Extract the Juice: Place apple peels and cores into a large pot. Add just enough water to cover them. Bring to a boil, then reduce heat and simmer for 30 minutes, until soft.

Strain the Liquid: Pour the mixture through a fine mesh strainer or cheesecloth into a bowl. Let it drain fully. Discard the solids. This is your apple juice base.

Measure and Add Sugar: Measure the juice. Return it to the pot and add about 1/2 cup sugar per cup of juice. Stir in lemon juice and spices if using.

Cook the Jelly: Bring the juice mixture to a boil over high heat. Stir constantly until sugar dissolves. Reduce heat to medium and cook until the jelly reaches 220°F (about 10-15 minutes). Test on a cold plate for gel set.

Jar and Seal: Pour hot jelly into sterilized jars, leaving 1/4 inch headspace. Wipe rims, apply lids and rings. Process in a boiling water bath canner for 5 minutes.