Apple Marmalade - cooking recipe

Ingredients

1 orange
6 tart apples, peeled, cored and chopped
3 Tbsp. lemon juice
5 c. sugar
1/2 bottle Certo

Preparation

Quarter unpeeled orange.
Remove seeds.
Slice orange to thick slices.
In a large kettle combine first three ingredients and 2 cups water.
Bring to a boil and simmer 10 minutes.
Add sugar and bring to a rolling boil, stirring constantly.
Continue cooking and stirring until thickened and clear.
Remove from heat and add Certo.
Skim off the foam. Pour into hot, sterile jars and seal.