Step 1

Inspect 1 quart jar and 1 pint jar for cracks and rings for rust, discarding any that are defective. Immerse in simmering water until jam is ready. Wash new, unused lids and rings in warm soapy water.

Step 2

Wear protective gloves to rub and rinse the prickly pears under running water to make sure all spines are removed. Cut each pear in half and scoop pulp and seeds into the bowl of a food processor. Pulse for 30 to 40 seconds. Transfer mixture to a strainer lined with cheesecloth set over a bowl. Gather cheesecloth into a pouch and squeeze out juice. Remove any remaining pulp from the seeds and add to the bowl with the juice.

Step 3

Combine prickly pear juice, pectin, and lemon juice in a medium saucepan over medium heat. Bring to a rolling boil that can't be stirred down. Add sugar and amaretto and stir until completely dissolved. Return mixture to a rolling boil, stirring constantly. Cook until jam is reduced by half, 5 to 7 minutes.

Step 4

Remove jam from heat and skim off and discard any froth that may have formed. Dip a metal spoon into the jam to test for desired thickness. Add another 1/2 teaspoon of pectin and boil for 1 minute more if a thicker jam is desired.

Step 5

Pack jam into hot, sterilized jars, filling to within 1/4 inch of the top. Run a clean knife or thin spatula around the insides of the jars to remove any air bubbles. Wipe rims with a moist paper towel to remove any spills. Top with lids and screw rings on tightly.

Step 6

Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil and lower jars 2 inches apart into the boiling water using a holder. Pour in more boiling water to cover jars by at least 1 inch. Bring to a rolling boil, cover, and process for 10 minutes.

Step 7

Remove the jars from the stockpot and let rest, several inches apart, for 12 to 24 hours. Press the center of each lid with a finger to ensure the lid does not move up or down. Remove the rings for storage and store in a cool, dark area.