Combine port wine, cinnamon, cardamom pods and whole cloves in saucepan and simmer until reduced by half.  

While port wine is reducing, wash the cherries in vinegar water and pit.

Add sugar and stir to combine

Prepare canner, jars and lids. See The Ball Complete Book of Home Preserving for guidance. Lay out a clean towel, along with a small bowl of white vinegar (to wipe off rims) and your canning supplies on a clean counter.

Strain spices from port wine

Ladle 1/2 cup of hot port wine syrup into each hot jar. 

Fill jar with cherries to within 1/2 inch of  top of jar. 

Gently shake jar to pack cherries closely, without crushing them.

Add hot syrup to cover cherries, leaving 1/2 inch headspace.

Add 1 TBSP balsamic vinegar to each jar

Wipe rim with white vinegar

Remove any air bubbles and adjust headspace.

Center lid on jar and screw band down until resistance is met, then increase to fingertip tight. Or, if using Weck Jar, place rubber gasket, glass lid and metal clips on the jar.

Place jars in canner, making sure they are completely covered with water by at least one inch.

Cover pot and bring to a boil

Boil for pints and quarts for full 25 minutes, or adjust for altitude via Ball Complete Book of Home Preserving. The time to bring your pot to a boil should not be counted in the minute boil time.

Remove lid, wait 5 minutes and remove from canner