Orange Marmalade - cooking recipe

Ingredients

3 1/3 lbs oranges, coarsely chopped, juice retained and seeds discarded
1 None lemon, coarsely chopped
7 1/2 cups sugar

Preparation

Preheat the oven to 300\u00b0F. Spread the sugar on a large baking pan. Bake for 10-15 mins, stirring occasionally, to warm through.
Place the oranges, orange juice and lemon in a saucepot on medium heat. Cook, stirring, for 5-10 mins.
When the fruit is hot, stir in the warmed sugar. Reduce the heat to low. Cook, stirring occasionally, until the sugar dissolves. Bring to a boil. Continue to boil, stirring occasionally, until the marmalade sets. Test this by putting a spoonful of the marmalade on a cold plate; it should set to a gel in a couple of minutes.
Meanwhile, place the sterilized jars in the oven for 10-15 mins.
Spoon the hot marmalade into the jars and seal tightly with the lids. Store in a cool, dry place for up to 6 months. Once opened, store in the refrigerator.