Peel whole quince and drop them in a sauce pot whole. Cover with water and lid and bring to a simmer. Cook until fork tender, about 40 minutes.

Remove from the water with a slotted spoon and cut the soft flesh away from the core with a knife.

Add all of the flesh to a food processor and puree until smooth and creamy.

Save the quince water to make this: https://georgiapellegrini.com/2018/01/03/food-drink/venison-braised-in-quince-juice/

Measure the puree with a measuring cup back into a sauce pan. Add an equal amount of sugar as puree.

Bring to a simmer and stir until all of the sugar is dissolved.

Add the lemon juice, 1 tablespoon for every cup of puree.

Continue to stir occasionally for about an hour and half until the mixture is viscous, dark red and very dense. Keep it on a low heat and continue to stir it occasionally. The instinct will be to remove it before it has cooked enough so really let it go.

Line a small baking pan or muffin tin with parchment or plastic and grease with cooking spray or butter. Spoon in the mixture and tap the pan against the counter to help it distribute evenly. Smooth the top with a knife.

Continue to cook over low heat, stirring constantly, until mixture is a thick paste that stays together in a ball. The mixture should seem stretchy and almost dry. The fruit will change color and become a bright orange-red.

Pour into a lightly oiled container and let cool.

Slice when firm or if in tins, gently pull out with the plastic.

Fruit paste will keep for several weeks, covered, in the refrigerator.