Courtesy of Faith Keating (keatinglang.com)
3 cups (12 oz/340 g) of blackberries
1/2 cup (1.3 oz/34 g) basil leaves
4 cups (16 fl oz/473 ml) white balsamic vinegar
1. Fill and preheat the water oven to 153°F (67°C).
2. Combine ingredients in a large (1 gallon/3.8 liter) zip-closure cooking pouch, use the Displacement (Archimedes’) Principle to evacuate the air, and zip closed.
3. Submerge in the water bath and cook for 2 to 3 hours.
4. Partway through the cooking process, squeeze the pouch to soften the blackberries.
5. Strain the vinegar through cheesecloth or a fine mesh strainer and discard the solids.
6. Pour the infusion into a clean bottle, cap tightly, label, date, and store in the refrigerator for up to a six weeks.