot jam into a hot jar leaving a ¼ inch (0.5 cm) headspace. Remove air bubbles. Wipe jar rim. Center lid on jar and apply band, adjust to fingertip tight. Place jar in boiling water canner. Repeat until all jars are filled.
Process jars 10 minutes, adjusting for altitude. Turn off heat, remove lid, let jars stand 5 minutes. Remove jars and cool 12-24 hours. Check lids for seal, they should not flex when center is pressed.