Put the vinegar into a medium, nonreactive saucepan and warm over low heat just until it begins to give off vapor (do not bring to a boil). Stir in the peach cubes and cook for 1 minute. Pour the mixture into a sterilized 1-quart Mason jar and allow to cool to room temperature, 10 to 15 minutes. Place a sterilized seal on top of the jar, screw on the ring, and shake a few times to mix. Store the jar out of direct sunlight and away from heat for 5 days, shaking it periodically, while the mixture steeps (the vinegar will absorb most of the pigment from the fruit). Strain the contents through a fine sieve into a 4-cup glass measuring cup. Discard the fruit residue and rinse the sieve. Rinse the Mason jar and return the strained vinegar to the jar. Dampen a flat-bottom coffee filter and fit it into the sieve. Rinse the measuring cup, place the sieve on top, and pour in the vinegar a bit at a time, allowing it to drip into the measuring cup. Transfer the vinegar to flasks, bottles, or cruets. The vinegar should be ready to use immediately, with a shelf life of at least 1 year.

container before pouring in the vinegar. Fill, seal, and let steep out of direct sunlight and away from heat for 1 day before using or shipping.