Add blueberries to a jar and smash slightly. Slightly warm the vinegar and pour it into the jar.
Add the herbs and let it sit for a few hours, ideally overnight.
Strain to remove the blueberries and herbs.
Transfer the infused vinegar to a glass jar and refrigerate.
Notes
Make sure you choose clean, unblemished berries for best results. Also wash them well to remove any dirt and grime that could cause the vinegar to spoil.
Use a clean, sterilized glass jar to store the blueberry vinegar. This will help it stay fresh for long.
Remember to smash the blueberries gently before you pour in the vinegar. This will help them release all their beautiful juices easily and you'll also get that nice pop of color you're looking for.