Step 1In a large, heavy-bottomed saucepan, combine the sugar and water. Add the quince and stir to coat.
Step 2Heat the mixture over medium heat until the sugar melts completely and begins to bubble, stirring often so the fruit does not burn. Reduce the heat to maintain a very gentle simmer and continue to cook, stirring occasionally, until the fruit is softened and turned to a rich rose or red color and the sugar has reduced to a thickened, syrupy consistency, about 1 1/4 hours. Remove from heat.
Step 3Serve with a little heavy cream or yogurt spooned over top, or use as a topping for vanilla ice cream.