Wash the oranges and lemons with clean, cool water, gently rubbing with your hands or a vegetable scrubber.  

Remove the outer colored part of the orange with a vegetable peeler. Try to cut only the very outer layer, and do not get too much of the thick, white inner peeling. Do the same with the lemons.

Chop the orange and lemon peels into fine pieces and place in a large saucepan.

Add 1/8 tsp. baking soda to the peelings, and cover with 2 ½ cups of water, stir to dissolve the baking soda.

Bring the orange and lemon peel mixture to a boil, cover, and reduce the heat to medium-low.

Simmer the mixture for 20 minutes, stirring occasionally.

Remove the remaining white layer of peeling from the oranges and lemons, discarding the white peels until you have the remaining fleshy citrus. 

Chop the remaining citrus into small pieces, and reserve juices from the fruit while peeling and cutting.

Add the chopped citrus and juices to the pan of cooked peels, stir to mix, and simmer for an additional 10 minutes.

Prepare jars and a hot water bath

Measure 4 cups of sugar into a medium bowl.

Using ¼ cup measure, take only ¼ cup of sugar from the 4 cups you just placed in a bowl, and pour the ¼ cup of sugar into a small bowl. Add the powdered pectin to the sugar in the small bowl, and stir to mix.

Add this sugar/pectin mix to the fruit mixture on the stove, stirring to dissolve.

Bring the jam mixture to a full rolling boil.

Slowly add the remaining premeasured sugar while stirring continuously. Continue to cook until the mixture returns to a full rolling boil.

Boil the jam for exactly one full minute.

Remove the marmalade from the stove and skim off any foam with a metal spoon if desired.

Immediately pour or ladle the hot marmalade into prepared hot jars, leaving ¼” headspace at the top of the jars.

Wipe the rims of the jars with a clean cloth, and apply the 2-part canning lids.

Preserve the marmalade using a hot water bath canning method for 10 minutes (or 15 minutes if above 6,000 feet in elevation).

After processing, allow the jars to cool and seal for 24 hours or longer. It may take up to two weeks for the marmalade to set firmly.

Sealed marmalade will retain peak quality for up to 12 months stored in a cool, dry place or pantry. Refrigerate the marmalade once opened.