This recipe is from “Preserving the Japanese Way” by Nancy Singleton Hachisu.
2 lb (6) quince
1 lb (3 cups) sugar
2 qt (8 cups) vodka
Wash, quarter and core the quince. Remove any blemished areas and worm holes. Place the prepared quince in a jar with the sugar and vodka. (I divided everything in half because I didn’t have a large enough jar on hand) Seal tightly and shake.
Store in a dark place and shake occasionally for 3 or more months while the liqueur infuses. The flavor of the cordial will deepen and mellow with age. The cordial will keep indefinitely. Serve cold or over ice as an aperitif.