1 quart red wine vinegar
1 handful rosemary sprigs
2 scrupulously clean 16-ounce jars with plastic lids
Wash and dry rosemary. Crush lightly to release fragrance, then divide into two jars. Pour vinegar into a nonreactive pan (almost anything but aluminum) and bring just to the boiling point (about eight to 10 minutes at medium-high heat). Pour vinegar into jars and put caps on jars. Let sit for two weeks.
To prepare a gift, strain vinegar into pretty bottles. Add a fresh sprig of rosemary to the new bottle. Seal and present.
Note: Vinegar's acidity makes it safer than most home-canning projects. But if your flavored vinegar starts to mold or show signs of fermenting (bubbling, severe cloudiness, or sliminess), throw it out!