Over high heat, bring the vinegar and sugar to a boil; reduce heat and simmer for a few minutes.
In the meantime, add a teaspoon of pickling spice and a garlic clove to three (500 ml) sterilized jars and pack in the corn cobs.
Add the hot vinegar to the packed jars, filling them just below the rims. Put the snap lid over the rim, then lightly screw the twist ring on.
Put the jars into a water bath just enough to cover them; boil for 10 minutes. Allow the jars to cool completely after being removed from the water bath.