Peel and chop the oranges, removing any seeds.

In a large pot, combine the chopped oranges and lemon juice.

Add the sugar to the pot and stir until dissolved.

Bring the mixture to a boil over medium heat, stirring frequently.

Once boiling, add the pectin and continue to boil for 10 minutes.

Remove the pot from heat and skim off any foam.

Using a ladle and canning funnel, fill sterilized jars with the hot jam, leaving 1/4 inch headspace.

Seal the jars with lids and process in a boiling water bath for 10 minutes.