Pour water into a large glass container with a lid. Stir in honey until dissolved. Zest the lemon, being careful not to include any white pith. Juice the lemon, then add both zest and juice to the glass container.

Working with one bunch at a time, hold mint in one hand; use your other hand to twist and squeeze the leaves, slightly bruising them to release their fragrance and oils. Immerse the squeezed bunches in the water mixture.

Cover the container and place it in direct sunlight for 2 hours.