Mash thawed blueberries with a fork in a bowl, then place into a 1-quart canning jar. Add the lemon zest, cloves, and vodka.
Seal the jar tightly with its lid and place in a cool, dark place. Allow the vodka to stand for 3 months, shaking the jar gently every few days.
After 3 months, strain out the blueberries, and filter the vodka through cheesecloth into another 1-quart jar. Pour in the simple syrup, seal the jar tightly with its lid, and shake until the syrup has dissolved.
Again place into a cool, dark place, and age for at least a month. When ready to bottle, filter again through cheesecloth, then pour into a decorative bottle of your choice.