Cooks in Greece get a little slaked lime from the yards that sell construction materials(!) to make this, as well as some other preserves that require the fruit to remain firm and crunchy as it cooks in the syrup.
I have adapted the recipe with pickling lime that is available online and in most cook’s stores in the US and Europe.
See also the very easy Baked Sweet Squash.
Makes about 2 pint jars
2 pounds peeled and seeded pumpkin or squash, cut into 1 inch cubes, OR balls, cut with a melon scoop (or the fusilli-like pieces made with the decorative cutter sold at street corners in Athens).
1 cup pickling lime
4 quarts water
5 cups sugar
4 cups water
2 four- inch cinnamon sticks
1/4 cup fresh lemon juice
Dilute the pickling lime in the water and add the diced pumpkin. Leave for 4 hours or overnight, and drain. Rinse thoroughly under cold water. Drain and lay on paper towels to dry the pieces.
Meanwhile make the syrup by boiling 5 cups sugar in 4 cups water with the cinnamon sticks for 3-4 minutes. Add the pumpkin and lower the heat. Simmer tossing often for 10 minutes. Add the lemon juice and cook another 4-5 minutes, until the pumpkin is pleasantly crunchy and sweet. Transfer to clean sterilized jars and store in the refrigerator, or better, process in water bath, cooking the sealed jars for 10 minutes in a pot filled with water that comes about 2 inches above the top of the jars. Let cool and store in a cool, dry place.