My mom brought me a bag of quince from Southern California. Little did I know that quince grow in Denver too...I recently spotted a tree in someone's front yard. I may just have to go knock on their door and be all like, "Um, are you going to use all those...?" —gabsimonelouise
Peel quince, then cut in half. Cut in half again, remove seeds and tough flesh from the middle, then cut each quarter in half again. Toss the quince in a large stock pot.
Add water, sugar, and lemon juice to stock pot. Bring to a boil, then turn heat down and let quince simmer for an hour, give or take. Check the quince periodically, a fork should pierce them easily and they are done.
Blend the mixture in a blender. Add more water to blend it up, if required. Blend in the rosewater. The mixture will be thick, as quince are pectin powerhouses and naturally thicken things. It will look like pinkish apple sauce!
Chill the mixture in the fridge until it is cold, at least four hours. Process in your ice cream maker according to manufacturer's instructions.