- 1 Cup balsamic vinegar
- 1 Cup ruby port wine
- 6 Cups California raisins
- 4 Pounds individually quick-frozen blackberries, thawed and crushed
- 7 Cups sugar
- 3 liquid pectin
Measure vinegar into small sautépan and heat on medium until reduced by 2/3. Meanwhile, heat port wine in 1-quart saucepan and add raisins; remove from heat and let stand, about 30 minutes. Then, turn blackberries, sugar and balsamic reduction into an 8-quart saucepan, and heat to boil. Add raisins-wine mixture and heat all to full rolling boil. Add pectin, all at once; stir well and return to full boil for 1 minute. Turn into sterilized jars or clean containers; cover, seal and cool. Store at room temperature or keep unsealed containers in refrigerator.
Note: Jam may also be prepared with an equal amount of fresh blackberries that have been crushed.