First, select a jar to use for the chive blossom infusion. Once you have your jar, harvest as many chive blossoms as needed to fill the jar. (Note - just harvest the blossoms, not the green chives themselves.)
Rinse your chive blossoms, removing any dirt, then pat dry with a towel.
Add the chive blossoms to the jar, then pour your vinegar of choice on top until the jar is completely filled. Using clean hands, submerge the blossoms so that they're entirely covered in vinegar.
Cover the jar with an airtight lid and put in the fridge for 5-7 days for infusion.
After 5-7 days have passed, strain the chive blossoms from the vinegar, then put the infused vinegar into a clean jar.
Vinegar will keep in the fridge for 4-6 months.
Enjoy!