Quince paste slow-cooked to a jewel-like consistency is a traditional Mexican confection. This family-friendly treat is a sweet, aromatic, versatile candy paired with cheese.
Wash and quarter the quinces, then core them. Do not peel, as the skins add flavor and natural pectin.
In a large pot, add quince pieces, water, and the juice of 1 lemon. Bring to a simmer over medium heat, then cover and cook until quinces are very soft, about 45–60 minutes.
Drain, reserving about ½ cup of cooking liquid. Puree the cooked quince with reserved liquid using a food processor or immersion blender until perfectly smooth.
Measure the quince puree volume, then return it to the pot with an equal volume of granulated sugar. Stir well to combine.
Cook the puree-sugar mixture over low heat, stirring constantly to prevent scorching. Continue for 1.5–2 hours, or until the paste thickens, turns deep orange-red, and pulls away from the sides. Allow to slowly caramelize for a richer flavor.
Pour the finished paste into a parchment-lined square pan, spreading evenly. Let cool completely and set at room temperature until firm, at least 6 hours or overnight.
Once set, unmold and slice with a knife. Serve with slices of cheese or store wrapped in wax paper.